HomeMy WebLinkAboutCUP 2017-0009; ECO-FRIENDLY AUTO SPA; PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR AVENIDA ENCINAS; 2020-02-26CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP) STORM
WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR
AVENIDA ENCINAS
CUP 2017-0009/ CDP 2017-0049, _________ --!,
GR2019-0011
DWG 517-2A
Dan Math, RCE 61013
PREPARED FOR:
PEGGY KELCHER
6030 AVENIDA ENCINAS,
STE. 220
CARLSBAD, CA 92011
760-496-2931
PREPARED BY:
CONSTRUCTION TESTING
ENGINEERS
1441 MONTIEL RD, STE.1 15
ESCONDIDO, 92026
760.746.4955
DATE: February
26, 2020
RECORD COPY
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TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1 a: DMA Exhibit
Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1 d: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment 1 e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 2: Backup for PDP Hydromodification Control Measures
Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas
Attachment 2c: Geomorphic Assessment of Receiving Channels
Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
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CERTIFICATION PAGE
Project Name: Eco Friendly Auto Spa -Avenida Encinas Carwash
Project ID: CUP 2017-0009 / CDP 2017-0049
I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs
for this project, and that I have exercised responsible charge over the design of the project as
defined in Section 6703 of the Business and Professions Code, and that the design is consistent
with the requirements of the BMP Design Manual, which is based on the requirements of
SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order.
I have read and understand that the City Engineer has adopted minimum requirements for
managing urban runoff, including storm water, from land development activities, as described in
the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability
and accurately reflects the project being proposed and the applicable source control and site
design BMPs proposed to minimize the potentially negative impacts of this project's land
development activities on water quality. I understand and acknowledge that the plan check review
of this SWQMP by the City Engineer is confined to a review and does not relieve me, as the
Engineer in Responsible Charge of design of storm water BMPs for this project, of my
responsibilities for project design.
~
Engineer of Work's Signature, PE Number & Expiration Date
Print Name
CTE Inc.
Company
03/04/2020
Date
SITE
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[Insert City's Storm Water Standard Questionnaire (Form E-34) here]
Ccityof
Carlsbad
STORM WATER STANDARDS
QUESTIONNAIRE
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
E-34
I INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY
DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City
staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and signed questionnaire must be submitted with each development project application. Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECT INFORMATION
PROJECT NAME: ECO-FRIENDLY AUTO SPA PROJECT ID: CUP 2017-009
GR2019-0011
ADDRESS: 6010 Avenida Encinas, Ste 220, Carlsbad , CA APN: 211-030-28
The project is (check one): D New Development IZI Redevelopment
The total proposed disturbed area is: 50,095 ft2 ( 1.15 ) acres
The total proposed newly created and/or replaced impervious area is: 39,469 ft2 ( 0.91 ) acres
If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
Project ID SWQMP#:
Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
E-34 Page 1 of 4 REV 02/16
STEP1
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building □ Ill or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If vou answered "no" to the above Question, the project is a 'development project', go to Step 2.
STEP2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-
erodible permeable areas; □ Ill b) Designed and constructed to be hydraulically disconnected from paved streets or roads;
c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets QUidance?
2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in □ Ill accordance with the USEPA Green Streets guidance?
3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? □ Ill
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ... " and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
If you answered "no" to the above Questions, vour proiect is not exempt from PDP, QO to Step 3.
E-34 Page 2 of 4 REV 02/16
STEP3 !:,,... ~. -.., . -TOIII COMPl.eTIO Foft AU;. NIW M _ ~r-·-~ ... ---. . •· .. , ... ..
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )):
YES NO
1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, □ Ill
and public development projects on public or private land.
2. Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of
impervious surface collectively over the entire project site on an existing site of 10,000 square feet or Ill □ more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is
a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and □ Ill
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside □ Ill
development project includes development on any natural slope that is twenty-five percent or greater.
5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is □ Ill a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a street, road, highway □ Ill freeway or driveway? A street, road, highway, freeway or driveway is any paved impervious surface
used for the transportation of automobiles, trucks, motorcycles, and other vehicles.
7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site, and discharges directly to an Environmentally
Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of □ Ill
200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to the ESA (i.e. not comminaled with flows from adjacent lands).*
8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop? An automotive repair □ Ill shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.
9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes □ Ill RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily
Traffic (ADTI of 100 or more vehicles per day.
10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land Ill □ and are expected to generate pollutants post construction?
11. Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC □ Ill
21 .203.040)
If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... "
and complete applicant information.
If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the
second box stating "My project is a 'STANDARD PROJECT' ... " and complete aoolicant information.
E-34 Page 3 of 4 REV 02/16
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
Existing impe~ious area (A)= 44,025 sq. ft. D
Total proposed newly created or replaced impervious area (B) = _3_9_,4_6_9 ________ sq. ft.
Percent impervious area created or replaced (B/A)*100 = 86 %
Ill
If you answered ·yes·, the structural BMPs required for PDP apply only to the creation or replacement of impervious
surface and not the entire development. Go to step 5, check the first box stating "My project is a PDP .. ." and complete
applicant information.
If you answered "no,• the structural BMP's required for PDP apply to the entire development. Go to step 5, check the
h k th fi t b tati "M 1• ct . PDP • d I t . t . 1 f . . . . .
•• ":M •• : • -...: • •• -· • :-• .... : ~ ~ ~ , ' -.;
~-,. . . . ~· "\?.:'. ,
Ill My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
0 My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT'
stormwater requirements of the BMP Manual. As part of these requirements, I will submit a • Standard Project
Requirement Checklist Fonn E-3~ and incorporate low impact development strategies throughout my project.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations
and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply.
D My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Name: PEGGY KELCHER
Applicant Signature: ::f~,-t6~ D
Applicant Title: PROPERTY DIRECTOR
Date: t; /~ ~~ \'j
• Environmentally Sensitive Areas include but are not limited to all Clean Water I'd Section 303(d) impaired water bodies; areas designated as Areas of Special
Biological Significance by the State Water Resources Control Board ,:,Nater Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (YVateK Quality Control Plan for the San Diego Basin (1994) and
amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County d Sen Diego; Habitat
Management Plan; and any ether equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Only
YES NO
City Concurrence: □ □
By:
Date:
Project ID:
E-34 Page 4 of 4 REV02/16
SITE INFORMATION CHECKLIST
ProJect Summarv lnfonnatlon
Project Name Eco Friendly Auto Spa -Avenida Encinas Carwash
Project ID tUP2017-0009
Project Address 6010 Avenida Encinas
!Carlsbad, CA 92011
Assessor's Parcel Number(s) (APN(s)) 211-030-28
Project Watershed (Hydrologic Unit) Carlsbad 904
Parcel Area
1.150 Acres ( 50095 Sauare Feet}
Existing Impervious Area
(subset of Parcel Area) 1.010 Acres ( 44025 Square Feet)
Area to be disturbed by the project
1.1 50 (Project Area) Acres ( 50095 Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 0.906 Acres (39,469 Square Feet)
Project Proposed Pervious Area
(subset of Project Area) 0.305 Acres ( 13,277 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
This mav be less than the Parcel Area.
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
X Existing development
□ Previously graded but not built out
D Agricultural or other non-impervious use
□ Vacant, undeveloped/natural
Description / Additional Information:
Existing Land Cover Includes (select all that apply):
X Vegetative Cover
□Non-Vegetated Pervious Areas
X Impervious Areas
Description / Additional Information: Pavement, building, landscaping.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
D NRCS Type A
D NRCS Type B
D NRCS Type C
X NRCS Type D
Approximate Depth to Groundwater (GW):
D GW Depth < 5 feet
D 5 feet < GW Depth < 10 feet
□ 1 0 feet < GW Depth < 20 feet
X GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
□ Watercourses
□ Seeps
□ Springs
□Wetlands
XNone
Description / Additional Information:
Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from
the site? At a minimum, this description should answer (1) whether existing drainage
conveyance is natural or urban; (2) describe existing constructed storm water conveyance
systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]:
lfhe existing site is urban conveyance consisting of sheet flow directed west out the driveways to the
public road Avenida Encinas. There are no natural features. There is no storm drain on the site. Runoff
K:onveying along Avenida Encinas joins surface flow which is captured in an underground storm drain
system which discharges west via a road culvert into what appears to be an artificial 5 foot deep pond. It
appears that higher flows pond up and continue as overland flow further west into an existing concrete
ditch along the rail road ROW continuing south. The ditch discharges into a box culvert crossing under the
rail road to enter the ocean. A flat area subject to tidal inundation which is vegetated and not a defined
channel lies between the RCB headwall and the ocean. There are no natural waterbodies which are subject
to erosion or require hydromodification protection.
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities: The site is a commercial I industrial
use which will have a car wash and parking. Car wash waters will not join runoff.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features): The site is pavement for parking,
drive aisles, and walkways, building, and landscaping over 1.15 acres. The site is mild to
moderate sloping with no amenities or public use spaces.
List/describe proposed pervious features of the project (e.g., landscape areas): Pervious features
include landscape areas and the BMP biofiltration basins.
Does the project include grading and changes to site topography?
XYes
□No
Description / Additional Information: The existing site and building will be demolished. The
proposed site grading will be similar to existing grades.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
XYes
□No
Description / Additional Information: The BMP's will have storm drain which will connect to the
adjacent private storm drain near the connection to the street public storm drain.
Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
X On-site storm drain inlets
□ Interior floor drains and elevator shaft sump pumps
□ Interior parking garages
X Need for future indoor & structural pest control
X Landscape/Outdoor Pesticide Use
□ Pools, spas, ponds, decorative fountains, and other water features
□ Food service
X Refuse areas
□ Industrial processes
□ Outdoor storage of equipment or materials
X Vehicle and Equipment Cleaning
□ Vehicle/Equipment Repair and Maintenance
□ Fuel Dispensing Areas
□ Loading Docks
□ Fire Sprinkler Test Water
□ Miscellaneous Drain or Wash Water
X Plazas, sidewalks, and parking lots
Identification of Recelvlna Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable): Hardened storm drain system leads directly to the Pacific Ocean.
See attached exhibits. The runoff exists the site in a storm drain connection to a public system
which discharges into a small artificial pond, continues west into a concrete ditch, then south
and conveyed further west by an existing RCB culvert under the railroad tracks, and into
vegetated tidelands without entering a natural channel.
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable}, identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs
none
Identification of Project Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
BMP Design Manual Appendix B.6):
Also a Receiving
Not Applicable to Anticipated from the Water Pollutant of
Pollutant the Project Site Project Site Concern
X
Sediment
X
Nutrients
X
Heavy Metals
X
Organic Compounds
X
Trash & Debris
Oxygen Demanding X
Substances
X
Oil & Grease
X X
Bacteria & Viruses
X
Pesticides
9 Regional Board 9 -San Diego Region Pacific Ocean Shoreline, Batiquitos HSA, at Moonlight State
Beach (Cottonwood Creek outlet) CAC9045100020091026142908 Coastal & Bay Shoreline C 5
1807303 90451000 0 Miles Total Coliform Fecal Indicator Bacteria Do Not
Delist from 303(d) list (TMDL required list) Original SA 2019 Source
Unknown A SOURCE UNKNOWN
ulrements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
□ Yes, hydromodification management flow control structural BMPs required.
X No, the project will discharge runoff directly to existing underground storm drains discharging
directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
□ No, the project will discharge runoff directly to conveyance channels whose bed and bank are
concrete-lined all the way from the point of discharge to water storage reservoirs, lakes,
enclosed embayments, or the Pacific Ocean.
□ No, the project will discharge runoff directly to an area identified as appropriate for an
exemption by the WMAA for the watershed in which the project resides.
Description/ Additional Information (to be provided if a 'No' answer has been selected above):
See Exhibit for depiction of the flowpath going from the site to the ocean over hardened drainage
facilities with no natural channel.
Critical Coarse Sediment Yield Areas*
*This Section on ulred If h romodlftcatlon mana ernent ulrernents a
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
□Yes
X No, No critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual
been performed?
□ 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
□ 6.2.2 Downstream Systems Sensitivity to Coarse Sediment
□ 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
□ No optional analyses performed, the project will avoid critical coarse sediment yield areas
identified based on WMAA maps
If optional analyses were performed, what is the final result?
D No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
□ Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
□ Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas
are identified on the SWQMP Exhibit.
Discussion / Additional Information:
Flow Control for Post.Project Runoff"
*This Section onl ulred If h dromodlflcatlon mana ement ulrernents a
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see Section 6.3.1 ). For each POC, provide a POC identification name or number
correlating to the project's HMP Exhibit and a receiving channel identification name or number
correlating to the project's HMP Exhibit.
NA
Has a geomorphic assessment been performed for the receiving channel(s)?
D No, the low flow threshold is 0.102 (default low flow threshold)
D Yes, the result is the low flow threshold is 0.102
o Yes, the result is the low flow threshold is 0.302
D Yes, the result is the low flow threshold is 0.502
If a geomorphic assessment has been performed, provide title, date, and preparer:
NA
Discussion/ Additional Information: (optional)
Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or City
codes governing minimum street width, sidewalk construction, allowable pavement types, and
drainage requirements.
NA
Optional Additional lnfonnatlon or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
NA
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-----[Insert City's Standard Project Requirement Checklist Form E-36 (here)]
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C City of
Carlsbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project Information
Project Name: ECO-FRIENDLY AUTO SPA
Project ID: CUP2017-0009
DWG No. or Building Permit No.: DWG 517-2A
Source Control BMPs
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual for information to implement source control BMPs shown in this
checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 Ill Yes □ No ON/A
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage Ill Yes O No ON/A
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □Yes □ No ~ N/A Dispersal
Discussion/justification if SC-3 not implemented:
No outdoor materials storage areas on proposed project.
