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HomeMy WebLinkAboutCT 15-09; Quarry Creek PA R-4A East; SEWER DESIGN REPORT; 2016-07-20... .. ... .. ... .. --.. -------------------------... --- Sewer Design Report CT 15-09 I PUD 15-18 I MS 15-13 QUARRY CREEK PLANNING AREA R-4A EAST City of Carlsbad, Ca County of San Diego PREPARED FOR: PRESIDIO CORNERSTONE QC, LLC 4365 E~!~u~~it~:~2~~TE 6ftEC~J\/ED ' JUL 2 9 2016 CITY or C,\i':L.SBAD PREPARED BY: PLAN SB&D~ NINGDIVISIQN PLANNING ENGINEERING SURVEYING 3990 RUFFIN ROAD, SUITE 120 SAN DIEGO, CA 92123 (858) 560-1141 SB&O JOB NO. 71632.60 July 20, 2016 ----TABLE OF CONTENTS --Vicinity Map -Scope of Report ............................................................................................................................... 1 .. Quarry Creek Development ............................................................................................................ 1 -.. Planning Area R-4 (East) ................................................................................................................ 1 -Methodology ................................................................................................................................... 1 -Sewer Hydraulics ............................................................................................................................ 2 -Results ............................................................................................................................................. 2 --Conclusion ...................................................................................................................................... 2 ---EXHIBITS -A. Sewer Flow Summary Site Sewer Map .............................................................................................................. Map Pocket -,. -APPENDIX --City/CMWD Design Standards Volume I Chapter 6 (Gravity Sewer) Excerpts ----,_ ---.. ---D:\71632 QC PA 4\Reports\Sewer\20160411, QCRIR2 Sewer Report.docx 1 - -.. .. .. -.. -.. -... -... ---------------... -------- a CAMINO COUNTHY CLUB VICINITY MAP ~ NOT TrJ SCA/.£ THOMAS BROTHERS PG. 1107, GRID A-2 2006 EDITION -D:\71632 QC PA4\Repons\Sewer\20160411, QCRIR2 Sewer Report.docx - .. - - -.. -----... ------------.. -----.. .. ---- Scope of Report This report is limited to sewage flow estimates and hydraulic calculations of the public private sewer main in the R-4 East sites. The project will connect to a public 8" sewer in Adobe Fall Road. Since this area is part of the Master Quarry Creek Development, no calculations were prepared to analyze the downstream flow conditions or potential impacts. Quarry Creek Development The Quarry Creek development is located in the City of Carlsbad (City), but is bordered to the east by the City of Oceanside. The development is situated west of College Boulevard, east of Interstate 5 and south ofHaymar Drive. The development is divided north and south by the Buena Vista Creek which runs east to west across the middle of the site. The Quarry Creek development is 155.36 acres in gross project size with the addition of some off-site grading and improvements. The first phase of Quarry Creek created large sheet graded pads, and infrastructure for the individual planning areas, including public roads, backbone public utilities, and the water quality and detention facilities to support the entire development. Planning Area R-4 East The R-2 area will be a multi-family residential development. A total of 150 units will be constructed, consisting of various attached product types. A private 8" sewer main will collect onsite flows and discharge into the proposed public 8" sewer line in Adobe Springs Road at the Salina Road entry driveway. A copy of the Sewer Site Map is provided in the Map Pocket at the back of the report. Methodology Public sewer lines are to be designed in accordance with City/ CMWD Engineering Design Standards Volume I, Chapter 6, as follows; Hydraulic calculations shall be based upon a normal "n" value of0.011. Minimum 8" diameter main. Sewer mains shall