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Home My WebLink AboutCT 05-21; GREYHAWK BUSINESS PARK LOT 5; PRELIMINARY STORM WATER MANAGEMENT PLAN; 2005-11-23Keith Hansen PRELIMINARY STORM WATER MANAGEMENT PLAN For PALOMAR FORUM LOTS P.I.P. 05-01 Revised: June 7,2005 Rev~sed: April 12, 2005 Prepared: February 9, 2005 IN 01-1010 Prepa~ed By: O'DA y CONSULTANTS 27lO Loker Avenue West, Suite 100 Carlsbad, CA 92008 RCE 60223 Date Prepared by: JAJ Keith Hansen '~ PRELIMINARY STORM WATER MANAGEMENT PLAN For PALOMAR FORUM LOTS P.I.P. 05-01 Revised: June 7, 2005 Revised: April 12, 2005 Prepared: February 9,2005 JN 01-1010 Prepared By: O'DAY CONSULTANTS 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92008 RCE 60223 Date Prepared by: 1A1 TABLE OF CONTENTS 1.0 PROJECT DESCRIPTION ................................................... ~ .............. 3 1.1 Hydrologic Unit Contribution ........................................................ 3 1.2 Beneficial Uses .............................................................................. 4 2,0 CHARACTERIZATION OF PROJECT RUNOFF ............................ 5 2.1 Soil Characteristics ........................................................................ 5 2.2 Potential Discharges ....................................................................... 5 3.0 MITIGATION MEASURES TO PROTECT WATER QUALITY .... 5 3.1 Site Design BMP's ......................................................................... 5 3.2 Source Control BMP's ................................................................... 6 3.3 Treatment Control BMP's .............................................................. 6 3.4 Construction BMPs ........................................................................ 7 4.0 MONITORING, INSPECTION, AND REPORTING ........................ 8 Attachments: 1. Vicinity map (/e 2. Beneficial uses for the hydrologic unit \. 3. 303(D) list for impaired water bodies 4. Table 2: Anticipated and potential pollutants 5. Table!: Storm Water BMP Requirements Matrix 6. Table 3:Numeric Sizing Treatment Standards 7. Summary SWMP & BMP Map 8. Source Control BMPs 9. Treatment Control BMPs 10. Catch Basin Insert Filters Calculations & Product Information 2 1:\98 I 022\SWMP\Lol S\Storm Water Management Plan-rev2.uoc STORM WATER MANAGEMENT PLAN Federal, state and local agencies have established goals and objectives for storm water quality in the region. The proposed project is a priority project as defined in Order No. 2001-01 by the San Diego Region of the California Water Quality Control Board. As a result, the project is subject to SUSMP requirements. In addition, prior to the start of construction activities, the project will comply with all federal, state and local permits including the Stormwater Management Plan (SWMP) required under the County of San Diego Watershed Protection, Stormwater Management, and Discharge Control Ordinance (WPO) (section 67.871), the City of Carlsbad's Standard Urban Storm Water Mitigation Plan, and the National Pollution Discharge Elimination System (NPDES) from the Regional Water Quality Control Board (RWQCB). The purpose of this SWMP is to address the water quality impacts from the proposed improvements as shown on the Planned Industrial Permit. This project will provide guidelines in developing and implementing Best Management Practices (BMPs) for storm water quality during construction and post construction. Since the site is more than 1 acre, a Storm Water Pollution Prevention Plan (SWPPP) will be required. A SWPPP will be prepared and approved prior to issuance of a grading permit. The approved SWPPP shall be implemented during the construction phase. The SWPPP will consist of the selected BMPs, guidelines and activities to carry out actions, which will prevent the pollution of storm water runoff. The SWPPP will also include the monitoring and maintenance of the construction BMPs during the construction phase. 1.0 PROJECT DESCRIPTION Lot 5 of Palomar Forum is currently mass graded per approved grading plan drawing 399-4A. A SWPPP prepared by O'Day Consultants dated June 2002 is being utilized for the construction phase of Palomar Forum. A planned industrial permit is currently being processed for Lot 5 which proposes the development of the site for industrial purposes. The site will include 204,018 S.F. of building space, 613 parking spaces, 81,551 S.F. of landscape area, and 11,328 S.F. of employee eating area. 1.1 Hydrologic Unit Contribution The project is located in the Agua Hedionda Hydrologic Subarea (904.31) of the Carlsbad Hydrologic Unit in the San Diego Region. Under existing conditions, storm runoff is collected in a drainage system and conveyed into a lower canyon terrain and westerly into Agua Hedionda Creek. The proposed project will not alter the drainage discharge patterns on site. The proposed flows are consistent with those proposed in the Hydrology and Hydraulic Study for Palomar Forum, CT 99-06, dated February 3, 2003 by O'Day Consultants. (see Hydrology Study for Palomar Forum Lot 5, Developed Condition) 3 1:\98 1 022\SWMP\Lot 5\Storm Water Management Plan-rcv2.doc ,(e 1.2 Beneficial Uses The beneficial uses for the hydrologic unit are included in attachment 2, and the definitions are listed below. This information comes from the Water Quality Control Plan for the San Diego Basin. REC 1 -Contract Recreation: Includes uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs. . REC 2 -Non-Contact Recreation: Includes the uses of water for recreational activities involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These include, but are not limited to, picnicking, sunbathing, hiking, camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. MUN -Municipal and Domestic Supply: Includes uses of water for community, military, or individual water supply systems including, but not limited to, drinking water supply. COMM -Commercial and Sport Fishing: Includes the uses of water for commercial or recreational collection of fish, shellfish, or other organisms including, but not limited to, uses involving organisms intended for human consumption or bait purposes. AQUA -Aquaculture: Includes the uses of water for aquaculture or mariculture operations including, but not limited to, propagation, cultivation, maintenance, or harvesting of aquatic plants and animals for human consumption or bait purposes. SHELL -Shellfish Harvesting: Includes uses of water that support habitats suitable for the collection of filter-feeding shellfish (e.g.! clams, oysters, and mussels) for human consumption, commercial, or sport purposes. IND -Industrial Service Supply: Includes uses of water for industrial activities that do not depend primarily on water quality including, but not limited to, mining, cooling water supply, hydraulic conveyance, gravel washing, fire protection, or oil well re-pressurization. EST -Estuarine Habitat: Includes the uses of water that support estuarine ecosystems including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, or wildlife (e.g., estuarine mammals, waterfowl, shorebirds). MAR -Marine Habitat: Includes uses of water that support marine ecosystems including, but not limj.ted to, preservation or enhancement or marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g., marine mammals, shorebirds). WILD -Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water food and sources. RARE -Rare, Threatened, or Endangered Species: Includes uses of water that support habitats necessary, at least in part, for the survival and successful maintenance of plant or animal species established under state or federal law as rare, threatened or endangered. MIGR -Migration of Aquatic Organisms: Includes uses of water that support habitats necessary for migration, acclimatization between fresh and salt water, or other temporary activities by aquatic organisms, such as anadromous tlsh. 4 1:\981 022\SWMP\Lot 5\Stonn Water rvlanagernen! Plan-rev2.doc 2.0 CHARACTERIZATION OF PROJECT RUNOFF According to the CWA 2002 30~(d) list published by the RWQCB (attachment 3), Agua Hedionda Lagoon and Creek are impaired water bodies associated with the direct storm water discharge from this project. Agua Hedionda Lagoon has low priority impairment for bacteria indicators and low priority for sedimentation/siltation. Agua Hedionda Creek has low priority for total dissolved solids. 2.1 Soil Characteristics The project area consists entirely of soil group D. 2.2 Potential Discharges There is no sampling data available for the existing site condition. The project will contain some pollutants commonly found on similar developments that could affect water quality. The following list is taken from Table 2 of the City of Carlsbad's Storm Water Standards Manual (attachment 4). It includes anticipated pollutants for streets & parking lots. Streets Parking Lots • Nutrients from fertilizers • Nutrients from fertilizers • Heavy metals • Heavy metals • Organic compounds • Trash and debris • Trash and debris • Oxygen demanding substances • Oxygen demanding substances • Oil and grease from paved areas • Oil and grease from paved areas • Pesticides from landscaping • Pesticides from landscaping 3.0 MITIGATION MEASURES TO PROTECT WATER QUALITY To address water quality for the project, BMPs will be implemented during constmction and post constmction. Required BMPs are selected from Table 1: Storm Water BMP requirements Matrix, of the City of Carlsbad's Storm Water Standards Manual (attachment 5). 3.1 Site Design BMPs Control of post-development peak storm water mnoff discharge rates and velocities is desirable in order to maintain or reduce pre-development downstream erosion. As part of the Palomar Fomm mass grading plans and neighboring Raceway mass grading, a number of measures have already been taken to prevent downstream erosion. These include energy dissipators, a master detention basin, and a permanent pollution prevention basin. Rip rap energy dissipators have been placed at the outlet of all storm drains per the Fomm and Raceway mass grading plans. CDWG 399-4A and DWG 409-1A, respectively) In order to control post-development peak storm water mnoff discharge rates, flow from Palomar Fomm will enter a detention basin adjacent to Melrose Dr. before entering Agua Hedionda Creek. The detention basin is part of the larger Rancho Carlsbad Channel & Basin Project being implemented by the City of Carlsbad. Lastly, a permanent pollution control basin will be built as part of the Raceway project and will treat the 5 1:\98 I 022\SWMP\Lot 5\Storm Water Management Plan-rev2.doc low-flow runoff from Lot 5. The basin has been designed as a volume-based BMP and calculations can be found in the "Hydrology and Hydraulic Study for Carlsbad Raceway" dated June 20, 2003 by O'Day Consultants. 3.2 Source Control BMPs Source Control BMPs help minimize the introduction of pollutants into storm water in order to maintain or reduce pre-development levels of pollutants by applying the following concepts (see attachment 8 for details): Street Sweeping: Private parking lots will be swept monthly in order to reduce introduction of trash, debris, sediment and siltation into drainage systems. The HOA will be responsible for this maintenance. Also, the City of Carlsbad will sweep city streets on a routine basis. Trash Storage Areas to Reduce Pollution Introduction: Trash storage areas will be built according to the City of Carlsbad Standard Drawing GS-16. The areas will be paved with an impervious surface, graded to drain away from the enclosure, screened and walled to prevent off-site transport of trash. Trash containers will contain attached lids that exclude rain to minimize direct precipitation. Use Efficient Irrigation Systems & Landscape Design: Irrigation systems shall employ rain shutoff devices to prevent irrigation during precipitation and be designed to each landscape area's specific water requirements consistent with the Carlsbad Landscape Manual. Provide Storm Water Conveyance System Stenciling and Signage: All storm water conveyance inlets and catch basins shall provide concrete stamping, porcelain tile, inset permanent marking or equivalent as approved by the City of Carlsbad within the project area with prohibitive language satisfactory to the City Engineer. 3.3 Treatment Control BMPs As identified in Table 1 (Attachment 5), a combination of treatment control BMP's shall be incorporated into the project in order to minimize pollutants of concern from entering the storm drain system. Structural Treatment BMPs were selected by comparing a list of pollutants for which the receiving water bodies are impaired to a list of expected pollutants for each basin. Combinations of treatment BMP's that maximized priority pollutant removal were selected. The Structural Treatment BMPs selected for the site are discussed below and are shown in Attachment 9. Permanent Pollution Control Basin: As discussed in Section 3.1, a volume-based pollution control basin'is currently being constructed per the Carlsbad Raceway grading plans. (DWG 409-1A) This basin will ultimately treat the high frequency storm event runoff from lot 5. 6 1:\9~ I 022\SWMP\Lot 5\Storm Water Management Plan-rev2.doc (. Vegetated Swale: A landscaped swale will run along the northern property line of lot 5 and treat roof runoff. The northern portion of buildings A through M will drain to the north and be treated by the vegetated swale before entering the storm drain system. Drain inlets will be placed throughout the swale to keep flow heights and velocities to a minimum. Storm Drain Inlet Baskets: Storm drainage inserts will be used for Structural Treatment BMPs. The drainage inserts will be catch basin and area drain inlet baskets. The drainage inserts are Suntree Technologies Inc. products. (See Attachment 10 for manufacturer's information) 51 drainage inserts will be used for this project. 25 inserts will be used in the catch basins located in the private parking areas. The remaining 26 inserts will be placed in the area drains located throughout the landscaped areas. Based upon Table 3. Numeric Sizing Treatment Standards (See Attachment 6), we are using a flow-based BMP designed to mitigate (infiltrate, filter or treat) the maximum flow rate of runoff produced from a rainfall intensity of 0.2 inches of rainfall per hour for each hour of a storm event. Calculations found in Attachment 10 show the maximum amount of flow each size of insert will be required to treat. To check for adequate capacity of all the inserts on-site, the largest drainage basin for each size of catch basin/area drain insert was used (Le. 18"xI8", 24"x24" and 36"x36" catch basin/area drain). All three sizes of catch basin/area drain inserts are capable of treating the maximum amount of flows produced, furthermore, the inserts are capable of treating all flows within the site. Hydrocarbon Booms: Hydrocarbon booms will be included in the catch basin inlet baskets in order to remove hydrocarbons from parking lot runoff. The booms are made of reclaimed paper products that store oils and grease, preventing leaching and draining of hydrocarbons. The booms shall be replaced yearly by the property owner or HOA. (See Attachment 10 for manufacturer's information) 3.4 Construction BMPs The following is a list of potential construction phase BMPs to be used. 1. Silt fence, fiber rolls, or gravel bag berms 2. Check dams 3. Street sweeping and vacuuming 4. Storm drain inlet protection 5. Stabilized construction entrance/exit 6. Vehicle and equipment maintenance, cleaning, and fueling 7. Hydroseed, soil binders, or straw mulch 8. Material delivery and storage 9. Stockpile management 7 I:\98I022\SWMP\Lot 5\Storm Water Management Plan-revl.doc 10. Spill prevention and control 11. Waste management for solid, liquid, hazardous and sanitary waste, contaminated soil. 12. Concrete waste management A SWPPP will be prepared and approved prior to issuance of a grading permit. Construction BMPs for this project will be selected, constructed, and maintained through the SWPPP to comply with all applicable ordinances and guidance documents. The approved SWPPP shall be implemented during the construction phase. 4.0 MONITORING, INSPECTION, AND REPORTING During construction, the BMPs will be monitored on a weekly basis, and observations recorded on the included checklists (see next page). The Owner and Developer will be responsible for the monitoring and maintenance of the BMPs. 8 I:\981022\SWMP\Lot 5\Stonn Water Management Plan-revl.doc ~ 1. • BMP CHECKLIST (TO BE COMPLETED WEEKLY) ---------... G:\Accts\021040\BMP CHECKLIST .doc :>--., • --'. c .~ ..... G:\Accts\U21040\BMP CHECKLIST .doc • BMP CHECKLIST (TO BE COMPLETED WEEKLY) ------------------- ;>-..,., • Attachment 1 ie e i(. PACIFIC OCEAN .~........... --_. CITY OF ENCINITAS VICINITY MAP NO SCALE • ~\}o. ~"E. e ~~S SITE ... ----BUSINESS PARK OR. .-, Ipped, edited, and published by the Geologl<::al Survey I1trol bi USGS, USC&GS, ilnd useE prCJecll.;n l'3,~i ~J'-)(\h ·\'nf.'(01:3.\ ';3t J;11 ),1)00 loot ~1'11 O'l",,~,j 'JI'l C lldol(\,,) ::O'JI,j·" ,i" ~.y·,t(·m :'jrp I~ )nO rr.~ter Url/l~(t,jl TrJr'5/1~'''Ii? Ml?fc.}lor gr,·j t.·:W,) r'e 1 \, ShO'NII I r' h: .... 1 • • ... 'V ( )' :~ i·~·· 'J '.;:/,.\ '~I~ I) :.nO I J':,~ /\,\.R,rtf.' 'R ." .... CI.rl·)I'\I"I~-I ;).: : ','I4 '£.? .)~ ,',-t I I =_ 3 :r;--=-:r. __ ICOO E-l':":E"-1 Attachment 2 ". '. -.--.~ '.. -j Table 2-2. BENEFICIAL USES OF INLAND SURFACE WATERS BENEFICIAL USE' Inland Surface Waters 1,2 Hydrologic M A I P G F P R R B W C W R S Unit Basin U G N R W R 0 E E I A 0 I A P Number N R D 0 R S W C C 0 R L L R W C H 1 2 L M 0, 0 E N San Diego County Coastal Streams -continued , Buena Vista Lagoon 4.21 See Coastal Waters-Table 2-3 Buena Vista Creek 4.22 + • • • • • • Buena Vista Creek 4.21 + • • • • • • • Agua Hedionda 4.31 See Coastal Waters-Table 2-3 • I Agua Hedionda Creek 4.32 • • • • • • • Buena Creek 4.32 • • • • • • • Agua Hedionda Creek 4.31 • • • • • • • Letterbox canyon 4.31 • • • • • • • Canyon de las Encinas 4.40 + 0 • • • San Marcos Creek Watershed Batiquitos Lagoon 4.51 See Coastal Waters-Table 2-3 San Marcos Creek 4.52 + • • • • • unnamed intermittent streams 4.53 + • • • • • I San Marcos Creek Watershed , San Marcos Creek 4.51 + • • • • • I Encinitas Creek 4.51 + • • • • • ----- 1 Waterbodies are listed multiple tim"es if they cross hydrologic area or sub area boundaries. • Existing Beneficial Use o Potential Beneficial Use 2 Beneficial use designations apply to all tributaries to the indicated waterbody, if not' listed separately. + Excepted 'From MUN (See Text) Table 2-2 BENEFICIAL USES 2-27 September 8, 1994 • • ,~ Table 2-3. BENEFICIAL USES OF COASTAL WATERS BENEFICIAL USE Coastal Waters Hydrologic I N R R C B E W Unit Basin N A E E 0 I S I Number 0 V C C M 0 T L 1 2 M L 0 Pacific Ocean • • • • • • • Dana Point Harbor • • • • • • Del Mar Boat Basin • • • • • • Mission Bay • • • • • • Oceanside Harbor • • • • • • San Diego Bay 1 • • • • • • • • Coastal Lagoons Tijuana River Estuary 11.11 • • • • • • Mouth of San Diego River 7.11 • • • • • Los' Penasquitos Lagoon 2 6.10 • • • • • San Dieguito Lagoon 5.11 • • • • • Batiquitos Lagoon 4.51 • • • • • San Elijo Lagoon 5.61 • • • • • Aqua Hedionda Lagoon 4.31 • • • • • • Includes the tidal prisms of the Otay and Sweetwater Rivers. 2 Fishing from shore or boat permitted, but other water contact recreational (REC-11 uses are prohibited. • Existing Beneficial Use Table 2-3 BENEFICIAL USES 2-47 • R M A M S W S A A Q I P A H R R U G 'W R E' E A R N M L L • • • • • • • • • • • • • • • • , • • • • • • • • • • • • • I • • • .1 • • • • • • • • • • • • • • • • • • • • • • September 8, 1994 Attachment 3 r: • • / 9 . -::--., r--.. : ~.002 CWA SECTION 303(d) LIST OF W AA. QUALITY LIMITED SEGMENT R Agua Hedionda Creek SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD 90431000 Total Dissolved Solids Urban Runoff/Storm Sewers Unknown Nonpoint Source Low 7 Miles : • Approl'(!tlliy USI';P4: .JIt~JI :!fJ('.~ '_ .: .. '-_"~~ __ """"";~'~'''''kid&''e' t ·,..'~;6,! .... ......s~·m*j4l'gIttQ1·,,!<"I(l!'nn'tif;?';';Wla"'5Ji!lWf':P5Q;t1'"irg1}='YPi __ rvrrrmrt • .."..,. P Unknown point source n _~ e & tt $$5'''1ffi'W:!!i'QW!Z~~~~~'~'.$;''<:1:.I'\'.'tt.t.<~ • .:~"!.\ 9 9 E Agua Hedionda Lagoon 9043100U Bacteria Indicators Low 6.8 Acres NonpointiPoint Source Sedimentation/Siltation Low 6.8 Acres NonpointiPoint Source l.tdj1':r&1~~"'-""~"~y'z~"t:.sci':,,: .. -n-~ ... \.\..t.!:",,";"'''''1-==nr77Jii&i11FZj .. e"*",¢,'&"'*~';llr¥ .. nz'?I~_ ~!15i '=7 • ... _. __ .. ___ ....... ...:.~ ,; ,.<j",,4"l' £='''i''~'''''l' 'Ir~?''il·#ii'wiiijt·!;ntf A ... fr'iSiSi51i ... 2ti. .... Tt1jici"tWi1'77n1!'1"YGiS"'~ R Aliso Creek 9011300U Bacteria Indicators Phosphorus Urban Runoff/Storm Sewers unknown point source NonpointiPoint Source Impainnent located at lower 4 miles. Toxicity Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Urban Runoff/Storm Sewers Unknown Nonpoint Source Medium 19 Miles Low 19 Miles Low 19 Miles _ ...... __ ..... ~. __ ~_,~= . .,.,..::. .. , .... " ... ;""t'.i~"'li'f&aw.~'"'.'""""".'W.liffiw;"ffR!foy_:I!lIF!ftii!lj!T ........, ""'" Unknown point source ISO ree mouth 90113000,--~,~'i&>;:l'.:z'«N""".u .... ":t.,~.:lT''''''''''';;''w.-.• : 9 E AI · C k ( ) ~IR'" 'f"iiii"""'"lI!lrrm·"'dilliBi!iW:".F.--~'~·'~~~"·"'"·· _.. ., Bacteria Indicators Medium 0.29 Acres ~ __ !3 .... ~_~~~~~.II.; .. i:t¥i:~r:;j iir-pi'>rWi'&S¥' ''''a'rU!.ot.!.~~~Hwr5C\Q'6&en 'W'iI'fWY..A»tiJI'iBWNt¥dz;;$'WWG&WWf Nonpomt/Point Source .. # • 9 E Buena VISta Lagoon 90421000 ..-rmrmm. 'ii'W1l"W'=·'W.l!i'4i":':lil'iil';!"I!!'):ii~;:"')Ii;!,"'*"",':<~II"";"i""'."':' Bacteria Indicators Low 202 Acres Nonpoint/Point Source Nutrients Low 202 Acres Estimated size of impairment is J 50 acres located in upper portion of lagoon. Nonpoint/Point Source Sedimentation/Siltation Medium 202 Acres NonpointiPoint Source ..... ,,..c,_\~.~~~.t.~~,,.;:;~~~~iSltGi·,~~m~tr'Sii*'fMi-e=aWf~.~'~""""'"f~1RWMtYRi_m~~~r"~t:; .... J,t~~~£~t.'&:t:.~&~~'{(.:;..,Vjii.· .. i;.,'$i;t~~~~e:;.; .... Page10f16 '. Attachment 4 • (.~ . (' '. Storm Water Standards 4/03/03 III.: PERMANENT' BEST MiN·AGEM~N.T PR~CTI6E$ SE~ECTlqN PROC'ED~'RE ':" .., ••• '," ". '. '.' '. ,,' .1 '" . .' '. ~ ,: '. :..', ',..;-: ~ . . When referred to this Section, by Step 2 of Section II, complete the analysis required for· your project in the subsections of Section 111.1 below. 1. IDENTIFY POLLUTANTS & CONDITIONS OF CONCERN A. Identify Pollutants from the Project Area Using Table 1, identify the project's anticipated pollutants. Pollutants associated with any hazardous material sites that have been remediated or are not threatened by the proposed project are not considered a pollutant of concern. Projects meeting the definition of more than one project category shall identify all general pollutant categories that apply. Table 2. Anticipate an o enta d dPt liP ollutants G enerate db L d )V an Use TVDe. General Pollutant Categories Project Trash Oxygen Bacteria Categories Heavy Organic & Demanding 011& & Sediments Nutrients Metals Compounds Debris Substances Grease Viruses Pesticides Detached Residential X X X X X X X Development Attached Residential X X X P(1) P(2) P(1) X Development Commercial Development P(1) P(1) P(2) X P(S) X PI31 PIS) > 1 00, 000 tt2 Automotive X X(4){5) X X Repair Restaurants X X X X Hillside Development X X X X X X >5,000 ft2 Parking Lots P(1) P(1) X X PI11 X P(1) Streets, Highways & X P(1)X X X(4) X P(5) X Freeways X = anticipated P = potential (1) A potential pollutant if landscaping exists on-site. (2) A potential pollutant if the project includes uncovered parking areas. (3) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons. I(S} Including solvents. 12 {,. Attachment 5 ((A. : ~ Storm Water Standards 4/03/03 Table 1. Standard Development Project & Priority Project Storm Water BMP R~ulrements Matrix. BMPs Applicable to Individual PrioritY Project Categories(3) en oo!I CtI tJ) ~ ~ ~ en ~ en C) ~ C) ~ CtI C C ~ !! .c 'B 'Q. ~ C) ~ ·c C) co c en .c ~ en en -0 Oc ~ en 2 ~ -0 CtI J!j~ tJ) ~ -If c & ~ c c 0. ~ co. ~ ~ ~ ~ ~1iS ~ cD 8 ~ C) cD ~ 13 .9-~ c :2 :E :s -£~ 'm :::J cD ~ Site Source ·c 0 ~ Jf :::J ::J ~ Treatment 0. 0 :::E 0 en ::t: Design Control cd .0 cj -d a; C, .c Control BMPsl1} BMPsPl .,.: '-'-' BMPsf4J Standard Projects R R 0 0 0 0 0 0 0 0 0 0 0 Priority Projects: Detached Residential R R R R R S Development Attached Residential R R R S Development Commercial Development R R R R R R S >100.000 ft2 Automotive Repair Shop R R R R R R R S Restaurants R R R R S Hillside Development ·R R R R S >5000 ft2 Parking Lots R R R(5) S Streets, Highways & R R S Freeways R = Required; select one or more applicable and appropriate BMPs from the applicable steps in Section 1I1.2.A-D. or equivalent as identified in Appendix C. o = Optional/ or may be required by City staff. As appropriate. applicants are encouraged to incorporate treatment control BMPs and BMPs applicable to individual priority project categories into the project design. City staff may require one or more of these BMPs. where appropriate. S = Select one or more applicable and appropriate treatment control BMPs from Appendix C. (1) Refer to Section "1.2.A. (2) Refer to Section 1I1.2.B. (3) Priority project categories must apply specific storm water BMP requirements, where applicable. Priority projects are subject to the requirements of all priority project categories that apply. (4) Refer to Section 111.2.0. tS) Applies if the p'aved area totals >5,000 square feet or with >15 parking sQaces and is potentially exposed to urban runoff. 8 ;'. \, Attachment 6 • '. ( '- Storm Water Standards 4/03/03 Table 3. Numeric Sizing Treatment Standards. Volume 1. Volume-based BMPs shall be designed to mitigate (Infiltrate, filter. or treat) the volume of runoff produced from a 24-hour 85th percentile storm event. as determined from isopluvlal maps contained in the County of San Diego Hydrology Manual. Flow 2. Flow-based BMPs shall be designed to mitigate (Infiltrate. filter, or treat) the maximum flow rata of runoff produced from a rainfall Intensity of 0.2 inch of rainfall per hour for each hour of a storm event ' I. Struptural Treatment BMP Se/ectlon Procedure PriOrity proJects shall select a single or combination of treatment BMPs from the categor.ies in Table 4 that maximize pollutant removal for the particular pollutant(s) of concern. A ny pollutants the project I s expected tog enerate t hat a re a Iso causing, a Clean Water Act section 303(d) Impairment of the downstream receiving waters of the project should be given top priority in selecting treatment BMPs. . . To select a structural treatment BMP using the Structural Treatment -Control BMP Selection Matrix (Table 4). each priority project shall compare the list of pollutants fot , which tne downstr~am receiving waters are impaired (if any).' According to the 1998 303(d) ,listing, the Agua Hedionda Lagoon is Impaired for sediment and siltation. Buena Vista lagoon also has impaired beneficial uses (aquatic life) due to high sedlm~htationlsiltation. Portions of Carlsbad where construction sites have the potential to d isc~arge I nto a tributary 0 fa 3 03(d) 0 r directly into a 3 03(d) water body 0 r sites locatediwithin 200 feet of an ESA require additional BMP implementation. These water bodies Include the Pacific Ocean, Buena Vista Lagoon. Encinas Creek, Agua Hedionda Lagoo~t and Batiquitos lagoon. Priority' projects that are not anticipated to g~nerate a pollutant for which the receiving water is Clean Water Act Section 303(d) impaired shall select a single or combination of structural treatment BMPs from Table 4 that are effective for pollutant removal of the identifi~d pollutants of concern determined to be most significant for the project. Selected BMPs must be effective for the widest range of pollutants of concern anticipated to be generated by a priority project (as identified in Table 1). Alternative storm water BMPs not identified in Table 4 may be approved at the discretion of the City Engineer. provided the alternative BMP is as effective in removal of pollutants of concern as other feasible BMPs listed in Table 4. fl. Attachment 7 __ LI=-==--=' ....•..• ~/_··· ' ____ 1_. _' )0- ----E-----r _II -/1 F" >.-,1 -.// ~//-// ' C PACIFIC OC£AII ,A _ .. ... " CIlY OF ENCINITAS VICINITY MAP . j W J I --~ _1- --~ ------ -,--------------------'\-------- -E- B C 0 E =~ =~ ..,. .. ..,. .. "'". ' "' ... 0' 25' '00' -----50' SCALE: ," = 50' --------- -- -:::::;:> -------------:..::;;---- AC H I F C ..... :: =s . ... -* .. " ---- BASIN A,B ~ ----- -~= :: ==: K """ ..... ..... "'" iiiiiii(1UJlll) .... · .' · . -.' >'.,: I I J I . \ ) I I ~..!----- - - - - -_. / / / '.\ \ BMP SUMMABY ',' .' ,; EXPECTED , APPliCABLE BlIP BlIP IIAINlENANCE " POST CfJI(S1RIJCTlON . HESPONSIBIIJTY POlLUTANTS IIAINlENANCE . BlIPs · .'. -NU'iRlENlS FROM FER17UZERS '-SlREET S/l£EPING . MONTHlY PRIVA IE MAINTENANCE RESPONSIBIUTY -HEA vr MEtAlS -INlET BASIN LABEUNG -17LE REPLACED AS NEEDED ~ )1;4RLY -ORGANIC COMPOUNDS '-STORM DRAIN INlET BASKElS -ROU17NEL Y CLEANED AND ' -TRAS!! AND DEBRIS WITH HYDROCARBON ABSORP17ON HYDROCARBON BOOMS REPLACED )1;4RLY . --~~ - --. -OXYGEN DEMANDING SUBSTANCES -TRAS!! STORAGE AREA 'DESIGN -NONE -OIL AND GREASE FROM PA VW AREAS -VEGETATED SWALE -ClEAN DEBRIS AS NEEDED -PES17C1DES FROM LANDSCAPING I":WATERtJ,AUTY CONTROL -ClEAN DEBRIS AS NEEDED . BASIN OFFSIT£} . LEGENJJ ,.SUMMARY S1rMP PALOMAR FORUM. - II SITE BOLINDARY MAJOR BASIN BOUNDARIES SUB BASIN BOUNDARIES EXlS17NG DRAINAGE SWALE PROPOSED DRAINAGE SWALE . "BIOClEAN-INlET BASKElS WITH HYDROCARBON ABSORP170N BOOMS. COVERED TRASH ENCLOSUREs VEGETATED SWALE , , " ; REVISED: APRIL 13, 2005 2710 Loker Avenue West . '_ Suite 100 Carlsbad, eanfornia 92008 760-931-nOO Fax: 760-931-8680 Odcy@Odayconsultants.com . Civil Engineering ~-Planning .-Processing Surveying . -,', .'--.: .~:: , LOT 5 DESIGNED BY: _-"J"".J~. -,-. DATE: FEB. 2005 DRAWN BY: B.O.O. SCALE: ~ SHOWN PROJECT MGR.· K.H. JOB NO.: 011010-11 ENGINEER OF WORK DATE: , KEnH HANSEN . RCE: 60223 ~ a E a N N '" m ~ I .. '," , Attachment 8 •• Section 4 Source Control BMPs 4.1 Introduction This section describes specific source control Best Management Practices (BMPs) to be considered for incorporation into newly developed public and private infrastructure, as well as retrofit into existing facilities to meet stonnwater management objectives. 4.2 BMP Fact Sheets Source control fact sheets for design are listed in Table 4-1. The fact sheets detail planning methods and concepts that should be taken into consideration by developers during project design. Th~ fact sheets are arranged in three categories: those that have to do with landscape, irrigation, and sign age considerations; those that have to do with use of particular materials, those that have to do with design of particular areas. 