E-36 Page 1 of 4 Revised 03/16
Source Control Requirement (continued) Annlled?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and □Yes □ No 1Z1 N/A Wind Dispersal
Discussion/justification if SC-4 not implemented:
No materials stored in outdoor work areas on project.
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal □Yes □ No 1Z1 N/A
Discussion/justification if SC-5 not implemented:
No outdoor trash storage areas on project.
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for Quidance).
IZI On-site storm drain inlets IZI Yes D No □ N/A
□ Interior floor drains and elevator shaft sump pumps □Yes □ No 1Z1 N/A
□ Interior parking garages □Yes □ No 1Z1 N/A
□ Need for future indoor & structural pest control □Yes □ No 1Z1 NIA
IZI Landscape/Outdoor Pesticide Use IZI Yes □ No □ N/A
□ Pools, spas, ponds, decorative fountains, and other water features □Yes □ No 1Z1 NIA
□Foodservice □Yes □ No 1Z1 N/A
□ Refuse areas □Yes D No 1Z1 N/A
□ Industrial processes □Yes □ No 1Z1 N/A
□ Outdoor storage of equipment or materials □Yes □ No 1Z1 NIA
□ Vehicle and Equipment Cleaning □Yes □ No 1Z1 N/A
□ Vehicle/Equipment Repair and Maintenance □Yes □ No 1Z1 N/A
□ Fuel Dispensing Areas □Yes D No 1Z1 NIA
□ Loading Docks □ Yes □ No 1Z1 N/A
□ Fire Sprinkler Test Water □Yes □ No 1Z1 N/A
□ Miscellaneous Drain or Wash Water □Yes D No 1Z1 N/A
□ Plazas, sidewalks, and parkinQ lots □Yes □ No 1Z1 N/A
For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers.
On-ste storm drain inlets:
Mark all inlets with the words "No Dumping! Flows to Bay" or similar.
All interior floor drains will be plumbed to sanitary sewer.
Landscape/Outdoor Pesticide Use:
Use low irrigated or drought tolerant plants.
E-36 Page 2 of 4 Revised 03/16
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual for information to implement site design BMPs shown in
this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion/ justification is not required.
• "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Source Control Requirement I Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features I IZl Yes I D No ID N/A
Discussion/justification if SD-1 not implemented:
SD-2 Conserve Natural Areas, Soils, and Vegetation I IZl Yes I D No I □ N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize Impervious Area I IZl Yes I D No ID N/A
Discussion/justification if SD-3 not implemented:
SD-4 Minimize Soil Compaction I IZl Yes I D No ID NIA
Discussion/justification if SD-4 not implemented:
SD-5 Impervious Area Dispersion I IZl Yes I D No ID NIA
Discussion/justification if SD-5 not implemented:
E-36 Page 3 of 4 Revised 03/16
Source Control Reauirement (continued) I Annlled?
SD-6 Runoff Collection I 121 Yes I □ No I □ NIA
Discussion/justification if SD-6 not implemented:
SD-7 Landscaping with Native or Drought Tolerant Species I 121 Yes I 0 No I □ N/A
Discussion/justification if SD-7 not implemented:
SD-8 HarvestinQ and UsinQ Precipitation I D Yes I 1Z1 No I □ N/A
Discussion/justification if SD-8 not implemented:
Harvest and use is considered to be infeasible.
See Appendix 1c for additional info.
E-36 Page 4 of 4 Revised 03/16
SUMMARY OF PDP STRUCTURAL BMPS
PDP Structural BMPa
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of
the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control
must be based on the selection process described in Chapter 5. PDPs subject to
hydromodification management requirements must also implement structural BMPs for flow
control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both
storm water pollutant control and flow control for hydromodification management can be
achieved within the same structural BMP(s).
PDP structural BMPs must be verified by the City at the completion of construction. This may
include requiring the project owner or project owner's representative to certify construction of
the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must
be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the
BMP Design Manual).
Use this form to provide narrative description of the general strategy for structural BMP
implementation at the project site in the box below. Then complete the PDP structural BMP
summary information sheet for each structural BMP within the project (copy the BMP summary
information page as many times as needed to provide summary information for each individual
structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information
must describe how the steps for selecting and designing storm water pollutant control BMPs
presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of
BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether
pollutant control and flow control BMPs are integrated together or separate.
The commercial I industrial site conveys runoff as surface flow to available landscape areas
which contain BMP treatment devices prior to discharging runoff to the existing underground
storm system.
The proposed structural BMPs consists of lined bio-filtration facilities, there is a high
probability of soil contamination due to current land uses i.e. vehicle maintenance, and
stationary used vehicle that have been subject to motor oil leakage.
HMP Exempt -The runoff conveys through hardened drainage features up to the ocean.
[Continue on next page as necessary.]
[Continued from previous page -This page is reserved for continuation of description of general
strategy for structural BMP implementation at the site.]
Structural BMP Summary lnfonnatlon
[Copy this page as needed to provide lnfonnatlon for each lndlvldual proposed
structural BMP]
Structural BMP ID No. BMP1
DWG 517-2A Sheet No. 3 5
Type of structural BMP:
o Retention by harvest and use (HU-1)
D Retention by infiltration basin (I NF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1)
X Biofiltration (BF-1)
D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
D Detention pond or vault for hydromodification management
D Other (describe in discussion section below)
Purpose:
X Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control
D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Discussion (as needed):
Per BMP spreadsheet, the drawdown time of the surface has been met to comply with the DEH
drawdown guidelines for vector control.
Structural BMP Summary lnfonnatlon
[Copy this page as needed to provide lnfonnatlon for each lndlvldual proposed
structural BMPl
Structural BMP ID No. BMP2
DWG 517-2A Sheet No. 3 5
Type of structural BMP:
□ Retention by harvest and use (HU-1)
D Retention by infiltration basin (INF-1)
□ Retention by bioretention (INF-2)
□ Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1)
X Biofiltration (BF-1)
□ Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
D Detention pond or vault for hydromodification management
D Other (describe in discussion section below)
Purpose:
X Pollutant control only
□ Hydromodification control only
D Combined pollutant control and hydromodification control
□ Pre-treatment/forebay for another structural BMP
□ Other (describe in discussion section below)
Discussion (as needed):
Per BMP spreadsheet, the drawdown time of the surface has been met to comply with the DEH
drawdown guidelines for vector control.
..
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 1 a OMA Exhibit (Required)
Attachment 1 b
Attachment 1 c
Attachment 1 e
See OMA Exhibit Checklist on the
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Tabular Summary of DMAs Showing
OMA ID matching OMA Exhibit, OMA
Area, and OMA Type (Required)*
*Provide table in this Attachment OR
on OMA Exhibit in Attachment 1 a
Form 1-7, Harvest and Use Feasibility
Screening Checklist (Required unless
the entire project will use infiltration
BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)
Refer to Appendices C and D of the
BMP Design Manual to complete
Form 1-8.
X Included
X Included on OMA Exhibit in
Attachment 1 a
□ Included as Attachment 1 b,
separate from OMA Exhibit
X Included
□ Not included because the entire
project will use infiltration BMPs
X Included
□ Not included because the entire
project will use harvest and use
BMPs
-GEO LETTER-
AND BIO-FILTRATION
FACT SHEET
Attachment 1d Pollutant Control BMP Design X Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
Use this checklist to ensure the required information has been included on the OMA
Exhibit:
The OMA Exhibit must identify:
X □ Underlying hydrologic soil group
X □ Approximate depth to groundwater
X □ Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
X □ Critical coarse sediment yield areas to be protected (if present)
X □ Existing topography and impervious areas
X □ Existing and proposed site drainage network and connections to drainage offsite
X □ Proposed grading
X □ Proposed impervious features
X □ Proposed design features and surface treatments used to minimize imperviousness
X □ Drainage management area (OMA) boundaries, OMA ID numbers, and OMA areas
(square footage or acreage), and OMA type (i.e., drains to BMP, self-retaining, or self-
mitigating)
X □ Structural BMPs (identify location and type of BMP)
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 2a Hydromodification Management □ Included
Exhibit (Required)
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of Critical Coarse □ Exhibit showing project drainage
Sediment Yield Areas (WMAA Exhibit boundaries marked on WMAA
is required, additional analyses are Critical Coarse Sediment Yield
optional) Area Map (Required)
See Section 6.2 of the BMP Design Optional analyses for Critical Coarse
Manual. Sediment Yield Area Determination
□ 6.2.1 Verification of Geomorphic
Landscape Units Onsite
□ 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
□ 6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
Attachment 2c Geomorphic Assessment of Receiving X Not performed
Channels (Optional) □ Included
See Section 6.3.4 of the BMP Design
Manual.
Attachment 2d Flow Control Facility Design and □ Included
Structural BMP Drawdown X Not Included
Calculations (Required)
HMP NOT REQUIRED See Chapter 6 and Appendix G of the
Attachment 3 Structural BMP Maintenance X Included
Thresholds & Actions □ Not Included
Use this checklist to ensure the required information has been included on the
Hydromodification Management Exhibit:
The Hydromodification Management Exhibit must identify:
□ Underlying hydrologic soil group
□ Approximate depth to groundwater
□ Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)
□ Critical coarse sediment yield areas to be protected (if present)
□ Existing topography
□ Existing and proposed site drainage network and connections to drainage offsite
□ Proposed grading
□ Proposed impervious features
□ Proposed design features and surface treatments used to minimize imperviousness
□ Point(s) of Compliance (POC) for Hydromodification Management
□ Existing and proposed drainage boundary and drainage area to each POC (when necessary,
create separate exhibits for pre-development and post-project conditions)
□ Structural BMPs for hydromodification management (identify location, type of BMP, and
size/detail)
ATTACHMENT 3
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural
BMP Maintenance Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
X □Typical maintenance indicators and actions for proposed structural BMP(s) based
on Section 7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
□ Specific maintenance indicators and actions for proposed structural BMP(s). This
shall be based on Section 7.7 of the BMP Design Manual and enhanced to reflect
actual proposed components of the structural BMP(s)
□ How to access the structural BMP(s) to inspect and perform maintenance
□ Features that are provided to facilitate inspection (e.g., observation ports,
cleanouts, silt posts, or other features that allow the inspector to view necessary
components of the structural BMP and compare to maintenance thresholds)
□ Manufacturer and part number for proprietary parts of structural BMP(s) when
applicable
□ Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level
posts or other markings shall be included in all BMP components that will trap and
store sediment, trash, and/or debris, so that the inspector may determine how full
the BMP is, and the maintenance personnel may determine where the bottom of
the BMP is. If required, posts or other markings shall be indicated and described
on structural BMP plans.)
□ Recommended equipment to perform maintenance
□ When applicable, necessary special training or certification requirements for
inspection and maintenance personnel such as confined space entry or
hazardous waste management
ATTACHMENT 1A
STEM WALL SEE
I
...J
0 ~
' z < t")<(~O:::
[/) I') C>
<{ w o._
...J
' ~ co <{
~ 0::
C>
I ATOP I
AaMP = AGRAVEL = AAMMENDED s = AaOT
6" PVC PERF. DRAIN
CURB/WALL
LINED SIDES AND BOTTOM
BIORETENTION ENGINEERED SOIL LA'!ER SH ALL BE MINIMUM 18" DEEP SANDY LOAM SOIL MIX \\!TH NO MORE
THAN 5% CLAY CONTENT. THE MIX SHALL CONTAIN 50-60% SAND, 20-30% COf.lPOST OR HARDWOOD MULCH,
AND 20 -30% TOPSOIL 0 BIO-FILTRATION FAC ILITY DETAIL
NOT TOSCAI.£
TOTAL LOT AREA = 1.15 ACRES
TOTAL DISTURBED AREA = 1.15 ACRE
(THIS AREA INCLUDES BUT IS NOT LIMITED TO
OFF-SITE WORK INCLUDING PUBLIC IMPROVEMENTS
AND TEMPORARY DISTURBANCE SUCH AS VEHICLE
AND EQUIPMENT STAGING AREAS, CONSTRUCTION
WORKER FOOT TRAFFIC, SOIL/GRAVEL PILES, UTILITY
TRENCHES, BACKFILL CUTS ANO SLOPE KEYWA YS)
TOTAL CREA TEO/REPLACED IMPERVIOUS AREA = 39.469 SF
DMA SUMMARY
DMA-1 -DRAINS TO BllflL TRA TION BASIN
SURFACE TYPE AREA (SF)
ROOF /PAVEMENT 33,219
LANDSCAPE 8,897
DMA-2 -DRAINS TO BILFIL TRA TION BASIN
SURFACE TYPE AREA (SF)
ROOF /PAl£MENT 6,108
LANDSCAPE 4,353
DMA-3 -DRAINS TO ROAD -OE MINIMUS
SURFACE TYPE AREA (SF)
PAVEMENT
LANDSCAPE
□MA SUMMARY
DMAID
DMA-1A
DMA-1B
TOTAL
DMAID
DMA-2A
DMA-2B
TOTAL
DMAID
DMA-3A
De Minimus
TOTAL
Roof/Pa\Ement
Landscape
Rooii'Pai.ement
Landscape
Roof/Pa\ement
Landscape
92
77
Type
Type
Type
Tota l Area
SF
33,219
8,897
42,1 16
Total Area
SF
6.108
4,353
10,461
Total Area
SF
92
77
169
Total Area
Acres
0.763
0.204
0.967
Total Area
Acres
0.140
0.100
0.240
Tota l Area
Acres
0.002
0.002
0.004
7
DMA-3
DE MIN/MIS
AREA
(ONSITE)
169SF -_,-,-.._
\
AJ .. ~ Construction Testing & Engineering, In c. ~CIE ~~-~---1-~-~-,g-l -Geotedm--~--1-~-~-~~t-d_&_Cmtatru_~~~~-iiesi,g--~~-~-~--g~l-~-~g
~ ~ 1441 Montiel Road, Suite 115, Escondido, CA 92026 Phone: (760) 746 -4955 fax: (760) 746 -9806
"'
DMA EXHIBIT -SWQMP
' \
\ PARC EL NO.