be designed for a minimum velocity of 2 feet per second (peak dry weather). Depth of flow shall not exceed½ full for 12" diameter pipe and smaller. Flowrate generation using I Equivalent Dwelling Unit (EDU) = 220 gallons per day. Peaking factors for small basins ( <l 00,000 gpd) are set at a constant 2.5 . Small sewer basins are typically limited in achieving a target cleansing velocity of 2 fps. A 6" minimum main may be used for 10 dwelling units or less. D:\71632 QC PA 4\Reports\Sewer\20160411, QCRIR2 Sewer Report.docx I -... ... -... --.. -.. -.. • .. • .. ---.. --• .. ---------.. --- Sewer Hydraulics The proposed sewer system is consistent with the generally mild slope of the development. Pipe slopes are generally in the range of 0.9% to 2%, with the connection to the public main at 4.4%. Pipe slopes at the upstream ends of the system are set at a slope of 1 %, in an effort to improve performance. . Detailed hydraulic calculations were prepared for the private sewer mains, and are included in Exhibit "A". Results A review of the hydraulic results indicates flow depths less than 1/4 full. Peak velocities are generally in the 1-2 fps range. Regardless of slope, a 2 fps cleansing velocity is not possible for the very small populations in the upstream reaches. These flow conditions are more properly designed using the Plumbing Code, which uses a much higher peaking factor, with minimum and desired pipe slopes in the 1 % to 2% range . The building pad for the future Cultural Center is located below the street grade, with the restrooms located to the rear of the site. The proposed sewer main in the street is set at the minimum elevation to provide service to the future facility in accordance with the Plumbing Code requirements for the sewer lateral. Conclusion The proposed private 8" sewer mains will generally not achieve 2 fps under peak flow conditions, with flow depths less than 1/4 full . Regardless of pipe diameter, a 2 fps cleansing velocity is not possible for very small populations . These conditions are more properly designed using the Plumbing Code, which uses a much higher peaking factor, with minimum and desired pipe slopes in the I% to 2% range. A change to 6" diameter mains would little effect upon flow velocities. ... ... ... ... .. ... ... -... ----------------------------- EXHIBIT A Proposed Sewer Summary for R-4 East r I I I I I I I Quarry Creek / R-4 East City of Carlsbad LINE FROM TO MH MH NORTH LINE 450 451 451 452 452 453 453 454 454 455 460 455 455 456 470 456 456 405 SOUTH LINE 440 441 441 405 WEST LINE 400 401 401 402 410 402 402 403 420 403 403 404 430 404 404 405 R-4 EAST 405 406 I I I I 1 EDU = 220 gals/day BASIN DU TELAGARD TELAGARD TELAGARD TONDI WAY NALA WAY TONDI WAY SALINA -ENTRY SIMBAWAY TONDI WAY SALi NA -ENTRY SALINA RD SALINA RD ROCA WAY SALINA RD CRECIDAWAY SALINA RD VESTRA WAY SALINA RD SALINA -ENTRY ADOBE SPRINGS D:\71632 QC PA 4\Reports\Sewer\QC R-4 sewer n_011 I I Pop/DU Pop/AC I I I I J I I I I I I I I I Ir I I I I I f I I I Exhibit A SEWER STUDY SUMMARY PF= 2.5 Proposed -Dry Weather Conditions Revised 7-19-2016 EDU EDU Population TOTAL AVERAGE FLOW PEAK PEAK FLOW LINE DIA DESIGN de dn/D VELOCITY Added Gumm G.P.D. C.F.S. M.G.D. FACTOR C.F.S. M.G.D. (INCHES) SLOPE 1% (FEET) (FPS} 8 8 1,760 0.003 0.002 2.50 0.007 0.004 8 1.01% 0.033 0.05 1.06 9 17 3,740 0.006 0.004 2.50 0.014 0.009 8 1.01% 0.047 0.07 1.33 17 3,740 0.006 0.004 2.50 0.014 0.009 8 1.02% 0.047 0.07 1.33 10 27 5,940 0.009 0.006 2.50 0.023 0.015 8 1.33% 0.055 0.08 1.68 9 36 7,920 0.012 0.008 2.50 0.031 0.020 8 1.94%, 0.058 0.09 2.09 5 5 1,100 0.002 0.001 2.50 0.004 0.003 8 1.00% 0.026 0.04 0.93 41 9,020 0.014 0.009 2.50 0.035 0.023 8 0.76% 0.077 0.12 1.56 12 12 2,640 0.004 0.003 2.50 0.010 0.007 8 1.00% 0.040 0.06 1.19 3 56 12,320 0.019 0.012 2.50 0.048 0.031 8 1.06% 0.082 0.12 1.94 12 12 2,640 0.004 0.003 2.50 0.010 0.007 8 1.00% 0.040 0.06 1.19 4 16 3,520 0.005 0.004 2.50 0.014 0.009 8 1.00% 0.046 0.Q7 1.31 9 9 1,980 0.003 0.002 2.50 0.008 0.005 8 1.51% 0.032 0.05 1.27 7 16 3,520 0.005 0.004 2.50 0.014 0.009 8 1.33% 0.043 0.06 1.43 12 12 2,640 0.004 0.003 2.50 0.010 0.007 8 0.90% 0.041 0.06 1.15 4 32 7,040 0.011 0.007 2.50 0.027 0.018 8 1.48% 0.058 0.09 1.84 18 18 3,960 0.006 0.004 2.50 0.015 0.010 8 0.94% 0.049 0.Q7 1.33 6 56 12,320 0.019 0.012 2.50 0.048 0.031 8 1.36% 0.077 0.12 2.11 18 18 3,960 0.006 0.004 2.50 0.015 0.010 8 0.92% 0.049 0.Q7 1.31 4 78 17,160 0.027 0.017 2.50 0.066 0.043 8 1.36% 0.091 0.14 2.33 150 33,000 0.051 0.033 2.50 0.128 0.083 8 4.37% 0.094 0.14 4.27 . --150 71632.60 ... .. ... .. ... .. -.. ... 