4.3 Fact Sheet Format A BMP fact sheet is a short document that provides information about a P·articular BMP. Typically each fact sheet contains the information outlined in Figure 4-1. Supplemental information is provided if it is available. The fact sheets also contain side bar presentations with information on BMP design objectives. Completed fact sheets. for each of the above activities are provided in Section 4.4. SDxx Example Fact Sheet 4.4 Table 4-1 Source Control BMPs for Design Design SD-1O Site Design and Landscape Planning SO-l1 Roof RUnoff Controls 8D-12 Efficient Irrigation 80-13 Storm Drain System Signs Materials SD-20 Pervious Pavements SO-21 Alternative Building Materials Areas SO-30 Fueling Areas SO-31 Maintenance Bays and Docks 80-32 Trash Enclosures SD-33 Vehicle Washing Areas SD-34 Outdoor Material Storage Areas SD-3S Outdoor Work Areas SD-36 Outdoor Processing AreaS BMP Fact Sheets Description of the BMP Approach Suitable Applications Design Considerations • Designing New Installations • Redeveloping Existing Installations Supplemental Information Source Control BMP Fact Sheets for design follow. The BMP fact sheets are individually page numbered and are suitable for photocopying and inclusion in stormwater quality management plans. Fresh copies of the fact sheets can be individually downloaded from the California Stormwater BMP Handbook website at www.cabmphandbooks.com. • Examples • Other Resources Figure 4-1 Example Fact Sheet ....awn cmFP¥C=== erne , 7 s=_ -c'rrn s· ........-wseg ... ....,e;w;er;Wme,U6S=TZ'Ql'~= .. 3t·nqr;_ January 2003 California Stormwater Bl'-lP Handbook . 4-1 New Develooment and Redevelopment Efficient Irrigation Description 5D-12 Design Objectives ./ Maximize Infiltration ./ Provide Retention ./ Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Irrigation water provided to landscaped areas may result in excess irrigation water being conveyed into storinwater drainage systems. Approach Project plan designs for development and redevelopment should include application methods of irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance system. Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes ar~ typically excluded from this requirement.) Design Considerations Designing New Installations The following methods to reduce excessive irrigation nmoff should be considered, and incorporated and implemented where determined applicable and feasible by the Permittee: II Employ rain-triggered shutoff devices to prevent irrigation after precipitation. • Design irrigation systems to each landscape area's specific water requirements. ~ Include design featuring flow reducers or shutoffvalves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines. Implement landscape plans consistent with County or City water conservation resolutions, which may include provision of water sensors, programmable irrigation times (for short cycles), etc. January 2003 California Stormwater BMP Handbook New Development and Redevelopment .. .'\i C ·\:~·O :\ . ." _ J.:t ..,"'1. ........... ...-..... .;. ........... -.. . e. ) CalifornIa . "'.' Stormwater . :;,} .~uality (..' AS$oci.a~I<illn 1 of 2 Efficient Irrigation - QI Design timing and application methods of irrigation water to minimize the runoff of excess irrigation water into the storm water drainage system. ill Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface filtration. Choose plants with low irrigation requirements (for example, native or drought tolerant species). Consider' design features such as: Using mulches (such as wood chips or bar) in planter areas without ground cover to minimize sediment in runoff Installing appropriate plant materials for the location, in a,ccordance with amount of sunlight and climate, and use native plant materials where possible and/or as recommended by the landscape architect ' Leaving a vegetative barrier along the property boundary and interior watercourses, to act as a pollutant filter, where appropriate and feasible Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain growth • Employ other comparable, equally effective methods to reduce irrigation water runoff. \.~deveIOPing Existing Installations , -various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervio\1s surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002 . ..:;:-0: .... ·4"1.-w.-"·"';~14'''''}''1S'i''G''bm''s).'k'''i'·'''~~~~~'''''~~''~.ta..a''' .. n;l2£q..G.sC!:mut:"'..eLA~~ 2 of 2 California Stormwuter BMP Handbook JJnuary 2003 New f)evplonmpn~ .:.nrl R.:>rl,,"plnnm.:>n~ Storm Drain Signage Description 5D-13 Design Objectives Maximize Infiltration Provide Retention Slow Runoff Minimize Impervious land Coverage ./ Prohibit Dumping of Imprqper Materials Contain Pollutants Collect and Convey Waste materials dumped into storm drain inlets can have severe impacts on receiving and ground waters. Posting notices regarding 4ischarge prohibitions at storm drain inlets can prevent waste dumping. Storm drain signs and stencils are highly visible source controls that are typically placed directly adjacent to storm drain inlets. . Approach The stencil or affixed sign contains a brief statement that prohibits dumping of improper materials into the urban runoff conveyance system. Storm drain messages have become a popular method of alerting the public about the effects of and the prohibitions against waste disposal. Suitable Applications Stencils and signs alert the public to the destination of pollutants discharged to the storIIl drain. Signs are appropriate in residential, commercial, and industrial areas, as well as any other area where contributions or dumping to storm drains is likely. Design Considerations Storm drain message markers or placards are recommended at all storm drain inlets within the boundary of a development project. The marker should be placed in clear sight facing toward anyone approaching the inlet from either side. All storm drain inlet locations should be identified on the development site map. Designing New Installations The following methods should be considered for inclusion in the project design and show on project plans: .. Provide stenciling or labeling of all storm drain inlets and catch basins, constructed or modified, 'within the project area with prohibitive language. Examples include "NO DUMPING- January 2003 CJlifornia Stormwater BMP Handbook i\Jpw n.:uu.lilnnrn,Qnfo :ann 00.,",0\10.1",,1"\'-__ • . :.':::) .r i\. ~ ~ ,\ .' '.1~"U· ._' t\:··;~-;'~~·· ... ~-.. ~ ........... , .... -: ..... ::!:. ..... ~ . . ' .. ~. California ',:. \~;. Stormwater . . ~: l Quality . . .~~'~. . , ..•. ' . Association .10.. 1 of 2 -Storm Drain Signage DRAINS TO dCEAN" and/or other graphical icons to discourage illegal dumping. II Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area. Note -Some local agencies have approved specific signage.and/or storm drain message placards for use. Consult local agency stormwater staff to determine specific requirements for placard types and methods of application. Redeveloping Existing Installations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. If the project ineets the definition of "redevelopment", then the . requirements stated under" designing new installations" above should be included in aU'project design plans. . Additional Information Maintenance Considerations • Legibility of markers and signs should be maintained. If required by the agency with , • jurisdiction over the project, the owner/operator or homeowner's association should enter t.( into a maintenance agreement with the agency or record a deed restriction upon the .' property. title to maintain the legibility of placards or signs. Placement • Signage on top of curbs tends to weather and fade. lI! Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms. Supplemental Information Examples III Most MS4 programs have storm drain signage programs. Some MS4 programs will provide stencils, or arrange for volunteers to stencil storm drains as part of their outreach program. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SU~MP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. ~entura Countywide Technical Guidance Manual for Stonnwater Quality Control Measures, ·,(WlY2002 . • .;.:,.~~....:::.....wl",;'""''-·n'" Zl!!%;" m~:.:.:.....------"" -j" .-""i7ip.--., -~. -n .. ~" ... ~.G='?t.;'·'!!··-,.-..:efmG'V"i~~m'n;ae:m. j!')-:g';w.:&L.:4:J.~g"nlW· -·r;;. .. ..:"' .. bl'.L.."~.-i;)t'o.-.. 'cr· ... r r; ..... 2 of 2 California Storll1water BMP Handbook JanuJI~Y 2003 Nt!w Develooment and Redevelooment Trash Storage Areas Description Trash storage areas are areas where a trash receptacle (s) are located for use as a repository for solid wastes. Stormwater runoff from areas where trash is stored or disposed of can be polluted. In addition, loose trash and debris can be easily transported by water or wind into nearby storm drain inlets, channels, and/or creeks. Waste handling operations that may be squrces of stormwater pollution include dumpsters, litter control, and waste piles. Approach This fact sheet contains details on the specific m~asures required to prevent or reduce pollutants in stormwater runoff associated with trash storage and handling. Preventative measures including enclosures, containment structures, and impervious pavements to' mitigate spills, should be used to reduce the likelihood of contamination. Suitable Applications 5D-32 Design Objectives Maximize Infiltration Provide Retention Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials ./ Contain Pollutants Collect and Convey Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes are typically excluded from this requirement.) Design Considerations Design requirements for waste handling areas are governed by Building and Fire Codes, and by current local agency ordinances and zoning requirements. The design criteria described in this fact sheet are meant to enhance and be consistent with these code and ordinance requirements. Hazardous waste should be handled in accordance with legal requirements established in Title 22, California Code of Regulation. Wastes from commercial and industrial sites are typically hauled by either public or commercial carriers that may have design or access requirements for waste storage areas. The design criteria in this fact sheet are recommendations and are not intended to be in conflict with requirements established by the waste hauler. The waste hauler should be contacted prior to the design of your site trash collection areas. Conflicts or issues should be discussed with the local agency. Designing New Installations Trash storage areas should be designed to consider the following structural or treatment control BMPs: .. J Design trash container areas so that drainage from adjoining roofs and pavement is diverted around the area(s) to avoid run-on. This might include berming or grading the waste handling area to prevent run-on of storm water. Make sure trash container areas are screened or walled to prevent off-site transport of trash. ",' "~or :,:';, (" ,!\ ,I '0 \. ....... "~~ 'it :" .~. :!_~ ~ .. ~., .... _:f . .." ... ~ : ~ ,California : ~ ,::,;" :itol'mw;l'ter ",1:;1","" 'Quality , ::'),;: : ,~$I()c3<J~~i,!m '.i~ WE' S!gj'~~~-wr;~t·trhl-f7V7h'E'2~~Q,I~cm~;;.,~~~.,....,,,,,,,z.""':~~~·et.~ January 2003 California Stormwater Br'tP Handbook 1 of 2 New Development and Redevelopment --=0-32 {(~ Trash Storage Are.as . II Use lined bins or dumpsters to reduce leaking of liquid waste. • Provide roofs, awnings, or attached lids on all trash containers to minimize direct precipitation and prevent rainfall from entering containers. • Pave trash storage areas with an impervious surface to mitigate spills. • Do not locate storm drains in immediate vicinity of the trash storage area. • Post signs on all dumpsters informing users that hazardous materials are not to be disposed of therein. Redeveloping Existing Installations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. ( .Additional Information I ( Maintenance Considerations The integrity of structural elements that are subject to damage (i.e., screens, covers, and signs) must be maintained by the owner/operator. Maintenance agreements between the local agency and the owner/operator may be required. Some agencies will require maintenance deed restrictions to be recorded of the property title. If required by the local agency, maintenance agreements or deed restrictions must be executed by the owner/operator before improvement plans are approved. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. . Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. · ... Q·£sm7W-;mG"i'''20m Tn .. ' r'M'tNF"WE HF!5RDki'S 'Z7'"'; === sc=vz • 2 of 2 California Stormwater Br-IP Handbook Nl"!w r1evelooment and Redevelooment :nan PF?'WY'7FiIlt 7M'W>,.. zn=DMW"- January 2003 Parking/Storage Area Maintenance SC-43 Description Parking lots and storage areas can contribute a number of substances, such as trash, suspended solids, hydrocarbons, oil and grease, and heavy metals that can enter receiving waters through stormwater runoff or non-stormwater discharges. The following protocols are intended to prevent or reduce the discharge of pollutants from parking/storage areas and include using good housekeeping practices, following appropriate cleaning BMPs, and training employees. Approach Pollution Prevention ~ Encourage alternative designs and maintenance strategies for impervious parking lots. (See New Development and Redevelopment BMP Handbook). II Keep accurate maintenance logs to evaluate BMP implementation. Suggested Protocols General ri Keep the parking and storage areas clean and orderly. Remove debris in a timely fashion. LI Allow sheet runoff to flow into biofilters (vegetated strip and swale) and/or infiltration devices. !;1 Utilize sand filters or oleophilic collectors for oily waste in low concentrations. January 2003 California Stormwater BIVIP Handbook Municipal 'Nww.cabmphandbooKs.COI11 Objectives • Cover • Contain • Educate • Reduce/Minimize • Product Substitution Targeted Constituents Sediment ./ Nutrients ./ Trash ./ Metals ./ Bacteria Oil and Grease Organics Oxygen Demanding 1 of 4 ,{. SC-43 Parking/Storage Area Maintenance • Arrange rooftop drains to prevent drainage directly onto paved surfaces. • Design lot to include semi-permeable hardscape. Controlling Litter • Post "No Littering" signs and enforce anti-litter laws. • . Provide an adequate number of litter receptacles. • Clean out and cover litter receptacles frequently to prevent spillage. • Provide trash receptacles in parking lots to discourage litter. • Routinely sweep, shovel and dispose of litter in the trash. Surface cleaning • Use dry cleaning methods (e.g. sweeping or vacuuming) to prevent the discharge of pollutants into the stormwater conveyance system. • Establish frequency of public parking lot sweeping based on usage and field observations of waste accumulation. • Sweep all parking lots at least once before the onset of the wet season. • If water is used follow the procedures below: Block the stonn drain or contain runoff. Wash water should be collected and pumped to the sanitary sewer 'or discharged to a pervious surface, do not allow wash water to enter storm drains. Dispose of parking lot sweeping debris and dirt at a landfill. a When cleaning heavy oily deposits: Use absorbent materials on oily spots prior to sweeping or washing. Dispose of used absorbents appropriately. Surface Repair 11 Pre-heat, transfer or load hot bituminous material away from storm drain inlets. fa Apply concrete, asphalt, and seal coat during dry weather to prevent contamination form contacting stormwater runoff. rJ Cover and seal nearby storm drain inlets (\Ai1th waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc., where applicable. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. 20f4 California Stormwater BMP Handbook January 2003 Municipal ~'. ww .cabmphandbooks.coITI Parking/Storage Area Maintenance .SC-43 • Use only as much water as necessary for dust control, to avoid runoff. • Catch drips from paving equipment that is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly. Inspection • Have designated personnel conduct inspections of the parking facilities and stormwater conveyance systems associated with them on a regular basis. • Inspect cleaning equipment/sV'Teepers for leaks on a regular basis. Training • Provide regular training to field employees and/or contractors regarding cleaning of paved areas and proper operation of equipment. • Train employees and contractors in proper techniques for spill containment and cleanup. Spill Response and Prevention • Refer to SC-ll, Spill Prevention, Control & Cleanup. • Keep your Spill Prevention Control and countermeasure (SpeC) plan up-to-date, nad implement accordingly. \I Have spill cleanup materials readily available and in a known location. • Cleanup spills immediately and use dry methods if possible. \I Properly dispose of spill cleanup material. Other Considerations III Limitations related to sweeping activities at large parking facilities may include high equipment costs, the need for sweeper operator training, and the inability of current sweeper technology to remove oil and grease. Requirements Costs Cleaning/sweeping costs can be quite large, construction and maintenance of stormwater structural controls can be quite expensive as well. Maintenance II Sweep parking lot to minimize cleaning with water. iii Clean out oil/water/sand separators regularly, especially after heavy storms. II Clean parking facilities on a regular basis to prevent accumulated wastes and pollutants from being discharged into conveyance systems during rainy conditions. January 2003 California Stormwater BfvlP Handbook ~~ui1icipal www.cabrnphandbuol<s.com 3 of 4 J-SC-43 Parking/Storage Area Maintenance Supplemental Information Fu .. the .. Detail of the BMP Surface Repair Apply concrete, asphalt, and seal coat during dry weather to prevent contamination form contacting stormwater runoff. Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. Use only as much water as necessary for dust control, to avoid runoff. References and Resources http://www.stormwatercenter.net/ California's Nonpoint Source Program Plan http://www.swrcb.ca.gov Inps/index.html Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality control Board. July 1998 (Revised February 2002 by the California Coastal Commission). Orange County Stormwater Program http://www.ocwatersheds.com/Storm Water /swp_introduction.asp Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for Maintenance Practices. June 1998. Pollution from Surface Cleaning Folder. 1996. Bay Area Stormwater Management Agencies Association (BASMAA) http://www.basma.org San Diego Stormwater Co-permittees Jurisdictional Urban Runoff Management Program (URMP) http://www.projectc1eanwater.org/pdf/Model%2oProgram%2oMunicipal%2oFacilities.pdf 4 of 4 California Stormwater aMP Handbook Municipal 'NVvw,cabmphalldbooks,com January 2003 (/ •. . ('~ Road and Street Maintenance SC-70 Objectives • Cover • Contain • Educate • ReduceJMlnlmlze II Product Substitution Targeted Constituents Sediment .t Description Nutrients Streets, roads, and highways are significant sources of pollutants in stormwater discharges, and operation and maintenance (O&M) practices, if not conducted properly, can contribute to the problem. Stonnwater pollution from roadway and bridge maintenance should be addressed on a site-specific basis. Use of the procedures outlined below. that address street sweeping and repair, bridge and structure maintenance, and unpaved roads win reduce pollutants in stormwater. Approach Pollution Prevention fl1 Use the least toxic materials available (e.g. water based paints, gels or sprays for graffiti removal) 1.1 Recycle paint and other materials whenever possible. II Enlist the help of citizens to keep yard waste, used oil, and other wastes out of the gutter. Suggested Protocols Street Sweeping and Cleaning ~ Maintain a consistent sweeping schedule. Provide minimum monthly sweeping of curbed streets. tlI Perform street cleaning during dry weather if possible. ....;...:;~ ._ ..... " ... . .,_ . ., Janua;y 2003 California Stormwater 6MP Handbook Municipal '.v'Nw.cJbmpllandbooks.,:oln Trash .t Metals ./ Bacteria on and Grease ./ Organl~ .t Oxygen Demanding ./ "-----~-----••... ---- ·,Jou';lii·'Y ,~:.;o.:ja~ioi'l '--.-~. or .~ .... '~. ~ • "_, ·'1 ..•. ~ .. ..::;.....t,II 1 of 9 l,. Road and Street Maintenance • Avoid wet cleaning or flushing of street, and utilize dxy methods where possible. • Consider increasing sweeping frequency based on factors such as traffic volume, land use, field observations of sediment and trash accumulation, proximity to water courses, etc. For example: Increase the sweeping frequency for streets with high pollutant loadings, especially in high traffic and industrial areas. Increase the sweeping frequency just before the wet season to remove sediments accumulated during the summer. Increase the sweeping frequency for streets in special problem areas such as special events, high litter or erosion zones. • Maintain clea~ing equipment in good working condition ancl purchase replacement equipment as needed. Qld sweepers should be replaced with new technologically advanced sweepers (preferably regenerative air sweepers) that maximize pollutant removal. • Operate sweepers at manufacturer requested optimal speed levels to increase effectiveness. !a To increase sweeping effectiveness consider the following: Institute a parking policy to restrict parking in problematic areas during periods of street sweeping. Post permanent street sweeping signs in problematic areas; use temporary signs if installation of permanent signs is not possible. Develop and distribute flyers notifying residents of street sweeping schedules. f.I Regularly inspect vehicles and equipment for lea:ks, and repair immediately. iii If available u~e vacuum or regenerative air sweepers in the high sediment and trash areas (typically industrial! commercia!). 11 Keep accurate logs of the number of curb-miles swept and the amount of waste collected. IJ Dispose of street sweeping debris and dirt at a landfill. OJ Do not store swept material along the side of the street or near a storm drain inlet . .JI Keep debris storage to a minimum during the wet season or make sure debris piles are contained (e.g. by berming the area) or covered (e.g. with tarps or permanent covers). Street Repair and Maintenance Pavement marking ~ Schedule pavement marking activities for dry weather. 2 of 9 California Stormwatar SNP Handbook JJi1ua,'y ~O()3 ,\lunici;Jdl www.cabmphandbool<s.com \. Road and Street Maintenance SC-70 II Develop paint handling procedures for proper use, storage, and disposal of paints. II Transfer and load paint and hot thermoplastic away from storm drain inlets. • Provide drop cloths and drip pans in paint mixing areas. II Properly maintain application equipment. II Street sweep thermoplastic grindings. Yellow thennoplastic grindings may require special handling as they may contain lead. II Paints containing lead or tn'butyltin are considered a hazardous waste and must be disposed of properly. II Use wa~r based paints whenever possible. If using water based paints, clean the application equipment in a sink that is connected to the sanitary sewer. II Properly store leftover paints if they are to be kept for the next job, or dispose of properly. Concrete installation and repair • Schedule asphalt and concrete activities for dry weather. II Take measures tO,protect any nearby storm drain inlets and adjacent watercourses, prior to breaking up asphalt or concrete (e.g. place san bags around inlets or work areas). II Limit the amount of fresh concrete or cement mortar mixed, mix only what is needed for the job. II Store concrete materials under cover, away from drainage areas. Secure bags of cement after they are open. Be sure to keep wind-blown cement powder away from streets, gutters, storm drains, rainfall, and runoff. Ia Return leftover materials to the transit mixer. Dispose of small amounts of hardened excess concrete, grout, and mortar in the trash. f;J Do not wash sweepings from exposed aggregate concrete into the street or storm drain. Collect and return sweepings to aggregate base stockpile, or dispose in the trash. Ii When making saw cuts in pavement, use as little water as possible and perform during dry weather. Cover each storm drain inlet completely with filter fabric or plastic during the sawing operation and contain the slurry by placing straw bales, sandbags, or gravel dams around the inlets. After the liquid drains or evaporates, shovel or. vacuum the slurry residue from the pavement or gutter and remove from site. Alternatively, a small onsite vacuum may be used to pick up the slurry as this will prohibit slurry from reaching storm drain inlets. IJ Wash concrete trucks off site or in designated areas on site designed to preclude discharge of wash water to drainage system. January 2003 California Stormwatoilr S'ivl? Handbook Municipal ~·l'Nw,(Jbmpi1andbook5.';U"i1 3 of 9 ire SC-70 I Road and Street Maintenance {\ \.. Patching, resurfacing, and surface sealing • Schedule patching, resurfacing and surface sealing for dry weather. • Stockpile materials away from streets, gutter areas, storm drain inlets or watercourses. During wet weather, cover stockpiles with plastic tarps or berm around them if necessary to prevent transport of materials in runoff. • Pre-heat, transfer or load hot l>ituminous material away from drainage systems or watercourses. • Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and maintenance holes before applying seal coat, slurry seal, etc. Leave covers in place until job is ~omplete and until alJ water from emulsified oil sealants has drained or evaporated. Clean any debris from covered maintenance holes and storm drain inlets when the job is complete. • Prevent excess material from exposed aggregate concrete or similar treatments from entering streets or storm drain inlets. Designate an area for clean up and proper disposal of excess materials. II Use only as much water as necessary for dust control, to avoid runoff. ((e. Sweep, never hose down streets to clean up· tracked dirt. Use a street sweeper or vacuum truck. Do not dump vacuumed liquid in storm drains. { I ( . \'1. ... • Catch drips from paving equipment that is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly. Equipment cleaning maintenance and storage iii Inspect equipment daily and repair any leaks. Place drip pans or absorbent matelials under heavy equipment when not in use. II Perform major equipment repairs at the corporation yard, when practical. ~ If refueling or repairing vehicles and equipment must be done onsite, use a location away from storm drain inlets and watercourses. II Clean equipment including sprayers, sprayer paint supply lines, patch and paving equipment, and mud jacking equipment at the end of each day. Clean in a sink or other area (e.g. vehicle wash area) that is connected to the sanitary sewer. Bridge and Structure Maintenance Paint and Paint Removal i4 Transport paint and materials to and from job sites in containers lNith secure lids and tied down to the transport vehicle. (. .] Do not tmnsfer or load paint near storm drain inlets or watercourses. -+ of 9 Ca,ifornia Stormwater BIVtP Handbook :"Iuniclpal www.cabI1lIJhal1dbooks.com January 2.003 ((. , \ \ " .... -- Road and Street Maintenance SC-70 • Test and inspect spray equipment prior to starting to paint. Tighten all hoses and connections and do not overfill paint container. • Plug nearby storm drain inlets prior to starting painting where there is significant risk of a spill reaching storm drains. Remove plugs when job is completed. • If sand blasting is used to remove paint, cover nearby storm drain inlets prior to sta~g work. • Perform work on a maintenance traveler or platform, or use suspended netting or tarpsto capture paint, rust, paint removing agents, or other materials, to prevent discharge of materials to surface waters if the bridge crosses a watercourse. If sanding, use a sander with a vacuum filter bag. • Capture-all clean-up water, and dispose of properly. • Recycle paint when possi~l~ (e.g. paint m.ay be used for graffiti removal activities). Dispose of unused paint at an appropriate household hazardous waste facility. Graffiti Removal III Schedule graffiti removal activities for dry weather. • Protect nearby storm drain inlets prior to removing graffiti from walls, signs, sidewalks, or other structures needing graffiti abatement. Clean up afterwards by sweeping or vacuuming thoroughly, and/or by using absorbent and properly disposing of the absorbent. • When graffiti is removed by painting over, implement the procedures under Painting and Paint Removal above. ill Direct runoff from sand blasting and high pressure washing (with no cleaning agents) into a landscaped or dirt area. If such an area is not available, filter runoff through an appropriate filtering device (e.g. filter fabric) to keep sand, particles, and debris out of storm drains. II If a graffiti abatement method generates wash water containing a cleaning compound (such as high pressure washing with a cleaning compound), plug nearby storm drains and vacuum/pump wash water to the sanitaty sewer. iii Consider using a waterless and non-toxic chemical cleaning method for graffiti removal (e.g. gels or spray compounds). Repair Work iI Prevent concrete, steel, wood, metal parts, tools, or other work materials from entering storm drains or watercourses. II Thoroughly clean up the job site when the repair work is completed. ::J When cleaning guardrails or fences follow the appropriate surface cleaning m~thods (depending on the type of smface) outlined in SC-7l Plaza & Sidewall< Cleaning fact shc~t. . ··t ... .,·i'" ... ~-~ .;;;;;-.. ..... _-.j"';.o-;-::. .• -.••.• ..,-. ... -. b-·· _'_A,.. .. ~~ ... ·-:;;:,..,~·;;:a~'"'t=-···i·..,-.. • .. rt·.,.· ... ~·--' .~--"/." -,,', ..... _ .... ~~-:.:..::.....~ January 2.003 California Stormwater 8~!? Hal1dbook 5 of 9 Municipal www.cabmphandbooks.com :(!'. SC .. 70 (" Road and Street'Maintenance II If painting is conducted, follow the painting and paint removal procedures above. • If graffiti removal is conducted, follow the graffiti removal procedures above. • If construction takes place, see the Construction Activity BMP Handbook. III Recycle materials whenever possible. Unpaved Roads and Trails • Stabilize exposed soil areas to prevent soil from eroding during rain events. This is particularly important on steep slopes. ,II For roadside areas with exposed soils, the most cost-effective choice is to vegetate the area, preferably with a mulch or binder that win hold the soils in place while the vegetation is establishing. Native vegetation should be used if possible. • If vegetation cannot be established immediately, apply temporary erosion control mats/blankets; a co~a straw, or gravel as appropriate. • If sediment is already eroded and mobilized in roadside areas, temporary controls should be installed. These may include: sediment control fences, fabric-covered triangular dikes, '. gravel-filled burlap bags, biobags, or hay bales staked in place. ,(( \ '. Non-StoMnwater Discharges \. ':, Field crews should be aware of non-stormwater discharges as part of their ongoing street maintenance efforts. II Refer to SC-lO Non-Stonnwater Discharges iI Identify location, time and estimated quantity of discharges. 11 Notify appropriate personnel. Training fI Train employees regarding proper street sweeping operation and street repair and maintenance. II Instruct employees and subcontractors to ensure that measures to reduce the stormwater impacts of roadway/bridge maintenance are being followed. II Require engineeling staff and/or consulting AlE firms to address stormwater quality in new bridge designs or existing bridge retrofits. !J Use a training log or similar method to document training. ,;3 Train employees on proper spill containment and clean up> and in identifying non- stormwater discharges. 