20'
PARCEL NO.
9.755 AC.
PM 1310
PM 1538 6
0 20'
SCALE: 1" = 20'
2
3
"..____
"..____
\
···-··-··-··>
ATTACHM ENT 1A
OMA EXH IBIT
BIO-FIL ffiA TION BMP
OMA BOUNDARY
DRAINAGE FLOW PATH & DIRECTION
LANDSCAPED AREAS
NO TES:
1. THE UNDERLYING SOIL TYPE GROUP IS "D" FOR THE ENTIRE PROPERTY AND SURROUNDING PARCELS
2. DEPTH TO GROUND WATER IS GREATER THAN 20 FEET
3. NO CCSYA TO PROTECT
4. EXEMPT FROM HYDROMODIFICATION
5. WA TER RUNOFF GENERATED WITHIN CAR WA SH, TO ENTER PUBLIC SEWER SYSTEM
40'
..
..
ATTACHMENT 18 •
...
...
....
..
..
....
..
..
Worksheets for PDP SWQMP.xlsx:Attach 1.b DMA & DCV Summary
I PDP SWQMP ATTACHMENT 1.b City of Carlsbad
TABULAR SUMMARY OF DRAINAGE MANAGEMENT AREAS (DMAs) AND DESIGN CAPTURE VOLUME (DCV) CALCULATIONS
~
I
Project Name: TOYOTA CARWASH
Date: 8/1/2019
85th Percentile Rainfall (inches):
I DMAID: 1 I
Hydrologic Soil Group
(A, B, C, or D)
D
D
Post-Project Surface
Type
(See Table 8.1-1)
Pervious: Landscape
Impervious: No Runoff
Reduction
o.ss]
Area of Surface Type
(ft2)
8,847
33,219
Permit No.: ---------Prepared by: CTE Consulting Inc
Post-Project Surface
Runoff Factor (C)
(See Table 8.1-1)
0.10
0.90
Runoff Reduction from Site
Design BMPs
(Select Only One)
NA: Pervious
None Claimed
Tribuary
Impervious/
Receiving
Pervious Area
Ratio1
NA
NA
C Factor Adjustment2
(See Table 8.2-1 )
1
1
Final C
Factor
0.1
0.9
Total OMA Area (ft")I 42,066 I 0.73 Weighted Average C Factor for OMA 1 -· 1
85th Percentile Rainfall (inches):
I DMAID:2
Hydrologic Soil Group
(A, B, C, or D)
D
D
Post-Project Surface
Type
(See Table 8.1-1)
Pervious: Landscape
Impervious: No Runoff
Reduction
o.ss]
Area of Surface Type
(ft2)
4,353
6,108
Total OMA Area (ft")I 10,461 I
Post-Project Surface
Runoff Factor (C)
(See Table 8.1-1)
0.10
0.90
Tribuary
Impervious/
Runoff Reduction from Site Receiving
Design BMPs Pervious Area
(Select Only One) Ratio1
NA: Pervious NA
None Claimed NA
C Factor Adjustment2
(See Table 8.2-1 )
1
1
Weighted Average C Factor for OMA
Final C
Factor
0.1
0.9
0.57 ..., ___ ..
Street Tree Rain Barrel
Volume Volume Design Capture
Reduction3 4 Reduction Volume (DCV)5
(ft3) (ft3) . (ft3)
0 0 43
0 0 1445
Total OCV for OMA (ft~)I 1,488 I
Street Tree Rain Barrel
Volume Volume Design Capture
Reduction 3 Reduction 4 Volume (DCV)5
(ft3) (ft3) (ft3)
0 0 21
0 0 266
Total OCV for OMA (ft") 287 -------
PDP SWQMP Worksheet B.2-1
Design Capture Volume Calculations
DMAs Requiring BMPs
DMANo.1 I
1 85th percentile 24-hr storm depth (Figure B.1-1)
2 Area tributary to BMP(s)
3 Area weighted runoff factor (Appendix B.1.1 and B.2.1)
4 Calculated DCV [C*d/12*A]
DMANo.2 I
1 85th percentile 24-hr storm depth (Figure B.1-1)
2 Area tributary to BMP(s)
3 Area weighted runoff factor (Appendix B.1.1 and B.2.1)
4 Calculated DCV (C*d/12*A]
I
I
I
City of Carlsbad
d= 0.58 inches
A= 42,116 square-ft
C= 0.73 unitless
DCVc= 1486 cubic-feet
d= 0.58 inches
A= 10,461 square-ft
C= 0.57 unitless
DCVc= 288 cubic-feet
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs -DMA-1
~;nnm ,,.,,~
mplementing retention BMPs 1 488 cubic-
' feet
Partial Retention
2 Infiltration rate from Form 1-9 if partial infiltration is feasible 0 in/hr.
3 Allowable drawdown time for a!!1rregate storage below the underdrain hours
4 Depth of runoff that can be infiltrated [Line 2 x Line 31 0 inches
5 A!!1rregate pore space 0.40 in/in
6 Required depth of gravel below the underdrain [Line 4/ Line 51 0 inches
7 Assumed surface area of the biofiltration BMP 950 sq-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8))/12) x Line 7 166.25 cubic-
feet
10 DCV that requires biofiltration [Line 1 -Line 9) 1,322 cubic-
feet
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximuml JO inches
12 Media Thickness [18 inches minimum], also add mulch layer thickness to 21 inches this line for sizing calculations
13 Aggregate Storage above underdrain invert (12 inches typical) -use O inches
for sizing if the aggregate is not over the entire bottom surface area 12 inches
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the
filtration is controlled by the outlet, use the outlet controlled rate) 5.00 in/hr.
Baseline Calculations
16 Allowable Routing Time for sizing 6 hours
17 Depth filtered during storm [ Line 15 x Line 16) 30.00 inches
18 Depth of Detention Storage inches
[Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)) 19
19 Total Depth Treated [Line 17 + Line 18) 49.00 inches
Option 1-Biofilter "1.5" times the DCV
20 Required biofiltered volume [1.5 x Line 1 OJ 1982.63 cubic-feet
21 Required Footprint !Line 20/ Line 191 x 12 486 SQ-ft
Option 2-Store 0.75 ofremainiruz DCV in pores and ponding
22 Required Storage ( surface + pores) Volume ro. 7 5 x Line 1 Ol 991.3125 cubic-feet
23 Required Footprint [Line 22/ Line 18) x 12 626 sq-ft
Footprint of the BMP
24 Area draining to the BMP 42,116 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.J and B.2) 0.73
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03) 922 sq-ft
27 Footprint of the BMP = Maximum(Minimum(Line 21 , Line 23), Line 26) 922 sq-ft
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs -DMA-2 F,!! ............. _, .. ,~
DCV after implementing retention BMPs 287 cubic-
feet
Partial Retention
2 Infiltration rate from Form 1-9 if partial infiltration is feasible 0 i1
3 Allowable drawdown time for agirregate storage below the underdrain 36 hours
4 Depth of runoff that .IJ i 111 d fLine 2 x Line 31 0 inches
5 Agirregate pore spa 0.40 in/in
6 Required depth of irr1 1 below the underdrain fLine 4/ Line 51 0 inches
7 Assumed surface area of the biofiltration BMP 400 SQ-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Line 7 70 cubic-
feet
10 DCV that requires biofiltration [Line I -Line 9] 217 cubic-
feet
BMP Parameters
11 Surface Ponding r6 inch minimum, 12 inch maximuml 10 inches
12 Media Thickness [18 inches minimum], also add mulch layer thickness to 21 inches this line for sizing calculations
13 Aggregate Storage above underdrain invert (12 inches typical)-use 0 inches
for sizing if the aggregate is not over the entire bottom surface area 12 inches
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the
filtration is controlled by the outlet, use the outlet controlled rate) 5.00 in/hr.
Baseline Calculations
16 Allowable Routing Time for sizing 6 hours
17 Depth filtered during storm [ Line 15 x Line 16] 30.00 inches
18 Depth of Detention Storage inches
[Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)] 19
19 Total Depth Treated [Line 17 + Line 18] 49.00 inches
Option 1-Biofilter "1.5" times the DCV
20 Required biofiltered volume [1 .5 x Line 1 0] 325.50 cubic-feet
21 Required Footprint fLine 20/ Line 191 x 12 80 sq-ft
Option 2 -Store 0.75 of remaining DCV in pores and ponding
22 Required Storage (surface+ pores) Volume f0.75 x Line 101 162.75 cubic-feet
23 Required Footprint [Line 22/ Line 18] x 12 103 sq-ft
Footprint of the BMP
24 Area draining to the BMP 10,461 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2) 0.57
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03] 179 sq-ft
27 Footprint of the BMP = Maximum(Minimum(Line 21 , Line 23), Line 26) sq-ft 179
ATTACHMENT 1C
Appendix I: Forms and Checklists
Han·cst and llsc Fcasihiliry Checklist Form 1-7
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
liiJ Toilet and urinal flushing
D Landscape irrigation 0 Other:. _____ _
2. I ere is a eman ; esbmate e antlcipate average wet season demand overa period of 36 hours. Guidance
for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section
B.3.2. Flushing: (15 employees)x(9.3 gal/emp) = 139.5 >» (55.8 gal)(1.5 days))/(7.48 gal/cu.ft.) = 27.97 cu.ft.
Irrigation: 36-hr Mod. Water per Table 8.3-3 = (1,470 gal days/acre)(0.26)/(7.48gal/cu feet)= 51.10 cu. ft.
Total demand= 79 cu. ft
3. Calculate the DCV using worksheet B.2-1.
DCV = _1754_ (cubic feet)
3a. Is the 36 hour demand greater
than or equal to the DCV?
□Yes /@ c::> -0,
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations
to confirm that DCV can be used
at an adequate rate to meet
drawdown criteria.
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV? □Yes /@ ~
.(),
Harvest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to detemiine
feasibility. Harvest and use may only be
able to be used for a portion of the site,
or (optionally) the storage may need to be
upsized to meet long term capture targets
while draining in longer than 36 hours.
Is harvest and use feasible based on further evaluation?
0 Yes, refer to Appendix E to select and size harvest and use BMPs.
X No, select alternate BMPs.
1-2
3c. Is the 36 hour demand
lessth~CV?
'T
Harvest and use is
considered to be infeasible.
NO
February 2016
June I, 2017
Toyota Carlsbad
Construction Testing & Engineering, Inc.
Inspection I Testing I Geotechn!cal I Environmental & Cons1ruction Engineering I Civl Engineering I Surveying
CTE Job No. 10-13214T
Attention: Ms. Peggy Keicher
5424 Paseo Del Norte
Carlsbad, California 92008
Telephone: (858) 679-1185 Via Email: pkelcher@toyotacarlsbad.com
Subject:
References:
Ms. Keleher:
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
6010 A venida Encinas
Carlsbad, California
Geotechnical Investigation
Proposed Carlsbad Toyota Car Wash
60 l 0 Avenida Encinas, Carlsbad, California
CTE Job No. 10-13214T
Dated September 16, 2016.
As Requested, Construction Testing and Engineering (CTE) performed four percolation tests and
two additional confirmation borings within the proposed biofiltration basin areas. The
percolation tests were performed in general accordance with the County of San Diego
Department of Environmental Health (SD DEH) procedures.
Percolation test holes and borings were excavated on May 11, 2017 with a truck-mounted drill
rig equipped with eight-inch diameter hollow-stem augers. Due to limited access, percolation
test holes P-1 and P-2 were excavated with a manually operated six-inch diameter. The
percolation tests were performed at the approximate elevations of proposed discharge.
Confirmation borings were excavated adjacent to each of the proposed basin areas to a depth of
approximately 20 feet bgs in order to verify that groundwater was not located within 10 feet of
the proposed discharge elevations. These explorations were performed to supplement the
previous exploratory borings advanced by CTE during the geotechnical investigation (9-16-16).
1.0 Groundwate1· Conditions
Groundwater was not encountered during the previous geotechnical investigation and was not
observed in either of the recent confirmatory borings that were advanced to a maximum explored
1441 Montiel Road, Suite 115 I Escondido, CA 92026 Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
6010 Avenida Encinas, Carlsbad, California
June l 2017
Page2
CTE Job No. 10-13214T
depth of approximately 20 feet bgs. Based on these site observations, groundwater is generally
not anticipated within 10 feet of proposed discharge elevations.
2.0 Percolation Test Data
Percolation testing was performed in accordance with SD DEH Case I and ill methods, which
are performed when presoak water remains in the test hole overnight and when presoak water
infiltrates through the hole overnight, respectively. The presoak duration for all of the recent
tests ranged from approximately 23 to 24 hours, which is within the SD DEH 15 to 30 hour
presoak range. The approximate percolation test and boring locations are presented on Figure 2.
The associated boring logs are attached. Results of the recent percolation testing are presented in
Table 2.0 below.
Time
Boring/Depth(Inches) Time Change Inches/hr Inches/min (min) inches
P-1/66.5 908 0 58.50 NIA NIA
938 30 58.50 58.94 0.438
Case 1008 60 58.94 59.00 0.063
III 1038 90 59.00 59.00 0.000
ll08 120 59.00 59.00 0.000 0.125 0.0021
Soil 1138 150 59.00 59.06 0.063
Qop 1208 180 59.06 59.13 0.063
1238 210 59.13 59.13 0,000
1308 240 59.13 59.19 0.063
1\ESC SERVER\Projeots\l0-13214T\Ltr_lnfiltration Test Results RJ.doc
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
60 JO Avenida Encinas, Carlsbad, California
June 1 2017
TA9LB2 0(--...----'--nm) . ~~ --~-~:: ..... P8RCtJ. nON fq?;i _QA:
Time Initial Final Water
Boring/Depth(lnches) Time Change Water Water Level
(min) Level Level Change
(inches) (inches) (inches)
P-2/60.0 910 0 52.00 NIA NIA
940 30 52.00 52.06 0.063
Case 1010 60 52.06 52.13 0.063
I
Soil
Qop
-Initial Final Water Time
Boring/Depth(lnches) Time Change Water Water Level
Level Level Change (min) (inches) (inches) (inches)
P-3/60.0 934 0 52.00 NIA NIA
1004 30 52.00 52.06 0.063
Case 1034 60 52.06 52.13 0.063
I
Soil
Qop
Page3
CTE Job No. 10-13214T
Percolation Rate
Inches/hr Inches/min
0.125 0.0021
Percolation Rate
Inches/hr Inches/min
0.125 0.0021
..