11111 -• -------------------------- APPENDIX City/CMWD Design Standards Volume I Chapter 6 (Gravity Sewer) Excerpts ---.. -.. ------------- CHAPTER 6 -DESIGN CRITERIA FOR GRAVITY SEWER LINES AND APPURTENANCES Engineer will submit a rough layout of system for review and approval by the City Engineer prior to preparation of improvement plans. 1. SEWER MAIN DEPTH AND SIZE A Sewer main depth and size shall be as shown below unless approved by the City Engineer. B. Minimum depth, finish grade to top of pipe 6 feet C. Maximum depth, finish grade to top of pipe 15 feet D. Design calculations shall be submitted to verify size and bedding design. (Manning "N" PVC= 0.011 is norm). E. Minimum size of mainline shall be 8". F. 6" main line may be allowed on cul-de-sac streets with a maximum of 10 units. G. All sewer laterals and main line invert elevatfons shall be shown In profile on the improvement plans and shall include stations, slope, and distance. H. All sewer mains over 15" in diameter shall require special design and City Engineer approval. -2. SEWER LATERAL DEPTH AND SIZE -----3. ---------- • A 4" minimum diameter for single-family residence. B. 6" minimum diameter for all other use. C. Desirable depth at property line Is 5 feet (top of pipe to finish grade@ top of curb). PIPELINE MATERIAL TYPES A. Gravity sewer pipe and fittings shall have PVC conforming to ASTM D3034 for diameters 4" -15" and ASTM F 679 for 18" -24", with integral-bell gasketed joints (gasket and spigot end joint design). Pipe shall be made of PVC plastic having a cell classification of 12454-B or 12364-B as defined in ASTM D 1784 and shall have SOR of 35 and a minimum stiffness of 46 psi according to ASTM D 2412. B. All fittings and accessories shall be as manufactured and finished by the pipe supplier or approved equal and have bell and spigot configurations compatible with that of the pipe. Volume 1 -Chapter 6 Page 1 of 8 Rev. 6/30/08 -.. -.. -.. .. .. .. .. ---.. .. ------.. ---------... ----- • 4 . C. PVC pipe joints shall be elastomeric gasket joints type conforming to Standard Specifications for Public Works (Greenbook) most recent edition. Rubber gaskets shall be factory Installed and conform to ASTM F 4 77. Pipe joints shall have been tested and meet watertight performance requirements of ASTM D 3212, "Joints for Pipe Using Flexible Elastomeric Seals." D. PVC C-900 shall be used for gravity sewer pipelines with depths equal or greater than 15 feet. Engineering calculations shall be provided to verify that the pipe material will accommodate the design depth. E. Use of other pipe and fitting materials and types may be required by the City Engineer to meet specific conditions during design or construction . F. Service connections to the sewer main shall be watertight and not protrude into the sewer pipe. All materials used to make the service connections shall be compatible with each other and with the pipe material to be joined and shall be corrosion proof. G. Couplings used for repair, or transition to dissimilar pipe materials shall be approved by the City Engineer and provide corrosion proof watertight seal. DESIGN PARAMETERS FOR GRAVITY SEWER MAIN SLOPE, FLOW AND DEMAND A. Gravity sewer pipelines shall be designed for a minimum velocity of 2 feet/second, Velocity, unless otherwise stated; shall be calculated fmm peak dry weather flow.