6 of 9 California Stormwater BtvlP Handbook ~'ul;;c;pal w'Nw.cabmphandbooks.com Jal1Uilry 2003 \'i .... :. Road and Street Maintenance SC-70 Spill Response and Prevention • Refer to SC-ll, Spill Prevention, Control Be Cleanup. • Keep your Spill Prevention Control and countermeasure (SpeC) plan up-to-date, and implement accordingly. ~ Have spill cleanup materials readily available and in a known location. • Cleanup spills immediately and use dry methods if possible. • Properly dispose of spill cleanup material. Other Conslderations • Densely populated areas or heavily used streets may require parking. regulations to clear streetS for:cleaning. • No currently available conventional sweeper ~ effective at removing oil and grease. Mechanical sweepers are not effective at removing finer sediments. • Limitations may arise in the location of new bridges. The availability and costofland and other economic and political factors may dictate where the placement of a new bridge will occur. Better design of the bridge to control runoff is required if it is being placed near sensitive waters. . Requirements Costs • The maintenance oflocal roads and bridges is already a consideration of most community public works or transportation departments. Therefore, the cost of pollutant reducing management practices will involve the training and equipment required to implement these new practices. tI The largest eKpenditures for street sweeping programs are in staffing and equipment. The capital cost for a conventional street sweeper is between $60,000 and $120,000. Newer technologies might have prices approaching $180,000. 'The average useful life of a conventional sweeper is about four years, and programs must budget for equipment replacement. Sweeping frequencies will determine equipment life, so programs that sweep more often should expect to have a higher cost of replacement. ~ A street sweeping program may require the following. Sweeper operators, maintenance, supervisory, and administrative personnel are required. Traffic control officers may be required to enforce parking restrictions, Skillful design of cleaning routes is required for program to be productive. Arrangements must be made fOt' disposal of collected wastes. -='--~--='-~-'=======-=-'~~-=TO~-'~--~'-~--=--='~--=.~-.= .. -=. ==-=='=--~r="~"~-~'-~=~~~"~"~' _-'~--=---;--~"'~'-~'~'-~_-='-=" __ ~-~_~~ January 2003 Call1'ornia Starmwater Bi'l? Handbool< 7 of 9 Municipal www . ..:abmphafldbooks.com i,GeSC-70 Road and Street Maintenance \ I '. I • If investing in newer technologies, training for operators must be included in operation and maintenance budgets. Costs for public education are small, and mostly deal with the need to obey parking restrictions and litter control. Parking tickets are an effeetive reminder to obey parking rules, as well as being a source of revenue. Maintenance • Not applicable Supplemental Information Further Detail olthe BMP Street sweeping There are advantages and disadvantages to the two common types of sweepers. The best choice depends on your specift~ conditions. Many communities find it useful to have a compliment of both types in their tleet. . Mechanical Broom Sweepers -More effective at picking up large debris and cleaning. wet streets. Less costly to purchase and operate. Create more airborne dust. Vacuum Sweepers -More effective at removing fine particles and associated heavy metals. Ineffective at cleaning wet streets. Noisier than mechanical broom sweepers which may restrict ~reas or times of operation. May require an advance vehicle to remove large debris. Street Flushers -Not affected by biggest interference to cleaning, parked cars. May remove finer sediments, moving them toward the gutter and stormwater iDlets. For this reason, flushing feU out of favor and is now used primarily after sweeping. Flushing may be effective for combined sewer systems. Presently street flushing is not allowed under most NPDES permits. Cross-Media Transfer a/Pollutants The California Air Resources Board (ARB) has established state ambient air quality standards including a standard for respirable particulate matter (less than or equal to 10 microns in diameter, symbolized as PM10). In the effort to sweep up finer sediments to remove attached heavy metals, municipalities should be aware that fine dust, that cannot be captured by the sweeping equipment and becomes airborne, could lead to issues of worker and public safety. Bridges Bridges that carry vehicular traffic generate some of the more direct discharges of runoff to surface waters. Bridge scupper drains cause a direct discharge of stormwater into receiving waters and have been shown to carry relatively high concentrations of pollutants. Bridge maintenance also generates wastes that may be either directly deposited to the water below or carried to the receiving water by stormwater. The following steps will help reduce the stormwater impacts of bridge maintenance: :I Site new bridges so that significant adverse impacts to wetlands, sensitive areas, critical habitat, and riparian vegetation are minimized. 3 of 9 California Stormwater 8MP Handbook ivhmicipal www.cabmphandbooks.com ,.0,. {' ... _ .. _ .... ~ J,II,uary 2003 I . \ '. \ .... ' ......... Road and Street Maintenance SC-70 • Design new bridges to avoid the use of scupper drains and route runoff to land for treatment control. Existing scupper drains should be cleaned on a regular basis to avoid sediment/debris accumulation. • Reduce the discharge of pollutants to surface waters during maintenance by using suspended traps, vacuums, or booms in the water to capture paint, rust, and paint removing agents. Many of these wastes may be hazardous. Properly dispose of this waste by referring to C.A21 (Hazardous Waste Management) in the Construction Handbook. • Train employees and subcontractors to reduce the discharge of wastes during bridge maintenance. De-icing • Do not over-apply deicing salt and sand, and routinely calibrate sp~eaders. • Near reservoirs, restrict the application of deicing salt and redirect any runoff away from reservoirs. • Consider using alternative deicing agents (less toxic, biqdegradable, etc.). References and Resources Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July • 1998. Orange County Stormwater Program http://www.ocwatersheds.com/stormwater Iswp introduction. asp Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for Maintenance Practices. June 1998. Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan. September 1997, updated October 2000. Santa Clara Valley Urban Runoff Pollution Prevention Program. 2001. Fresh Concrete and Mortar Application Best Management Practices for the Construction Industry. June. Santa Clara Valley Urban Runoff Pollution Prevention Program. 2001. Roadwork and Paving Best Management Practices for the Construction Industry. June. United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Roadway and Bridge Maintenance. On-line http://www.epa.gov/npdes/menuotbmps/poll13.htm ,,-",,'-"1"'''''' :;;:.::·-=·""='1=-·..:...· .... "'"~-=-'.........,,"-'-'-:...-.:.-'-'. -0...; •• =-'",-• .=-'=--""' .. -='· ..... f·¥=~='G;J;.;."-' ....... '-""-_. -"'-t·"";"";;;';·'·"""" -"-·"""····""-i:·~.-:..;.··~,.=···~-·= .. ·'-",_--=-· .... .-. ... ...:..'"' ....... ~ .... January 2003 California Storrl1wacer ~MP l-iandbool< r·lunicipal '.'lww,cClbmpnandbonks.com 9 01'9 • ( , Landscape Maintenance Description Landscape maintenance activities include vegetation removal; herbicide and insecticide application; fertilizer application; watering; and other gardening and lawn care practices. Vegetation control typically involves a combination of chemical (herbicide) application and mechanical methods. All of these maintenance practices have the potential to contribute pollutants to the storm drain system. The major objectives of this BMP are to minimize the discharge of pesticides, herbicides and fertilizers to the storm drain system and receiving waters; prevent the disposal of landscape waste into the storm drain system by collecting and properly disposing of clippings and cuttings, and educating employees and the public. Approach Pollution Prevention 1:1 Implement an integrated pest management (rPM) program. IPM is a sustainable approach to managing pests by combining biological, cultural, physical, and chemical tools. ::I Choose low water using flowers, trees, shrubs, and groundcover. II Consider alternative landscaping techniques such as naturescaping and xeriscaping. 3 Conduct appropriate maintenance (i.e. properly timed fertilizing, weeding, pest control, and pruning) to help preserve the landscapes water efficiency. California Stormwater Sf.1P Handbook ~'lU'1idp31 www.cabmphandboo!<s.com SC-73 Objectives • Contain • Educate • ReduceJMiliimlze • Product SubstltuUon Targeted Constituents Sediment ./ Nu~enm ./ Trash ./ Metals Bacteria au and Grease OrganIcs Oxygen Demanding ./ 1 of 6 ( ,'., - ''''.' Landscape Maintenance II Consider grass cycling (grass cycling is the natural recycling of grass by leaving the. clippings on the lawn when mowing. Grass clippings decompose quickly and release valuable nutrients back into the lawn), Suggested Protocols Mowing, Trimming, and Weeding • Whenever possible use mechanical methods of vegetation removal (e.g mowing with tractor- type or push mowers, hand cutting with gas or electric powered weed trimmers) rather than applying herbicides. Use hand weeding where practical. ' • Avoid loosening the soil when conducting mechanical or manual weed control, this could lead to erosion. Use ~ulch or other erosion control measures when soils are exposed. ' • Performing mowing at optimal times. Mowing should not be perfonned if significant rain events are predicted. ' • 'Mulching mowers m~ be recommended for certain flat areas. Other techniques may be employed to minimize mowing such as selective vegetative planting using low maintenance grasses and shrubs. Collect lawn and garden clippings, pruning waste, tree trimmings, and weeds. Chip if necessaIy, and compost or dispose of at a landfill (see waste management section of this fact sheet)# • Place temporarily stockpiled material away from watercourses, and berm or cover stockpiles to prevent material releases to storm drains. Planting II Determine existing native vegetation features (location, species, size, function, importance) a~d consider the feasibility of protecting them. Consider elements such as their effect on drainage and erosion, hardiness, maintenance requirements, and possible conflicts between preserving vegetation and the resulting maintenance needs. IJ Retain and/or plant selected native vegetation whose features are determined to be beneficial, where feasible. Native vegetation usually requires less maintenance (e.g., irrigation, fertilizer) than planting new vegetation. [J Consider using low water use groundcovers when planting or replanting. Waste Management ;,J Compost leaves, sticks, or other collected vegetation or dispose of at a permitted landfill. Do not dispose of collected vegetation into waterways or storm drainage systems. :.I Place temporarily stockpiled material away from watercourses and storm drain inlets, and berm or cover stockpiles to prevent material releases to the storm drain system. ::t Reduce the use of high nitrogen fertilizers that produce excess growth requiring more frequent mowing or trimming. -", " .... " --...--.". --" ... -. ••• _,d~ ___ ","r -·.,.. ... -rzv -k~··' ..... f3"'---~ ... ---,~--... ~-¥ •• ~ .. - 2 of 5 California Stoimwater 6NP Handbook i'<llJniclpal ',vww,e<:lbmpI1Zlndbooks • .::orn Jal1lJary 20Q3 " , \. ' ...... ' Landscape Maintenance S-C-73 • Avoid landscape wastes in and around stann drain inlets by either using bagging equipment or by manually picking up the material. Irrigation • Where practical, use automatic timer$ to minimize runoff. • Use popup sprinkler heads in areas with a lot of activity or where there is a chance the pipes may be broken. Consider the use of mechanisms that reduce water flow to sprinkler heads if broken. • Ensure that there is no runoff from the landscaped area(s) if re-claimed water is used for irrigation. • Ifbaillng of muddy water. is required (e.g. when repairing a water line leak), do not put it in the storm drain; pour over landscaped areas. • Irrigate slowly or pulse irrigate to prevent runoff and then only irrigate as much as is needed. • Apply water at rates that do not exceed the infiltration rate of the soil. FertilizeJ" and Pesticide Management • Utilize a comprehensive management system that incorporates integrated pest management (lPM) techniques. There are many methods and types of IPM, including the fC?llowing: Mulching can be used to prevent weeds where turf is absent, fencing installed to keep rodents out, and netting used to keep birds and insects away from leaves and fruit. -Visible"insects can be removed by hand (with gloves or tweezers) and placed in soapy water or vegetable oil. Alternatively, insects can be sprayed off the plant with water or in some cases vacuumed off of larger plants. Store-bought traps, such as species-specific, pheromone-based traps or colored sticky cards, can be used. Slugs can be trapped in small cups filled with beer that are set in the ground so the slugs can get in easily. In cases where microscopic parasites, such as bacteria and fungi, are causing damage tq plants, the affected plant material can be removed and disposed of (pruning equipment should be disinfected with bleach to prevent spreading the disease organism). Small mammals and birds can be excluded using fences, netting, tree trunk guards. Beneficial organisms, such as bats, birds, green lacewings. ladybugs, praying mantis, ground beetles, parasitic nematodes, trichogramma wasps, seed head weevils, and spiders that prey on detrimental pest species can be promoted. :l Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of fertilizers and pesticides and training of applicators and pest control advisors. January 2003 Califomia Sl:ormwater BMP Handbook Municipal W\wv.c30mpi1andbco!(s.con1 ((CeSC-73 Landscape Maintenance l \ ", "'" . • Use pesticides only if there is an actual pest problem (not on a regular preventative schedule). II Do not use pesticides if rain is expected. Apply pesticides only when wind speeds are low (less than 5 mph). ' II Do not mix or prepare pesticides for application near storm drains. • Prepare the minimum amount of pesticide needed for the job and use the lowest rate that win effectively control the pest. • Employ techniques to minimize off-target application (e.g. spray drift) of pesticides, including consideration of alternative application techniques. • Fertilizers should be worked into the soil rather than dumped or broadcast onto the surface. • Calibrate fertilizer and pesticide application equipment to avoid excessive application. II Periodically'test solls for determining proper fertilizer use. • Sweep pavement and sidewalk if fertilizer is spilled on these surfaces before applying irrigation water. . • Purchase only the amount of pesticide that you can reasonably use in a given time period (month or year depending on the product). • Triple rinse containers, and use rinse water as product. Dispose of unused pesticide as hazardous waste. • Dispose of empty pesticide containers according to the instructions on the container label. Inspection II Inspect irrigation system periodically to ensure that the right amount of water is being applied and that excessive runoff is not occurring. Minimize excess watering, and repair leaks in the irrigation system as soon as they are observed. ~ Inspect pesticide/fertilizer equipment and transportation vehicles daily. Training 11 Educate and train employees on use of pesticides and in pesticide application techniques to prevent pollution. Pesticide application must be under the supervision of a California qualified pesticide applicator. il Train/ encourage municipal maintenance crews to use rPM techniques for managing public green areas. :J Annually train employees within departments responsible for pesticide application on the appropriate portions of the agency's rPM Policy. SOPs, and BMPs, and the latest rPM techniques. -1-of 6 California Stormwater 8~'lP Han<lbook .',luniclpal www.cabmphandbooks.com January 2003 Landscape Maintenance SC-73 • Employees who are not authorized and trained to apply pesticides should be periodically (at least annually) informed that they cannot use over-the-counter pesticides in or around the workplace. • Use a training log or similar method to document training. Spill Response and Prevention • Refer to SC-l1, Spill Prevention, Control &: Cleanup • Have spill cleanup materials readily available and in a know in location • Cleanup spills immediately and use dIy methods if possible. • Properly dispose of spill cleanup materi~. Other ConSiderations • The Federal Pesticide, Fungicide, and RodenUcide Act and California Title 3, Division 6,. Pesticides and Pest Control Operations plaCe strict controls over pesticide application and handling'and specify training, annual refresher, and testirig requirements. The regulations· generally cover: a list of approved pesticides and selected uses, updated regularly; general application information; equipment use and maintenance procedures; and record keeping. The California Department of Pesticide Regulations and the County Agricultural . Commission coordinate and maintain the licensing and certification programs. All public agency employees who apply pesticides and herbicides in "agricultilral use" areas·such as parks, golf courses, rights-of-way and recreation areas should be properly certified in accordance with state regulations. Contracts for landscape maintenance should include simUar requirements. III All employees who handle pesticides should be familiar with the most recent material safety data sheet (MSDS) files. a Municipalities do not have the authority to regulate the use of pesticides by school districts, however the California Healthy Schools Act of 2000 (AS 2260) has imposed requirements on California school districts regarding pesticide use in schools. Posting of notification prior to the application of pesticides is now required, and IPM is stated as the preferred approach to pest management in schools. . Requirements Costs Additional training of municipal employees will be required to address IPM techniques. and BMPs. IPM methods will likely increase labor cost for pest control which may be offset by lower chemical costs. l'Waint.enance Not applicable _. '-~-''''T G'i'ZZ" "')' 4'U __ '~'--_ ... _,..¥ .,~ • -',---' ·---.,-_·-.... ';om-..... -..... ---.,..--. t .. •• '" •• -::-Ii "-. January 2Q03 California Stormwat<!r 3tv1[> Handbook Nunicipai 'Nw'N.cabmphandbooks.com . -"-...:::.a 5 of 6 Supplemental Information Further Detail qfthe BMP Waste Management Landscape Maintenance Composting is one of the better disposal altematives iflocally available. Most municipalities either have or are planning yard waste compo sting facilities as a means of reducing the amount of waste going to the landfill. Lawn clippings from municipal maintenance programs as well as private sources would probably be compatible with most composting facilities Contractors and Other Pesticide Users Municipal agencies should qevelop and implement a process to ensure that any contractor employed to conduct pest control and pesticide application on municipal property engages in pest control methodJ consistent with the IPM Policy adopted by the agency. Specifically, . municipalities should· require contractors to follow the agency's IPM policy, SOPs, and BMPs; provide evidence to the' agency ofbaving received training on current IPM techniques when feasible; provide documentati~n of pesticide use on agency property to the agency in a timely manner. . References and Resources • King County Stormwater Pollution Control Manual. Best Management Practices for Businesses. (,(' 1995. King County Surface Water Management. July. On-line: http;/Idnr.metrokc.goy/wlt/dss/spcm.btm i ..... Los Angeles County Storm water Quality Model Programs. Public Agency Activities http://Iad,pw,Qrg/wmd/npdes/model links,cfm Model Urban ;Runoff Program: A HOW-To Guide for Developing Urban Runoff' Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July. 1998. Orange County Stormwater Program bttpi/lwww.ocwatersheds.com/StormWaterlswp introduction,aSj} Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan, September 1997, updated October 2000 • . United States Environmental Protection Agency (USEPA). 2002. Pollution 'Prevention/Good Housekeeping for Municipal Operations Landscaping and Lawn Care. Office of Water, Office of Wastewater Management. On-line: httl?: I!www.epa.gov/npdes/menuotbmps/no1l8.htm ..... '''%'i. • ."., ---z"'<"'" -~:.>:il'" .... ~.;. .• '. '. * '. ~. '4~""" ' ...... """".0.:.::.' ........ ' ....... ""'.-.=_ .. -......... -...... ' --'-=-_-=--...::: ...... :::..--:;;;-="c.:.,-:.:.,-'=.=--'7 .s uf 6 California Storlilwater BMP Handbook Municipal "iWw,c:.omph;)naoooks.com january 20Q3 ! \' ...... Drainage System Maintenance SC-74 Description As a consequence of its function, the stonnwater conveyance system collects and transports urban runoff that may contain certain pollutants. Maintaining catch basins, stormwater inlets, and other stormwater conveyance structures on a regular basis will remove pollutants, prevent clogging of the downstream conveyance system, restore catch basins' sediment trapping capacity, and ensure the system functions properly hydraulically to avoid flooding. . Approach Suggested Protocols 'Catch Basins/Inlet Structures II Municipal staff should regularly inspect facilities to ensure the following: Immediate repair of any deterioration threatening structural integrity. Cleaning before the sump is 40% full. Catch basins should be cleaned as frequently as needed to meet this standard. Stenciling of catch basins and inlets (see SC-75 Waste Handling and Disposal). :I Clean catch basins, storm drain inlets, and other conveyance structures in high pollutant load areas just before the wet Objectives iii Contain • Educate • ReduceJMlnlmlze Targ~ted. Constituents . Sediment ..I • Nutrients Trash Metais Bacteria Oil and· Grease Organics Oxygen Demanding ..I ./ ..I ./ ..I ..I ./ season to remove sediments and debris accumulated during the __ summer. $'!orrnwat~r " ~ QuaU~lI " ~~.::;s\ahcia·':301l1 ~ .h_~.~ ~--(c--·-=_~r-~i'~·~··~·~"-~·=-==-~~~.--="=·"·=-'~?=!-~"='"~'·~H~--=-zcr~-~·-~·n~-·~-=~!~'~~-r~-=~~·"~~·~~~·-·~'X·~-·-~--~··~"-~·~~··~"'~~--~ January 2003 Caiiromia Stormwater 6!,,!P liandbook ~~unicipal www.cubrnphcll1dbouks.coiYl 1 of 9 , .• ,(1 SC-74 ( . Drainage System Maintenance ( • • Conduct inspections more frequently during the wet season for problem areas where sediment or trash accumulates more often. Clean and repair as needed. • Keep accurate logs of the number of catch basins cleaned. • Record the amount of waste collected. • Store wastes collected from cleaning activities of the drainage system in appropriate containers or temporary storage sites in a manner that prevents discharge to the storm drain. • Dewater the wastes with outflow into the sanitary sewer if permitted. Water should be treated with an appropriate filtering device prior to ~charge to the sanitary sewer. If discharge to. the' sanitary sewer is not allow~, water should be pumped or vacuumed to a tank and properly W.sposed of. Do not dewater near a storm drain or stream. • Except for small communities with relatively few catch basins that may be cleaned manually, most municipalities will require mechanical cleaners such as eductors, vacuums, or bucket loaders. Storm Drain Conveyance System • Locate reaches of storm drain with deposit problems and develop a flushing schedule ~t keeps the pipe clear of excessive buildup. • Collect flushed effluent and pump to the sanitary sewer for treatment. Pump Stations • Clean all storm drain pump stations prior to the wet season to remove silt and trash. [I Do not allow diseharge from cleaning a storm drain pump station or other facility to reach the storm drain system. . II Conduct quarterly routine maintenance at each pump station. i;J Inspect, clean, and repair as necessary all outlet structures prior to the wet season. III Sample collected sediments to determine iflandfill disposal is possible, or illegal discharges in the watershed are occurring. Open Channel iii Consider modification of storm channel characteristics to improve channel hydraulics, to increase pollutant removals, and to enhance channell creek aesthetic and habitat value. fll Conduct channel modification/improvement in accordance with existing laws. Any person, government agency, or public utility proposing an activity that will change th.e natural (emphasis added) state of any river, stream, or lake in California, must enter into a steam or Lake Alteration Agreement with the Depaltment of Fish and Game. The devdopcr-ap-plicant should also contact local governments (city, county, special districts), othel' state agencies California Stormwatdr etJiP Han.dbook i'JIul1icipal www.cabmpl1andblloks.c0m -.,. --~ .. -... ----.'-. ,'''-"c---,. January 2003 ' .. Drainage System Maintenance SC-74 (SWRCB, RWQCB, Department of Forestry, Department of Water Resources), and Federal Corps of Engineers and USFWS Illicit Connections and Discharges • During routine maintenance of conveyance system and drainage structures field staff should look for evidence of illegal discharges or illicit connections: -Is there evidence of spills such as paints, discoloring, etc. • Are there any odors associated with the drainage system Record locations of apparent illegal discharges/illicit connections • Track flows back to potential dischargers and conduct aboveground inspections. ThJs can be done through visual inspection of up gradient manholes or alternate techniques including zinc chloride smoke testing, fluorometric dye testing, physical inspection testing, or television camera inspection. . -Once the origin of flow is established, require illicit discharger to eliminate the discharge. • Stencil storm drains, where applicable, to prevent illegal disposal of pollutants. Storin drain inlets should have messages such as "Dump No Waste Drains to Stream" stenciled next to them to warn against ignorant or intentional dumping of pollutants into the storm drainage system. II Refer to fact sheet SC-10 Non-Stormwater Discharges. nlegal Dumping Ia Regularly inspect and clean up hot spots and other storm drainage areas where illegal dumping and disposal occurs. II Establish a system for tracking incidents. The system should be designed to identify the following: Illegal dumping hot spots Types and quantities (in some cases) of wastes Patterns in time of occurrence (time of day/night, month, or year) Mode of dumping (abandoned containers; "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) Responsible parties ill Post "No Dumping" signs in problem areas with a phone number for reporting dumpiJlg and disposal. Signs should also indicate fines and penalties for illegal dumping. :J Refer to fact sheet SC-lO Non-Stormwater Discharges . • _.>';;':; ...... -.... , .. ""'.g:t.u:.:', .. ;:;;;:;_ •• ""''"'''-.. ''::;--'=--.:..' ........... " ,,:' • ...:2~;;'<:-""","-=-===;;:.:, ""' •. ...!:;"',....",;;;;;-~""' .. =.,-= .. ""' .. -a:-:....;.~:.;: •.•. -=.j,... .• ~-;~""' .. ,~::..:::.....:....~~:.,.._.:...-... .-......:.-,. ...... _~ ... ~ January 2003 California Stormwater 8M? Handbook 3 of 9 ,'1unicipal - www.c .. i)mphandbooi~S.COI11 ,GesC-74 Drainage System Maintenance ; • The State Department of Fish and Game has a hotline for reporting viohitions called Cal TIP (1-800-952-5400). The phone number may be used to report any violation of a Fish and Game code (illegal dumping, poaching, etc.). • The California Department of Toxic Substances Control's Waste Alert Hotline, 1-800- 69TOXIC, can be used to report hazardous waste violations. lraining • Train crews in proper maintenance activities, including record keeping and disposal. • Only properly trained individuals are allowed to handle hazardous materials/wastes. • Train municipal. employees from all departments (public works, utilities, street cleaning, 'parks and recreatio~, industrial w~ste inspection, hazardous waste inspection, sewer maintenance) to recognize and report illegal dumping. • Train municipal employees and educate businesses, contractors, and the general public in proper and cc;msistent methods for disposal. • Train municipal staff regarding non-stormwater discharges (See SC-lO Non-Stormwater Discharges). ,: '. (('. Spill Response and Prevention • Refer to SC-ll, Prevention, Control &: Cleanup \. ...... •• ( • Have spill cleanup materials readily available and in a known location. • Cleanup spills immediately and use dry methods if possible. • Properly dispose of spill cleanup material. Other Considerations II Cleanup activities may create a slight disturbance for local aquatic species. Access to items and material on private property may be limited. Trade-offs may exist between channel hydraulics and water quality/riparian habitat. If stonn channels or basins are recognized as wetlands, many activities, including maintenance, may be subject to regulation and permitting. IJ Sto~ drain flushing is most effective in small diameter pipes (36-inch diameter pipe or less, depending on water supply and sediment collection capacity). Other considerations associated with storm drain flushing may include the availability of a water source, findin.g a downstream area to collect sediments, liquid/sediment disposal, and disposal of flushed effluent to sanitary sewer may be prohibited in some areas. tl Regulations may include adoption of substantial penalties for illegal dumping and disposal. ... Municipal codes should include sections prohibiting the discharge of soil, debris, refuse, hazardous wastes, and other pollutants into the storm drain system . .:I Private properl-y access l'ights may be l1eeded to track illegal discharges up gradient. 