\\ESC_SERVER\Projccts\J 0-13214T\Ltr_!nfiltration Teat Results RJ.doo
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
6010 Avenida Encinas, Carlsbad, California
June 1, 2017
TABU: 2.0 (CONllNUED)
PBRCOJATION.l'BST DATA
--Initial Final Water Time
Boring/Depth(Inches) Time Change Water Water Level
(min) Level Level Change
(inches) (inches) (inches)
P-4/60.0 936 0 52.00 NIA NIA
1006 30 52.00 52.06 0.063
Case 1036 60 52.06 52.13 0.063
I
-
Soil
Qppf
NOTES: Water level was measured from a fixed point at the top of the hole.
Hole diameter for P-l and P-2 was six inches
Hole diameter for P-3 and P-4 was eight inches
Weather was overcast during the percolation testing.
Qppf: Quaternary Previously Placed Fill
Qop: Quaternary Old Paralic Deposits
1.1 Calculated Infiltration Rates
Page4
CTE Job No. 10-13214T
I•
Percolation Rate
Inches/hr Inches/min
0.125 0.0021
As per the County of San Diego B:MP design documents (February 2016) infiltration
rates are to be evaluated through Porchet Method. CTE utilized the Porchet Method
through guidance of the County of Riverside (2011 ). The intent of the infiltration rate is
to take into account bias inherent in percolation test bore hole sidewall infiltration as
would not occur at a basin bottom where such sidewalls are not present.
The infiltration rate (It) is derived by the equation:
It = Aflm260 = Afl60 r
At( r+ 2H..v8) At(nr2 +2mH..v8)
Where:
I1 = tested infiltration rate, inches/hour
AH = change in head over the time interval, inches
At = time interval, minutes
* r = effective radius of test hole
IL.vs = average head over the time interval, inches
\IESC_SERVER\Projects\10-13214T\Ltr_lnfiltration Test Results RJ.doc
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
60 IO Avenida Encinas, Carlsbad, California
June I 2017
Page 5
CTE Job No. 10-13214T
Infiltration rates have been calculated utilizing the factor of safety (FOS) of 2 in the following
Table 1.1 . The project stormwater or basin designer may modify the factor of safety based on
their independent evaluation. The infiltration feasibility information is also presented on the
attached C. 4-1 Worksheet.
Percolation Rate Infiltration Rate with FOS of
inches/minute inches rhour 2A rhour
P-1 0.0021 0.021 0.011
P-2 0.0021 0.040 0.020
P-3 0.0021 0.025 0.013
P-4 0.0021 0.025 0.013
The calculated rates indicate that the site does not meet the minimum County requirements for
full or partial infiltration.
3,0 Limitations
The percolation test results were obtained in accordance with City and County standards.
However, it should be noted that percolation test results can significantly vary laterally and
vertically due to slight changes in soil type, degree of weathering, secondary mineralization, and
other physical and chemical variabilities. As such, the test results are considered to be an
estimate of percolation and converted infiltration rates for design purposes. No guarantee is
made based on the percolation testing related to the actual functionality or longevity of
associated infiltration basins or other BMP devices designed from the presented infiltration rates.
CTE's conclusions and recommendations are based on an analysis of the observed conditions. If
conditions different from those described in this report are encomtered during construction, this
office should be notified and additional recommendations, if required, will be provided.
The opportunity to be of service on this project is appreciated. If you have any questions
regarding this report, please do not hesitate to contact the undersigned.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
Aaron J. Beeby, CEG #2603
Certified Engineering Geologist
\\ESC_SERVER\Projccts\l 0-13214T\Ltr _lnfillnltion Te1t Rcaults RJ.doc
Percolation Test Results for Proposed Biofiltration Basins
Proposed Carlsbad Car Wash
6010 Avenida Encinas, Carlsbad, California
J\llle 1 2017
Attachments:
Figure 1
Figure 2
Boring Logs
Site Index Map
Exploration Location Map
Worksheet C.4-1
Page6
CTE Job No. 10-13214T
\\ESC _SERVER\Projcou\l0-13214T\Ltr_lnfiltntion Teat Rcsulll RJ.doo
ActMI Athieot,cism
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~ 1441 Mar1111Rd81t 116, r-ddo, CA 1211121 Pfl{JI0)74Mll6
SITB INDB KAP SCAl.£: DATE!
PROPOSID CARIS8All TOYOTA. CAI 'fASII &S IIIOIN 5/17 ecuo j_YINll)A ENCINAS CTE JOB NO.: FICURE:
CARLSBAD, CAIDORNU. 10-l321'T l
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LEGEND
B-5♦ APPROXIMATE BORING LOCATION
f 50' O 25' 50' P-4$-APPROXIMATE PERCOLATION TEST LOCATION
~ l! Qop QUATERNARY OLD PARALIC DEPOSITS
~r-------:~:;:-------------.------------,._._----1
Iii C Construction Testing & Engineering, Inc. EXPLORATION LOCATION MAP !!, rl""' ....a> CMIAtD CAI IMa lalllYlllllft'I
"----~ ./_},-1441 Monlilll Rd 9111 115, Eaxnldo, CA 9202a Ph (NII)) 7"4M955 MIO Afflllll INaNAI ·~ WUUll,CMJnlljl&
Cl P Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
DEFINITION OF TERMS
PRIMARY DMSIONS
GRAVELS
MORE THAN
HALF OF
COARSE
FRACTION IS
LARGER THAN
N0.4SIEVE
SANOS
MORE THAN
HALF OF
COARSE
FRACTION IS
SMALLER THAN
N0.4SIEVE
CLEAN
GRAVELS
<5% FINES
GRAVELS
WITH FINES
CLEAN
SANDS
<5% FINES
SILTS AND CLAYS
LIQUID LIMIT IS
LESSTHAN50
SILTS AND CLAYS
LIQUID LIMIT IS
GREATER THAN 50
HIGHLY ORGANIC SOILS
SECONDARY DMSIONS
WELL GRADED GRAVELS, GRAVEL-SAND MDl.'TURES
LITTLE OR NO FINES
POORLY GRADED GRAVELS OR GRAVEL SAND MIXTURES,
LITTLE OF NO FINES
SILTY GRAVELS, GRAVE!,SAND-SILT MIXTURES,
NON-PLASTIC F!Nr!.S
CJ..A YEY GRAVELS, GRAVEL-SANl).CLA Y MO.'TUJIBS,
PLASTIC FINES
WELL GRADED SANDS, GRAVELLY SANDS, Ll'JTI..E OR NO
FINES
POORLY GRADED SANDS, GRAVELLY SANDS, LITILE OR
NOFINES
SIL TY SANDS, SAND-SILT MIXTURES, NON-PLASTIC FINES
INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY
OR CLAYEY FINE SANDS. SLIOHTL Y PLASTIC CLAYEY SILTS
INORGANIC CLAYS OF LOW TO MEDJUM PLASTICITY,
GRAVELLY. SANDY SILTS OR LEAN CLAYS
ORGANIC SILTS AND ORGANIC Cl.A YS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR DIA TOMACEOUS FINE
SANDY OR SILTY son.s ELASTIC SILTS
GRAIN SIZES
INORGANIC CLAYS Of HJGH PLASTICITY. FAT CLAYS
ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SU.TY CLAYS
PEAT AND OTHER HIGHLY ORGANIC SOILS
BOULDERS COBBLES GRAVEL SAND SILTS AND CLAYS COARSE FINE COARSE MEDIUM FINE
12" 3" 3/4" 4 JO 40 200
CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SIZE
ADDITIONAL TESTS
(OTHER THAN TEST PIT AND BORING LOG COLUMN HEADIN'GS)
MAX-Maximum Dry Density
GS-Grain Siz.e Distribution
SE-Sand Equivalent
EI-Expansion Index
CHM-Sulfate and Chloride
Content , pH, Resistivity
COR -Corrosivity
SD-Sample Disturbed
PM-Permeability
SG-Specific Gravity
HA-Hydrometer Analysis
AL-Atterberg Limits
RV-R-Value
CN-Consolidation
CP-Collapse Potential
HC-Hydrocollapse
REM-Remolded
PP-Pocket Penetrometer
WA-Wash Analysis
DS-Direct Shear
UC-Unconfined Compression
MD-Moisture/Density
M-Moisture
SC-Swell Compression
OI-Organic Impurities
FIGURE: BL!
PROJECT:
CTEJOB NO:
• LOGGED BY:
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j ffi ~ 8 <I} f-It, ~
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Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
DRILLER: SHEET: of
DRILL METIIOD: DRILLING DA'IE:
SAMPLE METI-IOD: ELEVATION:
00 0 ....l BORING LEGEND Laboratory Tests
-~ .c 0.
cS
DESCRlPTION
Block or Chunk Sample
Bulk Sample
Standard Penetration Test
Modified Split-Barrel Drive Sampler (Cal Sampler)
Thin Walled Army Corp. of En~eers Sample
Groundwater Table
K :.::__ Soil Tvpe or Classification Change ----------------····
-?--?--?--?--?--?--?-
\._ Formation Cha~e [(Approximate boundaries queried(?)]
"SM" Quotes are placed around classifications where the soils
exist in situ as bedrock
FIGURE: I BL2
PROJECT:
CTEJOB NO:
LOOGEDBY:
-0
--
--
--.. -
.. 5
L 7
7 .. -7 .. -
.. -
.. -
'"lC+ ... s
7 ----IS
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8 .. -12 -.. -
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--
--
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--25-
c,~ Construction Testing & Engineering, Inc. ~c~ 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
TOYOTA OF CARLSBAD CAR WASH
I0-13214T
Alli
DRILLER:
DRILL METHOD:
SAMPLE METHOD:
BAJA EXPLORATION
HOLLOW-STEM AUGER
RING, SPT and BULK
SHEET: 1
DRILLING DATE:
ELEVATION:
of 1
8/12/2016
~58 FEET
]
[
(I) BORING: B-1 Laboratory Tests
v.i 0 Cl)
;j
CL
CL
"SC"
DESCRIPTION
Asphalt: 0-4"
Base Material: 4-7"
QUATERNARY UNDOCUMENTED FILL: Stiff,. moist.. bro\\11. fine .sratned sandy CI.,A Y . _________________ _
Loose to mediwn dense. moist, brown. silty to clayey fine grained
SAND.
Stiff to very stiff, mo 1st, brown, fine grained sandy CLAY.
QUATERNARY OLD PARALIC DEPOSITS:
Mediwn dense, moist, reddish brown, clayey fine grained
SANDSTONE, oxidized, massive.
sM/SC ---Modiwn dense~ moist, reddish brown, silty lo clayey fine grained
SANDSTONE. oxidized, massive.
--------SP-SM Medium dense, moist, reddish hrmm, poorly graded line groined
SANDSTONE with silt, massive, friuble, abundant mafics.
Total Depth: 20'
No Groundwater Encountered
El,CHM
CN
GS
I B-1
PROJECT:
<'TEJOH Nil;
L(XruEDRY:
..2 0.. " ffi ~ 0 " ti) I-1:::-(o
! Ii l -" 8 ~ 0 ffi
1-0
... -
... -
... -
... -
""5-[I 4
... -6
10
I--
... -
I--
... Ht ....
I 7
... -11
'-24
... -
... -
... -
.. 15-6
7 ... -9
... -
... -
... -
-2(t
-
... -.. -
... -
1-2s
(;J~ Construction Testing & Engineering, Inc. ~c: 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
TOY OT A OF CARLSBAD CAR WASH
I0-13214T
AJB
Q ] s,
DRU.Lrn:
DRILL r-.um IOI);
SAMPLE .MET! It >D:
BAJA EXPLORATION
HOLLO\V-S"ffiM Al •GER
RING, SPT and Bl lJ.K
SHHT:
DRll,LL\lG DATE:
ELEVATION:
of I
8/12/2016
--60 FEET
.f cc' ~-00 E, 0 ti) ...:i BORING: B-2 Laboratory Tests
,:: I 8 ·S § ~
vi
0 vi ;::;
"CI~"
0 sc·'
Q :E 0.. ~
DESCRIPTION
11\sphalt: 0-4.5"
Base Material: 4.5-7.5"
OUATER~RY ~oc~ED FILL: Loose lo mium ensc mmsl0\\'11 clave,· fine arained SAND.
OUA TERNARY OLD PARALIC DEPOSITS:
Very sttn, moist, reddish brown, fine gramed sandy CLAYSTONE,
oxidized, massive, carbonate nodules .
---Medium dense. moist, reddish brown, clayey fine grained
SANDSTONE, oxidized, massive .
Sandy clay interbeds
-------"SP-SM" Medium dense, moist, reddish bnmn, pt,orly graded, fine grained
SANDSTONE with silt, massive, friable .