--· 8. Pipeline slopes shall satisfy the minimum velocity requirement aforementioned. Maximum velocities greater than 10 ft/second should be avoided. Slopes for Specific Pipe Sizes 8 through 12-lnch diameter: 1) ~l 8" minimum 0.40% desirable 0.50% 1 O" minimum 0.28% desirable 0.40% 12" minimum 0.21% desirable 0.30% Slopes for larger than 12-inch diameter pipe shall be designed to meet flow and velocity criteria and require specific approval of the City Engineer. Pipelines with horizontal curvature will require increase slope to achieve minimum required velocities. C. Gravity pipelines with diameters of 12" and less shall be designed to flow at depths of 0.5D during peak hour dry weather flow. Gravity pipelines with diameters greater than 12" shall be designed to flow at depths of 0.75D during peak hour dry weather flow. D. Peak hour sewer flow rates do not include infiltration or inflow (1/1). Infiltration is defined as the addition of groundwater into the sewer collection system and inflow is the addition of storm water into the sewer collection system. Because sewer collection system 1/1 is dependent on a number of factors Including season, age of system, type of pipe material and joints, root intrusion, and presence of storm water system, the 1/1 flow rates will vary from system to system. The design of sewer pipelines connecting to sewer systems known to have 1/1, or are susceptible to 1/1, shall utilize peak wet weather flow estimates from the City of Carlsbad Sewer Master Plan or perform wet weather flow monitoring as directed by the City Engineer. Gravity pipelines designed to convey wet weather flow shall not exceed 0.90D for peak hour wet weather flow. Volume 1 -Chapter 6 Page2 of 8 Rev. 6/30/08 E. Flowrate Generation 1) An Equivalent Dwel ling Unit (EDU) = 220 gal/day, Average Daily Flow (ADF) 2) For ADF less than 100,000 gal/day, a peaking factor (PF) of 2.5 multiplied times the ADF shall' be used to determine Peak Daily Flows (PDF). PDF = ADF x 2.5 3) a) Residential: Single Family Residence= 1 EDU b) Com mercial Property: 1 EDU/1,800 ft2 (building space) i) To convert raw land to square feet of building space, assume 30% coverage. This could vary significantly dependent development constraints. ii) To convert Improved pads to square feet of building space, assume 40% of coverage. Industrial Property: 1 EDU/5,000 ft2 (warehouse space) 1 EDU/1,800 ft2 (office space) 9) ___ To QOrJ.Yert r;:iw_l.and to square Jeet of build ing space, assume 30% coverage. This coul.d vary significantly dependent issues such as environmental restrictions . b) To convert improved pads to square feet of build ing space, assume 40% of coverage. c) Assume 60 % of building space is warehouse, and 40% is office space. 5. HORIZONTAL AND VERTICAL LAYOUT A. Streets: See City of Ca rl sbad Standard Drawing No. GS-6 for location. B. Alley-: Main to ce nterline shall be a minimum of three feet (3') offset. C. Private Street: Shall require special design and conditions. Easement sha ll be 20 feet minimum. D. Horizontal Curve: SOR 35, PVC pipe may be curved horizontally through longitud inal bending with the following limitation: 6-lnch 150 feet 8-inch 200 feet 10-in ch 250 feet 12-inch 300 feet 15-inch 375 feet City Engineer shall approve cu rvatures for larger diameter pipe. Volume 1 -Chapter 6 Page 3 of 8 Rev. 6/30/08 I"" ... -... -------... ------------.. ---.. --------- E. F. G. Vertical Curve: Vertical curves shall be permitted only when specifically approved by the City Engineer. A detailed design drawing shall be required for review and approval. Utility Clearances: Show all underground utilltles in both plan and profile. Provide minimum separation per the State Department of Health Services "GUIDANCE MEMO NO. 2003-02: GUIDANCE CRITERIA FOR THE SEPARATION OF WATER MAINS AND NON-POTABLE PIPELINES". Manholes: Shall be located at areas described as follows: 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) Maximum spacing of manholes shall be three hundred fifty feet (350') for mains twelve inches (12") and smaller and five hundred feet (500') for mains over twelve inches (12") unless otherwise approved by the City Engineer. Install manholes at all changes of slope that exceeds 2% and show inlet and outlet inverts on all manholes. Install