40r9 California Stormwater B~'lP i-landbook 141Jnicipal www.cJOmphal1dbooks.com January 2U03 (. ~ ... •• \ Drainage System Maintenance SC-74 • Requirements of municipal ordinance authority for suspected source verification testing for nlicit connections necessary for guaranteed rights of entry. Requirements Costs • An aggressive catch basin cleaning program could require a significant capital and O&M budget. A careful study of cleaning effectiveness should be undertaken before increased cleaning is implemented. Catch basin cleanins costs are less expensive ifvacilum street sweepers are available; cleaning catch basins manually can cost approximately twice as much as cleaning the basins with a vacuum attached to a sweeper. • Methods used for nIicit connection detection (smoke testing. dye testing, visual inspection, and flow monitoring) can be costly and time-consuming. Site-sp~ific factors, such as the level of impervious area, the density and ages ofbuUdings, and type ofland use, will ' determine th~ level ofinveatigation necessary. Encouraging reporting ofiUicit discharges by , employees can offset costs by saving expense on inspectors and directing resources more . efficiently. Some programs have used funds av~lable from "environmental fees" or special assessment districts to fund their illicit connection elimination programs. Maintenance • Two-person teams may be required to clean catch basins with vactor trucks. • Identifying illicit discharges requires teams of at least two people (volunteers can be used), plus administrative personnel, depending on the complexity of the storm sewer system. • Arrangements must be made for proper disposal of collected wastes. II Requires technical staff to detect and investigate illegal dumping violations, and to coordinate public education. Supplemental Information FuJ9thet* Detail of the BMP Storm Drainjlushing Sanitary sewer tlushing is a common maintenance activity used to improve pipe hydraulics and to remove pollutants in sanitary sewer systems. The same principles that make sanitary sewer flushing effective can be used to flush storm drains. Flushing may be designed to hydraulically convey accumulated material to strategic locations, such as to an open channel, to another point where flushing will be initiated) or over to the sanitary sewer and on to the treatment facilities, thus preventing re-suspension and overflow of a portion of the solids during storm events. Flushing prevents "plug flow" discharges of concentrated pollutant loadings and sediments. The deposits can hinder the designed conveyance capacity of the storm drain system and potentially cause backwater conditions in severe cases of clogging. Storm drain flushing usually takes place along segments of pipe with grades th~t are too flat to maintain adequate velocity to keep particles in suspension. An upstream manhole is selected to place an intlatable device that temporarily plugs the pipe. Further upstream, water is pumped into the line to create a t1ushing w'ave. When the upstream reach of pipe is sufficiently full to January 2003 California Stormwatar i?i'I? Handbook Municipal 1,',';vW,(;doli1phandboOkS,(;I)/11 5 of 9 \ Drainage System Maintenance cause a flushing wave, the inflated device is rapidly deflated with the assistance of a vacuum pump, releasing the backed up water and resulting in the cleaning of the storm drain segment. To further reduce the impacts of stormwater pollution, a second inflatable device, placed well downstream, may be used to re-collect the water after the force of the flushing wave has dissipated. A pump may then be used to transfer the water and accumulated material to the sanitary sewer for treatment. In some cases. an interceptor structure may be more practical or required to re-collect the flushed waters. It has been found that cleansing efficiency of periodic flush waves is dependent upon flush volume. flush discharge rate, sewer slope, sewer length, sewer flow rate, sewer diameter, and population density. As a rule of thumb, the length onine to be flushed should not exceed 100 feet At this maximum recommended length, the percent removal efficiency ranges between 65- 15 percent for organics and 55-65 percent for dry weather grit/inorganic material. The percent removal efficiency drops rapidly beyond that. Water is commonly supplied .. by a water truck, but fire hydrants can also supply water; To make the best use of water, it is recommended that reclaimed water be used or that fire hydrant line flushing coincide with storm drain flushing. Flow Management Flow management has been one of the principal motivations for designing urban stream corridors in the past. Such needs mayor may not be compatible with the stormwater quality goals in the stream corridor. Downstream flood peaks can be suppressed by reducing through flow velocity. This can be accomplished by reducing gradient with grade control structures or increasing roughness with boulders, dense vegetation, or complex banks forms. Reducing velocity correspondingly increases flood height, so all such measures have a natural association with floodplain open space. :f1.ood elevations laterally adjacent to the stream can be lowered by increasing through flow velocity. . However, increasing velocity increases flooding downstream and inherently conflicts with channel stability and human safety. Where topography permits, another way to lower flood elevation is to lower the level of the floodway with drop structures into a large but subtly excavated bowl where flood flows we allowed to spread out. Stream. Corridor Planning Urban streams receive and convey stormwater flows from developed or developing watersheds. Planning of stream corridors thus interacts with urban stormwater management programs. If local programs are intended to control or protect downstream environments by managing flows delivered to the channels, then it is logical that such programs should be supplemented by management of the materials, fm'ms, and uses o( the downstream riparian corridor. NlY proposal for steam alteration or management should be investigated for its potential flow and stability effects on upstream, downstream, and laterally adjacent areas. The timing and rate of flow from various tributaries can combine in complex ways to alter flood hazards. Each section of channel is uniqueJ intluenced by its own distribution of roughness elements, management activities, and stream responses. ......._-_. >< ~ ... -.-.--" "'~'li'? '.-' -4.'i.~ .... :zz:tCj"'T' s .... -'.-_.," ... --.-~ " .. -....... :._.z._ ..... j_. 6 of 9 California Stoi"lnwater aMP Handbook January 2003 i"IUllicipal ·Nww.cJbmph.:lndbool<s.com (,. ~.( \ ' Drainage System Maintenance SC-74 Flexibility to adapt to stream features and behaviors as they evolve must be included in stream reclamation planning. The amenity and ecology of streams may be enhanced through the landscape design options of 1) corridor reservation, 2) bank treatment, 3) geomorphic restoration, and 4) grade control. Corridor reservation -Reserving stream corridors and valleys to accommodate natural stream meandering; aggradation, degradation, and over bank flows allows streams to find their own form and generate less ongoing erosion. In California, open stream corric;lors in recent urban developments have produced recreational open space, irrigation of streamside plantings, and the aesthetic amenity of flowing water. Bank treatment -The use of armoring, vegetative cover, and flow deflection may be used to influence a channel's form, stability, and biotic habitat. To prevent bank erosion, armor41g c~n be done with rigid construction materials, such as concrete, masomy, wood planks and logs, riprap, and gabions. Concrete linings have been criticized because of their lack of provision of biotic habitat. In contrast, riprap 'and gabions make relatively porous and flexible liningS~ Boulders; placed in the bed reduce velocity and erosive power. Riparian vegetation can stabilize the banks of streams that are at or near a condition of equilibrium. Binding networks of roots increase bank shear strength. During flood ,flows, resilient vegetation is forced into erosion-inhibiting mats. The roughness of vegetation leads 'to lower velocity, further reducing erosive effects. Structural flow deflection can protect banks from erosion or alter fish habitat. By concentrating flow, a deflector causes a pool to be scoured in the bed. . . ' GeOmorphic restoration -Restoration refers to alteration of disturbed streams so their form and behavior emulate those of undisturbed streams. Natural meanders are retained, with grading to gentle slopes on the inside of curves to allow point bars and riffl~pool sequences to develop. Trees are retained to provide scenic quality, biotic productivity, and roots for ,bank stabilization, supplemented by plantings where necessary. A restorative approach can be successful where the stream is already approaching equi1ibrium~ However, if upstream urbanization continues new flow regimes will be generated that could disrupt the equilibrium of the treated system. Grade Control -A grade control structure is a level shelf of a permanent material, such as stone, masonry, or concrete, over which stream water flows. A grade control structure is called a sill, weir, or drop structure, depending on the relation of its illvert elevation to upstream and downstream channels. A sill is installed at the preexisting channel bed elevation to prevent upstream migration of nick points. It establishes a firm base level below which the upstream channel can not erode. A weir or check dam is installed with invert above the preexisting bed elevatioll. A weir raises the local base level of the stream and causes aggradation upstream. The gradient, velocity, and erosive potential of the stream channel are reduced. A drop structure lowers tJ1e downstream invert below its preexisting elevation, reducing downstream gradient and velocity. Weirs and drop structm:e control erosion by dissipating energy and reducing slope velocity . • , "if / " .~.\.. • ·'.-.. •• .. -f··~ ... ,~.,. -..... -r-...... -.... ~ .... , ''''''''''"''-'--''='''~-5''';:''''':'';'' " January 2003 California Stormwater Bt-1P Handbook 7 of 9 Nunicipal ,'IWW .cdompha ,1dcooks.COI" ,!(e \ \. ' ". Drainage System Maintenance M When carefully applied. grade control structures can be highly versatile in establishing human and environmental benefits in stabilized channels. To be successful, application of grade control structures should be guided by analysis of the stream system both upstream and downstream from the area to he reclaimed. Example. The California Department of Water Resources began the Urban Stream Restoration Program. in 1985. The program provides grant funds to municipalities and community groups to implement stream restoration projects. The projects reduce damages from streambank aid watershed instability arid floods while restoring streams· aesthetic, recreational, and fish and wildlife values. In Buena VlSta Park, upper tloo.dway slopes are gentle and grassed to achieve continuity of usable park land across the cha~el of small boulders at the base of the slopes. The San Diego River is a large. vegetativ~ lined channel, which was planted in a variety of species to sU~Jlort riparian wildlife whUe s~bilizing the ~teep banks of the floodway •. References and Resources Ferguson, D.I<. 1991. Urban Stream Reclamation, p. 324-322, Journal of Soil and Water Conservation. Los Angeles County Storm water Quality. Public Agency Activiti.~s Model Program. On-line: http://ladpw,orsIwmd1npdes/publiC? TC·cfm Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Sman Municipalities. Prepared by City of Monterey. City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July. 1998. Orange County Stormwater Program http://www.ocwatersheds.com/StormWaterlswp introduction. asp Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan. September 1997, updated October 2000. San Diego Stormwater Co-permittees Jurisdictional Urban Runoff Management Program (URMP) Municipal Activities Model Program Guidance. 2001. Project Clean Water. November. United States Environmental Protection Agency (USEPA). 1999. Stormwater Management Fact Sheet Non-stormwater Discharges to Storm Sewers. EPA 832-F-99-022. Office aiWater, Washington, D.C. September. United States Environmental Protection Agency (USEPA), 1999. Stormwater O&M Fact Sheet Catch Basin Cleaning. EPA 832-F-99-011. Office of Water, Washington, D.C. September. z=sr •••. ~~--.... --.. -·~lt····· .... -.~ .. ;-.-.!--;,;;-~-·t· ....... -.. --~ .. ~> .-~;; -~.-,--"-~ -.... ~-~~ •••• ~ ... , •••••••• __ .-....... ~ 8 of 9 C"lifornia Stormwatl?r Bl'-lP Han!1bool< January 2003 Municipal W'NW, Cd b m phanoboo!(s.com \ .... Drainage System Maintenance SC~74 United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Ulegal Dumping Control. On line: bttpillwww.gpa·soy/npdes/menuofbmps/po1l7.htm United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Storm Drain System Cleaning. On line: http://www.epa·mv/npdes/menuofbmpS/poU16.htm JanU<lI-Y 2003 California S~ormwat~r Bl'-lP Handbook ;vllmfclpal www . ..:abmphandbooks . .:om Attachment 9 Section 5 Treatment Control BMPs 5.1 Introductio"n This section describes treatment control Best Management Practices (BMPs) to be considered for incorporation into newly developed public and private infrastructure, as wen as retrofit-into existing facilities to meet stormwater management objectives. BMP fact sheets are divided into two groups: public domain BMPs and manufactured (proprietary) BMPs. In some cases, the same BMP may exist in each group, for example, media filtration. However, treatment BMPs are typically very different between the two groups. Brand names of manufactured BMPs are not stated. Descriptions of manufactured BMPs in this document should not be inferred as endorsement by the authors. 5.2 Treatment Control BMps Public domain and manufactured BMP controls are listed in Table 5-1. Table 5-1 Treatment Control BMPs Public Domain Manufactured (Proprietary) Infiltration Infiltration TC-IO Infiltration Trench TC-l1 Infiltration Basin TC-12 Retention/Irrigation Detention and Settling Detention and Settling TC-20 Wet Pond MP-20 Wetland TC-21 Constructed Wetland TC-22 Extended Detention Basin Biofiltration Biofiltration TC-30 Vegetated Swale TC-31 Vegetated Buffer Strip TC-32 Bioretention Filtration Filtration TC-40 Media Filter MP-40 Media Filter Flow Through Separation Flow Through Separation TC-so Water Quality Inlet MP-50 Wet Vault MP-51 Vortex Separator MP-52 Drain Inserts Other Other TC-60 ~Illltiple Systems ,; ZE1ZMZ? am ~ January 2.003 California Stormwater B~lP Handbook 5-1 ·ct;on5 C reatment Control BMPs .. ' 5.3 Fact Sheet Format A BMP fact sheet is a short document that gives all the information about a particular BMP. Typically each public domain and manufactured BMP fact sheet contains the information outlined in Figure 5~1. The fact sheets al$O contain side bar presentations with information on BMP design considerations, targeted constituents, and removal effectiveness (if known). Treatment BMP performance, design criteria, and other selection factors are discussed in 5.4 -5.6 below. BMP Fact sheets are included in 5.7. TCxx/MPxx Example Fact Sheet Description California Experience Adyantas,es Limitations Desi&» and Sizjn& Guidelines Performance Sitinl Criteria Desipt Guidelines Maintenance References and Sources of Additional Information Figure 5-1 Example Fact Sheet 5.4 Comparing, Performance of Treatment BMPs With a myriad of stormwater treatment BMPs from which to choose, a question commonly C ed is "which one is best". Particularly when considering a manufactured treatment system, /' e engineer wants to know if it provides performance that is reasonably comparable to the >,( , pical public-domain BMPs like wet ponds or grass swales. With so many BMPs, it is not likely that they perfornl equally for all pollutants. Thus, the question that each local jurisdiction faces is which treatment BMPs will it allow, and under what circumstances. What level of treatment is desired or reasonable, given the cost? Which BMPs are the most cost-effective? Current municipal stormwater permits specify the volume or rate of stormwater that must be tre~ted, but not the specific level or efficiency of treatment: These permits usually require performance to the specific maximum extent practicable (MEP), but this does not translate to an easy to apply specific design criteria. Methodology for comparing BMP performance may need to be expanded to include more than removal effectiveness. Many studies have been conducted on the performance of stormwater treatment BMPs. Several publications have provided summaries of performance (ASCE, 1998; ASCE, 2001; Brown and Schueler, 1997; Shoemaker et aI., 2000; Winter, 2001). These summaries indicate a wide variation in the performance of each type of BMP, making effectiveness comparisons betwe~n BMPs problematic. 5.4.1 Variation in Performance There are several reasons for the observed variation. The Variability of Stormwater Quality • rmwater quality is highly variable during a storm, from storm to storm at a site, and between .' s even of the same land use. For pollutants of interest, maximum observed concentrations >'( mmonly exceed the average concentration by a factor of 100. The average concentration of a corm, known as the event mean concentration (EMC) commonly varies at a site by a factor of 5. One aspect of stormwater quality that is highly variable is the-particle size distribution (PSD) of 5-2 i'. '( Section 5 Treatment Control BMPs the suspended sediments. This results in variation in the settle ability of these sediments and the pollutants that are attached. For example, several performance studies of manufactured BMPs have been condu~ted in the upper Midwest and Northeast where deicing sand is commonly used. The sand, washed off during spring and summer storms, skews the PSD to' larger sizes not commonly found in stormwater from California sites except in mountainous areas. Consequently, a lower level efficiency may be observed if the same treatment system is used in California. . Most Field Studies Monitor Too Few Storms High variability of stormwater quality requires that a large number of storms be sampled to discern if there is a significant different in performance, among BMPs. The smaller the actual difference in performance between BMPs, the greater the number of storms that must be sampled to statistically discern the difference between them. For example, a researcher attempting to determine a difference in performanc~ between two BMPs of 10% must monitor ~any more storms than if the interest is to define the <Ufference within 50%. Given the expense and d~fficulty, few studies have monitored enough storms to determine the actual performance with a high level of precision. Different Design Criteria Performance of different systems within the same group (e.g., wet ponds) differs significantly in part because of differing design criteria for each system. This in tum can make it problematic to compare different groups of treatment BMPs to each other (e.g., wet ponds to vortex separators). Differing Influent Concentrations and Analytical Variability With most treatment BMPs, efficiency decreases with decreasing influent concentration. This is illustrated in Figure 5-2. Thus, a low removal efficiency may be observed during a study not because the device is inherently a poorer performer, but possibly because the influent concentrations for the site were unusually low. Also, as the concentration of a particular constituent such as TSS approaches its analytical detection limit, the effect of the variability of the laboratorY technique becomes more significant. This factor also accounts for the wide variability of observations on the left of Figure 5-2. The variability of the laboratory results as the TSS approaches its analytical detection limit may also account for negative efficiencies at very low influent concentrations (e.g., TSS less than 10 mg/L). However, some negative efficiencies observed at higher "Concentrations may not necessarily be an artifact of laboratory analysis. The cause varies to some extent with the type of treatment BMP. Negative efficiencies may be due to the resuspension of previously deposited pollutants, a change in pH that dissolves precipitated or sorbed pollutants, discharge of algae in the case of BMPs with open wet pools, erosion of unprotected basin side or bottom, and the , • degradation ofleaves that entered the system the previous fall. '( , -+ r-ns 'C'Srs:z:zv G?Y"'·'P·z:rr5J:·..,,.te"eYOt~'!o!',,,,,,=-==,",,,, ... -;a""'ZrCl''''''''-_ r?>,:t="l"'n'? ~"l"'I."'''-Uf:>.4-Q''' Q~"O W:'lf'lirl\... ......... I.. "-lanuar" 2003 • alion5 (. 'l3atment Conlrol BMPs I ,1. . I Different Methods of Calculating Efficiency Researchers (1) have used different methods to calculate efficiency, (2) do not always indicate which method they have used, and (3) often do not provide sufficient information in their report to allow others to recalculate the efficiency using a common method. One approach to quantifYing BMP efficiency is to determine first ifthe BMP is providing treatment (that the influent and effl~ent . ..... ~ t.. ~ c CD 'u al ! j 100% 80% 60% 40% 20% 0% -20% -40% -00% -80% -100% Influent Concentration .SWALE • STRIP EDB )( SF x WET BASIN Figure 5-2 Removal Efficiency Versus Influent Concentration C n event mean concentrations are statistically different from one anoth~r) and then examine I ~. er a cumulative distribution function of influent and effluent quality or a standard parallel ... ( ..>bability plot. This approach is called the Effluent Probability Method. While this approach .1as been used in the past by EPA and ASCE, some researchers have experienced problems with the general applicability of this method. A discussion of these issues is included in Appendix B. A second approach to comparing performance among BMPs is to compare effluent concentrations, using a box-whisker plot, the basic form of which is illustrated in Figure 5-3. The plot represents all of the data points, of one study, several studies, or of individual storms. The plots provide insight into the variability of performance within each BMP type, and possible differences in performance among the types. To explain the plot: 50% of the data points as well as the median value of all the data points is represented by the box. That is, the median falls within the 75th and 25th percentile of data (top and bottom of the box). The whisker extends to the highest ~nt within a range of 1.5 times the , ~rence between the first and third . \ u'tiles. Individual points beyond this '. tnge are shown as asterisks. kW +awe SSr:r;;c;;k ,. Third Quartile II- First Quartile ... • Whisker extends to the highest value tapoints orda ~ Median Whisker extends to ( the lowest value of data points I? A line is drawn across the box at the median. The bottom of the f I box is at the 25th percentile and the top is at the 75th percentile. .: The whiskers are the lines that extend from the top and bottom : ofthebox ,: ":~"'T; :-.-~-;-.... -•••• ---:---....... ; .......... -..... -_ ••• " ---T:r:--~~ -, .... :-........ ~ ... ___ ... I: Figure 5-3 :Sox.-Whisker Plot 5-4 California Storm water BMP Handbook 7'Vi=xn-!rsm=m»"'V'FJl-"S'Mt'tTnH'~J'IllW l:1(1, I '3~~.f" 'In.,, ') ,. '\ Section 5 TreatmentContnolBA4Ps . . Recognizing the possible effect of influent concentration on efficiency, an alternative is to compare effluent concentrations. The reasoning is that regardless of the influent concentration, a particular BMP will generate a narrower range of effluent concentrations. Figure 5-4 shows observed effluent concentrations for several different types of BMPs. These data were generated in an extensive field program conducted by the California Department of Transportation (Caltrans). As this program is the most extensive effort to-date in the entire United States, the observations about performance in this Handbook rely heavily on these data. The Caltrans study is unique in that many of the BMPs were tested under reasonably similar conditions (climate, storms, freeway stormwater quality), with each type of BMP sized with the same design criteria. An additional factor to consider when comparing BMPs is the effect of infiltration. BMPs with concrete or metal structures will have no infiltration, whereas the infiltration in earthen BMPs will vary frOI:Jl none to substantial. For example, in the Caltrans study, infiltration in vegetated swales averaged nearly 50%. This point is illustrated with Figure 5-4 where effluent quality ~f several BMPs are compared. As seen in Figure 5-4, effluent concentration for grass swales is' higher than either filters or wet basins (30 vs. 10 to 15 mg/L), suggesting that swales in comparison are not particularly effective. However, surface water entering swales may infiltrate into the ground, resulting in a loading reduction (flow times concentration) that is similar to those BMPs with minimal or no infiltration. 200r---------------------------------------------------~ ~ 180 -.. S 160 ._ 1: CD :3 140 lfi .5 120 !& :a 100 rn '0 80 CD '0 C 60 CD 0. lit ~ 40 rn 3 0 20 ... 0 :t:: .~. ~ ... Te-20 Wet Pond TC-22 TC·30 TC-31 TC·40Medl. TC·40Madla TC.40Medl. Extended Vagetated Vagelatad FlIte, (Austin Filter Fllte, (M ultf. o .tantlon Swale Suff., Sand Filter) (Delaware chamber aasln Llnaal Sand Treatment Filter) Train) Figure 5-4 Observed Effluent Concentrations for Several Different Public Domain aMPs ·ection5 ( ( !atment Control BMPs I i With equation shown below, it is possible using the data from Figure 5-4 to estimate different levels ofloading reduction as a function of the fraction of stormwater that is infIltrated. EEC = (1-I)(EC) + (I)(Ge) Where: EEC = the effective effluent concentration I == fraction of stormwater discharged by infiltration EC = the median concentration observed in the effluent GC = expected concentration of stormwater when it reaches the groundwater To illustrate the use of the equation above, the effect of infiltration is considered on the effective effluent concentration ofTSS from swales. From Figure 5-4, the median effluent concentration for swales is about 30 mg/L. Infiltration of 50% is assumed with an expected concentration of 5 . mg/L when the stormwater reaches the groundwater. This gives: ". EEC = (1-0.5)(30) + (0.5)(5) = 17.5 mgJL. \( J. 'he above value can be compared to other BMPs that may directly produce a lower effluent concentration, but do not exhibit infiltration, such as concrete wet vaults. 5.4.2 Other Issues Related to Performance Comparisons A further consideration related to performance comparisoIis is whether or not the treatment BMP removes dissolved pollutants. Receiving water standards for most metals are b.ased on the dissolved. fraction; the form of nitrogen or phosphorus of most concern as a nutrient is the dissolved fraction. The common practice of comparing the performance of BMPs using TSS may not be considered sufficient by local governments and regulatory agencies as there is not always a strong, consistent relationship between TSS and the pollutants of interest, particularly those identified> in the 303d list for specific water bodies in California. These pollutants frequently include metals, nitrogen, nutrients (but often nutrients without specifying nitrogen or phosphorus), indicator bacteria (i.e., fecal coliform), pesticides, and trash. Less commonly cited pollutants include sediment, PAHs, PCBs, and dioxin. \Vith respect to metals, typically, only the general term is l1sed. In some cases, a specific metal is identified. The most commonly listed metals are mercury, copper, lead, selenium, zinc, and nickel. Less frequently listed metals afe cadmium, arsenic, silver, chromium, molybdenum, and thallium. Commonly, only the general term· _tals" is indicated for a water body without reference to a particular metal. \ desirable to know how each vf the tr~atrnent DMPs f)f:rforrns with respect to the removal of > ,Ie above pollutants. Uufol,tunately, the perforrnCtl1ce d:1.1.~ are non-~xlstent or very limited for many of the cited. pollutants, particularly trash, PAHs, PCBs, d)oxin, mercnry, selenium, and pesticides. Furthermore, the concentrations of these constituents are 'iery low, often below the r~~~~~·U::"'I:!\'ir.rs:~;lcn~":l"~~5!;;:'Jjj=s?5i'WT'7Pt~r=an[::p;rtS'CZA"i:F"ll'J'!'terr:D-,....,....-5-6 ~-'<,.-'. <" •••••• --• > • • Section 5 TreatrnentConuolBAlPs detection limit. This prevents the detenninatjon of-which BMPs are most effective. However, with the exception of trash and possibly dioxin, these pollutants readily sorb to sediments in stormwater and therefore, absent data at this ti...TIle, can be considered to be removed in proportion to the removal ofTSS (i.e., sediment). Therefore, in general, those treatment systems that are most effective at removing TSS will be most effective at removing pollutants noted above. While there are little data on the removal of trash, those treatment BMPs that include a basin such as a wet pond or vault, or extended detention basin should be ~imilarly effective at removing tr.ash as long as the design incorporates a means of retaining the floating trash in the BMP. Whether or not manufactured products that are configured as a basin (e.g.,. round vaults or vortex separators) are as effective as public domain BMPs is unknown. However, their ability to retain floating debris may be limited by the fact that many of these products are relatively small and therefore may have limited storage capacity. Only one manufactured BMP is specifically designed to remove floating debris. There are considerable amounts of performance data for zinc, copper, and lead, with a less substantial database for nickel, cadmium, and chromium. An exception is high-use freeways where metals in g~neral are at higher concentrations than residential and commercial properties. Lead sorbs easily to the sediments in stormwater, with typically only 10% in the dissolved phase. Hence, its removal is generally· in direct proP9rtion to the removal of TSS. In contrast, zinc, copper, and cadmium are highly soluble with 5096 or more in the dissolved phase. Hence, two treatment BMPs may remove TSS at the same level, but if one is capable of removing dissolved metals, it provides better treatment overall for the more soluble metals. 5.4.3 Comparisons of Treatment BMPs for Nitrogen, Zinc, Bacteria, and TSS Presented in Figures 5-5 through 5:-8 are comparisons of the effluent concentrations produced by several types of treatment BMPs for nitrogen, zinc, and fecal coliform, respectively (TSS is represented in Figure 5-4). Graphs for other metals are provided in Appendix C. These data are from the Caltrans study previously cited. Total and the dissolved effluent concentratjons are shown for zinc. (Note that while box-whisker plots are used here to compare BMPs, other methodologies, such as effluent cumulative probability distribution plots, are used by others.) ..• ection5 (, Treatment Control BMPs ! . t'e '( e ( 14 r-----------------------------------------------------------------~ 12 ~ 10 .§. .... ; ~ .5 z ~ 8 8 4 2 :c I :c :c lIC :c OL-----------------------------~------~----~--------------~ TC·2. Wol Pond TC·22lxllndd TC·3. Voglilio' TC·31 VOllolo'.' TC.~, "odl. Flllor (Auilin Sind PUlo,' TC·41 Modi. TC ••• "odl. I'U'o, \M uill. cha",bo, Dllintlon 1 •• 1" Sw.lo Bu".r Fllt',IDolow ... Lln .. 1 Sond Filter) T .. 1'",onl Train) Figure 5-5 Total Nitrogen in Effluent 300 r---------------------------------------------------------~ .5 150 ~ J 100 1 Q 50 o TC·20 Wet Pond Tc·n Extended Detention Basin Te·30 Vegetated Swal. TC·3f Veget~ted Buffer TC.40 MadIa Filler (Austin Sand Filter) TC ·40 Media Filter (Oelaware Lineal Sand Filtar) TC·40 Medl. FIlter (1.1 ultl· chamber Treatment Train) Figure 5-6 Total Dissolved Zinc in Effluent • ( 500 :1 400 } .. i .. 300 ~ .5 100 * ':.c Section 5 Treatment Control BMPs o~--------------------------~----------~----------------~----------~--------------~----~ -i 8 ,.. ~ ~ .. C QJ :::I ~ .5 !II E ~ 8 B QJ U. TC.20 Wit Pond 1,000,000 100,000 10,000 1,000 x 100 , ~~'~~ ~i~Y 10 TC·22 Extlndad Oltlntlon' BasIn :E TC·30 Vagatated Swal. TC·31' Vagatatad Burrar ::I( Te .... ~ Idla TC·'" Madia, TC·'" Madia Filter IAustln Flltar Flltar 1M ulU- Sand Flltar) IOalawarl chambar ::I( ! ::I( Llnaa. Sand Tr.atmant Filter) Train) Figure 5-7 Total Zinc in Effluent I ----------.-------------------------------,----- TC·20 Wet Pond Te·22 Extended Detention Basin TC·30 Vegetaled Swal. TC·31 TC·40 Media TC-40 Media TC·40 Media Vegetated FiIt.r Filter Filhr 1M ultl- B utfer (Austin Sand (Oelaw~re chamber Filter) Lineal Sand Treatment Filt"r) Train) Fi'9ure5-:8 Total Fecal Coliforms in Effluent <::;:~_s 'iii II ··wl ...... ~~""=="".r'"""",';::c:c._e_~"Wl'<l"'..,==""_""~= .. """'=>:==W..,.,W .... ~,:c""·"''' ... -== ... 'b-.·''' ..... p'''''' ...... '''·' ...... t!taia'~.4'"t*~'-.:t::J.,..w,.. .. ;.