Total Deplh: 16.S'
No Groundwater Encountered
GS
GS
I B-2
PROJECT:
CTEJOB NO:
LOGGED BY:
... o
... -
.. -
... -
.. -
.. 5 [ 7
... -7
II .. -
--
--
-Ht-7
9 --13
--
--
.. -
.. 1 j-
... -
... -
--
--
-2{+-
--
... -
... -
.. -
--2,-
CJ ~ Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
TOY OT A OF CARLSBAD CAR WASH
I0-13214T
AJB
DRILLER:
DR.Il,L METIIOD:
SAMPLE METIIOD:
BAJA EXPLORATION
HOLLOW-S1EM AUGER
RlNG, SPT and BULK
SHEET:
DRil..LING DA'm:
ELEVATION:
of I
8/12/2016
--{i0 FEET
]
J BORING: B-3 Laboratory Tests
vi 0 vi
;:i
SC
"CL11
DESCRIPTION
l~halt: U-::l"
Base Material: 3-6"
OUATFRN A.RY IJNDOCIJMENTED FILL:
Looiie to mcdmm dense, moist, br0\\11 to reddish brown, fine
grained SAND .
QUATERNARY OLD PARALIC DEPOSITS:
Very stiff, moist, reddish brown, fine grained sandy CLAYSTONE,
oxidized, massive.
Medium dense or very stiff, moist, reddish brown, clavey fine ------
grained SANDSTONE/ sandy CLA YSTONE, oxidized," massive.
Total Depth: 11.5'
No Groundwater Encountered
I B-3
..
PROJECT:
CTEJOD NO:
1.(XlllED BY: •
" -a
j ~ ~ <Zl f-, ~ t " :!:!i " ;,.
" 8 Q ~
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,_ -
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•5--
I---.. -
--
--
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-----
--
--
•15-.. -
I--
-----
-2~
.. -
I--
,_ -
... -
-25-
;;e
~ iii
5
7
JO
5
11
11
8
10
13
C) P' Construction Testing & Engineering, Inc. ~c: 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
TOY OT A OF CARLSBAD CAR WASH
I0-13214T
AJB
G ] s
DRII.IJ.Jt:
DRILL MElHuD:
SAMPLE :ME'Jl-10D:
BAJA FXPLORATIO}.!
HOLLOW-STEM Al'GER
RING, Sl'T and Dl'U:
SHEET: I
DRil..LING DATE:
ELEVATION:
of I
5/11/2017
~58 FEET
-~· 'c' ~ bO t 0 V) ....:l BORING: B-4 Laboratory Tests
" I! 8 .a "' § ·s ;E
vi 0 u :.a i:,. vi ~ ;:i
CL
"SC"
DESCRIPTION
Asphalt: U-4"
Base Material: 4-6"
OIIATERNARV UNDOl"IIMENTED FILL:
Stiff. mmsl dark red1.hsh hrou11 tme oromed s1md\' CLAY.
OUATERNARY OLD PARALIC DEPOSITS:
JIJediwn dense, mmst, hro\\11 to reddish bw\\11. clayey fine grained
SANDSTONE, oxidized
-------"CL" Very stiff, moist, dark reddish gray, fine grained sandy CLAYSTONE
with silty to clayey interbeds.
"SP-SM" Mediwn dense, moist, reddish bnmn, poorly iu:adcd fine grained
SANDSTONE with silt, oxidized. massive, fnab)e, abW1dant mnfics.
Total Deptl1: 20'
No Groundwater Encountered
I 8-4
PROJECT:
CTEJOB NO:
LOGGED BY:
-o
--
--
--
--
-s-I 4
--5
7
----
... -
--Ht --~ 9
13 --16
... -
.. -
--
-15-
--
--
--
l 8 --11
--2~ 16
.. ---
--
--
-25-
ctP' Construction Testing & Engineering, Inc. ~c~ 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
DRILLER: BAJA EXPLORATION Sl-ffiET: of l TOYOTA OF CARLSBAD CAR WASH
10-13214T DRILL METHOD: HOLLOW-STEM AUGER DRllLINGDAm: 5/11/2017
AJB SAMPLE METHOD: RING, SPT end BULK ELEVATION: ~58 FEET
]
i
vi c.J vi ;:5
('I,
''CL"
~ ...:I
0
1
BORING: B-5
------------------------DESCRIPTION
~halt: 0-3.Y'
Ilasc Material: 3.5-5.5"
QUATERNARY UNDOCUMENTED FILL:
Stiff, mmst, dark reddish brown, fine grained sandy CLAY
QUATERNARY OLD PARALIC DEPOSITS:
Stiff, moist, dark olive grav, fine grained sandy CLA YSTONE,
oxidized mottling, cnrbomite nodules.
-• • Medium dense, moist, li~t reddish brown, clayey fine grained
SANDSTONE, oxidized mottling.
--------"CL" Very stiff, moist, dark reddish olive, fine grained sandy CLAYSTONE
"SP-SM" Medium dense, moist, light gray, poor½• grudcd fmc grained -------
SANDSTONE with silt, massive, tiioblc.
Total Depth: 20'
No Groundwater Encountered
Laboratory Tests
I B-5
Worksheet C.4-1: Categorization oflnfiltration Feasibility Condition
Categorization of Infiltration Feasibility Condition \X1orksheet C.4-l
Pan 1 -full Infiltration Feasibility Sl-rccning Criteria
Would infilttution of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
Ts the estimated reliable infiltration rate below proposed facility locations
greater than 0.5 inches per hour? The response to this Screening Question shall
be based on a comprehensive evaluation of the factors presented in Appendix
C.2 and Appendix D.
X
Provide basis: The NRCS soils across the site are all Type D soils with very high surface runoff. The site soils
are consistent with the NRCS mapped soil types based on site explorations and percolation testing.
Two soil types were present in the area of the proposed development, Quaternary Previously
Placed Fill and Quaternary Old Paralic Deposits.
Four percolation tests were completed, with three tests performed within the Old Paralic Deposits
and one performed in the Previously Placed Fill. The calculated infiltration rates (with an applied
factor of safety of two) ranged from 0.011 to 0.020 inch per hour.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of gcotechnical hazards (slope stability, groundwater mounding, utilities, or
other factors) thllt cannot be mitigated to an acceptable levd? The response to
this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendb, C.2.
X
Provide basis: Due to the minimal penneability of the geologic units encountered at the site, surface water would
likely migrate laterally or mound locally. This could result in the water migrating into utility
trench backfill or saturating down gradient foundations or other improvement areas.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
C-11
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4-1 Page 2 of 4
Criteria Screening Question
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water pollutants
or other factors) that cannot be mitigated to an acceptable levd? The response
to this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.3.
Yes No
X
Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 7,000 feet away
from the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface waters?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
X
Provide basis: The nearest down gradient surface waters are the Pacific Ocean which is over 900 feet from the
site. Due to the significant distance to the ocean it is unlikely to be impacted by infiltrating site
water.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
Part t
If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The
feasibility screenin~ category is Full Infiltration
Result'4' If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
No Full
.-Yo be complewd using gathered site information and best professiorutl judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/ or studies may be required br City Engineer to substantiate findings.
C-12
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4-1 Page 3 of 4
Pan 2 -P:irt:ial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of \\'liter in any appreciable amount be physically fe:isible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question
5
Do soil and geologic conditions nllow for infiltration in any appreciable rote or
volume? 111e response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.2 and
AppendixD.
Yes No
X
Provide basis: Due to the native soils percolating at a very slow rate, it is unlikely that any appreciable volume of
water will infiltrate.
P-1
1'-2
P-3
~1-tion R•tc
ioohes/rninu1e
0.0021
0.0021
0.0021
0.002)
0.025 0.013
0.013
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability and why it was not feasible to mitigate low
infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed without increasing risk
of gcotcchnical hazards (slope stability, groundwater mounding, utilities, or
other factors) that cannot be mitigated to an acceptable level? The response to
this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.2.
X
ProYide basis: Due to the minimal permeability of the geologic units encountered at the site, surface water would
likely migrate laterally or mound locally. This could result in the water migrating into utility
trench backfill or saturating down gradient foundation or other improvement areas.
Summari:;,;e findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and ,vhy it was not feasible to mitigate low
infiltmtion rates.
C-13
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4-l Page 4 of 4
Criteria Screening Question
7
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Yell No
X
Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 7,000 feet away
from the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrati,·e discussion of study/data source applicability and why it was not feasible to mitigate low
infiltration rates.
8
Can infiltration be allowed without violating do\\,nstream water rights? The
response to this Screening Question shall be based on a comprehensi,·e
evaluation of the factors presented in Appendix C.3.
X
Prm•idc basis: The nearest down gradient surface waters are the Pacific Ocean which is over 900 feet from the
site. Due to the significant distance to the ocean it is unlikely to be impacted by infiltrating site
water.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narratiYe discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
If all answers from row 1-4 are yes then partial infiltration design is potentially feasible.
Part 2 The feasibility screening category is Partial Infiltration.
Result>< If any answer from row 5-8 is nu, then infiltration of any Yolurne is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
No Inf.
*To be completed usmg b,athered site infotmaaon and best profess1on.'l.! Judgment cons1denng the definition of ~IEP 1n
the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings
C-14
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Hydrologic Soil Group-San Diego County Area, California
(TOYOTA CARWASH)
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
D Area of Interest (AOI)
Soils
Soll Rating Polygons
D A
D AID
O B
□ BID
□ C
D CID
D D
D Not rated or not available
Soll Rating Lines
-A -AID -B -BID -C -CID -D
-,, Not rated or not available
Soll Rating Points
■ A
■ AID
■ B
■ BID
USO,\ Natural Resources =-Conservation Service
• C
• CID
• D
□ Not rated or not available
Water Features
.,,,._, Streams and Canals
Transportation
++t Rails --Interstate Highways --us Routes
~ Major Roads
.... Local Roads
Background
• Aerial Photography
Web Soil Survey
National Cooperative Soil Survey
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 12, Sep 13, 2017
Soil map units are labeled (as space allows) for map scales
1 :50,000 or larger.
Date(s) aerial images were photographed: Nov 3, 2014-Nov
22,2014
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
2/25/2018
Page 2 of4
Hydrologic Soil Group-San Diego County Area, California TOYOTA CARWASH
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres lnAOI Percent of AOI
HrC Huerhuero loam, 2 to 9 D 2.3
percent slopes
Totals for Area of Interest 2.3
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (ND, B/D, and CID). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (ND, BID, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
USDA Natural Resources
alli Conservation Service
Web Soil Survey
National Cooperative Soil Survey
100.0%
100.0%
2/25/2018
Page 3 of 4
Hydrologic Soil Group-San Diego County Area, California
~
Tie-break Rule: Higher
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
TOYOTA CARWASH
2/25/2018
Page 4 of 4
E. 2 BF-1 Bio iltrati n
Location: 43"1 Street and Logan Avenue, San Diego, California
Description
Appendix E: BMP Design Fact Sheets
MS4 Permit Category
Bio filtration
Manual Cate o
Bio filtration
Applicable Performance
Standard
Pollutant Control
Flow Control
Primary Benefits
Treatment
Volume Reduction (Incidental)
Peak Flow Attenuation (Optional)
Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter
water through vegetation, and soil or engineered media prior to discharge via underdrain or
overflow to the downstream conveyance system. Bioretention with underdrain facilities are
commonly incorporated into the site within parking lot landscaping, along roadsides, and in open
spaces. Because these types of facilities have limited or no infiltration, they are typically designed to
provide enough hydraulic head to move flows through the underdrain connection to the storm drain
system. Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and
plant uptake.
Typical bioretention with underdrain components include:
• Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips)
• Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap)
• Shallow surface ponding for captured flows
• Side slope and basin bottom vegetation selected based on expected climate and ponding
depth
• Non-floating mulch layer (Optional)
• Media layer (planting mix or engineered media) capable of supporting vegetation growth
• Filter course layer consisting of aggregate to prevent the migration of fines into
uncompacted native soils or the aggregate storage layer
• Aggregate storage layer with underdrain(s)
• Impermeable liner or uncompacted native soils at the bottom of the facility
E-63 February 2016
• Overflow structure
::.~ ...... ~~
CURB RO ·
·,
A ·:• .... .. I
CURB CUT';°
12• N •
"" •
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~ PROP FROM CORB CUT TO APRON
8" M TO 12• MAX.
SURFACE P()t.JOINO
C
--1
EXC,\VATEt> SL
(SHOINN AT IH 1
Appendix E: BMP Design Fact Sheets
. . .
NAN.ct ,
ACCESS
JAS ~EE_DEDJ ..
2" MIN FREEBOARO
3• WELL-AGED, SHREDDED
HARD'NOOD MULCH
(OPTI()t,iAl,) MAINTENA
ACCESS
(AS NEEDED)
,>"'--i ,, •----
,,,' ,-NJU.LOW
• / aTR~ -M,.W.,.,,~' ., ,.,.. M 1e• ME.DIA WITH
MN 5 NIHR
FtL TRATION RA TE
SAl\JRAT£0 STORAGE
(OPTIONAL)
\ IMPERMEASlE LINER (OPTIONAl.)
MIN 3• AGGREGATE BB.OW ~DERDRAIN
F T RCOU
AGGREGATE STORAGE 1.AYE.R
M N 8" OIAtJETER lJ OERORAIN
EXISTING UNCOMPACTED SDJLS
SECTION A-A'
NOTTOSCAlE
Typical plan and Section view of a Biofiltration BMP
E-64 February 2016
Appendix E: BMP Design Fact Sheets
'Design Adaptations for Project Goals
Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined
to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered
runoff. This configuration is considered to provide biofiltration treatment via flow through the
media layer. Storage provided above the underdrain within surface ponding, media, and aggregate
storage is considered included in the biofiltration treatment volume. Saturated storage within the
aggregate storage layer can be added to this design by raising the underdrain above the bottom of
the aggregate storage layer or via an internal weir structure designed to maintain a specific water level
elevation.
Integrated storm water flow control and pollutant control configuration. The system can be
designed to provide flow rate and duration control by primarily providing increased surface ponding
and/ or having a deeper aggregate storage layer above the underdrain. This will allow for significant
detention storage, which can be controlled via inclusion of an outlet structure at the downstream
end of the underdrain.