manholes at all changes in horizontal direction. Install manholes at all intersections of mains. Install manholes at changes of pipe sizes. Install manholes at the end of all sewer mains. · All standard manholes shall be a minimum of five feet (5') in diameter with no steps. Man holes shall be sequentially numbered on the plans with manhole numbers beginning at the lowest Invert. Three-foot stubs shall be provided for future tie-ins and main extensions. Manholes shall be PVC lined per Std. Dwg. S-1A when: depth is 15-feet or greater; slope of sewer pipe coming info the manhole is greater than 7%; all force main discharge manhofes; the immediate upstream and downstream manholes of inverted siphons; drop manholes; on sewer lines 15-inch and greater; when required by the City Engineer. Where there is a slope change from steep to flat of 5% or greater, the manhole at the grade change and the next manhole upstream shall be PVC lined. Install manholes for all lateral connection in pipelines 15-inch diameter and larger. When lnterceptinq, flows from smaller pipelines in manholes, set invert of a smaller main at ¼ of the depth of the larger main. Locking manhole lids may be required in unpaved areas as directed by the City Engineer . The top cone shall be 6" below finished subgrade. Circular steel covers shall be placed on the manholes during subgrade preparation and base rock grade work, In order to keep the sewer system clean. Additionally, roadwork above live sewer manholes shall require plywood type sheeting be placed inside the manhole and above the channel to keep any debris from entering the sewer line. In unpaved areas, sewer manhole frames and covers shall be set 6"above finished grade with concrete ring and marker post marked "sewer" per Standard Drawing S-9. Volume 1 -Chapter 6 Page 4 of 8 Rev. 6/30/08 .. -.. ----.. ----------------------.. ------ H . I. Cleanouts: Extend beyond permanent pavement when street is a temporary dead end. See Standard Drawing No. S-6 for type of cap and box, Laterals: Laterals shall be constructed per Std. Dwg, No. S-7. Minimum horizontal distance from water service, fire hydrants, light standards, electrical transformers, etc., is 5 feet. Desirable horizontal distance Is 10 feet. 1) 2) 3) 4) 5) 6) 7) Install at right angle or radial to the main. Laterals shall not be located In driveways. No connections shall be permitted on laterals other than provided in Standard Drawing No. S-7. Location of property cleanout: See Standard Drawing No. S-7. If the lowest plumbing fixture on a property is lower than 2-feet above the nearest upstream manhole cover, then the owner must provide a Backwater Valve to prevent a sewage backup onto the property. The valve must be installed In a valve box for easy access and be visible from . the public right-of-way .. The property owner shall. be.responsible for the installation and maintenance of the sewer Backwater Valve.. The Backwater Valve shall be shown on the precise grading and improvement plans. The Contractor shall install sewer laterals using wye fittings sized and located as shown on the Approved Plans. Laterals shall be bedded, backfilled and compacted in the same manner as the sewer main they are connected to. J. Steep Slope Protection: K 1) Sewer pipelines on 20 percent slopes or greater shall be anchored securely with a cut-off wall per RSD SP-05 or SP-07, spaced as follows: a. b, C, Not over 36 feet center to center on grades 20 percent and up to 35 percent; Not over 24 feet center to center on grades 35 percent and up to 50 percent; and Not over 16 feet center to center on grades 50 percent and over. All sewer mains, not located within the public right-of-way shall be provided with a minimum 20-foot wide sewer easement. In some special cases, a wider easement may be required; the City Engineer shall determine size. All easements shall be easily accessible to City maintenance equipment with all weather roadways. Volume 1 -Chapter 6 Page 5 of 8 Rev, 6/30/08 .. .. -.. -.. ... .. -.. -.. -.. .. -- 6 . 