HomeMy WebLinkAboutCT 2017-0005; Grand West; SWQMP for Grand West; 2020-10-20CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
GRAND WEST
SWQMP No. CT 2017-0005/PUD 2017-0005
ENGINEER OF WORK:
Robert D’Amaro, RCE# C081699, 03/31/2020
PREPARED FOR:
Eric DeJong
807 E Mission Rd.
San Marcos, CA 92069
858-755-0216
PREPARED BY:
Masson & Associates, Inc.
200 E. Washington Ave. Suite 200
Escondido, California 92025
760-741-3570
DATE:
January 22, 2019
Updated: May 22, 2019
Updated: July 22, 2019
Updated: August, 21 2019
Final Update: October, 20 2020
2
I
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 1a: DMA Exhibit
Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
CERTIFICATION PAGE
Project Name: Grand West
Project ID: CT 2017-0005
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
Robert D’Amaro, P.E.
Print Name
Masson & Associates, Inc.
Company
October 20, 2020
Date
12/07/2020
Engineer of Work's Signature, PE Number & Expiration Date
Robert D'Amaro, P.E.
Print Name
Masson & Associates, Inc.
Company
October 20, 2020
Date
PROJECT VICINITY MAP
STORM WATER STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
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: Grand West PROJECT ID: CT 2017-0005
ADDRESS: (street number not assigned) 972, 988 Grand Ave, Carlsbad CA APN: 203-130-25-00, 203-130-26-00
The project is (check one): New Development X Redevelopment
The total proposed disturbed area is: 18,550 ft2 ( 0.43 ) acres
The total proposed newly created and/or replaced impervious area is: 13,243 ft2 ( 0.30 ) 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: No
Project ID N/A 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
STEP 1
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
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 you answered “no” to the above question, the project is a ‘development project’, go to Step 2.
STEP 2
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;
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 guidance?
2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in
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?
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, your project is not exempt from PDP, go to Step 3.
E-34 REV 02/16
STEP 3
TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS
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, 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 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
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
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 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 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 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 commingled 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 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
RGO’s that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic
(ADT) 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
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
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 applicant information.
* Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas
designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water 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 (Water 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 of San Diego; Habitat
Management Plan; and any other 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:
STEP 4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP)
ONLY
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 impervious area (A) = 7,020 sq. ft.
Total proposed newly created or replaced impervious area (B) = 13,243 sq. ft.
Percent impervious area created or replaced (B/A)*100 = 188 %
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
check the first box stating “My project is a PDP …” and complete applicant information.
STEP 5
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
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.
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 Form E-36” 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.
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: Arie E. de Jong III and Silvia de Jong Applicant Title: Owner
Jewel Development, LLC
Applicant Signature: Date:
E-34 REV 02/16
SITE INFORMATION CHECKLIST
Project Summary Information
Project Name Grand West
Project ID CT 2017-0005
Project Address 972 & 988 Grand Avenue
Assessor's Parcel Number(s) (APN(s)) 203-130-25-00, 203-130-26-00
Project Watershed (Hydrologic Unit)Carlsbad 904.21
Parcel Area 0.42 Acres ( 18,550 Square Feet)
Existing Impervious Area
(subset of Parcel Area) 6,795 Acres ( 0.15 Square Feet)
Area to be disturbed by the project
(Project Area) 0.42 Acres ( 18,550 Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 13,208 Acres ( 0.30 Square Feet)
Project Proposed Pervious Area
(subset of Project Area) 5,342 Acres ( 0.12 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
Existing development
Previously graded but not built out
Agricultural or other non-impervious use
Vacant, undeveloped/natural
Description / Additional Information:
Existing Land Cover Includes (select all that apply):
Vegetative Cover
Non-Vegetated Pervious Areas
Impervious Areas
Description / Additional Information:
The site is an existing residential site with impervious area like footprint, driveway and patio.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
NRCS Type A
NRCS Type B
NRCS Type C
NRCS Type D
Approximate Depth to Groundwater (GW):
GW Depth < 5 feet
5 feet < GW Depth < 10 feet
10 feet < GW Depth < 20 feet
GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
None
Description / Additional Information:
E-34 REV 02/16
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]:
The project site is located at 972 and 988 Grand Avenue in Carlsbad. The site bounded by
Grand Avenue to the southeast and residences on all other sides. The project is zoned RD-M
with a General Plan Land Use designation of R15, which allows for 11.5 du/acre per Staff. The
project site is generally flat at an approximate elevation of 68 feet msl and consists of
residential buildings, driveways and landscapes. The site is located approximately 0.46 miles
south of the Buena Vista Lagoon. The surface runoff from the site currently drains into Grand
Avenue and which ultimately reaches Buena Vista Lagoon and Pacific Ocean via curb, gutter
and storm drain system.