Design Criteria and Considerations
Bioretention with underdrain must meet the following design criteria. Deviations from the below
criteria may be approved at the discretion of the [City Engineer] if it is determined to be appropriate:
Siting and Design
□
□
□
Placement observes geotechnical
recommendations regarding potential hazards
(e.g., slope stability, landslides, liquefaction
zones) and setbacks (e.g., slopes, foundations,
utilities).
An impermeable liner or other hydraulic
restriction layer is included if site constraints
indicate that infiltration or lateral flows should
not be allowed.
Contributing tributary area shall be '.S 5 acres ('.S
1 acre preferred).
E-65
Intent/Rationale
Must not negatively impact existing site
geotechnical concerns.
Lining prevents storm water from
impacting groundwater and/ or sensitive
environmental or geotechnical features.
Incidental infiltration, when allowable,
can aid in pollutant removal and
groundwater recharge.
Bigger BMPs require additional design
features for proper performance.
Contributing tributary area greater than 5
acres may be allowed at the discretion of
the [City Engineer} if the following
conditions are met: 1) incorporate design
features (e.g. flow spreaders) to
February 2016
Siting and Design
□ Finish grade of the facility is :S 2%.
Surface Ponding
□
□
□
□
Surface ponding is limited to a 24-hour
drawdown ti.me.
Surface ponding depth is 2: 6 and :S 12 inches.
A minimum of 12 inches of freeboard is
provided.
Side slopes are stabilized with vegetation and
are= 3H:1V or shallower.
Vegetation
E-66
Appendix E: BMP Design Fact Sheets
Intent/Rationale
minimizing short circuiting of flows in the
BMP and _c;;;.;;.;;~::...;;..,;,ate additional design
es the [City Engineer
E! -~~-ce of the regional
P.
Flatter surfaces reduce erosion and
channelization within the facility.
Surface ponding limited to 24 hours for
plant health. Surface ponding drawdown
ti.me greater than 24-hours but less than
96 hours may be allowed at the discretion
of the [City E ngineer] if certified by a
landscape architect or agronomist.
Surface ponding capacity lowers
subsurface storage requirements. Deep
surface ponding raises safety concerns.
Surface ponding depth greater than 12
inches (for additional pollutant control or
surface outlet structures or flow-control
orifices) may be allowed at the discretion
of the [City Engineer] if the following
conditions are met: 1) surface ponding
depth drawdown ti.me is less than 24
hours; and 2) safety issues and fencing
requirements are considered (typically
ponding greater than 18" will require a
fence and/ or flatter side slopes) and 3)
potential for elevated clogging risk is
considered.
Freeboard provides room for head over
overflow structures and minimizes risk of
uncontrolled surface discharge.
Gentler side slopes are safer, less prone to
erosion, able to establish vegetation more
quickly and easier to maintain.
February 2016
Siting and Design
□
Plantings are suitable for the climate and
expected ponding depth. A plant list to aid in
selection can be found in Appendix E .20.
Appendix E: BMP Design Fact Sheets
Intent/Rationale
Plants suited to the climate and ponding
depth are more likely to survive.
□ An irrigation system with a connection to water Seasonal irrigation might be needed to
supply should be provided as needed. keep plants healthy.
Mulch Qptioaa/ or Mandatory-Dependent on jurisdiction)
□
A minimum of 3 inches of well-aged, shredded
hardwood mulch that has been stockpiled or
stored for at least 12 months is provided.
Media Layer
□
□
□
Media maintains a minimum filtration rate of 5
in/hr over lifetime of facility. An initial filtration
rate of 8 to 12 in/hr is recommended to allow
for clogging over time; the initial filtration rate
should not exceed 12 inches per hour.
Media is a minimum 18 inches deep, meeting
either of these two media specifications:
City of San Diego Storm Water Standards
Appendix F (February 2016, unless superseded
by more recent edition) .ru: County of San Diego
Low Impact D evelopment Handbook:
Appendix G -Bioretention Soil Specification
Gune 2014, unless superseded by more recent
edition).
Alternatively, for proprietary designs and
custom media mixes not meeting the media
specifications contained in the 2016 City Storm
Water Standards or County LID Manual, the
media meets the pollutant treatment
performance criteria in Section F.1.
Media surface area is 3% of contributing area
times adjusted runoff factor or greater. Unless
E-67
Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch
kills pathogens and weed seeds and allows
the beneficial microbes to multiply.
A filtration rate of at least 5 inches per
hour allows soil to drain between events.
The initial rate should be higher than long
term target rate to account for clogging
over time. However an excessively high
initial rate can have a negative impact on
treatment performance, therefore an
upper limit is needed.
A deep media layer provides additional
filtration and supports plants with deeper
roots.
Standard specifications shall be followed.
For non-standard or proprietary designs,
compliance with F.1 ensures that
adequate treatment performance will be
provided.
Greater surface area to tributary area
ratios: a) maximizes volume retention as
February 2016
Appendix E: BMP Design Fact Sheets
Siting and Design Intent/Rationale
□
demonstrated that the BMP surface area can be required by the MS4 Permit and b)
smaller than 3%. decrease loading rates per square foot and
therefore increase longevity.
Where receiving waters are impaired or have a
TMDL for nutrients, the system is designed
with nutrient sensitive media design (see fact
sheet BF-2).
Adjusted runoff factor is to account for
site design BMPs implemented upstream
of the BMP (such as rain barrels,
impervious area dispersion, etc.). Refer to
Appendix B.2 guidance.
Use Worksheet B.5-1 Line 26 to estimate
the minimum surface area required per
this criteria.
Potential for pollutant export is partly a
function of media composition; media
design must minimize potential for export
of nutrients, particularly where receiving
waters are impaired for nutrients.
Filter Course Layer
□
□
□
A filter course is used to prevent migration of
fines through layers of the facility. Filter fabric
is not used.
Filter course is washed and free of fines.
Filter course calculations assessing suitability for
particle migration prevention have been
completed.
Aggregate Storage Layer
□
Class 2 Permeable per Caltrans specification 68-
1.025 is recommended for the storage layer.
Washed, open-graded crushed rock may be
used, however a 4-6 inch washed pea gravel
filter course layer at the top of the crushed rock
is required.
E-68
Migration of media can cause clogging of
the aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to
clog.
Washing aggregate will help eliminate
fines that could clog the facility and
impede infiltration.
Gradation relationship between layers can
evaluate factors ( e.g., bridging,
permeability, and uniformity) to
determine if particle sizing is appropriate
or if an intermediate layer is needed.
Washing aggregate will help eliminate
fines that could clog the aggregate storage
layer void spaces or subgrade.
February 2016
Siting and Design
□
The depth of aggregate provided (12-inch
typical) and storage layer configuration is
adequate for providing conveyance for
underdrain flows to the outlet structure.
In.iow, Underdrain, and Out.iow Structures
□
□
□
□
□
□
□
□
Inflow, underdrains and outflow structures are
accessible for inspection and maintenance.
Inflow velocities are limited to 3 ft/ s or less or
use energy dissipation methods. (e.g., riprap,
level spreader) for concentrated inflows.
Curb cut inlets are at least 12 inches wide, have
a 4-6 inch reveal (drop) and an apron and
energy dissipation as needed.
Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.
Minimum underdrain diameter is 6 inches.
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent or
corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.
An underdrain cleanout with a minimum 6-inch
diameter and lockable cap is placed every 250 to
300 feet as required based on underdrain length.
Overflow is safely conveyed to a downstream
storm drain system or discharge point Size
overflow structure to pass 100-year peak flow
for on-line infiltration basins and water quality
peak flow for off-line basins.
E-69
Appendix E: BMP Design Fact Sheets
Intent/Rationale
Proper storage layer configuration and
underdrain placement will minimize
facility drawdown time.
Maintenance will prevent clogging and
ensure proper operation of the flow
control structures.
High inflow velocities can cause erosion,
scour and/ or channeling.
Inlets must not restrict flow and apron
prevents blockage from vegetation as it
grows in. Energy dissipation prevents
erosion.
A minimal separation from subgrade or
the liner lessens the risk of fines entering
the underdrain and can improve hydraulic
performance by allowing perforations to
remain unblocked.
Smaller diameter underdrains are prone to
clogging.
Slotted underdrains provide greater intake
capacity, clog resistant drainage, and
reduced entrance velocity into the pipe,
thereby reducing the chances of solids
migration.
Properly spaced cleanouts will facilitate
underdrain maintenance.
Planning for overflow lessens the risk of
property damage due to flooding.
February 2016
Appendix E: BMP Design Fact Sheets
Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only
To design bioretention with underdra.in for storm water pollutant control only (no flow control
required), the following steps should be taken:
1. Verify that siting and design criteria have been met, including placement requirements,
contributing tributary area, maximum side and finish grade slopes, and the recommended
media surface area tributary ratio.
2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas.
3. Use the sizing worksheet presented in Appendix B.5 to size biofiltration BMPs.
Conceptual Design and Sizing Approach when Storm Water Flow Control Is Appl/cable
Control of flow rates and/ or durations will typically require significant surface ponding and/ or
aggregate storage volumes, and therefore the following steps should be taken prior to determination
of storm water pollutant control design. Pre-development and allowable post-project flow rates and
durations should be determined as discussed in Chapter 6 of the manual.
1. Verify that siting and design criteria have been met, including placement requirements,
contributing tributary area, maximum side and finish grade slopes, and the recommended
media surface area tributary ratio.
2. Iteratively determine the facility footprint area, surface ponding and/ or aggregate storage
layer depth required to provide detention storage to reduce flow rates and durations to
allowable limits. Flow rates and durations can be controlled from detention storage by
altering outlet structure orifice size(s) and/ or water control levels. Multi-level orifices can be
used within an outlet structure to control the full range of flows .
3. If bioretention with underdra.in cannot fully provide the flow rate and duration control
required by this manual, an upstream or downstream structure with significant storage
volume such as an underground vault can be used to provide remaining controls.
4. After bioretention with underdra.in has been designed to meet flow control requirements,
calculations must be completed to verify if storm water pollutant control requirements to
treat the DCV have been met.
E-70 February 2016
Appendix E: BMP Design Fact Sheets
E.13 BF-2 Nutrient Sensi ive Media esign
Some studies of bioretention with underdrains have observed export of nutrients, particularly
inorganic nitrogen (nitrate and nitrite) and dissolved phosphorus. This has been observed to be a
short-lived phenomenon in some studies or a long term issue in some studies. The composition of
the soil media, including the chemistry of individual elements is believed to be an important factor in
the potential for nutrient export. Organic amendments, often compost, have been identified as the
most likely source of nutrient export. The quality and stability of organic amendments can vary
widely.
The biofiltration media specifications contained in the County of San Diego Low Impact
Development Handbook: Appendix G -Bioretention Soil Specification Qune 2014, unless
superseded by more recent edition) and the City of San Diego Low Impact Development Design
Manual (page B-18) Quly 2011, unless superseded by more recent edition) were developed with
consideration of the potential for nutrient export. These specifications include criteria for individual
component characteristics and quality in order to control the overall quality of the blended mixes.
As of the publication of this manual, the June 2014 County of San Diego specifications provide
more detail regarding mix design and quality control.
The City and County specifications noted above were developed for general purposes to meet
permeability and treatment goals. In cases where the BMP discharges to receiving waters with
nutrient impairments or nutrient TMDLs, the biofiltration media should be designed with the
specific goal of minimizing the potential for export of nutrients from the media. Therefore, in
addition to adhering to the City or County media specifications, the following guidelines should be
followed:
1. Select plant palette to minimize plant nutrient needs
A landscape architect or agronomist should be consulted to select a plant palette that minimizes
nutrient needs. Utilizing plants with low nutrient needs results in less need to enrich the biofiltration
soil mix. If nutrient quantity is then tailored to plants with lower nutrient needs, these plants will
generally have less competition from weeds, which typically need higher nutrient content. The
following practices are recommended to minimize nutrient needs of the plant palette:
• Utilize native, drought-tolerant plants and grasses where possible. Native plants
generally have a broader tolerance for nutrient content, and can be longer lived in
leaner/lower nutrient soils.
• Start plants from smaller starts or seed. Younger plants are generally more tolerant of
lower nutrient levels and tend to help develop soil structure as they grow. Given the lower
cost of smaller plants, the project should be able to accept a plant mortality rate that is
somewhat higher than starting from larger plants and providing high organic content.
2. Minimize excess nutrients in media mix
E-71 February 2016
Appendix E: BMP Design Fact Sheets
Once the low-nutrient plant palette is established (item 1 ), the landscape architect and/ or
agronomist should be consulted to assist in the design of a biofiltration media to balance the
interests of plant establishment, water retention capacity (irrigation demand), and the potential for
nutrient export. The following guidelines should be followed:
• The mix should not exceed the nutrient needs of plants. In conventional landscape
design, the nutrient needs of plants are often exceeded intentionally in order to provide a
factor of safety for plant survival. This practice must be avoided in biofiltration media as
excess nutrients will increase the chance of export. The mix designer should keep in mind
that nutrients can be added later (through mulching, tilling of amendments into the surface),
but it is not possible to remove nutrients, once added.
• The actual nutrient content and organic content of the selected organic amendment
source should be determined when specifying mix proportions. Nutrient content (i.e.,
C:N ratio; plant extractable nutrients) and organic content (i.e, % organic material) are
relatively inexpensive to measure via standard agronomic methods and can provide
important information about mix design. If mix design relies on approximate assumption
about nutrient/ organic content and this is not confirmed with testing ( or the results of prior
representative testing), it is possible that the mix could contain much more nutrient than
intended.