7 . CONNECTIONS TO EXISTING MANHOLES New connections to existfng manholes where stubs have not been provided shall be made by core drilling through the walls and base as directed by the City Engineer or their representative. If intercepting flows from smaller pipelines in manholes, set Invert of a smaller main at ¾ of the depth of the larger main. Special care shall be used to facilitate the flow when forming the tributary channel into the existing channel. MISCELLANEOUS REQUIREMENTS A B. C. D. The City of Carlsbad will only maintain sewer mains located in dedicated City right-of-ways and easements which have all weather vehicular access . New sewer lines and appurtenances shall remain plugged and/or disconnected until the City authorizes lts use . Maintenance of sewer laterals from the main to the building shall be the responsibility of the property owner. Sewer laterals constructed from the property line to the building shall be per the Uniform Building Code. 1) 2) 3) The vertical cleanout shall be stubbed and capped 3 feet above rough grade during grading and/or construction of project. All sewer lateral taps on existing sewer lines shall be by "shewer" or approved equal. All work will be Inspected by a City Representative. A three-inch (3") high "S" shall be stamped on the curb face at all sewer lateral locations. ,.. GENERAL GUIDELINES FOR SEWER FORCE MAINS ---------.. ---... - "" .. -.. 1. 2. 3. 4. 5. 6. 7. The developers engineer shall submit a preliminary design report showin~ the alignment, pipe size, pressure conditions, pipe materials, a rough layout plan including surge protection design and flow analysis for review and approval by the City Engineer prior to the preparation of improvement plans. Minimum cover of sewer force mains shall be 48 inches (48") from tof of pipe to ultimate finished grade. Top of pipe profile shall be shown on the improvemen plans. Show all other underground utilities in both plan and profile. Provide minimum clearances per the State of California Department of Public Health (CDPH) "GUIDANCE MEMO NO. 2003-02: GUIDANCE CRITERIA FOR THE SEPARATION OF WATER MAINS AND NON-POTABLE PIPELINES". Sewer force mains shall be High Density Polyethylene (HOPE) manufactured in accordance with ASTM F714, or ductile iron pipe with polyethylene liner, and exterior corrosion control as approved by the City Engineer . Where possible, force mains shall be designed with a continuous uphill slope without high points so that air-release valves are not required on the force mains. If this is not possible, provide air-release valves manufactured by Vent-0-Mat. Dual force mains may be required at the discretion of the City Engineer where maintenance will be required on a regular basis or due to environmental constraints . At the discretion of the City Engineer, Force mains longer than 1-mile or with excessive detention times may require the use of chemical addition to prevent odors at the discharg.e location of!he force main. Volume 1 -Chapter 6 Page 6 of 8 Rev. 6/30/08 EXHIBIT A \ \ \-:::. ~r--J==cc,=9_' _l==i==f7 ~ I . /!L1 ,. • -SALINA GRAPHIC SCALE 50 0 50 100 150 SEWER EXHIBIT FOR: QUARRY CREEK PLANNING AREA '11·4' EAST 453 : I\ ,~, I \ --1.A'GA TE. . \ @ • .• \ ROAO - "". @ LDT 9 DP.F.!V SP.ACF (!'RIVA T£} _ ~· . @ "' -- 3 -- ® • I C7 ® i S.M.H. NO. 403 --------""7'- ---.--. LDT DPDV SP.,lJ CF -' ' _...:::::...~------ p;.-;, NO. ¢ LEGEND PROPERTY UNE/PROJECT BOUNDARY RIGHT-OF-WAY LINE / .// 0 / . t; ! / 0 PROPOSED SEWER AND SEWER MANHOLE CURB AND GUTTER BUILDING NO. EXISTING CONlVUR \ \ ' \ LDT 13 DP£)V SPA CF SEWER EXHIBIT FOR: QUARRY CREEK PLANNING AREA '11·4' EAST -s --0--1s• 0 ~-----395 -----,--..;_; ~,::;---- \~ ___(~ ,__,;, ~\9,, ,,.fj;;- -~"'\-7,I ' ! '\\ '\ PLANNING 3880 Ruffin Road, Suite 120 San Diego, Ca. 92123 85B-560-1 1 41 B5B-560-6157 Fax ,• . i . • I I I ;1 !1 !I ii !I 'I !I !i !1 il Ii ..... ------------------------------------------------------------------------------------------------------------------------------+-!·-' 7-22-16 71632£X08 R-4 EASTSEWER EXHIBIT.DWG j .71~JO g ii <o ~ " "' '4 " ~ "' ~ I ; •J 11 : ; : i 1~"-1--~-