~~#;!"i'.fJ=-... " ,r I'" 1 (.actiOn5 \ ( -reatment Control BMPs i While a figure is provided for fecal coliform, it is important to stress that the performance comparisons between BMPs is problemavr:-. Some California BMP studies have shown excellent removal of fecal coliform through constructed wetlands and other BMPs. However, BMP comparisons are complicated by the fact that several BMPs attract wildlife and pets, thereby elevating bacteria levels. As bacteria sorb to the suspended sediments, a significant fraction may be removed by settling or filtration. A cautionary note regarding nitrogen: when comparing nitrogen re.moval between treatment systems it is best to use the parameter total nitrogen. It consi~ts of Total Kjeldahl Nitrogen -TKN(organic nitrogen plus ammonia) plus nitrate. Comparing TKN removal rates is misleading in that in some treatment systems the ammonia is changed to nitrate but not removed. Examination of the performance data of many systems shows that while TKN may decrease dramatically, the nitrate concentration increases correspondingly. Hence, the overall removal of nitrogen is considerably lower than implied from looking only at Kjeldahl Nitrogen. 5.4.4 General·Performance of Man·ufactured BMPs . . An important question is how the performance of manufa~tured treatment BMPs compares to those hi the. public domain, illustrated previously in Figures 5-4 through 5-8. Figure 5-9 (and Figure 5-10 in log format) presents box-whisker plots of the removal ofTSS for the ..• anufactured systems. Data are presented for fiv~ gen~ra1. types of manufactured B~PS: wet ( ( vaults,. drain inserts, constructed wetlands, media filters, and vortex separators. The· figures ! indicate wide,ranges in effluent concentrations, reflecting in part the different products 'and design criteria within each type. Comparing F:igures 5-4 and 5-9 suggests thl:!-t mariufactured products may perform. as well as the less eff~ctive public-domain BMPs. such as swales and extended detentipn basins (excluding the additional benefits of infiltration with the latter). Manuf3:ctured wetlands may perform as well as the ~ost effective pub~ic-domain BMPs; however, the plot ·pre~ented in Figure 5-9 for the manufactured wetlands represents only five data points. It should be noted that each type of BMP illustrated in Figure 5-9 contains data from more than one prodUct. Performance of particular products within that grouping may not perform as well as even the le~t effective public-domain BMPs. This observation is implied by the greater spread within some boxes in Figure 5:'9, for example, manufactured wet vaults and vortex separators. Product performance within each grouping of manufactur~d BMPs vary as follows: • Filters -TSS effluent cOll:centrations range from 2 to 280 mg/L, with a median value of 29 mg/L • Inselts -TSS effluent concentrations range from 4 to 248 mg/L with a median value of 27 mg/L Wetlands -TSS effluent concentratipns vary little, and have a median value of 1.2 mg/L Vaults -TSS effluent concentrations range from 1 to 467 mgjL, "'-lith a median value of 36 mg/L ~ Vortex -TSS eft1uent concentrations range from 13 to "359 mg/L, with a median value of 32 mg/L stsr'p mo= zan c_ ===ZSf :srv='ZW California Stormwater BMP Htlndbook l~nll;:\rv Jocn (~ I' ( '. ~, Section 5 TreatrnentConuolBAdPs 800 r---------------------------------------------------~--~ .5 .g :g en 400 l~ ;, 200 en i :c :c {!. 100 I o~~~--~-~· ~~ January 2003 M P -20 Wetland M P -40 M adta Filter M P-SO Wet Vault MP.S1Vortex Separator MP·S2 Drain Inlet Figure 5-9 Total Suspended Solids in Effluent 1.000.0 r----------------------:-----------, 100.0 10.0 1.0 0.1 M P·20 Watland :Ie I M P·40 Media Filter M .. ·50 Wet Vault MiI·51Vortax MP·52 Drain Inlet Saparato r Figure 5-10 Total Suspended Solids in iEfflu.ant (log-format) (ection5 t,.! Jatment Control BMPs As noted earlier, performance of particular products in a grouping may be due to different design criteria within the group. For example, wet vault products differ with respect to the volume of the permanent wet pool to the design event volume; filter products differ with respect to the type of media. ' 5.4.5 Technologv Certification This Handbook does not endorse proprietary products, although many are described. It is left to each community to determine which proprietary products may be used, and under what circumstances. When considering a proprietary product, it is strongly advised that the community consider performance data~ b~t only performance data that have been collected following a widely accepted protocol. Protocols have been developed by the American Society of Civil Engineeing (ASCE BMP Data Base Program), and by the u.s. Environmental Protection Agency (Enviromental Technology Certification Program). The local jurisdiction should ask the manufacturer o,f the product to submit a report that describes the product and protocol that was followed to produce the performance data. It can be expected that subsequent to the publishing of this Handbook, new public-domain ~hnologies will be proposed (or design criteria for existing technologies will be altered) by ~elopment engineers. As with proprietary products, it is advised that new public-domain : .( !hnologies be considered only if performance data are available and have been collected I, JIlowing a widely accepted protocol. ' 5.5 BMP Design Criteria for Flow and Volume Many municipal stormwater discharge permits in California contain provisions such as Standard Urban Stormwater Mitigation Plans, Stormwater Quality Urban Impact Mitigation Plans, or Provision C.3 New and Redevelopment Performance Standards, commonly referred to as SUSMPs, SQUIMPs, or C.3 Provisions, respectively. What these and similar provisions have in common is that they require many new development and redevelopment projects to capture and then infiltrate or treat runoff from the project site prior to being discharged to storm drains. These provisions include minimum standards for sizing these treatment control BMPs. Sizing standards are prescribed for both volume-based and flow-based BMPs. A key point to consider when developing, reviewing, or complying with requirements for the sizing of treatment control BMPs for stormwater quality enhancement ~s that BMPs are most efficient and economical when they target small, frequent storm events that over time produce more total runoff than the larger, infrequent storms targeted for design of flood control facilities. The reason for this can be seen by examination of Figure 5-11 and Figure 5-12. Figure 5-11 shows the distribution of storm events at San Jose, California where most storms ~oduce less than 0.50 in. of total rainfall. Figure 5-12 shows the distribution of rainfall wensities at San Jose, California, where most storms have intensities ofless than 0.25 in/hr. \ 'le patterns at San Jose, California are typical of other locations throughout the state. Figures ;-11 and 5-12 show that as storm sizes increase, the number of events decrease. Therefore, when BMPs are designed for increasingly larger storms (for ex:ample, storms up to 1 in. versus storms of up to 0.5 in.), the B.MP size and cost increase dramatically, while the number of additional .~"'·w:e·,en:· ... '''"it5Pft=·?'''=1 m-m7D''1'tZYTI'C'tn'dFrC:AY;;~rnr "rr.;;;;v,s "';rsmMg'(~ rn&"iSaFiX.,. .<' znjMQ *. t:::: -~ r "::... - , ~ -~ • -•• • • . Section5 Treatment Control BMPs treated storm events are small. Table 5-2 shows that doubling the design storm depth from 0.50 in. to 1.00 in. only increases the number of events captured by 23%. Similarly, doubling the design rainfall intensity from 0.25 in/hr to 0.50 in/hr only increases the number of events captured by 796. J!I ! IU '0 .8 e ::I Z 1200 1067 1000 800 600 400 242 200 I. Rain Storms at San Jose, CA 1948-2000 113 • 42 -30 5 -9 2 1 Figure 5-11 Rain Storms at San lose, CA RaIn Intensity at San Jose, CA 3000 2963 1948-2000 ~ 2500 c QI 2000 ~ ... 1500 Q i 1000 .Q e ;:, 500 z 0 ~? ~~ ~~ 207 10 ~ ~'" ,\':1 ~. ro~ !\,-.$) I;)'Y ~~ 9,33~ hourly readings less than 0.10 In/hr are not shown 0 1 ~~ ~ ". ,,'Y ro~ ~1-,,-s> ,,~ Rainfall Intensity, Inches per Hour figure 5-12 Rain Intensity at San Jose, CA er.ction 5 I ' , eatment Control BMPs Table 5-2 Incremental Design Criteria VS Storms Treated at San lose, CA Proposed Number of Incremental Incremental Historical Events Increase in Increase in BMP Design Target in Range Design Criteria Storms Treated Storm Depth 1,067 0.00 to 0.50 in. +100% +23% Storm -Depth 242 0.51 to 1.00 in. Rainfall Intensity 2,963 0.10 to 0.25 injhr +100% +7% Rainfall Intensity 207 0.26 to 0.50 in/hr Due to economies of scale, doubling the capture and treatment requirements for a BMP are not likely to double the cost of many BMPs, but the incremental cost per event will increase, making ~creases beyond a certain point generally unattractive. Typically, design criteria for water _ -.ality control BMPs are set to coincide with the "knee of th~ curve," that is, the point of ~" flection where the magnitude of the event increases more rapidly than number of events ( -aptured. Figure 5-13 shows that the "knee of the curve" or point of diminishing returns for San Jose, California is in the range of 0.75 to 1.00 in. ofrai~fal1. In other words, targeting design storms larger than this will produce gains at considerable incremental cost. Similar curves can be developed for rainfall intensity and runoff volume. • Rain Storms at San Jose. CA 1600 1948-2000 1400 1200 1000 800 600 400 200 o "Knee of the Curve" is in this vicinity ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~. ~. ",. ",. "". ",. .". ~. boo boo ~. ~. '0' '0' '\. Storm Depth, Inches Figur-e :';-13 ~:tain :Storms Clt -San J,os,e, CA ( Section 5 Treatment Control BMPs It is important to note that arbitrarily targeting large, infrequent storm events can actually reduce the pollutant removal capabilities of some BMPs. This occurs when outlet structures, detention times, and drain down times are designed to accommodate unusually large volumes and high flows. When BMPs are over"designed, the more frequent, small storms that produce the most annual runoff pass quickly through the over"sized BMPs and therefore receive inadequate treatment. For example, a detention basin might normally be designed to capture 0.5 in. of runoff and to release that runoff over 48 hrs, providing a high level of sediment removal. If the basin were to he oversized to capture 1.0 in. of rup.off and to release that runoff over 48 brs, a more common 0.5 inch runoff event entering basin would drain in approximately 24 brs, meaning the smaller, more frequent storm that is responsible for more' total runoff would receive less treatment than if the basin were designed for the smaller event. Therefore, efficient and economical BMP sizing criteria are usually based on design criteria that correspond to the "knee of the c':1rv~" or point of di~inishing returns. 5.5.1 Volume-Based BMP Design Volume-based BMP design standards apply to BMPs whose ,primary mode of pollutant removal depends on the volumetric capacity of the BMP. Examples of ~MPs in this category includes detention basins, retention basins, and infiltration. Typically, a volume"based BMP design criteria calls for the capture and infiltration or treatment of a certain percentage of the runoff from the project site, usually in the range of the 75th to 85th percentile average annual runoff volume. The 75th to 85th percentile capture range corresponds to the "knee of the curve" for many sites in California for sites wQ.ose composite runoff coefficient is in th~ 0.50 to 0.95 range. , . The following are examples of volume-based BMP design standards from' cU:rrent municipal stormwater permits. The permits require that volume-based BMPs be designed to capture and then to infiltrate or treat stormwater runoff equal to one of the following: . ': . • Eighty (80)% of the volume of annual runoff, determined in accordance with the methodology set forth in Appendix D of the California Storm Water Best Management Practices Handbook (Stormwater Quality Task Force, 1993), using local rainfall data. • The maximized storrnwater quality capture volume for the area, based on historical rainfall records, determined using the formula and volume capture coefficients set forth in Urban Runoff Quality Management (WEF Manual of Practice No. 23/ ASeE Manual of Practice No. 87, (1998), pages 175"178). The reader is referred to the municipal stormwater program manager for the jurisdiction processing the new development or redevelopment project application to determine the specific requirements applicable to a proposed project. California Stormwater BlVIP Handbook Approach The volume-based BMP sizing methodology included in the first edition of the California Storm Water Best Management Practice Handbook (Stormwater Quality Task Force, 1993) has.been included in this second edition of the handbook and is the method recommended for use. :'!'cl.;rU"""'ZT~Y1Z'"'i'i"""_"""-::""·Ul:lWOMk""""'·=IZ''''',,",·'''''''''~'''''' ==""'=es"'iGl,;g=&""""",""',~¥J.,.;;wa:;;;::mIlGl!:!"""'''"''''''''''''''F&£~'':.s>: .... = flIT)· .i __ ... ...u~'S'tr..~~,~~ c: _,_"' ___ ~_--' (.~tion5 ( J, atment Control BMPs The California Stormwater BMP Handbook approach is based on results of a continuous simulation model, the STORM model, dE'''· ... loped by the Hydrologic Engineering Center of-the u.s. Army Corps of Engineers (COE-HEr i977). The Storage, Treatment, Overflow, Runoff Model (STORM) was applied to long-term hourly rainfall data at numerous sites throughout California, with sites selected throughout the state representing a wide range of municipal stormwater permit areas, climatic areas, geography, and topography. STORM translatesrainfaU into runoff, then routes the runoff through detention storage. The volume-based BMP sizing curves resulting from the STORM model provide a range of options for choosing a BMP sizing curve appropriate to sites in most areas of the state. The volume-based BMP sizing curves are included in Appendix D. Key model assumptions are also documented in Appendix n~ San Jose (7821) • Santa Clara County, California 1QO Ca I 51 90, I 80 , . I 24-hl'Drawdown I 70 ,~. {(. I f 60 ~ & 50~ '8 .. ; of, ~ j 40 j ~ 30: ;. -Runolf Co,fftcl,nt -0.25 : -Runoff CoeffiCient_ 0.50 20 • . : -RunoIfCoelflcl,nt-O.7S : -RunoffCoelflcl.nt-1.00 ' -_. r·-·····---··· 10 I O! 0.0 0.1 0.2 0.3 0t" 0.5 0.1 0.7 Unit Bas n Storage Volume (Inches) 0.1 0.11 1.0 Figure 5-14 Capture/Treatment Analysis at San Jose, CA The California Stormwater BMP Handbook approach is simple to apply, and relies largely on commonly available information about a project. The following steps describe the use of the BMP sizing curves contained in Appendix D. 1. Identify the "BMP Drainage Area" that drains to the proposed BMP. This includes all areas that will contribute runoff to the proposed BMP, including pervious areas, impervious areas, and off-site areas, whether or not they are directly or indirectly connected to the BMP. '(. Calculate the composite runoff coefficient "C' for the area identified in Step 1. 3. Select a capture curve representative of the site and the desired drain down time using. See Appendix D. Curves are presented for 24 hour and 48 hour draw down times. The 48 hour curve should be used in most areas of California. Use o{the 24 hour curve should be limited 'r;;;:; Wi. = == r~ \ I I •• c( • ( Section 5 Treatment Control BMPs to drainage areas with coarse soils that readily settle and to watersheds where warming may be detrimental to downstream fisheries. Draw down times in excess of 48 hours should be used with caution as vector breeding can be a problem after water has stood in excess of 72 .hours. 4. Determine the applicable requirement for capture of runoff (Capture, % of Runoff). 5. Enter the capture curve selected in Step 3 on the vertical axis at the "Capture, % Runoff' value identified in Step 4. Move horizontally to the right across capture curve until the curve corresponding to the drainage area's composite runoff coefficient ICC" determined in Step 2js intercepted. Interpolation between curves may be necessary. Move vertically down the. from for this point until the horizontal axis is intercepted. Read the "Unit Basin Storage Volume" along the horizontal axis. If a local requirement for capture of runoff is not specified, enter the vertical axis at the ''knee of the curve" for the curve representing composite runoff coefficient "C." The ''knee of the curve" is typically in the range of 75 to 8596 capture. 6. Calculate the required capture volume of the BMP by multiplying the "~MP Drainage Area" from Step 1 by the "Unit Basin Storage Volume" from Step 5 to give the BMP volume. Due to the mixed units that result (e:g., ac-in., ac-ft) it is recommended that the resulting volume be converted to cubic feet for use during design. Urban RunoffQ~ality Management Approach The volume-based BMP sizing methodology described in Urban Runoff Quality Management (WEF Manual of Practice No. 23/ ASeE Manual of Practice No. 87, (1998), pages 175-178) has been included in this edition of the handbook as an alternative to the California Stormwater BMP Handbook approach described above. The Urban Runoff Quality Management Approach is suitable for planning level estimates of the size of volume-based BMPs (WEF/ASCE, 1998, page 175). The Urban Runoff Quality Management approach is similar to the California Stormwater BMP Handbook approach in that it is based on the translation of rainfall to runoff. The Urban Runoff Quality Management approach is based on two regression equations. The first regression equation that relates rainfall to runoff. The rainfall to runoff regression equation was developed using 2 years of data from more than 60 urban watersheds nationwide. The second regression equation relates mean annual runoff-producing rainfall depths to the "Maximized Water Quality Capture Volume" which corresponds to the "knee of the cumulative probability curve". This second regression was based on analysis of long-term rainfall data from seven rain gages representing climatic zones across the country. The Maximized Water Quality Capture Volume corresponds to approximately the 85th percentile runoff event, and ranges from 82 to 88%. The two regression equations that form the Urban Runoff Quality ~Ianagement approach are as follows: ··W • ~ ms" (".ection5 ( , "eatmant Control BMPs " Where C = runoff coefficient i = watershed imperviousness ratio which is equal to the percent total imperviousness divided by 100 Po = Maximized Detention Volume, in watershed inches a = regression constant, a=I.582 and a=1.g63 for 24 and 48 hour draw down, respectively P6 = mean annual runoff-producing rainfall depths, in watershed inches, Table #-1. See AppendixD. The Urban Runoff Quality Management Approach is simple to apply. The following steps describe the use of the approach. Identify the "BMP Drainage Area" that drains to the proposed BMP. This includes al~ areas that will contribute runoff to the proposed BMP, including p~rvious areas, impervious areas, and off-site areas, whether or not they are directly or indirectly connected to the BMP. 2. Calculate the "Watershed Imperviousness Ratio" (i), which is equal to the percent of total impervious area in the "BMP Drainage Area" divided by 100. 3. Calculate the "Runoff Coefficient" (C) using the following equation: C = o.8S8i3 -O.78i2 + O.774i + 0.04 4. Determine the "Mean Annual Runoff' (P6)for the "BMP Drainage Area" using Table #-1 in AppendixD. 5. Determine the "Regression Constant" (a) for the desired BMP drain down time. Use a=I.582 for 24 hrs and a=1.963 for 48 hr draw down. 6. Calculate th~ "Maximized Detention Volume" (Po) using the follOwing equation: Po = (a • C) • P6 7. Calculate the required capture volume of the BMP by multiplying the "BMP Drainage Area" from Step 1 by the "Maximized Detention Volume" from Step 6 to give the BMP volume. Due to the mixed units that result (e.g., ac-in., ac-ft) it is recommended that the resulting • volume be converted to ft3 for use during design. ( i.S.2 Flow-Based BMP Design Flow-based BMP design standards apply to BMPs whose primary mode of pollutant removal depends on the rate of now of runoff through the BMP. Exa"mples of BMPs in this category sa • -_en.mIN., •• \. Section 5 Treatment Control BMPs includes swales, sand filters, screening devices, and many proprietary products. Typically, a flow-based BMP design criteria calls for the capture and infiltration or treatIrient of the flow runoff produced by rain events of a specified magnitude. The following are examples of flow-based BMP design standards from current municipal stonnwater permits. The permits require that flow-based BMPs be designed to capture and. then to infiltrate or treat stormwater runoff equal to one of the following: • 10% of the 50-yr peak flow rate (Factored Flood Flow Approach) • The flow of runoff produced by a rain event equal to at least two times the 85th percentile hourly rainfall intensity for the applicable area, based on historical records of hourly rainfall depths (California Stormwater BMP Handbook Approach) • The flow of runoff resulting from a rain event equal to at least 0.2 in/hr intensity (Uniform Intensity Approach) The reader is referred to the municipal stormwater program manager for the jurisdiction processing the new development or redevelopment project application to determine the specific requirements applicable to a proposed project. The three typical requirements shown above all have in common a rainfall intensity element. That is, each criteria is based treating a flow of runoff produced by a rain event of specified rainfall intensity. In the first example, the Factored Flood Flow Approach, the design rainfall intensity is a function of the location and time of concentration of the area discharging to the BMP. The intensity in this case is determined using Intensity-Duration-Frequency curves published by the flood control agency with jurisdiction over the project or available from climatic data centers. This approach is simple to apply when the 50-yr peak flow has already been determined for either drainage system design or flood control calculations. In the second example, the California Stormwater BMP Handbook Approach (so called becaUSe it is recommended in this handbook), the rainfall intensity is a function of the location of the area discharging to the BMP. The intensity in this case can be determined using the rain intensity cumulative frequency curves developed for this Handbook based on a~alysis of long- ter~ hourly rainfall data at numerous sites throughout California, with sites selected throughout the state representing a wide range of municipal stormwater permit areas, climatic are~s, geography, and topography. These rain intensity cumulative frequency curves are included in Appendix D. This approach is recommended as it reflects local conditions throughout the state. The flow-based design criteria in some municipal permits require design based on two times the 85th percentile hourly rainfall intensity. The factor of two included in these permits appears to be provided as a factor of safety: therefore, caution should be exercised when applying additional factors of safety during the design process so that over design can be avoided. = = rnn:s-XiT5EJi Aection5 (Wr"eatment Control BMPs In the third example, the Uniform Intensity Approach, the rainfall ~ntensity is specified directly, and is not a function of the location or time of concentration of the area draining to the BMP. This approach is very simple to apply, but it is not reflective Qf10cal conditions. The three example flow-based BMP design criteria are easy to apply and can be used in conjunction with the Rational Formula, a simplified, easy to apply formula that predicts flow rates based on rainfall intensity and drainage area characteristics. The Rational Formula is as follows: Q=CiA where Q = flow in {ta/s i = raill intensity in in/hr A = drainage area in acres ". c = runoff coefficient (( :he Rational Formula is widely used for hydrologic calculations, but it does ,have a number of 'limitations. For stormwater BMP design, a key limitation is the ability of the Rational Formula to predict runoff from undeveloped areas where runoff coefficients are highly variable with storm intensity and antecedent moisture conditions. This limitation is accentuated when predicting runoff from frequent, small storms used in stormwater quality BMP design because many of the runoff coefficients in common use were developed for predicting runoff for drainage design where larger, infrequent storms are of interest. Table 5-3 provides sQme general guidelines on use of the Rational Equation. Table 5-3 Use of Rational Formula for Storm water BMP Design Composite Runoff Coefficient, "C" BMP Drainage Area 0.00 to 0.25 0.26 to 0.50 0.51 to 0.75 0.76 to 1.00 (Acres) oto25 Caution Yes Yes Yes 26 to 50 High Caution Caution Yes Yes 51 to 75 Not High Caution Caution Yes Recommended Not Caution Yes ,. 76 to 100 Recommended High Caution '{ \ \ summary, the Rational Formula, when used with commonly tabulated runoff coefficients in .!ldeveloped drainage areas, will likely result in predictions higher than will be experienced under actual field conditions. However, given the simplicity of the equation, its use remains 5-20 California Stormwater BMP Ya,nrhM'< -.. Section 5 TreafmentConuolBAdPs practical and is often the standard method specified by local agencies. In general, use of alternative formulas for predicting BMP design flows based on the intensity criteria above is acceptable if the formula is approved by the local flood control agency or jurisdiction where the project is being developed. The following steps describe the approach for application of the flow-based BMP design criteria: 1. . Identify the "BMP Drainage Area" that drains to the proposed BMP. This includes all areas that will contribute runoff to the proposed BMP, including pervious areas, impervious areas, and off-site areas, whether or not they are directly or indirectly connected to the BMP. 2. Determine rainfall intensity criteria to apply and the corresponding design rainfall intensity. a. Factored Flood Flow Approach: Determine the time of concentration for "BMP Drainage Area" using procedures approved by the local flood control agency or using . standard hydrology methods. Identify an Intensity-Duration-Frequency Curve representative of the drainage area (usually available from the local flood control agency or climatic data center). Enter the Intensity-nuration-Frequency Curve with the time of concentration and read the rainfall intensity corresponding the 50-yr return period rainfall event. This intensity is the "Design Rainfall Intensity." b. California Storm water BMP Handbook Approach: Select a rain intensity cumulative fr~quency curve representative of the "BMP Drainage Area." See Appendix D. Read the rainfall intensity corresponding to the cumulative probability specified in the criteria, usually 85%. Multiply the intensity by the safety factor specified in the criteria, usually 2, to get the "Design Rainfall Intensity." c. Uniform Intensity Approach: The "Design Rainfall Intensity" is the intensity specified in the criteria, usually 0.2 in/hr. 3. Calculate the composite runoff coefficient" "C" for the "BMP Drainage Area" identified in Stepl. 4. Apply the Rational Formula to calculate the "BMP Design Flow" a. Factored Flood Flow Approach: Using the "BMP Drainage Area" from Step 1, the "Design Rainfall Intensity" from Step 2a, and "C" from Step 3, apply the Rational Formula and multiply the result by 0.1. The result is the "BMP Design Flow." b. California Stormwater B1.VIP Handbook Approach: Using the "BMP Drainage Area" from Step 1, the "Design Rainfall Intensity" from Step 2b, and "e" from Step 3, apply the Rational Formula. The result is the "BMP Design Flow." c. Uniform Intensity Approach: Using the "BMP Drainage Area" from Step 1, the "Design Rainfall Intensity" from Step 2C, and "C" from Step 3, apply the Rational FannuIa. The result is the "BMP Design Flow." ... = ______________ • ____________ ta;JM"..--.-~-- January 2003 -... "<:: ........ -... I· '( (eection5 (eatment Control BMPs 5.5.3 Combined Volume-Based and Flow-Based BMP Design Volume-based BMPs and flow-based BMPs do not necessarily treat precisely the same stormwater runoff. For example, an on-line volume-based BMP such as a detention basin will treat the design runoff volume and is essentially unaffected by runoff entering the basin at an extremely high rate, say from a very short, but intense storm that produces the design volume of runoff. However, a flow-based BMP might be overwhelmed by the same short, but intense storm if the storm intensity results in runoff rates that exceed the flow-based BMP design flow rate. By contrast, a flow-based BMP such as a swale will treat the design flow r~te of runoff:aild is essenpaUy unaffected by the duration of the design flow, say from a long, low intensity storm •. However, a volume-based detention basin subjected to this same rainfall and runoff event will begin to provide less treatment or will go into bypass or overflow mode after the design runoff volume is delivered. Therefore, there may be some situations where designers need to consider both volume-based and tlow ... based BMP design criteria. An example of wbeJ;'e both types of criteria might apply is an off-line detention basin. For an off-line detention basin, the capacity ofthe diversion • ructure could be designed to comply with the flow-based BMP design criteria while the ~" etention basin itself could be designed to comply with the volume-based criteria. When both volume-based and flow based criteria apply, the designer should determine which of the criteria apply to each element of the BMP system, and then size the elements accordingly. 5.6 Other BMP Selection Factors Other factors that influence the selection of BMPs include cost, vector control issues, and . endangered species issues. Each of these is discussed briefly below. 5.6.1 Costs The relative costs for implementing various public domain and manufactured BMPs baSed on flow and volume parameters are shown in Tables 5-4 and 5-5 below: Table 5-4 Economic Table 5-5 Economic Comparison Matrix Comparison Matrix --Volume Flow BMP cost! acre-ft BMP Cost/cfs Austin Sand Filter Basin $$$$ Strip $$ Delaware Lineal Sand Filter $$$$ Swale $$ Extended Detention Basin (EDB) $$ Wet Vault Not available Multi Chamber Treatment Train $$$$ Filter $$$$ (MCTT) Not available Wet Basin $.$$.$ Drain Insert Not available Manufactured Wetland Not available Infiltration Basin $ Wet Pond and Constructed Wetland .$.$.$$ ,", =m "'_ .. : ......... r,· .......... _ ...... r"""I1.~ II_-_.J~ __ I .. 5.6.2 Vector Breeding Considerations Section 5 Treatment Control BMPs The potential of a BMP to create vector breeding habitat and/or harborage should be considered when selecting BMPs. Mosquito and other vector production is a nuisance and public health threat. Mosquitoes can breed in standing water almost immediately following a BMP installation and may persist at unnaturally high levels and for longer seasonal periods in created habitats. BMP siting, design, construction, and maintenance must be considered in order to select a BMP that is least conducive to providing habitat for vectors. Tips for minimizing vector breeding problems in the design and maintenance of BMPs are presented in the BMP fact sheets. Certain BMPs, including ponds and wetlands and those designed with permanent water sumps, vaults, and/or catch basins (including below-ground installations), may require routine inspections and treatments by local mosquito and vector control agencies to suppress vector production. 