• Nutrients are better retained in soils with higher cation exchange capacity. Cation
exchange capacity can be increased through selection of organic material with naturally high
cation exchange capacity, such as peat or coconut coir pith, and/ or selection of inorganic
material with high cation exchange capacity such as some sands or engineered minerals (e.g.,
low P-index sands, zeolites, rhyolites, etc). Including higher cation exchange capacity
materials would tend to reduce the net export of nutrients. Natural silty materials also
provide cation exchange capacity; however potential impacts to permeability need to be
considered.
• Focus on soil structure as well as nutrient content. Soil structure is loosely defined as the
ability of the soil to conduct and store water and nutrients as well as the degree of aeration
of the soil. Soil structure can be more important than nutrient content in plant survival and
biologic health of the system. If a good soil structure can be created with very low amounts
of organic amendment, plants survivability should still be provided. While soil structure
generally develops with time, biofiltration media can be designed to promote earlier
development of soil structure. Soil structure is enhanced by the use of amendments with
high humus content (as found in well-aged organic material). In addition, soil structure can
be enhanced through the use of organic material with a distribution of particle sizes (i.e., a
more heterogeneous mix).
• Consider alternatives to compost. Compost, by nature, is a material that is continually
evolving and decaying. It can be challenging to determine whether tests previously done on a
given compost stock are still representative. It can also be challenging to determine how the
E-72 February 2016
Appendix E: BMP Design Fact Sheets
properties of the compost will change once placed in the media bed. More stable materials
such as aged coco coir pith, peat, biochar, shredded bark, and/ or other amendments should
be considered.
With these considerations, it is anticipated that less than 10 percent organic amendment by volume
could be used, while still balancing plant survivability and water retention. If compost is used,
designers should strongly consider utilizing less than 10 percent by volume.
3. Design with partial retention and/ or internal water storage
An internal water storage zone, as described in Fact Sheet PR-1 is believed to improve retention of
nutrients. For lined systems, an internal water storage zone worked by providing a zone that
fluctuates between aerobic and anaerobic conditions, resulting in nitrification/ denitrification. In
soils that will allow infiltration, a partial retention design (PR-1) allows significant volume reduction
and can also promote nitrification/ denitrification.
Acknowledgment: Tbis fact sheet has been adapted from the Orange County Technical Guidance
Document (May 2011). It was originally developed based on input from: Deborah Deets, City of
Los Angeles Bureau of Sanitation, Drew Ready, Center for Watershed Health, Rick Fisher, ASLA,
City of Los Angeles Bureau of Engineering, Dr. Garn Wallace, Wallace Laboratories, Glen D ake,
GDML, and Jason Schmidt, Tree People. The guidance provided herein does not reflect the
individual opinions of any individual listed above and should not be cited or otherwise attributed to
those listed.
E-73 February 2016
Appendix E: BMP Design Fact Sheets
.1 BF-3 Proprietary BiofiEt ation Systems
The purpose of this fact sheet is to help explain the potential role of proprietary BMPs in meeting
biofiltration requirements, when full retention of the DCV is not feasible. The fact sheet does not
describe design criteria like the other fact sheets in this appendix because this information varies by
BMP product model.
Criteria for Use of a Proprietary BMP as a 8/oflltratlon BMP
A proprietary BMP may be acceptable as a «biofiltration BMP" under the following conditions:
(1) The BMP meets the minimum design criteria listed in Appendix F, including the
pollutant treatment performance standard in Appendix F.1;
(2) The BMP is designed and maintained in a manner consistent with its performance
certifications (See explanation in Appendix F.2); and
(3) The BMP is acceptable at the discretion of the [City E ngineer]. In determining the
acceptability of a BMP, the [City Engineer] should consider, as applicable, (a) the data
submitted; (b) representativeness of the data submitted; (c) consistency of the BMP
performance claims with pollutant control objectives; certainty of the BMP performance
claims; (d) for projects within the public right of way and/ or public projects: maintenance
requirements, cost of maintenance activities, relevant previous local experience with
operation and maintenance of the BMP type, ability to continue to operate the sys tem in
event that the vending company is no longer operating as a business; and (e) other relevant
factors. If a proposed BMP is not accepted by the [City Engineer], a written
explanation/ reason will be provided to the applicant.
Guidance for Sizing a Proprietary BMP as a Bloflltratlon BMP
Proprietary biofiltration BMPs must meet the same sizing guidance as non-proprietary BMPs. Sizing
is typically based on capturing and treating 1.50 times the DCV not reliably retained. Guidance for
sizing biofiltration BMPs to comply with requirements of this manual is provided in Appendix F.2.
I.Jurisdiction-specific Guidance and Criteria
· dance and criteria for Biofiltration BMPs.
E-74 February 2016
...
..
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 2a Hydromodification Management □ Included
Exhibit (Required)
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of Critical Coarse □ Exhibit showing project drainage
Sediment Yield Areas (WMAA Exhibit boundaries marked on WMAA
is required, additional analyses are Critical Coarse Sediment Yield
optional) Area Map (Required)
See Section 6.2 of the BMP Design Optional analyses for Critical Coarse
Manual. Sediment Yield Area Determination
□ 6.2.1 Verification of Geomorphic
Landscape Units Onsite
□ 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
□ 6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
Attachment 2c Geomorphic Assessment of Receiving ~ Not performed
Channels (Optional) □Included
See Section 6.3.4 of the BMP Design
Manual.
Attachment 2d Flow Control Facility Design and
Structural BMP Drawdown □Included
Calculations (Required) ~ Not included
See Chapter 6 and Appendix G of the HMP NOT REQUIRED
BMP DesiQn Manual
..
...
ATTACHMENT 2
Use this checklist to ensure the required information has been included on the
Hydromodification Management Exhibit:
The Hydromodification Management Exhibit must identify:
□ Underlying hydrologic soil group
□ Approximate depth to groundwater
□ Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)
□ Critical coarse sediment yield areas to be protected (if present)
□ Existing topography
□ Existing and proposed site drainage network and connections to drainage offsite
□ Proposed grading
□ Proposed impervious features
□ Proposed design features and surface treatments used to minimize imperviousness
□ Point(s) of Compliance (POC) for Hydromodification Management
□ Existing and proposed drainage boundary and drainage area to each POC (when necessary,
create separate exhibits for pre-development and post-project conditions)
□ Structural BMPs for hydromodification management (identify location, type of BMP, and
size/detail)
PROJECT IS EXEMPT FROM HYDROMODIFICATION MANAGEMENT
Watershed Boundaries
Municipal Boundaries
-Exempt Bodies:
Water Storage Reservoirs. Lakes,
Enclosed Embayments. Pacific
Ocean. Buena Vista Lagoon
-Exempt River Reaches:
Reaches of San Luis Rey River. San
Dieguito River. San Diego River,
forester Creek, Sweetwater River.
otay River
-Exempt Conveyance Systems:
Existing underground storm drains or
conveyance channels whose bed
and bank are concrete-lined.
discharging direcHy to exempt water
bodies. exempt rivers. or loca6zed
areas of Agua Hedlonda Lagoon and
BatlqultosLagoon
Carlsbad Watershed Management Area
HU 904.00, 211 mi2
'Receiving Waters and Conveyance Systems Exempt
1from Hydromodification Management Requirements
2.5
Exhibit Date: Sept. 8, 2014
5
Geosyntec t> RICK
consultanLs E....,o,~r1:R1Nt1 CoMPASY
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Miles IT]
10 l.IJ
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□
I
I
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DISCHARGE FROM HARDENED STORM DRAIN
SYSTEM OF PIPE, CONC DITCH, AND RCB TO
OCEAN CONNECTION. SURFACE FLOW OVER
;g;_:::JUNDEFINED CHANNEL SUBJECT TO TIDAL
INUNDATION.
..
.. ATTACHMENT 3
Structural BMP Maintenance Thresholds and Actions ...
...
...
◄
◄
..
..
..
BMP MAINTENANCE FACT SHEET
FOR
STRUCTURAL BMP BF-1 BIOFILTRATION
BF-1
Biofiltration
Biofiltration facilities are vegetated surface water systems that filter water through vegetation, and soil or
engineered media prior to discharge via underdrain or overflow to the downstream conveyance system.
Biofiltration facilities have limited or no infiltration. They are typically designed to provide enough hydraulic head
to move flows through the underdrain connection to the storm drain system. Typical biofiltration components
include:
• Inflow distribution mechanisms (e.g., perimeter flow spreader or filter strips)
• Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap)
• Shallow surface ponding for captured flows
• Side slope and basin bottom vegetation selected based on climate and ponding depth
• Non-floating mulch layer
• Media layer (planting mix or engineered media) capable of supporting vegetation growth
• Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils
or the aggregate storage layer
• Aggregate storage layer with underdrain(s)
• Impermeable liner or uncompacted native soils at the bottom of the facility
• Overflow structure
Normal Expected Maintenance
Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris;
maintain vegetation health; maintain infiltration capacity of the media layer; replenish mulch; and maintain
integrity of side slopes, inlets, energy dissipaters, and outlets. A summary table of standard inspection and
maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure
If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream
waterways from pollution and/or erosion. Corrective maintenance, increased inspection and maintenance, BMP
replacement, or a different BMP type will be required.
• The BMP is not drained between storm events. Surface ponding longer than approximately 24 hours
following a storm event may be detrimental to vegetation health, and surface ponding longer than
approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage
can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet
structure. The specific cause of the drainage issue must be determined and corrected.
• Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one
month. This means the load from the tributary drainage area is too high, reducing BMP function or
clogging the BMP. This would require pretreatment measures within the tributary area draining to the
BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of
components that are more expensive to replace such as media, filter course, and aggregate layers.
• Erosion due to concentrated storm water runoff flow that is not readily corrected by adding erosion
control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage
according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and
grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction.
BF-1 Page 1 of 11
January 12, 2017
..
..
Other Special Considerations
BF-1
Biofiltration
Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or
connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters
or wetlands. As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United
States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish
and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to
perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine
maintenance is key to preventing this scenario .
BF-1 Page 2 of 11
January 12, 2017
.. ' • • • •
BF-1
Biofiltration
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to
an agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently.
Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections
to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior
to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the
minimum inspection and maintenance frequency can be determined based on the results of the first year inspections.
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Accumulation of sediment, litter, or debris Remove and properly dispose of accumulated materials, • Inspect monthly. If the BMP is 25% full* or more in
without damage to the vegetation or compaction of the one month, increase inspection frequency to monthly
media layer. plus after every 0.1-inch or larger storm event.
• Remove any accumulated materials found at each
inspection.
Obstructed inlet or outlet structure Clear blockage. • Inspect monthly and after every 0.5-inch or larger
storm event.
• Remove any accumulated materials found at each
inspection.
Damage to structural components such as weirs, inlet or Repair or replace as applicable • Inspect annually.
outlet structures • Maintenance when needed.
Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original • Inspect monthly.
plans. • Maintenance when needed.
Dead or diseased vegetation Remove dead or diseased vegetation, re-seed, re-plant, • Inspect monthly.
or re-establish vegetation per original plans. • Maintenance when needed.
Overgrown vegetation Mow or trim as appropriate. • Inspect monthly.
• Maintenance when needed.
2/3 of mulch has decomposed, or mulch has been Remove decomposed fraction and top off with fresh • Inspect monthly.
removed mulch to a total depth of 3 inches. • Replenish mulch annually, or more frequently when
needed based on inspection.
*"25% full" is defined as¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the
bottom elevation, then the materials must be removed when there is 3 inches of accumulation -this should be marked on the outflow structure).
BF-1 Page 3 of 11
January 12, 2017
• ' i ' •
BF-1
Biofiltration
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION (Continued from previous page)
Threshold/Indicator
Erosion due to concentrated irrigation flow
Erosion due to concentrated storm water runoff flow
Standing water in BMP for longer than 24 hours
following a storm event
Surface ponding longer than approximately 24 hours
following a storm event may be detrimental to
vegetation health
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
httQ:LLwww.mosguito.orgi'.biologl'.
Underdrain clogged
Maintenance Action
Repair/re-seed/re-plant eroded areas and adjust the
irrigation system.
Repair/re-seed/re-plant eroded areas, and make
appropriate corrective measures such as adding erosion
control blankets, adding stone at flow entry points, or
minor re-grading to restore proper drainage according
to the original plan. If the issue is not corrected by
restoring the BMP to the original plan and grade, the
[City Engineer] shall be contacted prior to any additional
repairs or reconstruction.
Make appropriate corrective measures such as adjusting
irrigation system, removing obstructions of debris or
invasive vegetation, clearing underdrains, or
repairing/replacing clogged or compacted soils.
If mosquitos/larvae are observed: first, immediately
remove any standing water by dispersing to nearby
landscaping; second, make corrective measures as
applicable to restore BMP drainage to prevent standing
water.
If mosquitos persist following corrective measures to
remove standing water, or if the BMP design does not
meet the 96-hour drawdown criteria due to release
rates controlled by an orifice installed on the
underdrain, the [City Engineer] shall be contacted to
determine a solution. A different BMP type, or a Vector
Management Plan prepared with concurrence from the
County of San Diego Department of Environmental
Health, may be required.
Clear blockage.
BF-1 Page 4 of 11
January 12, 2017
Typical Maintenance Frequency
• Inspect monthly.
• Maintenance when needed.
• Inspect after every 0.5-inch or larger storm event. If
erosion due to storm water flow has been observed,
increase inspection frequency to after every 0.1-inch
or larger storm event.
• Maintenance when needed. If the issue is not
corrected by restoring the BMP to the original plan
and grade, the [City Engineer] shall be contacted prior
to any additional repairs or reconstruction.
• Inspect monthly and after every 0.5-inch or larger
storm event. If standing water is observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed.
• Inspect monthly and after every 0.5-inch or larger
storm event. If mosquitos are observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed.
• Inspect if standing water is observed for longer than
24-96 hours following a storm event.
• Maintenance when needed.