5.6.3 Threatened and Endangered Species Considerations The presence or potential presence of threatened and endangered species· should also be considered when selecting BMPs. Although preservation of threatened endangered species is crucial, treatment BMPs are not intended to supplement or replace species habitat except under special circumstances. The presence of threatened or endangered species can hinder timely and routine maintenance, which in turn can result in reduced BMP performance and an increase in vector production. In extreme cases, jurisdictional rights to the treatment BMP and surrounding land may be lost if threatened or endangered species utilize or become established in theBMP. . When considering BMPs where there is a presence or potential presence of threatened or endangered species, early coordination with the California Department of Fish and Game and the U.S. Fish and Wildlife service is essential. During this coordination, the purpose and the long-term operation and maintenance requirements of the BMPs need to be clearly established through writt~n agreements or memorandums of understanding. Absent firm 'agreements or understandings, proceeding with BMPs under these circumstances is not recommended. 5.7 BMP Fact Sheets BMP fact sheets for public domain and manufactured BMPs follow. The BMP fact sheets are individually page numbered and are suitable for photocopying and inclusion in·stormwater quality management plans. Fresh copies of the fact sheets can be individually downloaded from the Caltrans Stormwater BMP Handbook website at www.cabmphandbooks.com . . z:::;:;m-''iz,;$!?; ~; 51!t1 i Pi zmm:m:;n;;=wj'llj'$~ """";;===;-"i2"'J"j8 i 151'!Ji'I:I;;R'Wle~"'!..lI.:Il:;:.:l2;S;S."itlo/i::r7;OW;iH"T:rIF'7'TT?F7i) ~ ... ].Jnuary 2003 California Stormwater BMP Handbook c; ..,.., /(e Vegetated Swale Description Vegetated swales are open, shallow channels with vegetation covering the side slopes and bottom that collect and slowly convey runoff flow to downstream discharge points. They are designed to treat runoff through filtering by the vegetation in the channel, filtering through a subsoil matrix, and/or infiltration into the underlying soils. Swales can be natural or manmade. They trap particulate pollutants (suspended solids and trace metals), promote infiltration, and reduce the flow velocity of stormwater runoff. Vegetated swales can serve as part of a stormwater drainage system and can replace curbs, gutters and storm sewer systems. . California Experience Caltrans constructed and monitored six vegetated swales in southern California. These swales were generally effective in reducing the volume and mass of pollutants in runoff. Even in the areas where the annual rainfall was only about 10 inches/yr, the vegetation did not require additional irrigation. One factor that strongly affected performance was the presence of large numbers of gophers at most of the sites. The gophers created earthen mounds, destroyed vegetation, and generally reduced the effectiveness of the controls for TSS reduction. Advantages • If properly designed, vegetated, and operated, swales can serve as an aesthetic, potentially inexpensive urban development or roadway drainage conveyance measure with significant collateral water quality benefits. TC-30 DeSign Considerations • Tributary Area • Area Required • Slope • Water Availability Targeted Constituents ./ Sediment • ./ Nutrients • ./ Trash • ./ Metals • ./ Bacteria • ./ Oil and Grease • ./ Organics • Legend (Removal Effectiveness) • Low • High • Medium . . ~:.:;,:: \:;:~ :.)$. .. f9. A , ~ .. ;) Californsa , ':., '\ StormW<'3ter : , ... ; ,::::. Quality .. :.:;)-Assad-alta.)l1 ~~~~~=as:~"'_""'. =""""'..,..",......,""""....,.,"""""==""""""""""""""~~1!!!G~ January 2003 California Stormwater BIVIP Handbook 1 of 13 New Development and Redevelopment Vegetated Swale • Roadside ditches should be regarded as significant potential swale/buffer strip sites and should be utilized for this purpose whenever possible. Limitations • Can be difficult to avoid channelization. • May not be appropriate for industrial sites or locations where spills may occUr • Gras$ed swales cannot treat a very large drainage area. Large areas may be divided and treated using multiple swales. • A thick vegetative cover is needed for these practices to function properly. • They are impractical in areas with steep topography. • They are not effective and may even erode when flow velocities are high, if the grass covet is not properly maintained. • In some places, their use is restricted by law: many local municipalities require curb and gutter systems in residential areas. Swales are mores susceptible to failure if not properly maintained than other treatment BMPs. Oesign and Sizing Guidelines • Flow rate based design determined by local requirements or sized so that 85% of the annual runoff volume is discharged at less than the design rainfall intensity. • Swale should be designed so that the water level does not exceed 2/3rds the height of the grass or 4 inches, which ever is less, at the design treatment rate. • Longitudinal slopes should not exceed 2.5% • Trapezoidal channels are normally recommended but other configurations, such as parabolic, can also provide substantial water quality improvement and may be easier to mow than designs with sharp breaks in slope. II Swales constru,cted in cut are preferred, or in fill areas that are far enough from an adjacent slope to minimize the potential for gopher damage. Do not use side slopes constructed of fill, which are prone to structural damage by gophers and other burrowing animals. , • A diverse selection aflow growing, plants that thrive under the specific site, climatic, and watering conditions should be specified. Vegetation whose growing season corresponds to the wet season are preferred. Drought tolerant vegetation should be considered especially for swales that are not part of a regularly irrigated landscaped area . • '{ The width of ~he swale should be determined using Manning's Equation using a value of 0.25 for Manning's n. ~~~~~~~ __ w=~~~~~m=W~6~~~~DWW_Mne_~~mzQ~~amm'ABa~ves~la_~mmwn~~~=-~.~iaa __ .... 2 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment -. ( Vegetated Swale TC-30 Construction/Inspection Considerations • Include directions in the specifications for use of appropriate fertilizer and soil amendments based on soil properties determined through testing and compared to the needs of the vegetation requirements. • Install swales at the time of the year when there is a reasonable chance of successful establishment without irrigation; however, it is recognized that rainfall in a given year may not be sufficient and temporary irrigation may be used. • If sod tiles must be used, they should be placed so that there are no gaps between the tiles; stagger the ends of the tiles to prevent the formation of channels along the swale or strip. • Use a roller on the sod to ensure that no air pockets form between the sod and the soil. • Where seeds are used, erosion controls will be necessary to protect seeds for at least 75 days after the first rainfall of the season. Performance The literature suggests that vegetated swales represent a practical and potentially effective . technique for controlling urban runoff quality. While limited quantitative performance data exists for vegetated swales, it is known that check dams, slight slopes, permeable soils, dense grass cover, increased contact time, and small storm events all contribute to successful pollutant removal by the swale system. Factors decreasing the effectiveness of swales include compacted soils, short runoff contact time, large storm events, frozen ground, short grass heights, steep slopes, and high runoff velocities and discharge rates. Conventional vegetated swale designs have achieved mixed'results in removing particulate pollutants. A study performed by the Nationwide Urban Runoff Program (NURP) monitored three grass swales in the Washington, D.C., area and found no significant improvement in urban runoff quality for the pollutants analyzed. However, the weak performance of these swales was attributed to the high flow velocities in the swales, soil compaction, steep slopes, and short grass height. Another project in Durham, NC, monitored the performance of a carefully designed artificial swale that received runoff from a commercial parking lot. The project tracked 11 storms and concluded that particulate concentrations of heavy metals (Cu, Pb, Zn, and Cd) were reduced by approximately 50 percent. However, the swale proved largely ineffective for removing soluble nutrients. The effectiveness of vegetated swales can be enhanced by adding check dams at approximately 17 meter (50 foot) increments along their length (See Figure 1). These dams maximize .the retention time within the swale, decrease flow velocities, and promote particulate settling. Finally, the incorporation of vegetated filter strips parallel to the top of the channel banks can help to treat sheet flows entering the swale. Only 9 studies have been conducted on all grassed channels designed for water quality (Table 1). The data suggest relatively high removal rates for some pollutants, but negative removals for some bacteria, and fair performance for phosphorus . • January 2003 California Stormwater BMP Handbook New Development and Redevelopment 3 of 13 Vegetated Swale Table 1 Grassed swale pollutant removal efficiency data Removal Efficiencies (% Removal) Study TSS TP TN NOa Metals Bacteria Type Caltrans 2002 77 8 67 66 83-90 -33 dry swales Goldberg 1993 67.8 4·5 -31·4 42-62 -100 grassed channel Seattle Metro and Washington 60 Department of Ecology 1992 45 --25 2-16 -25 grassed channel Seattle Metro and Washington 83 Department of Ecology, 1992 29 --25 46-73 -25 grassed channel ~angetal.,1981 80 ---70-80 -dryswale Dorman et al., 1989 98 18 -45 37-81 -dryswale Harper,1988 87 83 84 80 88-90 -dryswale Kercher et al., 1983 99 99 99 99 99 -dryswale Harper, 1988. 81 17 40 52 37-69 -wetswale Koon,1995 67 39 -9 -35 to 6 -wetswale While it is difficult to distinguish between different designs based on the small amount of available data, grassed channels generally have poorer removal rates than wet and dry swales, although some swales appear to export soluble phosphorus (Harper, 1988; Koon, 1995). It is not clear why swales export bacteria. One explanation is that bacteria thrive in the warm swale soils. Siting Criteria The suitability of a swale at a site will depend on land use, size of the area serviced, soil type, slope, imperviousness of the contributing watershed, and dimensions and slope of th,e swale system (Schueler et al., 1992). In general, swales can be used to serve areas ofless than 10 acres, with slopes no greater than 5 %. Use of natural topographic lows is encouraged and natural drainage courses should be regarded as significant local resources to be kept in use (young et aI., 1996). Selection Criteria (NCTCOG, 1993) • Comparable performance to wet basins • Limited to treating a few acres • Availability of water during dry periods to maintain vegetation Sufficient available land area • \ esearch in the Austin area indicates that vegetated controls are effective at removing pollutants .. even when dormant. Therefore, irrigation is not required to maintain growth during dry periods, but may be necessary only to prevent the vegetation from dying. 4 of 13 California Stormwater BMP Handbook January 2003 Ne"" ')e"r=al("',., ........ ,t:l-&. ~..,..~ Q-:::a ..... !),'r-I..,,...--...-........ &O' Vegetated Swale . TC-30 The topography of the site should permit the design of a channel with appropriate slope and cross-sectional area. Site topography may also dictate a need for additional structural controls. Recommendations for longitudinal slopes range between 2 and 6 percent. Flatter slopes can be used, if sufficient to provide adequate cOJ.1.veyance. Steep slopes increase flow velocity, decr~ase detention time, and may require energy dissipating and grade check. Steep slopes also can be managed using a series of check dams to terrace the swale and reduce the slope to within acceptable limits. The use of check dams with swales also promotes infiltration . . Additional Design Guidelines Most of the design guidelines adopted for swale design specify a minimum hydraulic residence time of 9 minutes. This criterion is based on the results of a single study conducted' in Seattle, Washington (Seattle Metro and Washington Department of Ecology, 1992), and is not well supported. Analysis of the data collected in that study indicates that pollutant removal at a residence time of 5 minutes was not significantly different, although there is more variability in that data. Therefore, additional research in the design criteria for swales is needed. Substantial pollutant removal has also been observed for vegetated controls designed solely for conveyance (Barrett et aI, 1998); consequently, some flexibility in the design is warranted. Many design guidelines recommend that grass be frequently mowed to maintain dense .coverage near the ground surface. Recent research (Colwell et aI., 2000) has shown mowing frequency or grass height has little or no effect on pollutant removal. Summary of Design Recommendations 1) The swale should have a length that provides a minimum hydraulic residence time of at least 10 minutes. The maximum bottom width should not exceed 10 feet unless a dividing berm is provided. The depth of flow should not exceed 2/3rds the height of the grass at the peak of the water quality design storm intensity. The channel slope should not exceed 2.5%. 2) A design grass height of 6 inches is recommended. . 3) Regardless of the recommended detention time, the swale should be not less than 100 feet in length. ' 4) The width ofthe swale should be determined using Manning's Equation, at the peak of the design storm, using a Manning's n of 0.25. 5) The swale can be sized as both a treatment facility for the design storm and as a conveyance system to pass the peak hydraulic flows of the 100-year storm if it is located "on-line." The side slopes should be no steeper than 3:1 (H:V). 6) January 2003 Roadside Cl.itches should be regarded as significant potential swale/buffer strip sites and should be utilized for this purpose whenever possible. If flow is to be introduced through curb cuts, place pavement slightly above the elevation of the vegetated areas. Curb cuts should be at least 12 inches wide to prevent clogging .. Swales must be vegetated in order to provide adequate treatment of runoff. It is important to maximize water contact with vegetation and the soil surface. For general purposes, select fine, close-growing, water-resistant grasses. If possible, divert runoff (other than necessary irrigation) during the period of vegetation California Stormwater BMP Handbook New Develo'Jmp-,r-~nrl Rpr'",,,,,'," .. "." 5 of 13 Vegetated Swale establishment. Where runoff diversion is not possible, cover graded and seeded areas with suitable erosion control materials. Maintenance The useful life of a vegetated swale system is directly proportional to its maintenance frequency. If properly designed and regularly maintained, vegetated swales can last indefinitely. The maintenance objectives for vegetated swale systems include keeping up the hydraulic and removal efficiency of the channel and maintaining a dense, healthy grass cover. Maintenance activities should include periodic mowing (with grass never cut shorter than the design flow depth), weed control, watering during drought conditions, reseeding of bare areas, and clearing of debris and blockages. Cuttings should be removed from the channel and disposed in a local composting facility. Accumulated sediment should also be removed manually to avoid concentrated flows in the swale. The application of fertilizers and pesticides should be minimal. Another aspect of a good maintenance plan is repairing damaged areas within a channel. For example, if the channel develops ruts or holes, it should be repaired utilizing a suitable soil that is properly tamped and seeded. The grass cover should be thick; if it is not, reseed. as necessary. Any standing water removed during the maintenance operation must be disposed to a sanitary • sewer at an approved discharge location. Residuals (e.g., silt, grass cuttings) must be disposed ,( in accordance with local or State requirements. Maintenance of grassed swales mostly involves maintenance of the grass or wetland plant cover. Typical maintenance activities are summarized below: • Inspect swales at least twice annually for erosion, damage to vegetation, and sediment and debris accumulation preferably at the end of the wet season to schedule summer maintenance and before major fall runoff to be sure the swale is ready for winter. However, additional inspection after periods of heavy runoff is desirable. The swale should be checked for debris and litter, and areas of sediment accumulation. • Grass height and mowing frequency may not have a large impact on pollutant removal. Consequently, mowing may only be necessary once or twice a year for safety or aesthetics or to suppress weeds and woody vegetation. • Trash tends to accumulate in swale areas, particularly along highways. The need for litter removal is determined through periodic inspection, but litter should always be removed prior to mowing. • Sediment accumulating near culverts and in channels should be removed when it builds up to 75 mm (3 in.) at any spot, or covers vegetation. • Regularly inspect swales for pools of standing water. Swales can become a nuisance due to mosquito breeding in standing water if obstructions develop (e.g. debris accumulation, invasive vegetation) and/or if proper drainage slopes are not implemented and maintained. --6 of 13 California Stormwater BMP Handbook \',,,,,, n"",,,","'''',....'''~'" ""','" QprlPIIPln"l1"f'nt January 2003 ~. •• '\ •• '( Vegetated Swale Cost Construction Cost TC-30 Little data is available to estimate the difference in cost between various swale designs. One study (SWRPC, 1991) estimated the construction cost of grassed channels at approximately $0.25 per ft2. This price does not include design costs or contingencies. Brown and Schueler' (1997) estimate these costs at approximately 32 percent of construction costs for most stormwater management practices. For swales, however, these costs would probably be significantly higher since the construction costs are so low compared with other practices. A more realistic estimate would be a total cost of approximately $0.50 per ft2, which compares favorably with other stormwater management practices . January 2003 California Stormwater BMP Handbook New Development and Redevelopment 7 of 13 ~-;r~ Vegetated Swal~ Table 2 Swale Cost Estimate (SEWRPC, 1991) Unit Cost Component Unit Extent Low Moderate High Low Mobilization I SwalQ 1 $107 $214 $441 $107 Oemobilization-Ught Sits PreparatiaJ Claaringb._ •••••••••••.• Aaa 0.5 $2,200 $3,800 $5,400 .$1,100 Grubbing" .........•.... Aaa 0.25 $3,aoo $5,200 $8,600 $950 General Excavatiorfl ........•..• Yd3 312 $2.10 $3.70 $5.30 $7&1 Laval and Til~ ........ Yd2 1,210 $020 $0.35 $).60 $242 Sits5 OQV9lopment Salvaged Topsoil Yd2 1,210 $0.40 $1.00 $1.60 $484 Seed, and Mulchr .. SOcj; ..................... Yd2 1,210 $1.20 $2.40 $3.60 $1,452 SUbtotal -------.$5,116 ContingenCies Swale 1 25~ 25% ~ $1,210 Total ---. --$8.395 ~ .. ~ ..... a....,.., ..._"..., Nota: Mobilization/dQrnobilization rafws to tlla organizatial and planning inwlvad in Glidlblishing a vQgelaive _Ie. • Swale has a bottom width of 1.0 foot. a top WIdth Of 10 feet With 1:3 side slopes, and a 1.000-tootlength. b Area cleared = (top Width ... 10 feet) xswale length. C Area grubbed = (top wIdth x swale length). d Volume excavated = (0.67 x top width x swale depth) x swale length (parabolic cross-section). Q Area tilled = {top width ... §{swale depUe> x swale lengih (parabolic cross-section). 3(top width) r Area seeded ::: area cleared x 0.5. 9 Area sodded ::: area cleared x 0.5. 8 of 13 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbobks.com TatalCost Moderate High .$214 $441 $1,Il00 $2,100 $1,300 $1,650 $1,376 $1,f1l2 .$424 $605 $1,210 $1,936 $2,004 $4,356 $51,_ $13,660 $2.341 $3,415 $11735 $11»75 January 2003 ·-------. Ve~.ated Swale • Table 3 Estimated Maintenance Costs (SEWRPC. 1991) Component Unit Cost lawn Mowing $0.85/1,000 ffl movring Ganeral Lawn Cala $D.QO I 1,000 fflyaar Swala Oabris iilnd Utl8r $0.10 I linear feat 1 year RQmoval Grass RQsaading with $0.30 1 yd2 Mulch and Fartilizsr Program Administlation and $O.15/1inaar foot I year, SWalalnspaclion plus $251 inspaction Total -------. __ .. January 2003 SwaleSiza (Depth and Top WIdth) 1.5 Foot DepthJ 0 .... 3-Foot Oeptb. 3-Foot Foot Bottom Width, Bottom \IIt1dIh, 21.foot 1o.FootTop Width Top Width $O.14/Iin.rfaot $0.21 I Una. foot $O.18111n.rfoot .$O.28/linur foot $0.10 Ilio.rfaot $0.10 I Una. foot $O.o1/lin.rfaot 4O.o1/1ina. foot $O.15/Iin.rfoot .$0.151 iIlUI' foot $(UlIllnHr foot $03511-.,oot California Stormwater BMP Handbook New Development and Rec;!evelopment www.cabmphandbooks.com ~ TC-30 • Comment Lawn maiotcInanc:Q ar_a{tap widt1 + 10 faat) X length. Maw eight tim8a par year I.nIn maintarlanl'» ar_ -(tap Wid1h + 10faat) xtangll - Alva l8W1gatatad aqUIlla 1 % cflawn rnairianancaaraa par yasr Inspact1bur tim8s per y.r - 90fr3 Vegetated Swale Maintenance Cost Caltrans (2002) estimated the expected annual maintenance cost for a swale with a tributary area of approximately 2 ha at approximately $2,700. Since almost all maintenance consists of mowing, the cost is fi.tndamentally a function ofthe mowing frequency. Unit costs developed by SEWRPC are shown in Table 3. In many cases vegetated channels would be used to convey runoff and would require periodic mowing as well, so there may be little additional cost for the water quality component. Since essentially all the activities are related to vegetation management, no special training is required for maintenance personnel. References and Sources of Additional Information Barrett, Michael E., Walsh, Patrick M., Malina, Joseph F., Jr., Charbeneau, Randall J, 1998, "Performance of vegetative controls for treating highway runoff," ASCE Journal of Environmental Engineering, Vol. 124, No. 11, pp.1121-1128. Brown, W., and T. Schueler. 1997. The Economics of Storm water BMPs in the Mid-Atlantic Region. Prepared for the Chesapeake Research Consortium, Edgewater, MD, by the Center for Watershed Protection, Ellicott City, MD. Center for Watershed Protection (CWP). 1996. Design of Stormwater Filtering Systems . • prepared for the Chesapeake Research Consortium, Solomons, MD, and USEPA Region V, , Chicago, IL, by the Center for Watershed Protection, Ellicott City, MD. \( Colwell, Shanti R., Horner, Richard R., and Booth, Derek B., 2000. Characterization of Performance Predictors and Evaluation of Mowing Practices in Biofiltration Swales. Report to King County Land And Water Resources Division and others by Center for Urban Water Resources Management, Department of Civil and Environmental Engineering, University of Washington, Seattle, WA Dorman, M.E., J. Hartigan, R.F. Steg, and T. Quasebarth. 1989. Retention, Detention and Overland Flow for Pollutant Removal From Highway Stormwater Runoff. Vol. 1. FHWA/RD 89/202. Federal Highway Administration, Washington, DC. Goldberg. 1993. Dayton Avenue Swale Biofiltration Study. Seattle Engineering Department, Seattle, W A. Harper, H. 1988. Effects ofStormwater Management Systems on Groundwater Quality. Prepared for Florida Department of Environmental Regulation, Tallahassee, FL, by Environmental Research and Design, Inc., Orlando, FL. Kercher, W.C., J.C. Landon, and R. Massarelli. 1983. Grassy swales prove cost-effective for water pollution control. Public Works, 16: 53-55. Koon, J.1995. Evaluation o/Water Quality Ponds and Swales in the Issaquah/East Lake Sammamish Basins. King County Surface Water Management, Seattle, WA, and Washington • Department of Ecology, Olympia, W A. (, Metzger, M. -B., D. F. Messer, C. L. Beitia, C. M. Myers, and V. L. Kramer. 2002. The Dark Side Of Stormwater Runoff Management: Disease Vectors Associated With Structural BMPs. Stol'mwater 3(2): 24-39.0akland, P.H. 1983. An evaluation of stormwater pollutant removal 10 of 13 California Stormwater BMP Handbook January 2003 /. '{ • >( Vegetated Swale TC-30 through grassed swale treatment. In Proceedings of the International Symposium of Urban Hydrology, Hydraulics and Sediment Control, Lexington, IT. pp. 173-182. Occoquan Watershed Monitoring Laboratory. 1983. Final Report: Metropolitan Washington Urban Runoff Project. Prepared for the Metropolitan Washington Council of Governments, Washington, DC, by the Occoquan Watershed Monitoring Laboratory, Manassas, VA. Pitt, R., andJ. McLean. 1986. Toronto Area Watershed Management Strategy Study: Humber River Pilot Watershed Project. Ontario Ministry of Environment, Toronto, ON. Schueler, T. 1997. Comparative Pollutant Removal Capability of Urban BMPs: A reanalysis. Watershed Protection Techniques 2(2):379-383. Seattle Metro and Washington Department of Ecology. 1992. Biofiltration Swale Performance: Recommendations and Design Considerations. Publication No. 657. Water Pollution Control Department, Seattle, W A. Southeastern Wisconsin Regional Plap.ning Commission (SWRPC). 1991. Costs of Urban Nonpoint Source Water Pollution Control Measures. Technical report no. 31. Southeastern Wisconsin Regional Planning Commission, Waukesha, WI. U.S. EPA, 1999, Stormwater Fact Sheet: Vegetated Swales, Report # 832-F-99-oo6 http://www.epa.gov/owm/mtb/vegswale.pdf, Office of Water, Washington DC. Wang, T., D. Spyridakis, B. Mar, and R. Horner. 1981. Transport, Deposition and Control of Heavy Metals in Highway Runoff. FHWA-WA-RD-39-10. University of Washington, Department of Civil Engineering, Seattle, W A. Washington State Department of Transportation, 1995, Highway Runoff Manual, Washington State Department of Transportation, Olympia, Washington. Welborn, C., andJ:Veenhuis. 1987. Effects of Runoff Controls on the Quantity and Quality of Urban Runoffin Two Locations in Austin, TX. USGS Water Resources Investigations Report No. 87-4004. U.S. Geological Survey, Reston, VA. Yousef, Y., M. Wanielista, H. Harper, D. Pearce, and R. Tolbert. 1985. Best Management Practices: Removal of Highway Contaminants By Roadside Swales. University of Central Florida and Florida Department of Transportation, Orlando, FL. Yu, S., S. Barnes, and V. Gerde. 1993. Testing of Best Management Practicesfor Controlling Highway Runoff. FHWAjVA-93-R16. Virginia Transportation Research Council, Charlottesville, VA. Information Resources Maryland Department of the Environment (MDE). 2000. Maryland Stormwater Design Manual. www.mde.state.md.usLenvironment/wma/stormwatermanual. Accessed May 22, 2001. Reeves, E. 1994. Performance and Condition of Biofilters in the Pacific Northwest. Watershed Protection Techniques 1(3):117-119. January 2003 California Storm water BMP Handbook New Develooment and Redevelopment 11 of 13 Vegetated Swale Seattle Metro and Washington Deparfment of Ecology. 1992. Biofiltration Swale Performance. Recommendations and Design Considerations. Publication No. 657. Seattle Metro and Washington Department of Ecology, Olympia, WA. USEPA 1993. Guidance Specifying Management Measuresfor Sources of Non point Pollution in Coastal Waters. EPA-840-B-92-002. U.S. Environmental Protection Agency, Office of Water. Washington, DC. Watershed Management Institute (WMI). 1997. Operation, Maintenance, and Management of Stormwater Management Systems. Prepared for U.S. Environmental Protection Agency, Office of Water. Washington, DC, by the Watershed Management Institute, Ingleside, MD . • 12 of 13 California Stormwater BMP Handbook New Develo'Jment and Redevelooment January 2003 Vegetated Swale ·:~'~l ~I_. L Provide for scour (a) Cross scetioll of swafe wltll cheek dam. proteCtion. HotaHon: L = LtnQlh ofswale Irnpoundmont area por chock dam (ft) (b) Dlmensiona' view or swalo Impollndment am. D. .. Dopth of check clam IIIJ s, = Bottom slIM of await IftJII) W = Top wfdth ofcbock daM (II) W. = Bottom width of chKk dam ttl) Zw = Rallo of horizonlal to vertlcl' chanlle In swalt side sloP. (ftIft) January 2003 California Stormwater BMP Handbook New Development and Redevelopment TC-30 13 of 13 ( \" • \. Drain Inserts Description Drain inserts are manufactured filters or fabric placed in a drop inlet to remove sediment and debris. There are a multitude of inserts of various shapes and configurations, typically falling into one of three different groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. The fabric may be attached to a frame or the grate of the inlet holds the sock. Socks are meant for vertical (drop) inlets. Boxes are constructed of plastic or wire mesh. Typically a polypropylene "bag" is placed in the wire mesh box. The bag takes the fonn of the box. Most box products are one box; that is, the setting area and filtration through media occur in the same box. Some _ products consist of one or more trays or mesh grates. The q-ays may hold different types of media. Filtration media vary by manufacturer. Types include polypropylene, porous polymer, tJ.'el;lted cellulose, and activated carbon. California -Experience The number of installations is unknown but likely exceeds a thousand. Some users have reported that these systems require considerable maintenance to prevent plugging and bypass. Advantages • Does not require additional space as inserts as the drain inlets are already a component of the standard drainage systems. fa Easy access for inspection and maintenance. 111 As there is no standing water, there is little concern for mosquito breeding. ]I A relatively inexpensive retrofit option. Limitations Performance is likely significantly less than treatment systems that are located at the end of the drainage system such as ponds and vaults. Usually not suitable for large areas or areas with trash or leaves than can plug the insert. :Design ;and Sizing -.Guideih'l..as Refer to manufacturer's guidelines. Drain inserts come any many configurations but can be placed into three general groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. The fabric may be attached to a frame or the grate of the inlet holds the sock. Socks are meant for veliical (drop) inlets. Boxes are constructed of plastic or wire m~sh. Typkally a. pulypropyl~ne "bag" is placed in ~hc \llir~ mesh h\)x. Th8 bo.g takes the form \)f the box. }-Iost box products are MP-S2 Design Considerations -.. '-----• Use with other BMPs • Fit and Seal Capacity within Inlet Targeted Constituents ./ Sediment· ./ Nutrients ./ Trash ./ Metals Bacteria ./ Oil and Grease ./ OrganiCS Removal E«ectlvenes. See New Development and Redevelopment HandbOok·SecUon 5. _ ~ ~ • ...... __ , _ ..... L ,,_ ..... _'" ... _~. • \-' . ' . .i -0 )~ \ .. ~.. . . "', I <C .. !J:i,'olnia ..)~~;·.'1t,vat·~r ~u;Jli'2y .~.)~o~i.:l;:j.l1l1 ._-_--_'-':'-'::..-:--.~..:"-' •• ---,.--~ - -•••• ,. •• .... 4~ "-p~ .• ,-;;." '~ .......... ~~~.......o..-....=..:;-;:.:..::.:...:.;.;.:.=--.:.