._ j_
References
American Mosquito Control Association.
http://www.mosquito.org/
California Storm Water Quality Association (CASQA). 2003. Municipal BMP Handbook.
https://www.casqa.org/resources/bmp-handbooks/municipal-bmp-handbook
County of San Diego. 2014. Low Impact Development Handbook.
http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html
San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet BF-1.
http://www.projectcleanwater.org/index.php?option=com content&view=article&id=250&Itemid=220
BF-1 Page 5 of 11
January 12, 2017
• A "
BF-1
Biofiltration
• i
Page Intentionally Blank for Double-Sided Printing
BF-1 Page 6 of 11
January 12, 2017
"
BF-1
Biofiltration
&
Date:
Permit No.:
Property/ Development Name:
Property Address of BMP:
Threshold/Indicator
Accumulation of sediment, litter, or debris
Maintenance Needed?
□ YES
□ NO
□ N/A
Poor vegetation establishment
Maintenance Needed?
□ YES
□ NO
□ N/A
'
I Inspector: I BMP ID No.:
I APN(s):
Responsible Party Name and Phone Number:
Responsible Party Address:
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 1 of 5
•
BF-1
Biofiltration
Maintenance Recommendation Date Description of Maintenance Conducted
□ Remove and properly dispose of
accumulated materials, without damage
to the vegetation
□ If sediment, litter, or debris accumulation
exceeds 25% of the surface ponding
volume within one month (25% full*),
add a forebay or other pre-treatment
measures within the tributary area
draining to the BMP to intercept the
materials.
□ Other/ Comments:
□ Re-seed, re-plant, or re-establish
vegetation per original plans
□ Other/ Comments:
*"25% full" is defined as¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the
bottom elevation, then the materials must be removed when there is 3 inches of accumulation -this should be marked on the outflow structure).
BF-1 Page 7 of 11
January 12, 2017
•
Date: Inspector:
Permit No.: APN(s):
•
BMP ID No.:
BF-1
Biofiltration
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 2 of 5
Threshold/Indicator
Dead or diseased vegetation
Maintenance Needed?
□ YES
□ NO
□ N/A
Overgrown vegetation
Maintenance Needed?
□ YES
□ NO
□ N/A
2/3 of mulch has decomposed, or mulch has
been removed
Maintenance Needed?
□ YES
□ NO
□ N/A
Maintenance Recommendation
D Remove dead or diseased vegetation, re-
seed, re-plant, or re-establish vegetation
per original plans
□ Other/ Comments:
D Mow or trim as appropriate
□ Other/ Comments:
□ Remove decomposed fraction and top off
with fresh mulch to a total depth of 3
inches
□ Other/ Comments:
BF-1 Page 8 of 11
January 12, 2017
Date Description of Maintenance Conducted
Date: Inspector:
Permit No.: APN(s):
BMP ID No.:
BF-1
Biofiltration
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 3 of 5
Threshold/Indicator
Erosion due to concentrated irrigation flow
Maintenance Needed?
□ YES
□ NO
0 N/A
Erosion due to concentrated storm water runoff
flow
Maintenance Needed?
□ YES
□ NO
□ N/A
Maintenance Recommendation
□ Repair/re-seed/re-plant eroded areas and
adjust the irrigation system
□ Other/ Comments:
D Repair/re-seed/re-plant eroded areas,
and make appropriate corrective
measures such as adding erosion
control blankets, adding stone at flow
entry points, or minor re-grading to
restore proper drainage according to
the original plan
□ If the issue is not corrected by restoring
the BMP to the original plan and grade,
the [City Engineer] shall be contacted
prior to any additional repairs or
reconstruction
□ Other/ Comments:
BF-1 Page 9 of 11
January 12, 2017
Date Descrip_tion of Maintenance Conducted
•
Date: I nsp_ector:
Permit No.: APN(s):
!.
BMP ID No.:
'
BF-1
Biofiltration
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 4 of 5
Threshold/Indicator
Obstructed inlet or outlet structure
Maintenance Needed?
□ YES
□ NO
□ N/A
Underdrain clogged (inspect underdrain if
standing water is observed for longer than 24-96
hours following a storm event)
Maintenance Needed?
□ YES
□ NO
□ N/A
Maintenance Recommendation
□ Clear blockage
□ Other/ Comments:
□ Clear blockage
□ Other/ Comments:
Damage to structural components such as weirs, I □ Repair or replace as applicable
inlet or outlet structures
Maintenance Needed?
□ YES
□ NO
□ N/A
□ Other/ Comments:
BF-1 Page 10 of 11
January 12, 2017
Date Description of Maintenance Conducted
i
.. • " £
Date:
Permit No.:
i
Inspector:
APN{s):
BMP ID No.:
BF-1
Biofiltration
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGES of S
Threshold/Indicator
Standing water in BMP for longer than 24-96
hours following a storm event*
Surface ponding longer than approximately 24
hours following a storm event may be
detrimental to vegetation health
Maintenance Needed?
0 YES
□ NO
□ N/A
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosguito.org/biology
Maintenance Needed?
0 YES
□ NO
0 N/A
Maintenance Recommendation
D Make appropriate corrective measures
such as adjusting irrigation system,
removing obstructions of debris or
invasive vegetation, clearing
underdrains, or repairing/replacing
clogged or compacted soils
D Other/ Comments:
D Apply corrective measures to remove
standing water in BMP when standing
water occurs for longer than 24-96
hours following a storm event.**
D Other/ Comments:
Date Descrip_tion of Maintenance Conducted
*Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours
following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain,
or outlet structure. The specific cause of the drainage issue must be determined and corrected.
**If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates
controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared
with concurrence from the County of San Diego Department of Environmental Health, may be required.
BF-1 Page 11 of 11
January 12, 2017
..
...
...
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural
BMP Maintenance Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
X □Typical maintenance indicators and actions for proposed structural BMP(s) based
on Section 7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
□ Specific maintenance indicators and actions for proposed structural BMP(s). This
shall be based on Section 7.7 of the BMP Design Manual and enhanced to reflect
actual proposed components of the structural BMP(s)
□ How to access the structural BMP(s) to inspect and perform maintenance
□ Features that are provided to facilitate inspection (e.g., observation ports,
cleanouts, silt posts, or other features that allow the inspector to view necessary
components of the structural BMP and compare to maintenance thresholds)
□ Manufacturer and part number for proprietary parts of structural BMP(s) when
applicable
□ Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level
posts or other markings shall be included in all BMP components that will trap and
store sediment, trash, and/or debris, so that the inspector may determine how full
the BMP is, and the maintenance personnel may determine where the bottom of
the BMP is . If required, posts or other markings shall be indicated and described
on structural BMP plans.)
□ Recommended equipment to perform maintenance
□ When applicable, necessary special training or certification requirements for
inspection and maintenance personnel such as confined space entry or
hazardous waste management
ATTACHMENT 4
-City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City's standard Single Sheet BMP Plan.] ..
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NAME STEI I AR PROPER TIES LLC
ADDRESS 6030 AVENIDA ENCINAS SU ITE 220 CONTACT PEGGY KELCHER
CARI $BAO CA 92017
PHONE NO. (760) 438-2000
PLAN PREPARED BY:
SIGNATURE
COMPANY CTE INC.
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SCALE: 1" = 20'
BMP ID# BMP TYP[ SYMBOL
TREATMENT CONTROL
® BIOFIL TRA T/ON AR[A I-= ---I
@) BIOFIL TRA TION AR[A 1-= ---1
LOW IMPACT DESIGN (LLD.)
@ ROOF DRAINS TO
LANDSCAP[
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@ V[G[TA TED SWAL[ =;>
SOURCE CONTROL
@ STENCILS NO DUMPING
DRAINS TO OCEAN
@ TRASH [NCLDSUR[ I I I
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BMPTABLE
CASQA NO. QTY DWG. NO. SHT. NO. INSP[CTION MA INT£NANC[
FR[QU[NCY FR[QU[NCY
TC-32 945 SF 517-2A 3 MONTHLY MONTHLY
TC-32 400 SF 517-2A 3 MONTHLY MONTHLY
SD-1 1 2 [A 3, 6 ANNUALLY ANNUALLY
TC-30 18 LF. 517-2A J, 6 ANNUALLY MONTHLY
SD-13 2 8 5 S[MI-ANNUALL Y AS N[ED[D
SD-32 1 517-2A 3 MONTHLY AS NEEDED
Construction Testing & Eng in eering, Inc .
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CIE3: Inspection I Testing I Geotechnical I Environmental & Construction Engineering
1441 Montiel Road , Suite 115, Escondido, CA 92026 Phone: (760) 746 -4955
I Civi l Engineering I Surveying
Fax: (760) 746 -9806
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INFLOW PIPE
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ORIFICE PLATE: MIN SQUARE
DIMENSIONS 1.0 FT. GREATER
THAN PIPE DIA HOT-DIP
GALVANIZED PLATE AFTER
HOLES HAVE BEEN DRILLED
MIN. 6"
0
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1. ORIFICE PLATE & FLANGE CONNECTION
TO CONCRETE SHALL BE FITTED 'MTH 30
DURDMETER NEOPRENE RING.
2. MAINTENANCE ACCESS FROM 24"X24"
RISER.
3. CLEARING OF ORIFICE TO BE CLEANED
WITH WATER JET OR EQUIVALENT
METHODS
ORIFICE 4.6" DIAMETER (DIA)
llWIL
FLOW CONTR<l, OBIEICE PLAJE
NTS
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CONSTRUCTION NOTES:
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@@) CONSTRUCT BIO-FILTRATION FACILl1Y PER DETAIL 6 SHEET 5
~'-T .
.., ' ?-.,. ... o No.61013
EXP 12/31/20
DATE IN\11AL
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9,755 J-\C,
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2-J-J~oao~27
ROW
18" X 18" BIO-FILTRATION OUTL[T
STRUCTURE WITH GRAT[D INL[T FOR
HIGH BYPASS FLOW
STEM WALL PER DETAIL 4
SHEET 5
AV£NIDA
ENCINAS
PHONE NO. (760) 746-4955 CERTIFICATION R CE NO. 61013
BMP NOTES:
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S
RECOMMENDATIONS OR THESE PLANS.
2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOU T PRIOR
APPROVAL FROM TH E CITY ENGINEER.
3. NO SUBSTITUTIONS TO Tl-IE MATERIAL OR TYPES OR PLANTING TYPES
WI THOUT PRIOR APPROVAL FROM THE CITY ENGINEER.
4. NO OCCUPANCY WILL BE GRANTED UNTIL TH E CITY INSPECTION STAFF
HAS INSP ECTED TH IS PROJECT FOR APPROPRIATE BMP CONSTRUCTION
AND INSTALLATION.
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
6. SEE PROJECT SWMP FOR ADDITIONAL INFORMATION.
• NO ADOfTIONAL EXPORT OU[ TO POT[NTIAL SOIL CONT AMINA T/ON
IS ANTIC/PA T£D SINCE PHASE 2 ENVIRONMEN TAL ASSESSMENT AND
SOIL VA POR STUDY CONCLUDED THAT SOIL CONDfTIONS DID NOT
POSE ANY RISK TO HUMAN HEAL TH OR TH[ [NVIRONM[NT.
PERMAN ENT WATER QUALITY
TREATMENT FAC ILITY
KEEPING OUR WATER WAYS CLEAN
MAINTAIN WITH CARE -NO MODIFICATIONS \\1THOUT AGENCY APPROVAL
DETA IL
WATER QUALITY SIGN PLA CED
EACH BIOFIL TRATION BAS IN
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NOTE: ALL BIOFlLTRATION AREAS WILL
HAVE A SIGN POSTED TO BE
'119BLE AT ALL TIMES.
STABILIZED COBBLE INLET
6" MODIFIED CURB W/
CUT PER DETAIL #1
CURB
AT
RIBBON GUTTER FLOW PARKING LOT
_/"-..
(•) BIO FILTRA T/ON SOIL MEDIA LA YER SHALL BE MINIMUM 18" DEEP SANDY LOAM SOIL MIX. TH[ MIX SHALL CONTAIN 85-90% SAND, 10% SILT
AND 5% MAX, CLAY FROM SAN Dl[GO BMP D[S/GN MANUAL LIST
TH[ [FF[CT/V[ AREA OF TH[ BASIN SHALL B[ L[V[L AND SHALL BE SIZED BASED ON STORM WATER MANUAL CALCULATIONS. TYPICALLY, TH[
SURFACE AREA OF THE 810 FILTRATION BASIN IS 4% OF THE IMPERVIOUS AREA DRAINING TO IT.
SOIL MIX SPECIF/CATIONS SHALL BE MEET COUNTY OF SAN DIEGO LOW IMPACT DEVELOPMENT HANDBOOK: APPENDIX G-BIORETENT/ON SOIL
SPECIFICATION (JULY 2014, UNL[SS SUPERSEDED BY MORE RECENT EDITION) "AS BUil T"
RCE __ _ EXP. ___ _
REVIEWED BY:
INSPECTOR
I SH1ET I CITY OF CARLSBAD
ENGINEERING DEPARTMENT
GRADING PL ANS FOR:
ECO-FRIENDLY AUTO SPA
6010 AVENIDA ENCINAS
CARLSBAD CA. 92011
DATE
DATE
I SH1ETS I
GR 2019-0011 BMP SITE PLAN CDP2017-0D49
APPROVED: JASON S. GELDERT
CITY ENGINEER RCE 63912 EXPIRES 9/30/20 DATE
1
DATE lNITI AL DATE IN111AL DWN BY: JM PROJECT NO. DRAWING NO .
CHKD BY:
ENGINEER OF WORK RE VISION DESCRIP TION OTHER APPROVAL CITY APPROVAL RVWO BY: CUP2017-0009 5 17-2.A ~L------------------------------------------------------------------------------------...;;;;_ __ .,:; ____ ~---------------~----;:;;;----~-------------------:.1
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