~::;-....o:::t j,lnlJary :21)03 C,J;JomiJ Stu!",'-, ,'/-Jter 8i'IP :'o,1CCO\JX 1 ,)r 3 i';ew O.::veiopmel1t ..l'ld R"deveiOprncllt '.wiw.G_brn~h~,ndbo')l<s_com Drain Inserts one box; that is, the setting area and filtration through media occurs in the same box. One manufacturer has a double"box. Stonnwater enters the first box where setting occurs. The stormwater flows into the second box where the filter media is located. Some products consist of one or more trays or mesh grates. The trays can hold different types of media. Filtration media vary with the manufacturer: types include polypropylene, porous polymert treated cellulose, and activated carbon. Construction/Inspection Considerations Be certain that installation is done in a manner that makes certain that the stormwater enters the unit and does not leak around the perimeter. Leakage between the frame of the insert and the framl3 of the drain inlet can easily occur with vertical (drop) inlets. Performance . Few products have performance data collected under field conditions. Siting Criteria It is recox.nmended that inserts be used only for retrofit situations or as pretreatment where other treatment BMPs presented in this section area used. Additional Design Guidelines Follow guidelines provided by individual manufacturers. Maintenance Likely require frequent maintenance, on the order of several times per year. Cost III The initial cost of individual inserts range\, from less than $100 to about $2,000. The cost of using multiple units in curb inlet drains varies with the size of the inlet. . III The low cost of inserts may tend to favor the use of these systems over other, more effective treatment BMPs. However. the low cost of each unit may be offset by the number of units that are required, more frequent maintenance, and the shorter structural life (and therefore replacement) . . References and Sources of Addutioll1al Information Hrachovec, R., and G. 1'Iinton, 2001, Field testing of a sock-type catch basin insert, Planet CPR, Seatde, VVashington Interagency Catch Basin Insert Committee, Evaluation of Commercially-Available Catch Basin Inserts for the Treatment of Stormwater Runoff from Developed Sites, 1995 Larry Walker Associates, June 1998, ND;.\lP Inlet/In-Line Control :Measure Study Report Manufacturers literature Santa Monica (CHy), Santa ;.\Ionica Bay Municipal Stormwater/Urban Runoff Project- Evaluation of Potential Catch b:lsin Retrotlts, Woodward Clyde, S,~ptember ~!4, 1998 \._--~ -," ,-~_£.:_~:.~ :'-"'::"~-.~.;:;:-~.:;'::; •. :~":;':"':'=:':'~.::=:::_-:<;;' -'--"~=c=--==:o..::-:::...='-:;.--~' =.--:;-,.:. ... _ ... ___ ._ .... _ .:_ ~::....:..:..: •. ____ ...:.,. .::.3 .2 of 3 Callfornid Stormwatdr BivlP Handbook Ja,luclry 2.j03 ~j0W 00v0iOpmcilt .](1d Red2vdopmcl1t www.cabmphandbooks.com . I ~ • ........ •• (" Drain Inserts MP-52 Woodward Clyde, June 11, 1996, Parking Lot Monitoring Report, Santa Clara Valley Nonpoint Source Pollution Control Program. Jan,.Jry :003 ..... ~ "--'..c.:~ .-. ~ ••. -,.-~ --_._.-.• --•.• CII:fCnll.:l Storml"dter 8i"IP H3f1d'Jook New D~velopment and RtldevelojJl11ent ·.I'Nw.cJbil1jJhJndboaj.,s,com ---=-.;.;., .. -_.-'-_ .• "".-:;:-= 3 .Jf 3 Attachment 10 • Catch Basin Insert Capacity Calculations • 18" x 18" Catch basin Insert Max. Area (A) = 0.31 acres C=0.85 Iavg = 0.2 inlhr Qavg = C*Iavg* A Qavg = 0.85*0.2*0.31 = 0.053 cfs The 18" x 18" catch basin insert is capable of treating up to 0.8 cfs of flow and will be adequate to treat 0.053 cfs average peak runoff. • 24" x 24" Catch basin Insert Max Area (A) = 1.07 acres C=0.85 Iavg = 0.2 in/hr Qavg = C*Iavg* A Qavg = 0.85*0.2*1.07 = 0.18 cfs The 24" x 24" catch basin insert is capable of treating up to 4.4 cfs of flow and will be adequate to treat 0.18 cfs average peak runoff. • 36" x 36" Catch basin Insert Max Area (A) = 0.91 acres C=0.85 Iavg = 0.2 in/hr Qavg = C*Iavg*A Qavg = 0.85*0.2*2.01 = 0.34 cfs The 36" x 36" catch basin insert is capable of treating up to 18.8 cfs of flow and will be adequate to treat 0.34 cfs average peak runoff. 9 I:\981022\SWMP\Lot 5\Storm Water Management Plan-revl.doc '{ t;IBi-Flow Specifications fl. Oo'CI'~riott (JpM SQUQI'It Inches Rol. oI1ilC'" OPetlRtt ~. Inchtla of Total (Cubic TOP VIEW ~~':. JHN' Unit , •• , pM Skim,"" .50.j [[iJ PI'OCHtfld ,aos SD.:J 1.8 s.r-PaA 18l 62" ,SO.l 31.2 .. 3 1 Medium Senter" 10 it 111 ,..... 56:1 do:.3· 2&~ (U ft4/nlen .t~ FirwI S~ .. ' F"lOV SCHEMATIC '4 11 5 tn ... 88& r~.tS 8,1 2." $rOl"'''''' st. STORM BIlOM THROAT FLOW 1Itli' TREATED FLOW 1iAT£ Totol:o.. cis Tota!: 5.0 ~I. OP£NINGS GRATE --f,. ~f, .. ~;;;;; ~, I: . -',4' • I( SID£ VIEW _TURBULENC£ !J£F"LECTOR .. '. I 1-11-----SKIMMER PROTECTED BVPASS . 1OOC4'-+----COARSE SCREEN 25 rif-----MEDIUM SCREEN ht'----.,-fINE SCREEN'· BOX MANUrACTURED FROM ~lARIN( GRADE FI:3EQGLASS Sc GEL COATED FOR UV PROTECTION '5 VE:AR MANUFACTURER'S \.JARRANTY PATENTED • ,~LL fIL TrR SCREENS ,~Re: STAINLESS $r~EL eRA TE iNLET S:<I .. 'IfJ,I[R 80X FOF< FLORIDA DOT ((j;J[ x INLET ST/?UCTU/?fS. Pnrt .I{ GIS8-X-18-18-78 ~~!ii!i!iiir" o " "~ , .... . " .1 e it .. : • f • • • .. . " ~ . ... • • • J. ' .. • ,4 ", .. . .. . . ;. . I '" ' • •• .,. '-:1: ___ ----"". • .. 4 •• " • '! I CONCRETE STRUCTUREI R€)iQVE, GRATE INSERT GISB ;~(INSTAI..L GRATE ::k) C/a1.311 :-:""":"/"!"'7Ic:J"!,;-':'1 ,C::l .... :.~~ , • !..Ii 'fJI vlill, 'w~ HCiI .:J", ~'{";;"J .i.;'1(., ?O Box ai,9 '''f''':''J~::l''''a r·t ,':1)11,,('9 t-..... ...,':..1 '-'fU .... ' ......... "1 ::I_v .l- Ph," (760) tI.J.J~7(;iO C''''.,. ('7t.:"1'H "?'3.,~17(: ... _. __ , • .".VI vv .... " &.,,~ !ttl 003 f .• '! r \ ~24" Flow Specifications 1 __ TQf VIEW .. , .... ~"': 24- F'LD\t SCHEMATIC ...----STORM BOOM . . Oescflplr-or) . ~, oIl,'If .. apM cpellint :E";' Slclmrn.,. PlCtwrcknl ~PoQ 'QO~ S2~ ~ SCI"IHt'I I' JI tlJ m.Ia $~oItI/"" .t'" Sf:r nn. $et'HfI 14 •• meIIt 6U sf"r,.,.. .'fIIII 'THROAT no'll RATC TotCII:4.4 c& . ... , GRATE --1-..... . '. TURBULENCE " "----1-4--1--DEnECTOR SID~ VlfW FIori S4~ IJtdtd Rol. Inchu of Tot. {Cubic pe.-Clnil rNI pM" '62.3 l61.J 6.7 t4.J.S 89.0 4.J 743.5 80.4 ".J IS .. , 106.1 U TRrA1ED FI.o'I( RATE Toto/: 2'" t:1 • I ~_ SJ<lMM£R PROTECTED '-_--" BYPASS ~mm'f-COARSe: SCREEN 25'~ Ht--MEDIUM SCREEN tt---... F" (Nt SCREEN BOX MANUFACTURED PROM MARINE GRADE fIB(RGLASS ~ GEL COATED FOR UV PRQTrCTION 5 YEAR MANUFACTURER'S VARRANTY PATENTED .. £ND VI£W :-iOUNT TO V,i\LL 3ELOV Ci~A n: '.lITH MOUNTI~IG KIT CONSISTING OF' .a.LUMINU:.t ANGLES. TAPCONS. ,~ND DRILL SiTS .LL fILTER SCREENS ARE STAINLESS STEEL Ii.!' MOUNTING KIT SOLD SEPl\RI6. TEL Y J '\ CRATE ,'NLfT SK/ft.JilvlER BOX FeR FI081DA DOT TYPE I ;NLET srRUCTUi~ES. ---.--------.-~ -. - PQt"t l GISB-I-24-24-25 '. 'lJJ l')i;rr~~~;i,c,J"4 .;;.'~ .:~ .;n.;;,.:::1o u~ lol~K' ,npt<:d. ·Scaltl~ Page Title Page lof2 Storm Boom Hj~dr(Jeal'hnn Ah.ftorhtinn Bnom.~ Designed For Stol'"mwater Applications Absorbs Hydrocarbons On Contact The Storm Boom has been specifically designee for stormwater applications to remOVt hydrocarbons. The outside covering will no clog with sediment, allowing indefinitt stormwater penetration, all the way to the cente of the boom. The absorbent filler is Absorben W, and is made from reclaimed paper mill by products. It is certified by Green Cross as 100'1. recycled material. Absorbed liquid is drawn inte the cellulose fibers through capillary action ane locked into the boom. This process prevent leaching and draining which is a commol problem with polypropylene booms. AllfJ§ ol!4l;emrlt W F f!lJcfls: ®Absorbs 2-3 times more" volume than polypropylene @Absorbs up 10 14 times more volume than clay ®Absorbs immediately on contact @Absorbs and retains up to 7 tilnes its weight G?Retains absorbed hydrocarbons; prevents leaching elf is hydrophobic • will not absorb water @ Works in all temperatures, sub-freezing to hot ® 100% organic .. environmentally friendly o It is not toxic to hUI)Jans or the environlnent @It will biodegrade naturally if lost in the environment @No dangerous fumes when burned Q)incinerate at low temperature with less than 1% ash ~.J ade FrOIl ?" tJ Gl'~:~ -~ Recycle,! ,Hate1'ial '.' -.... "-.,,._ ....... --.." .. -.. ........ ~----J6"------'~ Flow Specifications Desc'/t"fiotl SqUGtc 01 ,,~ Ope,. Squanr Incha Rot, opening ...... ItICh_ Df 10tol (C~ 5b.-,.., unit rMf IW ....... SlIlmmtW 36" /HOttlef. ~~. 100" .18f.5 JlJ.5 1.14 6211 2JI.D 74.l2 6.2 MetJlurrt s~ ,Q. ,D"... 56% stoin/... sf • ., ZJ1.D '21,S 6.4 Fin. $ ___ 14 /I " man 681f 2~.S '92..' 10.8 lito,",.. :I"" THROAT FLOW RATE Tolol: ~tl.t1 tl. TREATm FLOYI ~TF Totol: JII.' cr. T 25" GRATE $IDE VIEW ~J--SKiMMER PROTECTED __ -' .... __ :BVPASS ~!XI-t-II--COARSE SCREEN t-/Io-MEDTUM SCREEN 1-11--...... FINE SCREEN SOX MANUFACTURED FROM (-1ARINE GRADE FIBERGLASS & GEL COATED FOR UV PROTECTION '5 YEAR MANUFACTURER'S WARR.~NTY P/~ TENTED .•. ';LL F'IL TER SCREENS ARE ST.~INLESS STEEL \ {;I~~ r£ INLET S/(J:lJ/,I}/£/1 30X FOFl .. • ' . • .a. , .. ..... .. . ' . .. . '. .-~ , : oj I FLORIDA DOT iNLET STRUCrUf?ES. 1 1'"--------~-----~ ::lJI·DJ;t.~ .. /::..'t:;;£] .:.,,i.:; lu:c1£!d:l. ... d"J"d0J8 O",,,f -/1 r:(~,q-3n-35-25 UW':i;~1I o'h"Itiid. 4,. .. ,.. •••• ,. END VIEW .. STRUCTURE f~Ei'lOVt: l~~A H: INSERT GISS Rt:INST ALL GRATE 3/0 'C'.'i~all .:3'n,?if"JIJ;j7-3J7tal5eIYic$, ./l}c. .~O .::J""ox a"l6fJ DC::::'1(J$k:'/~, c·~ :':J2CtJ9 ,:;11'7: (J'SfJ) ",l.33-/!~40 ~':!I". 17nnJ 4""'1 ... 11;'." .. . . . • 4 • I . .. • . 4 ..... , . . . it • • '( ( " B: '1-0' /'~L?"E:" A", :~I " , c'·,··~ .... 1'~ _. I " :{ • iii -4~ ENVIRONMENTAL SERVICES, INC. Grate Inlet Skimmer Box Curb Inlet Basket Nutrient Separating Baffle Box REPORTS" DATA PoDutant Loading Analysis for Storm water Retrofitting in Melbourne Beach, Florida Ponutant Removal Testing tor A Suntree Technologies Grate Inlet Skimmer Box Site Evaluation of Suntree Teebnologies, Inc. Grate Inlet Skimmer Boxes for Debris, Sediment And on .& Grease , Removal ~ '." , '; ,'" ", , ': "'j",:}1 ,':~ "",""',i '1)1 '!: '\J"," "\ 1 ,r ~ 'j''\. ."j <"~ i '" " , .-':> , ',: '., " ' ._,' ," c=g'iJ' ',j':.:~~'.r'-'i.l",a~j j:l M .. l~ ...:) L .• ·.!), :J 'J!,,;. ;~ •• )} I.!'"J \,3>~ ; /iI, "('<:."1 :'l',~ ""''''11\'''~:l-'~1''' ~! -"1',\ ',,:\ '>i/ :..;:"iI~"" :';,(').':J, 1:.;I~~~~ ... -,J·,j)~:t..U:f ~ ... ::" 'J),~~L .. j~;;' (j (i).0) :}<~:J .. l,~~.11 .. :: ... \.i{ fj.~,j)) .~::l 2,,;:3 j'13 --. (( Pollutant Loading Analysis For Stormwater Retrofitting in Melbourne Beach, i Florida • '( IntrodudioD By: Gordon England, P .E. Creech Engineers, Inc. 4450 W. Eau Gallie Blvd, #232 Melbourne, FL 32932 At Gemini Elementary School in Melbourne Bea~h:, Florida, there has been a history of repeated flooding on the school grounds and .in. properties adjacent to the schooL In 1999 Creech Engineers, Inc. (CEI) was chosen by Brevard County Storm water Utility to design drainage improvements to alleviate these flooding conditions, as wen as to provide ror stormwater treatment within this 20.06 hectare drainage basin. The project was divided into two phases. Phase 1 improvements were made in order to accelerate initial flood control measures for homes downstream olthe schooL Phase 2' involved the design of more extensive flood and water quality control measures along Oak Street ror further protection of school property and roa4way flooding at nearby church property. This paper highlights the political challenges of retrofitting storm water systems in developed areas. as well. as demonstrates a methodology for performing a nonpoint source ponutant loading analysis. Existing Conditions Gemini Elementary School is located on a 8.02 hectare, triangular shaped property along the south side of Oak Street, a two lane collector road in Melbourne Beach, about one half mile from the Atlantic Ocean. See Exhibit 1. Residential properties lie downstream of the school, along its southeast and southwest borders. 8.51 hectare Do~g Flutie Park is on the north side of Oak Street. A SOC~ club uses the park and school grounds on a daily basis. There was no stonnwater system at the park, along Oak Stree~ or on the school site. Stormwater flowed southward off Doug Flutie Park, across Oak Street, through the school site, and into the yards and homes south of the schooL These yards, .and the roads downstream of them, are very flat and only a few ~t above sea level Once water stages high enough in the yard~ it gradually sheetflows down the adjacent l"Oads a few hundred yards to the Indian River. . The affected homeowners naturally hJatllOO the school for allowing the schoors water to flood them. Vvest of the schoo~ a few hundred yards along Oak Street, was a low point. in the roaq where water ponded and flooded the road and all adjacent churchyard. Due to a thin clay :ens at 26 em deep causing a perched water table, water stood ill ihe road for several days ft . I . ~ 1\ 'rho rl' ,. 1 l' , '1 • h .;a er even a norruna rarnl<:lU. 1 l IS ,J1'amage casm was 31.l'nOst ':Oi'flp~eteIY ,:;UI.!.t out, Nit 110 easy path tor develop~g outtails to relieve tloodillg. ,-. (, --/ • This section of the Indian River,. is a Class 2 water body, with a Shellfish Harvesting classification bringing-intense scrutiny from the St. Johns River Water Management District. Corp of Engineers permitting is required for new outfiUls in the area due to seagrasses near the shoreline. - The park, the school, and Oak Street lie in unincorporated Brevard County. The church, and properties west of the school are in Melbourne Beach. Being a collector road, all of the utility companies have major transmission lines in the road right-of-way. As c~ be seen, this challenging project involved Brevard County, Melbourne Beach, the School Board, Brevard County Parks and Recreation Department, Brevard County Road and Bridge Department, Brevard County Stormwater Utility, a church, three different Homeowners Associations. a soccer club, tho Water Management District, the Corp of Engineers. and several utility companieS. Stakeholder involvement and partnerships were going to be critical to weave a solution through the many players involved. Proposed ImprovemeDts The first priority was to alleviate flooding in: the homes adjacent to the school. As an interim measure, a berm was designed and constructed by County personnel along the south property ~es of the schoo], with a swalo behind the berm directing water to the southernmost point of the school property. At that location, an inlet and 1 SIt outfilll pipe were constructed in a utility easement through two heavily landscaped and fenced yards, to Pompano Street, where it was tied into an existing storm drain pipe. A short time later, heavy rains overflowed the benna and swales and flooded homes adjacent to the school again. eEl was engaged at that point to provide more effective drainage improvements. Fortunately, Gemini Elementary School had a significant area of vacant land on their site. The school entered into agreements with Brevard CoWlty allowing the construction of three dry retention ponds totaling 2.95 hectare to reduce flows leaving the school site, as wen as provide stOm1water treatment where none existed. These dry ponds were wound around several soccer and baseball fields. The soccer field's lccatiom had to remain in place due to previous agreements with the school and Parks and Recreation Dept. The ponds were only 26-40 em (12"-18'') deep and sodded, allowing the soccer teams to use -u'1e pond areas as practice fields when dry. 'l,JV'llen the ponds were .excavated, the confining clay layer was removed to allow for infiltration though the heach sand at the site. Construction was scheduled during the summer when school was out. A control structure was designed at the outmll pipe location to provide protection for a 25 year storm. The temporary connection to the existing downstream pipe had overloaded tl:e dOWTi.St1eam system in a ::eaV'-j 1'l1"l .event. :30 a 11i;W outfull to the I:c.dhn Rj·!.~r 'Nas designed. through a :?ark :ldjacent to the River. The park was owned by a Homeowners .I J 1 ( ((-. • Association, which reluctantly gave a drainage easement through the park. The County agreed to make several improvements to the park and its boat ramp in exchange for the easement. The Corp of Engineers was concerned that the new outfall pipe discharges would impact the nearby seagrasses, so the new discharge pipe was not permitted to be constructed in the Indian River. A bubbleup box was designed ten feet back from the shoreline and rock rlprap was placed between the bubbleup box and the mean high water line to prevent erosion. As mitigation for disturbing the shoreline, spartina and other plants were planted among the rocks to further buffer the shoreline iom the stormwater discharges. This first phase of improvements was finished in September 2000 at a cost of $124,000. The improvements implemented proved successful in preventing any flooding of adjacent homes in several large rainfalls in 2001. The second phase of the project addressed storm water quantity and quality concerns along 1650 meters of Oak Street, from AlA to Cheny Street. To provide further flood protection at Gemini Elementary Schoo), retention swales were designed along both sides of Oak Street and 625 meters of storm drain pipe was designed to intercept runoff and prevent it from crossing the road onto school property. The piping also provided an outfaU for the low spot in the road by the church. This new pipe syste~ discharged into a residential canal system, which was used by many of the adjacent residents for boating to the Indian River Lagoon (Bay). These canals were very politically sensitive· since they were in need, of dredging and the Town of Melboume Beach does not ·dIedge canals. The residents were concerned that the new stormwater system would lead to further sedimentation oftbe canals. The. first· alternative for treatment was to use land at the church site fur a pond for the road ~ff. The church was willing to donate the land where their septic tank fields were located if the County would provide a sewer connection. This scenario was designed, but when it came time for the church to give easements to the County, they balked and it W8$ back to the drawing board.· . St. Johns River Water Management District, (District), criteria requires stonnwater treatment for improvements which a) increase discharge rates b) which increase pollutant loadings, or c) whlch increase impervious areas. With this project, no new increased impervious areas were propose~ but there would be additional water flowing to the residential canal from the extension of the pipe system to the flood prone areas. These ;:ew :flows create the potential for incr~"'<i pollutant loadings to the crurnal. Normal design methods would have used treatment ponds to offset these potential impacts. Due to lack of available land for ponds, ~<>rmtive treatment methods w~e pro~sed for t~.is project. The District will consider alternative treatn"~nt methods if it can be demonstrated that all other possible alternatives have been exhausted. It would not be possible politically to use .1l.ore school or park: area for tr,eatD1.ent ponds. Por ·.:r.ds project, eEl showed tb.at tr.£: only alternatives "Nere 10 tear dm.vn houses for ~{)nds, or llse :l1~en1i.lte t~-eatment t~c:ll!ulog~es. 3 I J ~". '. ( The treatment strategy involved maximizing treatment methods within the project basin with alternative B:MPs, as well as retrofitting two adjacent watersheds as additional mitigation. A total of 1.67 acre feet of retention storage was ptovided in Phase 2 in the roadside swales and small ponds. This was equivalent to 0.032 inches of retention from the drainage areas flowing to the retention areas. . A treatment train along Oak Street was designed by using 9 Orated Inlet Skimmer Boxes, from Suntree Technologies, Inc., in the new inlets to trap debris entering the inlets, constructing berms to slow runoff from the ball fields, and instaUing one baffle box at the downstream end of the new pipe system along Oak Street. Baftle Boxes are in-lin~ stonnwater treatment devices which trap sediment, trash, and debris. They have been used by Brevard County successfblly for the last 9 years. In otrsite Basin 4, which only had one existing baffle box to provide sediment removal, 16 Curb Inlet Skimmer Boxes were installed in all of the existing inlets to provide nutrient removal by trapping grass clippings, 1eav~ and yard debris. Nutrients were a concern in the canals since the nutrients promote algae blooms, which in tum increase muck build up in the canals. In offsite drainage Basin S, there are 3 existing pipes which discharge directly to the canals. Three baffle boJr;es and 6 curb inlet skimmer boxes were designed to provide se4iment and nutrient treatment for this drainage basin. Brevard County Stonnwater Utility will implement this project and be responsible for aU maintenance of the improvements. The baffle boxes will be inspected twice a year and cleaned as needed. The inlet traps will be cleaned .twice Ii year. Brevard County has a vacuum truck dedicated to cleaning stonnwater BMPs. . ' Using numetoua BMPs used on this project provided a high degree af treatment for the new piping system along Oak Street, and P1'9vided treatment for two affsite basins where little treatment existed. The retrofitting of the offsite areas was, in effect, mitigation for the new discharges to the canaL See Exhibit 1 for a map oithe improvements. Calcu lations In Phase 1 of the projec~ the dry ponds and outmIl pipes were modeled hydraulically using the Intercomected Pond Routing program. Since the dry ponds in the Phase 2 project area were too small to provide effective attenuation, tIte predevelopment and post development Iilnoff calculations were made using Hydraflow and the rational method. The only available storm drain pipe for Phase 2 was a 36" pipe m. offsite Basin 4. T':ae new piping along Oak Street was cmmected to the existing 36" pipe, and the piping downstream of the connection was upgraded to a 42" pipe. The pipes were designed for a 25 year storm. Basins 1~2, and 3 were a much longer distance from the outfall than Basin 4. As a result of different times of concentration, the peak. flows from Basin 4 passed sooner than Basins 1,2, and 3, giving only a slight increase in peak discharge, . cespite adding 12.25 hectares to the area flowing to the existing outfall. . l J ] ( • residents did not want to increase the frequency of costly dredging. The main pollutants of concem leading to muck deposition in the canals were Total Suspended Solids (TSS), Total Nitrogen (TN)~ and Total Phosphorus (TP). Sediment build up at the end of the pipes was common. Nutrient loadings ftom grass clippings, leaves, and fertilizers leads to algae blooms and low dissolved oxygen in the canals, which in tum leads to muck build up :from the eutrophication process. Most of the material dredged ftom residential canals is typically muck. To address this co~em, a pollutant loading analysis of the existing and proposed stormwater discharges was performed. In the existing conditions, the only storm water treatment for the canal system was a baftle box along Cherry Street for offsite Basin 4 of 24.24 hectares. There were a total of7 outfall pipes discharging into the canal system. In the first phase of this project stormwater treatment was provided for 3.02 hectares of the school grounds with 3 dry detention ponds. The discharge from these ponds was to the Indian River, rather than the canal system, so these pollutant loads were not included in the ponutant load analysis for the canal outfall. The existing ponutant load to the canal only came from the" drainage Basins 4 and 5, totaling 31.2 hectares. The runoff ftom Oak Street did not drain to the canal in existing conditions, only in the post development conditions. The strategy for tho ponutant ana1ysis Was to calculate the poRutant loads in the existing conditions, and then calculate the ponutaht loads after the new pipes were added to the system and offsite areas retrofitted for .stormwater treatment. The pollutants used in this analysis were TSS, TP, and IN. Each drainage basin was categorized by land use. Areal, annual, mass loading rates from OIStormwater Loading Rate Parameters for Central and South Florida", Harper, 1994, were multiplied by each basin's area to give existing and pctential annual pollutant loadings. See Table 1. . The next step was to calculate the pollutant removal :rates for the different BMPs. Individual BMP removal efficiencies were take from "A Guide for BMP Selection in Urban Developed Areas", EWRI, 2000. What was challenging with this analysis 'VITaS the use of multiple BMPs in series for the treatment train. Each BMP receives cleaner :and cleaner water as the water rooves down the train.. At each BMP, the removal efficiency :for each constituent 'N3S multiplied by the remaining :percentage of the mitial loading to give .a weighted, cumulative, removal efficlency ior ·cach constituent. See Table 2. These calculated removal efficiencies were then multiplied by "ihe total calculat~d polluta:nt toads to give the reduced pollutant loadings after the BMPs were installed. See Table 3. Table 4 shows that the total loads to the canal were reduced as a result of the ~'ctrofittirlg of onsite fuid 0 ifsite basins . "'f:~~e fol1t.tant :oadh1g anal-ysis Ge!o~J» .:!.ei'.uO:L!3ti:s.~.as g1at S!s a r.eswIt OJ! (::~ Jj.Ll1:~rOl':;S 3r/!l1g )ioposed, the total :Jollutant loadings '~i1t~ring the canals after project ~ompletfon wiH 5 l... • ( actually be significantly reduced from the existing pollutant loadings entering the canals. The key to overall pollutant reduction is to provide additional treatment in offsite drainage basins. This win result in a net benefit of reduced pollutants entering the canals and a reduction of the severe flooding often seen along Oak Street. Table 1 Existing Pollutant Loading Loading Rate* Potential Pollutant Loading Total, ~ From "Stormwater Loading Rata ?arameters for Central and South Florida" 1 SQ4. Harper ** aaain 4 has :3n .axisting ba't1!e box providing tr.eatment. I 3asins 4 and 5 :are thIS existing poUutant loadings to the caoa\$ . 6 (i'· (, 1 J •• ( Table 1 BMP Pollutant Removals aMP POLLUTANT REMOVAL TABLE- aMP 8MP Removal Efftclenc~ TYIM .(%) TS8 TP TN iDrvPond 85 61 91 ~e 80 45 25 BameBox 80 30 0 nlet Trao (grated) 73*" 79fr11 . 79** Inlet Trap (curb) 2**" 11*" 10- lSwaIe + Inlet T~ (a) + Baffle Box 98.9 91.9 84.2 brY Pond + ln1etTrap (g) + Bame Box 99.2 94.3 98.1 nlet.Trap (~SaftIe Box 84 31.7 10 olet TrapJQ)t Same Box 81.1 85.3 79 Multip'e 8MP Pollutant Removal Calculation. SWart + Inlet Trap (9) + Baffle Box , TSS -100xO.8 + (10Q..80)x0.73 + (100-80-14.6)xO.8 = 98.9% Removal TP -100xO.45 + (1f»..45}x.79 +i. (1~45) ::II 91.9% Removal TN -100x.25 + {1QO..25)x.79 = 84.2% Removal ~IY Pond + Inlet Trap (g) + Baffle Box TSS -100x0.85+ (1QO.85)xO.7S + (100-85-10.95)xO.8::11 99.2% RemOIai TP -100x0.61 + (1()()..61)xO.79 + (100-61-30.8)x.3 = 94.3% Removal TN -100x.91 + (100-91)x.79 = 98.1% Removal aiel Trap (e) + Baffle Sox TSS -100-xO.2 + (100-20»(0.8 = 84% Removal TP-100xO.11 + (100-11)x.3= 37.7% Removal TN -100x.10 = 10% Removal ·aliU~rat T~p (g) + :83\118 iBox TSS -100xO.73 + (1()()"73)xO.30 = 31.1 % ltaklUOVall TP -100xO.79 + (100-79)x0.3 = 35.3% ~~llinov:Q1 TN -100x.79 = 1S% Rl9moval " . -. All iemoval values a;e from Gusde for Best Managerr.ent Practice ** From Creech Engir.eers $iudy "Pollutant Remova T ~ii1g For a Suntree T acnnologies Grate 1.11et Skimmer 8ox", 2001 ''''Jr'''From visual obselVation by 8revard County staff T~:;'~e 3 ?d·o~Q(isced ponut:a!llt LO:2ldi:ilg 7 ;' •• ( BMPRemovai emcfencJ Pollutant Load Proposed Polll.dant Sasin BMP From New BMPs Reduction Type (-At, From SMPs(kglyear) Loading (kglyear) . ,.. TP TN 188 TP TN rss TP TN 2A swale + inlet IraD tA) + baftle box 98.9 91.9 84.2 69.38 0.39 8.32 0.77 0.03 1.56 2B swalCtt-lnl. \rap (g)+ baffte box 98.9 91.9 84.2 8.64 0.0& 1.04-0.10 0.00 0.19 20 dry QoncI + iNet trao (Q) + baffle booc 9Q.2 9U 98.1 5.81 0.03 0.81 0.05 0.00 0.02 2D dIv DCIRCI + inlet fraD (g) + bama box 99.2 94.3 98.1 10.93 0.08 1.52 0.09 0.00 0.03 2E dIy PGRd + Inlet trap (g)+ bafHe bale 99.2 94.3 98.1 19.83 0.11 2.78 . 0.18 .0.01 . 0.05 2F swakt + inllt no Cal + baft1e bole 98.0 91.9 &4.2 14.81 0.08 1.71 0.18 0.01 • 0.33 2G + inlet fraD (a) + bailie box 99.2 94.3 S8.1 5.85 O.OS 0.79 0.05 0.00 0.02 . 2K .. + Inlet tn» (g) + baffle box 9Il2 Sol3 98.1 9.13 0.08 1.35 0.08 .0.00 0.03 21 $Wale + inlet 1raD Cal + baffle box 9&.9 91.9 84.2 0.60 0.00 0.07 0.01 0.00 0.01 2J inlet trapJgt + bailie bot 81.t 55.3 79 4.9$ 0.03 0.68 1.15 0.01 0.18 2K inlet Irap{m. + baftle bole St.1 85..3 79 3.51 om 0.41 0.82 0.00 0.13 2L Inlet trap. em + bailie bale 81.1 85..3 79 2.1Q 0.01 0.29 0.49 0.00 0.08 3A inlet Irap(g)+ baIII.box 81.1 85.3 79 99.84 1.11 8.10 23..22 0.19 2.15 38 inIal 1raP (g) + bailie box 81.1 85..3 79 137.40 1.53 11.17 32.02 0.28 2.97 3C . \II Y """ .... inlet tnG (a) + baII1e bale 99.2 94.3 98.1 1387.83 2.48 2M3 11.03 0.15 0.40 4 inlet IraD 10)+ baftte box 81.1 85.3 79 544.911 21.25 221.48 127.01 3.68 58.81 SA Inlet !r&D (c) + baffle box 84 'S1 10 278.05 1.30 2.78 52.98 2.21 24.85 58 inlet lrSP ((:} ... baffta box 84 $I 10 4ClB.2t 1.8t 4.03 n,37 3.23 36.31. , 50 inlet traD (el'" bafle box 84 "S1 10 126.29 ·0.58 1.25 24.08 1.00 11.29 Total 230S.'17 27.M 281.03 197.11 4.34 67.01 Table 4 Net Pollutant :Removals TSS (kgIyr) TP (kglyr) 'l'N(kg/yr) Predevelopment 3015.78 35.13 380.83 Postdevelo])ment 630.97 21.95 289.15 Net Reduction 2384.81 (79%) 13.18 (37.52%) 91.68 (24.07%) Th~ cays of 30hiii.g flooding problems ill -communities with simple ditch 3..t1.d pipe solutions ~1ave Jisapp~a.t·ed. :2.1wirorlinenlal COi'lCernS :;,ow d:ct~r~.:: t.Jat ::LOlTi1\V;t~l' ; ... .:;st.-:r.ent 'tcdmIques ce 1irt;:~~i'1t~(i i_t1£o i:b.ese l1o-od .elief }i"ojects. By .1dding ',vst;:;!' I :1 '1 quality components to water q~tity projects, communities can help achieve pollution remediation goals being established for NPDES, T:MDL, and PLRG programs. Retrofitting' existing st~rmwater systems to providc water quality treatment is more complicated, expensivc, and time consuming than traditional stormwater designs for new development. The scarcity of available land and numerous existing utilities in older built out areas will tax an engineer's imagination to provide innovative BMPs in these locations. An carefully planned treatment train was designed consisting of swales, ponds, beims, baftle boxes, and inlet traps ~ provide overall storm water pollution reduction. In order to address storm water pollution concerns. treatment mitigation was designed in otisite drainage basins. The pollutant loadings and removals were calculated using a simple but etfective spreadsheet analysis incorporating the latest in BMP efficiency studies. While complicated storm water modeling software can be used fot pollutant anSlysis. this type of modeling is more cost effective on large basin studies than small basins and indhidual projects. The pollutant removal calculations showed an annual net reduction of 19% for TSS, 37% fOE Total PhospbonlS, and 24% for Total Nitrogen in the . Oak Street basin despite the creation of a new stonndrain system for a landlocked area. As this project demonstrates, there are typically numerous stakeholders that need to be brought into the project early in the process and kept in ~ process throughout the life of the project. Many meetings were held with city, county~ and state officials,homeownets associations, s~hools, soccer clubs, churches, and utility compani~ AD it takes is one uncooperative stakeholder to set back or. kill a project, as was demonstrated with the church backing out of the land acquisjtion process after many verbal indications of approval Using creative partnerships with other entities and agencies allowed the development of a unique strategy to solve flooding at several locations in the project area. References AseE -"Guide For Best Management Practice Selection in Urban Developed Areas"~ 2001 GOi'don England, P.E. "Pollutant Removal Testing For a Suntree T~chnologies Grate Inlet Skimmer Boxft , 2001 Harvey Harper, Ph. D, P .E., ",Stormwat~r L03ding Rate Parameie(s fOf C.ak1tral :and South Floridan. 1994 9 ( ( (. , I :;'! , ! i ! :.',1 , -{ \ POLLUTANT REMOVAL TESTING FOR A SUNTREE TECHNOLOGIES' GRATE~ETS~RBOX ,~L ~, , , Prepared for Suntree Technologies, Inc. ' November 2001 eEl Project #21121.00 Prepared By: \ .. • '( Background Methodology Results TABLE OF CONTENT§ Table 1 -Sediment Sieve Analysis Conclusions AFPENDIXA )to Sitt Photos APPENDIXB PAGE 1 2 2 3 3 )-Universal Engineering Sciences Grate Inlet Skimmer Sox Svaluatlon Report ( (' ...... Pollutant Removal Testing for a Suntree Technologies Grate Inlet Skimmer Box by , Creech Engineers, Inc. November 1001 With special tltallks to Joanie Relaa of the Cocoa Beaell Stormwater UtiHty Background: Over' the last several years, a number of BMPs have been developed to provido stormwater treatment by trapping ponutants and debris iD. inlets. Inlet trap BMPs are quasi source controls, being iDcxpensive, requirina DO roadway construction or utility Ie1ocation, and keeping pollutants out of the water bodies, rather tII8Il1ryiDg to telmW the po1lutants ftom tho Water OD£O it is contaminated. SUDtree Teclmolo~ of Capo Canaveral. Florida cornrnissKnJed Creech Bngineers. Inc. and Universal Engirwring to pedbrm. testmg on a Grate Inlet Skimmer Box (018B) to deternJinD its pollutant mnoval eB.ectiveness ror sediment and grass clippings. ,Tho testing was per1brmed on September 26, 2001. Attached are photographs ftom. tho test aDd the accompanying report by . Univ~ Engineering Sciences. The GISB is designed to trap sediment, grass. leaves, organic debris, fIo~ trash, and hydrocarboris as tIIey enter a grated inlet, thereby preventing tbeso pollutants from entering tho stormdrain system where they would. cause detrimental impacts· on downstream waterbodies. 1.be GISB is a 3/1~ thick fiberglass device custom made to fit most types of grated inlets. Tho overflow capacity of the GISB is designed to bo greater than the cUrb grate capacity, thereby insurina that there will be lllO loss of hyc:b.u1ic capacity duo to the device being inside the inlet. Tho bottom of the GIsa is designed to be above any pipes entering or leaving the inlet so that flow through the mIet is not blocked. Water flowing through &, grate first encounters a hydrocarbon absorbing cellUlose. Tillis boom aIso serves to trap !arge debris between the boom.alWl the body afthe OISB. At the bottom of tho tIap arc a series of stainless steel :BIter ~ covering 3.S ':inch wide cutouts in the fiberglass body. These screens trap debris 'While a1lowmg wuer to paSs 'i:m:ough the oottom of the body and out to tho stOrol dl'ain S)"Stem. The sct.eens in the floor and first vertical row of the GISB are fine mesh. T'.ae S~OM va-tical i"OW' of st"ieeriS are medium iMsh and the highest row are coarse mesh. On the outside of the cutouts the screens are backed by stainless diamond plate to provide sum:-ort to the scteeJlS since ceavy loads of debris build up in t};e box. If the flow l'ate throu.gh tl1e inlet ,exceeds the. i~apacity of '!he filter SC'ree11S there is another 't."OW of {jv~:8.ow bJ!~ cut out ?lith r.D screens. l1i.ese overflow holes allow water to 'pass through the GISB even if it eecon.."es " U .... .3.,.. ,.~~ 1 1 of":t... .. 1 .., .1 ~ .. ~ ''t.-.. '1 ~. 't ..., .. 1J OI <,;~u;.1S. J..::.e .fJV.,; v w.~ ,4·0 . ..es ~ soov.e L.:e ~'~mm O{ w.e 'W? 'C:5.y, ~ .. : .. ~t).21:g ,2e ·l: .... ay ~o ·~t ~ a :31ci .... m:er to :;~·~V~iilt lo::.ili:t1tJ i::i'("sb 1-.cm ':;S'C3..tl1n2 ·~tlL',:r1l"1h ';h~ \Y!{;rt!oW' no~.es. ... .., .so..,'.., 1 I. (, About haliWay down the box is a diffilser plate to minimize resuspension of trapped- sediment. Inlet traps such as these are generally designed to capture hydrocarbons, sediment, and floating debris. There is generally a large build up of grass, leaves, and yard debris in the GISBs; which represent a source of nutrients, which do not enter the waterbodies. Royal and England, 1999, determined that leaves and grass leach most of their nutrients into the water within 24-72 bours after being submerged ill water. GlSBs are designed to keep captured debris in' a dty state, otfthe bottom of the inlet, thus preventing phosphates - and nitrates from leaching into the stormdraio. system. ~ much more expensive BMPs would be required to remove the dissolved nutrients. Methodolol)': A test was designed to simulate a rain&Il event and measure the ability of a GISB to remove sediment and grass leaves Rom a typical grated inlet at 600 South Brevard Avr:., Cocoa Beacb, Florida. Joanie Regan of the Cocoa Beach Stonnwater Utility proVided ~ location fbr the test, as weD as a water truck to flush the curbs. Universal Engineerina Sciences perfurmed the testing, measurements, and sediment sampling. Creech Engineering, Inc. observed tho testing. Tho City has installed a number of these devices and Joanie indicated this location was . typical of a no~ installation. The grate, curb, and sutter around and upstream of the inlet were brushed and washed clean. A Dew, clean GISB was placed imido the inlet. A water truck with a pump discharged reuse watec into the gutter upstream of tho inlet at a xate of 500 gpm (1.1 c&). DIy, green St. AusustiM grass ctippings ftom a yard th$ bad been recently :ferti1ized were slowly ted into the guttel" and flusbed into tho inlet. _ It vias observed that the cast iron grate trapped a sigoi:JiCaDt amount of grass 3I.'OUDd tho <edges of the grate. . The grato was removed fur an tests to enable aU oftbe grass an4 sediment to . ",nter the box. After all of a measured sampJc of grass had beenwashcd into the inlet, the grass was removed from the inlet, dried, and weighed. Samples of grass befbre and after tho test were sent to PC&B Laboratories in Oviedo, Florida. Laboratory analysis was performed to determino tho Total Phosphorus and TKN content of the grass. Next, a sediment sample was washed through tbe GISB using tho same methodology. Universal Engineering ~"3D. a sieve size am1ysis, using ASnA D 422 p:rocedw;-e8, before and der the test. 1'he sediment was classified sa a poorly graded ;gra.vdy sand. The sediment was removed from the GISB, drl~ and weighed. During hoth of t]:-e t~sts, ill 'Water 1eaving the GISB ~ -furougb fue illter scr.eens. The water !evels in the oox only rose a rew inches, with no w.tter ~~:iJllg' 'through -i:he o"lerlJow holes or ,':oar:se scrael1St ·even thougll the bottom s.~!::ns 1lF~l"a co:repletely 4)o'Veroo 'with grass or ~~ent. T'~re "JI'>l-S a srn.all .m.f.lunt of grass :~'ii:d ~e(Hil";~l1t ~~at ~,J' -' .. ". -d'" t ." .'" .• , -' -~ " l?:ass~ C<;:l.ween u:e COX..iJ. l.J.a .,;onCl~ e \·,allS or fu"'e m!-et ;;~cama or ii:..a -tU:.;;ven .;'crges vI (e I I ': ( I ie \ the inlet. This situation is fairly common in most inlets due to loose tolerances in construction techniques. In the grass test, 6.58 Ibs. of grass were .washed into tho inlet and S.22 lbs. were captured, resulting in 1.36 Ibs. of grass passing through the GISB. This represents a removal efficiency of79.3%. The pretest grass sample bad a Total Phosphorus content of' 950 mg/kg and a TI<N content of510 mglkg. The grass samplo removed from the GISB had a Total Phosphorus content of2,270 mglkg and TKN content 01905 mglkg. The sediment test was a little more complex. The initial results showed that of the 57.87 lbs. of sediment introduood to the GISB, 42.41 lbs. were captured, giving a total mass removal efficiency of 73.3%. Universal Engineering indicates that the Pretest samplo bad 10.7 % gmvel, 88.0% sand, and 1.4% clay. The Post test sample bad 2S.goA gravel, 14.7% sand, and 1."''' clay. Gravel is considered to be particles No.4 ~ larger. Silt and clay is defined as particles passing the No. 200 sieve. Sieve Size 3/8" PreTest 94.3 % Passing Post Test 88.8 %Passina Difference 5.5 ConclusioDs: Tabl.1 Sediment Sieve Analysl. No.4 No. 10 No. 41 No. 60 89.3 81.' 64.8 50.3 74.1 62.6 44.2 31.8 15.2 19.2 20.6· 18.5 No.IOO No.200 25.5 1.4 "14.7 1.7 10.8 -0.3 At the flow rate tested, the GISB removed 79.3% of the grass clippings washed into it. The ability of the OISB to remove grass during large flows wbeo. water passes through the bypass holes vvas not tested. In Florida, 90%. of the storms are low rain&ll events of I" or less, resulting in low flows similar to the test conditio~. This makes tb.e GISa a very etl'ective BMP for Low flowevents. It is unknoWn. how effectively the GISB works in large storm events. By keeping grass and -other trapped <orgamc .debris iin a diy state, the :i1utrlents 1n fue debris do not leach out :and ~me dissolved mtrates and phosphates. T'li1e GISB is a very effective BMP for preventing nutrients from organic debris ·from ~ntermg waterbodies. rne significant increase n nutrient concentration :miter 'If:e test is probably attributed to the u..~ of wastewater reuse water during the test.. 'The grass matted ~venU inches thick in the bottom of the box. This thlck layer could have acted as !I. illter to remove i.lutrients from the water soutce. At the flow: ... ate of 1.1 ciS, the GISB ~ a sedi1rlent lamov:ai affici~i:cy of 73.3% •. As would be expected, most of the trapped sedirr&nt 'N3S gl1ivel and sand, with litUe ii'1e ·,~~~·",·"';al ;'ol!..ect,"'d J1[',"! t'1~B 1.,.",." ·:-~Hy:te'··" ~"""'~''''''i':\1 ...... :.~~ .. :')!,,:1:;'-;e';: ._"'/]]\,,;;]' .,',,.,,, .. ~,·c-..:l .... i._ ... ,""",;. 'OJ .'V _ ~-.., -JI L.,; .~~ ~V\.. "!lL Jo1 • ..,u...,v'l.;a '" .~iU.io .. \J~ J..L' 1 '0 ·.....:U.'ua:.~ :..v~t.i. .~ i.l~y ~tructl.lral ~~l1Ps~ 3t a. ~.ction OnJ:e (!Ost, .i.-:d 'Without ~ptiv,e ccm511"UcU0l1. 3 UNIVERSAL ENGINEERING SCIENCES ~IUI""!I CcmianIsh: Gedectrical~· EmiromIertaI Sciences· ~ MaleriaJs Tesli'Ig.1MsIdd Irlsptdian 820 Brevard Avenue • Rockledge, Florida 32955 (321) 638·0808 Fax (321) 638·0978 November 2, 2001 Mr. Gordon England. P.E. Creech Englneers,lnc. 4450 West Eau GaUle Boulevard Melbourne, Florida 32934 Reference: Grate Inlet Skimmer Box Evaluation Northwest Comer of South Brevard Avenue and South 8'" Street Cocoa Beach, Brevard County, Florida Universal Project No. 33186-002-01 Universal Report No. 51479 Dear Mr. England: I. t, Universal Engineering Sciences, Inc. (Universal) has completed an evaluation of a Grate rnlet Skimmer Box (GISS) In accordance with Universal Proposal No. P01-0781. The evaluation was conducted to document the pollutant removal effectiveness at the above-referenced site. A Location Map, Site Map and Site Photographs are presented as Attachments 1, 2 and 3, ,. . \ I . respectively. . Sediment Testing , Universal supplied the sediment sample for the GISB evaluation. The sediment sample consisted of fine sands. coarse grain sands with crushed sheDs, and gravel. A gradation analysis of the sediment sample (S-1) was performed. prior to GISB performance tasting. The percentages of soil grains, by 'Nelg~t, retained on each sieve were measured and a grain size distribution curve generated, to determine the textural nature of the sample and provide a control (baseline) prior to fieldwork.. A sediment sample of known weight (57.87 Ibs.) was placed on the pavement upstream of the GISB and washed into the GISe with a portable water source simulating a' storm avent. The captured sediment was then removed ~Tom the GISS, dried and weighed. The captured sediment weighed 42.41 !bs. resulHng in a loss of 15.46Ibs. from fue GISa testing. A gradatIon analysis of the captured sediment sample (8-2) was parformad. Universal completed particle size analyses on aha two representative sadiment samples (S-1 and S-2). The samples were tasted according to the procedures for machanical sieving of ASTM 0 422 (Standard Method for Particle Size Analysis of Soils). 10 part. ASm 0 422 rsquires passing each specimen over a standard sat of nested $[svas (% ii1ch~ No.4, No; i 0, :'Jo. 40. No. 50, ~o. 100. No. 200). The parcentage of the soil grains i·~iaii;ed on sacn sleva siza ara determined to provide the grain size distribution of the sample. The dlsbibunon detenl1ines (:~a '~axtUiall;atur·9 of the soil 8.amp;a :~I;d .::!ds il' 51vafuafk:g i'~s Ji1gwnddI1.:g ..;;~ar:?,ct;3ris~ics . JC. I }1 " " ~I , I ,i .• ( Mr. Gordon England Project No. 33186-002-01 November 2. 2001 Report No. 51479 Page 2 8-1 consisted of 10.7 percent gravel (grain size larger than 4.75 mm). 88.0 percent sand (grain size between 0.075 mm and 4.75 mm), and 1.4 percent flnes (grain size less than 0.075 mm). S .. 2 consisted of 25.9 percent gravel, 72.4 percent sand. and 1.7 percent fines. The grain size distribution curves are presented as Attachment 4. According to the Unified Soil Classification System (USeS), S-1 and S-2 were classified as poorfy-graded gravely sand [SP). Based on the· gradation analysis. the major portion of the lost sediment was the fine sand component. Grass Clippings Test . The grass clippings were supplied by Suntree Technologies. A grab sample of grass (G-1) was collected and submitted for laboratory analysis to determine the TKN (EPA Method 351.2) and Total Phosphorus (EPA Method 365.3) contenl A grass sample of known weight (6.58Ibs.) was placed on the pavement upstream of the GISB. The grass cUpplngs were washed into the GISa in the same manner as the sediment sample. The captured grass clippings were then remoV$d from the GISB. dried and weighed. The captured grass clippings weighed S.22lbs. resulting in a· loss of 1.38 Ibs. A second grab sample (G-2) was coHected from the captured' grass cUpplngs and submitted for laboratory analysis to detennlne the removal efffciency for TKN and Total Phosphorus. The samples were shipped to PC&B Laboratories, Inc. in OvIedo, Rorida. Laboratory analysis documented 950 milligrams per Kilogram (mg/Kg) of Total Phosphorus and 510 mgIKg of TKN for <3-1. Laboratory analysis documented 2,270 mgll<g of Total Phosphorus and 905 mglKg of TKN for G-2. Laboratory Analytical Results and CI'lain-of..custody Documentation are presented as Attachment 5. Universal appreciates the opportunity to provide environmental services as part of your project team. Should you have any questions, please do not hesitate to contact the undersigned at (321 ) 638-0808. ~espectfully submitted, Universal Engineering SCiences, Bnc. ~c;.~ James E. Adams Staff Scientist II (2) Addressee Attachments Attachment 1: Site Location Map Attachment 2: Site Map Attachment 3: Site Photogiaphs Attachment 4: Soil Gradation Curves Robert AJan Speed Regional Manager ,~ockledge 8ranch Office Aitachmant 5: Laboratory Allaiytic;al ;~a";l.i~s al,a Ci1aijl-of~CI ... ;3tcdy O(jGi.II-;;&n~a(;O,1 '3 .. a~a in!at Skfmmar :Sox E'i~!u:si!on .~.Q!.;ih .ai';~~id 3aLl!a'j~fd Coccs 3e:lcl1, 3raV:llrd COtJii':ty. i::~»!~(':S\ 1 j :] ATTACHMENT 2 SITE MAP I · (( " I 1-' j" t ........ J .1 'I I~ i 'j I I J ;:. ~. RESIOENTIAl CONDOMINIUMS CONDOMINI,UM DRIVEWAY ( lANDSCAPED MEDIUM RESIDENTIAL CONDOMINIUMS ) i w a Ci5 I I I , , , , , I I , , , _--1---CONCRETE DRAINAGE SWALE SOUTH ani STREET Grate In!et Skimmsr Box Evaluation ;-3cu'i:h 3rav:srd o>::iu:ev3id Cocca 3each, 3ravard Cour:ty, F!or!da HESiOENTIAL ;!------------------- " , ATT~CHMENT 3 SITE PHOTOGRAPHS ( . \0 .... ] ''" J I,:~t:) ,:.,~, .•• :;:. ::,:.;1>: .. ;. J:': ~' .. ', Grate Inlet· at 600 South Br~ Avenue, 'Cocoa Beach Grate Inlet Skimmer Box Features florida Type C Inlet Storm Boom" ". Zap ~1 Skimmer Tray···· ,.-.. -... ;v.:: .. ·:··~;l '::::'\l'~;.;J.i:::i;i.~~!~ Deflection Shield --"~-i: . . . ,;};! . , . /"'. ,/ Flange us i'elniorced./ ~vith knitted 1 a08 ±45° biaxial fiberglass = I' .-! I ~ I '.' '.' , I " \ II I I , ... ... .l ",' .=.' ~J ! ______ ~.,..J 2oJ1u~aut:':'{~r1:.0'lJ:al T~~tk1g .ror a ~31.::A::\"".:'" ... .:;a~ • ... f'~~1 .. ,~~" .... 1.oot'/·:O'.;1 G~"':··i·,~ T ... , ~~t l~ ... iJ.J _..J,"'.oIII..&.1 ... V~ .;,. __ ~ _ .... ,,'.1 ,;1..,1_ :3krr~:cc.:5A" ~3o,{ · I Sediment Entering OISS Sediment Trapped in GISB P·ollt;.taill: ~_emo"/a1 Tes'dng for a Srmtr~e '!.ad"lllo1c'gies a.--~teI:clet ,)1r~·"",,,,.I" "". 'lJ>cx 4 u.:.'-L.LU.il .. OJ,. D I.. __ .. __ ?J'~~~ }'Br:OTOG:~~~§ ~~-.-.-..... "'~,-, ... -~,~.~ .. =~~ "'--""=-~~ ........ ~-.. V"_.~J...y.~._-=-... ~._ ..... _ ..... =..~ ..... ..:.~;..-.. __ ~_._ ._ ........ ~ _ ~ ( " .... • • ,::.~~ I~~ ~ J(~' 'j I,,:::::~, r: _.:;~":"=::',: L :-:"'~":::'I!IU':C,;: U'i' 61SB Inserted into Inlet . .... .', ~J T" u'trus .;sm:.g .Grass CliPP. Entering OISB ~. Poll!~taut R~ra.ov-al Testmg )'l11' a Slliltree Tecrm.o logies Grate fulet 3!cT:t'r;ii.:ar :Sox '---_.j~~~ P:arOTDIQJt4I.PE~_. J ••• G ======-=~~=-~======================~ ( \ \ ... ::., • \ ~'''l , . J , I . -.-.. -.!~ . . , -' cleaning. [:;, i--·,"ft":":';:::::"-=--==::-~rate ~rllat Skim:~-~;~~~ltJaticn --=....:= .. --=-::~:: -:-:.. .;=,;-.:, i I NiNe cl Sot.th 8ravard AventitS snd Sc~th alh S'tr'38t . . \ Cocca 3each. Brevard County, florida .. '1 II SITE PHOTOGRAPHS : 1.!diH~~B~!~ ~1'l,)il!\~";""Y: (Ill':: c;T~TfaJ'Ii'il wr-------·---; : ! :'~IA _ .,;t.')I:Jti'I I x.~-\ I .; .iJ::m01 : ; ,SC,'f..Ei ·jjR~J~cr:~ 1~~I"~h\\l 31 ~~tk . l-:-=-=~-::-. ,.::.".-.,.=-:-•• !!."",--,-=---:-:...!:!.iL--_--=J-=-:-::--)~~~u.ti:!:~_.. .. t ___ .i~'!7_:) _ .-=--r:._~_. ___ ._.: (' , J \-.. , J ~j J J , 1/ ~ . r ~ ! . Grate Inlet Skimmer 80x Evaluation 'NWC of SOlJih Brevard Avenue and Salim 8th Sii'sst Cccoa 3each. 3r-svard COLinty, Flo,~da SiTE P}-:-OTOGR~PHS '" - '-'::., .~-.. -(~-- ! ,. i ( ~ . , t ATTACHMENT 4 SOIL GRADATION CURVES :1 J J 1· [ (~I u.s. SIEVE OPENING lIIiNCIIES I U.s. SIEVE NUMBERS I . e 4, 2 1:S 1 31ol 11Z.' • .. • 10 1.1':!II 30 411 50 10'00 140 a ) I . ,I I " I I II t ' I : I t 95 I I ~ · · 90 1 ~i'. i I : • · 8S '\ • • I I · I • 80 " I ; 75 • · · • I · I , i~ 70 • · · ~65 ~ 11\ • · T60 . : i , I ~ 55. · · · I 1 • I • ,;50 \ ~-45 . I \ .V <40 ~: .' I '\ i 1\ · : l.. · 2S : . · · I : 20 I \ 15 \ 10 I 5 ! 'j 0 . 100 10 1 0.1 GRAVN sIZe UN MllLlMe1'ERS I COBBLES I r~A.\II: L ~. I I COI:se I VIne GOIIfSe f 'JU1e , Specimen Identification CBassiftcation MC% LL .' 81 SEDHMENT1 Spedmen MenOOcation 0100 D~ D30 010 %Gra'Jel ~I :S1 12.~O !)).2S D.-JM ~.C9$1 :11.1 3/4-3lS" NO.4 NO. 'jO NO. 40 i>10.00 l ~.3 .$9.3 31.3 e4.J ~.3 CJ!snt :CREeCH :eNG!Ne:am~a Cli.ant ~o: ~-.'.5~ w. ':i~U GAlli!! 30U~J.AAO :!e~.i ;.Jr.>: .~'j::!'30URl\'le r~Ol~OA :31~34 Dii1t~: :':J;ca~-(;:t; .' .L~I~! ~j3lJ:'T ~3KJ:'i5~fc:S~~ ~o:,)X ~V~~LU,;\-rC~ ~:~!.:J.'1f .. ~.fZD ccU"t)'-'f~ j~~~~.: J~~lf:,;'~ ,; .., """rr ""~~:o~q··1·~:')j "'tJx" ','~,,,, SJV~ .... " .. lli',.;··I. a JU::' \... . ~ J .: . .) ,I I ".,.'M,-._ .... ~ -:: .. ,.t'1',~c;.lrl!l1\(1'1 $cj2n(:~, li"lc. HYDROMET$ ., - , 0.01 0.001 OR CLAY PL PI Cc CU 0.7t 3.7 %Sand %Sitt I %Clay , 83.0 1." ~O.1CO NO. 200 :liS.S 1.4 ~3t3S..uj:o:z-a1 ; J1,~'79 '1 i],$ivi , .----- ( '. U.s. ~IEVE OPENING IN INCHES I I ., U.S. SIEVE. NUMBERS HYDROMETER " • • S 2 1.5 1 31\1 ~ 311 :t 4 • ,11 14\121 31 41 lit 11 10G t..o 101 ,( I I, I' T 1 II ! I -, • • 95 • , ! • • • • I · 90 I I • · • I · • 85 • I • 80 I " :; 75 I • • I ~ I 1,;7Q t\. :~65 ~ · · Tao ~ i " ,I 1 r 55 I · i is: I . . I!~ 40 ~ . I , · ~35 1 Il.o' I 30 \ : · I I 25 l' I . l ~ I 20 . ! \ I , , 15 " 10 \ I 5 I 0 100 10 1 0.1 0.01 -0.001 G~NS~aN~RS I COBBLES I coaJ~~nIt I (lOaMI ~Q 1'I':!211!!!..; I !lin. I, SILT OR ClAY I Spedmen Identiftcatfon C~assiffc:atlon MC% LL PL PI Co. eli \. S2 o.~o 13.7 I " SEDBMENT2 Specimen ldenMCl.iitlon 0100 060 030 010 %Gi'8vel %Sand %Silt I %Clay il~ 52 112.150 1.;$1 ~.237 -0:11.:0, 25.t 12.4 1.1 ; \ -I ; '3/"-~~ NO.4 ~O.'lO NO."-lO NO.&) ;~IO. '100 NO.2()O ~ I, I ']3.1 14.1 '~2.8 ..t!4.2 '1.7 : 31.4 14.7 I ; .caUefili: 'CREECH ;SNGiNiEreRij~,;jG Cif'.ent i'!o: 33·13~~~"';1 I , .. ~ 'fl. ::AU G.,b..!I..L,: :OOUl::V.~.~O ",-q~~cti }Jo: Ji479 I :JIEliiOU~,j!5 rl:O~~jD.\ ~~$:34 ':').J'1\): :j :;l':9i~1 : ;P{C-j3ll!t )~~AC-lS }; ~~..,. ;;'~~;,:l;~';'!3~!t ,::lOX :::v.\!.uxnc.i.i ! J;~~fA~~D .c03;~"f'1. ,~t(~~"!.~{J"i. -- ~. C I I. '( , I i 1 '", ", J J '1 ,e ( ATTACHMENT S LABORATORY ANALYTICAL RESULTS AND CHAIN-OF-CUSTQDY DOCUMENTATION I' , " pe&s Environmental Laboratories, Inc. 210 Park Road, Oviedo, Florida 32765 Phone: 407-359-7194 Fax: 407-359-71~7 Client: Universal Engineering Sciences 820 Brevard Avenue Rockledge. FL 32955- Laboratory Reference Number: 201090199 Project Nama: Inlet Skimmer Box Evaluation Project Number: Laboratory 10 Matrtx 201090199-1 Solid Number 1 1 Parameter' EPA601Q EPA 92001351.2 ClientlD 0-1 DesCription Phosphorus by ICAP Total Nitrogen Contact: James Adams Pllona : (321) 638-0808 Chain of Custody: 24025 status Oatelfime Sampled RUN 0912612001 14:20 • I \. ] J PC&S Environmental Laboratories, Inc. -210 Park Road James Adama Universal Engineering Sciences 820 Brevard Avenue Rockledge, FL 32955- Oviedo, FL 32765-8801 407-359·7194 -(FAX) 407-359·7197 Casa Narrative . CAse NARRATIVE for Work Order: 201090199 Project Number. . Project Name: Inlet Skimmer Box.EvaluaUon This Case Narrative Is a summary of events and/or problems encountered with this Work Order. ,4IIbnalYSiS for TKN was perfor.med by Environmental ~cience Corporation (E87487). \( Deffnition of FIat:j! C '. Environmental Laboratories, Inc. (' "ark Road , A FL 32165-8801 ( ON' 407-359-7194 ab Refarenc:e Number lIent Sample 10 Oatell1me Sampled SaroDI. Matrix <a' Becelyej:1l EPA 6010 Phoaphoru., Total EPA 92001351.2 Total Nitrogen •• . :'(' .. . (. "~" \ ~ Report of Analysis ~2010901gg..1 G-1 0912612001 14:20 Solid mg/kg 950 mgJl<g 510 CLIENT NAME: Universal Engineering Sciences PROJECT NAME: Inret Skimmer Box Evaluation PROJECT NUMBER: DAle RECEIVED: 0912612001 ~. \ .: c,,;;,.,:!~t.Jct·~d. -t:'IS v3fu~ :r..=c.icdh18 (he IU' :$ ':1d ;~L l\Jr ~11.a ii,,:;..(\!Lcl. 1~':;Sl..!aS :3lJortad t,j(l a V\j~t \Nair.i1t basis -.. ~~ fO~P CoropdXpp":',I# 900134G -FDOt-i"Caliiflcatioll '# S83239 ' .. i I Anal~ (' \ . "' .... ~ ... Quality Control Report for Spike Analysis aa saleh: 26011bRC&i INORGANICS Spia Amount samjiii Ibi 2iH06020S01 10.0 mglka LoWer Sample SplU PetCent Control Resul . Ruuli ~ LImI &LIfb1100il2OOt i5&~d&ri w\YiEdG 70. 78.1 81 70 Upper Conflol Umi 120 ... :~I.>",., , Piioirk ,_.~ . .J. /"".~.' '::~~~lIliw~O~1 ~ ''''-, -' Y '0, FL 32765 r . . ~/-·--""" .~. ICh~i~~:-:.OdYl· Work Order: 2£>,,', 'rJt:_~~ Page __ .II_--=--. ., ..... ----, .. ' '. • -'0 . PNiY; ',Jf~ .. 5 ANAlVSIS REQUESTEQ JCI:;Ol;a: t/;iZJ 'UQ:2JI',e.J'\ AV e~u\~--:::Jl: f: .t2 lU...... ~9S5 -,'< ~~ !! ~'I:iV: \. -A6.A~: \L_~) .... J -----I' \;:~ 6·.,I(C~; • , ,Vi " ~~ 'HI:: -PAX: . --=:::;: . ..,) 15 J .-... . . ... , . , , IiI6lBII i I ~ lo'.j\:;.i~I?Lt; w uAn;r(.Mi; i I ! & .. .1. '2 0,-{ IC)/Z(p /D tLl'izo IX X K .. I .~. . . . . i=.:~_~ __ ~_.,._. ~ r-... '/lJQuISl·a-':JJ I.:iY.. DAT~ RECEIVED B ~ DAlELTIME PROJeCT INFORMATION SAMPLE RECEIPT }(2.d~ ctlv.i61 Ci. hA.U 'f·i'!:% PfIOJfCTNAME! I~ $tu~-'&O)( Total # 01 Containers €.V.AAI~" '-~ J l-'41''';;;:';' • PfIDoECT« " Cbain of c~y StIiIIa ,--- ;;,: IITE~: <kt.oAr ~,*", n.... RtcY'd In GuQd CGndWon ~,-~ ... ~--~.-~ t.l.. 1i'';'( .. \JQ'II(,)i'''''COMl.i~'IHS: I'ROoIIiGT 1IWMGiR: ' ,-.blAR~~ PO. I INVOICE TO: , ~.-:.:;..--~-. -!~ , 't::I~uili'''t~';; Y t;i: -=a-'''z'''' ~. )-.. -"-~",,-._. _~ '" -_.. ..--~ " wtIlU: ......... ~-..... -. -_. ' -~-IChain ~-::~.Od~ :~~rder: ..?":;e·:~1 '" ~ J '& ~~~~~~~~~~'~~""~'U~~r--'-~-'~~~=NM~,~~4r~i[;rat-~~-r--r--t--t--1--i1"ir-i---t---t--1---t--r---'1 ~::-:?!i--'-jIPl1Pl;, 'r "~II ~p5-1 1 1 I· I 1 F I I zi ~H:iDt:y-OATfrnlVlc I RECEIVED BY _ '7"" I I 4-• __ " .9 DATEITIME I ' PROJECT'INFORMATION lVIii/II I'RO.IICT NMIi: /1/.2~ SAMPlE RECEIPT Tatal1# of ConIainers ~ ~~ I ' I CbiinofCUstodyaula I ~ litE NlOIUiill8: MO.IICT« ~ U'""1~UC'iWl>~CO~~-;'~:·"· N ~i ·1 /4-1 ( 1-..-: 1---"'-• PO.. I ~~. ~----~ .. ~ ~-I-"'7TW701"'J_~'--WMr-rF;Z'~fsm ac:-'-I-~(;",\n'j~'''",: ' I --T?.,.n ..... ·~~· I ... ~:.<:..:.= .• _.-_-r..= ... ~.,,..-,-,-_. __ .. WIIIY8: ........ -~"..",...-. _ •• --. .,.a Envkonmental Laboratories,lnc. ~' Park Road , . ,ado. FL 32765-8801 i 10NE: 491-359-7194 '1. '. j; J ' 1 j. i I -ab Reference Number .lIent Sample ID OatelTtmt Sampled SamDIe 0* (at Bece!yed) EPA 6010 Phosphorus. Total EPA 9200J351.2 Total Nitrogecl mglkg mglkg Report of Analysis -201100168-1 0.2 10110120010:00: So!td 2270 90$ CLIENT NAME: Universal Engineering Sciences PROJECT NAME: PROJECT NUMBER: ' OAlE RECENED: 1011812001 "{ •• "".,,,,,«1. I~a ."," pre" •• " ,he 'U' I, th •. 'L "" ~'!:!i"'1!.!..,.rt.d 'l!!' ~J" w~!2!it ,,,1. " ,=OEP CompQA~:lP.'I-900134(; • j:OOH Cartificatioll i~ Ea3239-~-- I \. "',:' pe&s Environmental Laboratories, Inc. 210 Park Road. Oviedo, Ronda 32765 Phone: 407-359-7194 Fax: 407-359-7197 Client: . Universal Engineering Sciences 820 Brevard Avenue Rockledge, FL 32955- Laboratory Referenci Number: 201100168 Project Nama: Project Number : Contact: Bob Speed Phone: (321) 638-0808 ChanofC~:20344 ·.r.t • Laboratory 10 Matdx CDentlD Status Oatemme Sampled 201'100108-1 Sol~ Number 1 1 ParBnieter EPA 6010 EPA 92001351.2 gescnptlon Phosplloru8 by leAP Total NitragEm RUN 10/1012001 -/ \ I .1 Quality Control Report for Spike Analysis INORGANICS Spike AmounI ftll.30 20.0 mgncg Low .. Sample SpIte Percent Cantrol RHuIt Result Reco~ LimI 61. F.1&ti2dIH I5&Xiiit 1 i AiiaI)'iE GG 178.0 199.0 105 7. Upper Control UmIt 121 fe i '. t . " . SITE EVALUATION OF SUNTREE TECHNOLOGIES, INC. GRATE INLET SKIMMER. BOXES FOR DEBRIS, SEDIMENT, AND OIL & GREASE lEMOVAL Reedy Creek Improvement District Planning &; Engineering Department 13ddie Snell, Compliance Specialist Stonnwafer is JDW recopitecl ;as die 1eadinj soua of poIiutioD to our muainin, natuIal wafS' bodies iii *' United StateI. Deve10pmeut and urbanizatiCll bavo' R.IIlOVed most of· tho natural Dltrdion and sedim. trappins systems provided by tho environment. Cwrent development must address this ileed through the implementation of .~water, natmenll sysfeIDt in abe project desiga. Most of these systems pedbnn reasonably weD" if properly . desigoed. ~ and maUdained. ' Refrofit of older mban area. lacking these modem stmmwaler ~stcma is a continuaJJy ~', cbaUenae. The Downtown Disney complex, bmerIJ thO Lake Buena ,Vista Shoppina lJiIJap, has sev~ draiDago basins willa '1970'. stolID.... systems. Thesct older systems discbargo directly Do' &.0 adjacent \dmiDago canal 'l.vith 00 pollutant treatment. Over timo the 3£Cumulatton of' sedimenti, nutrients, intensive development, and recreational/entertainment pressures ate contributing' to water quality degradation. Whenc~a" Kiew development or l~evelopment cccms. 'io ~rmwata' system as ~ to current wde/permit :requhements. In tho interim, several areas a ht· illeed for rapid, .;;ifectivo, and economical improvement an the ~1.y of its stonnwater discharge. 3W!AliJree T~boolc~~ rnlOOr~ l~ Un 0l1p0 C~~ a., mm~es stormnet' grato inlet sIdmm.er boxes. They so made of a lbigh tpafity fiberglass. ir'4me, ·~'1lidl stalmess ateel {dt,-S~ backed hy heavy-duty juminum graWng. Each lnt is custom inado tIQ acco~mnoclate vadous wet ,gizes. A nydrooarbon :absotption ~1)om. 1s .~ttached -» :ili.e top of '&.e &rnrd1lil« oox :1lr p~troleum, on~ :md .gr~~ l~vat, These devices :at below 11e gate :md catch sedim.mt, 'deeds, ~d ~trc!euir.st oHs 1 J'{eases. Clean·(m~ mamtenance, and performance tepol'tll1g is provided by 31.lli.t"ee on a xw.fu1~ GJSis. c. Picture of Grate Inlet Skimmer Box , , , I '" Tho Reedy Creek Iinprovement District (ReID) selected six (6) test sites in illo Lake Buena Vista area to evaluato dio performance of 1heso units. One unit was placed in a curb inlet along Hotel Plaza BOOlovard to 1rap landscape leaf litter, sediment, and oil &' grease from a high use roadway. Three (3) units were placed in tho backstage service area of tho Rain Forest Cafo. Two (2) units were placed in tho backstage service area of the McDonald's restaurant and Lagos merchandise shop. After sevaral field meetings, during which Suntree teok extensive measurements, photos, and other documentation of each stolmwater drain, the Grato Inlet Skimmer Boxes were manufactured md delivered for installation. An mits "1,re,-o lIh,1al!ed 1Nithout :iilushap ,~pproxiInately iwo weeks ~fore 'ihe 1999 C'Mi:stmas holiday S?asGn. l"aj& iE~et !1iKne period for particle catchment was one month. Mr. Henry ~d Tom Happel, Suntree r.~hnologies, visited each site several times during the month to ensure that ceb:ds 'Would ~lot fill the units roo soon. ( I ~. ...... j . l ,,. '(, units performed as expected removing. _ average, 20 pounds of debris from eam of the six sites. Tho composition of debris varied considerably. The Hotel Plaza (roadway) site was goo,4 leaf litter and l<1A sediment The Rain Forest Cafe sites ran in opposition as you got close to the lake. First inlet was about 50% leaf litter and cigarette butts and 50% sediment The middJa inlet was 60 % sediment and 30 % leaf litter (lott4 miscellaneous). The inlet closest to the lake was 95% sediment and 5% leaf litter. Tho two sims at the McDonaldslLegos area were similar to each other. The site closest to the lake was 95% sediment and S% leaf litter. Tho site closest to the entraoco· gate was 98% litter sediment and 2% leaf litter. t 'I .1 .;* ., . ~':'. . '.' ~ .4. .'. : . , This composition is indicative of tho human activities and drainage flow patterns of that site. Backstago :areas in tho Walt Disney Wood Rem receive an :artificial rain event ~ach night during cleaning operations. This washes a continual flow over dle impelVious site, washing all materials intO ilie stormwater system. Municipalities m Brevard, Volusia ilnd Dade <COUnties nave :i)'Uooessftilly ilISa<! 1j~et . skimmers :in Florida. ReID iJru.1nared with 'W ~ Disaey Imagir.~ring CNDI) :~search 2nd Development to coordinato some basic -chemical sampling for pollutant· removal efficiency determination. Mr. Craig Du.~ury, WDI, provided ·tecMical SUppCit :and guidance for ~js. An ingeniously simple diMco 'was fabricated by Suntree 'k) allow sampling of the First Flush of water going into the units and ultimately coming out of tl1e skiau:ner boxes. c· (' <-, (' Pollutant Removal Efficiency i 80% .: I I 700/0 .i-'" ..... . I r 600/0 I. ..... " -.,-.. 1 I , I :20% !.., I , I 10%,:, I D% :. i. _. ____________ . "'!Jl ~~ :I'i) {\u:n;airn~e J'):aJ7[~rJl,~t~r I Ammonia. SaRcyl •. I Chemical' Oxygen Demand :I Nitrate and Nitrite [J Nitrogen, Total KJeldahl ;2 Oil and Grease \I Phosphate, Total . . ~IO CLEAN· .. (v lNViRONMENTAL SERVICES, INC. The Canrornta Curb Shelf Basket Water Auule1 . ,- t. :1- • V . J-.. ~. \( '--'----- \ . Ali!.:."" 3 Manhole ... . ~ .. Ic;t:J • J · :j ... ~l • . .J.. • •• • q, '4" I ~ III " ...... • \I ~ -. -}~ .-:r--'Q .• • • . . .. ' .. CIiI8III or Z-mold FlQlh2 NOTES: 1.~~5Wvld-~r\llllll\lll~~ • ~InbtOpaMIg so:O do'lr-art ,~il\'liJtR~ ~ 2. Sbalttyldllrn ~G1d ~'1\ Marin. ~~ _ cna10d aof"uv ;prot~cn. 3. So'lal ~ alJdIGd ~ClI.Ch IaasIn INlm \..m~hsidMJl8. -3. .. ~a&si1i1l~~mt8flI~,tild ill .iWlnapda \~ 1Oa1~1Iad ~UVj,!tO~. s.. ~ 26sket I1nosaill8n aM t:oaI'S~ ~taCl".oon ''Mnl.dacluilad fram~~ '. S. FIlIraIfOll &IIlket ~ boQm 4f ab~ ;~~!a(O~~~ 3.iam III ~~~\"rlhQut"~Qltlng . jl"'AlJn1t4~ 1wtf1rJ&t. ..,. :::1r....!f"-an 2aaI~~;;.l!.o.n 1u dlr..;-,;.ly i.U\J.ll :.~~\c!a ~ «~'V ':.n~~4i-;.c.t. :'.0. al.JX a.s'i O':~u(':;lda, CA 92049 (760) 433·7640 " i:ax (760) 433.3176 'Nwvr .. bjqdcl'IJcrlvin)IJln~lltul.n~t