Stormwater discharges from the site are not considered direct discharges, as defined by the
State Water Board. Existing site topography, drainage patterns, and stormwater conveyance
systems are shown on the Grading Plans. The site accepts no off site runoff from the adjacent
roadways or adjoining properties.
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The proposed site is planned to be developed into Two (2) Triplex Townhome Condominiums, for
a total number of 6 units. The proposed projects land use is consistent with the surrounding
development and will not adversely impact the adjoining lands or the character of the
neighborhood.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
As with any residential development, the project will include impervious surfaces. Impervious
surfaces will include; roofs, driveways, parking areas, streets, patios and hard landscaping. The
increase in runoff as a function of the new impervious surfaces will be mitigated by a retention
basin.
List/describe proposed pervious features of the project (e.g., landscape areas):
The project will include several types of pervious surfaces within the design. The pervious surfaces
include; landscaping, grass areas and bio-filtration Basins, and planting areas.
Does the project include grading and changes to site topography?
Yes
No
Description / Additional Information:
Considering the site has previously been developed, the site will require minor re-contouring to
make the site developable for the new propose plan. Although, every effort has been made to
reduce the earthwork, the site will require approximately 350 cubic yards of fill be implemented
for the proposed design presented.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
Yes
No
Description / Additional Information:
As shown on the plan, few new drainage systems have been included in the designs which play
an important role in controlling surface runoff. The facilities include; area yard drains, storm
drainage pipe, perforated underdrain pipes, rip rap energy dissipaters and three bio-filtration
basins. All of these systems work in conjunction to control and discharge flows in a manner most
similar to the existing condition.
E-34 REV 02/16
Identify whether any of the following features, activities, and/or pollutant source
areas will be present (select all that apply):
On-site storm drain inlets
Interior floor drains and elevator shaft sump pumps
Interior parking garages
Need for future indoor & structural pest control
Landscape/Outdoor Pesticide Use
Pools, spas, ponds, decorative fountains, and other water features
Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
Plazas, sidewalks, and parking lots
Identification of Receiving 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):
Surface runoff draining from the site is discharged in a controlled fashion into a storm drain on
Monroe Street approximately 1 mile upstream of the Buena Vista Lagoon. Runoff then travels an
additional 1.5 miles within the Lagoon before reaching the Pacific Ocean.
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
Buena Vista Creek/ 904.21 Toxicity, Selenium, Bifenthrin,
Benthic Community Effects Needed
Buena Vista Lagoon/ 904.21 Indicator Bacteria, Nutrients,
Sedimentation/Siltation, Toxicity Needed
Pacific Ocean Shoreline, Buena
Vista Creek HA / 904.21 Indicator Bacteria Needed
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):
Pollutant
Not Applicable to
the Project Site
Anticipated from the
Project Site
Also a Receiving
Water Pollutant of
Concern
Sediment X NA
Nutrients X NA
Heavy Metals X NA
Organic Compounds X NA
Trash & Debris X NA
Oxygen Demanding
Substances P(1)NA
Oil & Grease P(2)NA
Bacteria & Viruses P
Pesticides X NA
P = Potential
(1) = A potential pollutant if landscaping exists onsite.
(2) = A potential pollutant if the project uncovered parking areas.
E-34 REV 02/16
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
Yes, hydromodification management flow control structural BMPs required.
No, the project will discharge runoff directly to existing underground storm drains
discharging directly to water storage reservoirs, lakes, enclosed embayment’s, 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 embayment’s, 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):
Since the project is exempt from hydromodification, the critical coarse sediment is not an
issue for this project site.
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
Yes
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?
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 only required if hydromodification management requirements apply
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.
N/A, 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.
Therefore the HMP is not required.
Has a geomorphic assessment been performed for the receiving channel(s)?
No, the low flow threshold is 0.1Q2 (default low flow threshold)
Yes, the result is the low flow threshold is 0.1Q2
Yes, the result is the low flow threshold is 0.3Q2
Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion / Additional Information: (optional)
N/A, 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.
E-34 REV 02/16
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.
Site is flat, which prevents gravity discharge to the street. Pad cannot be raised due to
previously planning department approvals.
No existing storm drain system in the street to tie into.
Optional Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
STANDARD PROJECT
REQUIREMENT CHECKLIST
E-36
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
Project Information
Project Name: Grand West
Project ID: CT 2017-0005
DWG No. or Building Permit No.:
Source Control BMPs
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 (Volume 5 of City Engineering Standards) 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 X Yes No N/A
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage X Yes No N/A
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind
Dispersal Yes No X N/A
Discussion/justification if SC-3 not implemented:
No post development storage of material is proposed.
E-36 Page 1 of 4 Revised 09/16
Source Control Requirement (continued)Applied?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and
Wind Dispersal Yes No X NIA
Discussion/justification if SC-4 not implemented:
No post development outdoor work areas are proposed.
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal X Yes No N/A
Discussion/justification if SC-5 not implemented:
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 guidance).
D On-site storm drain inlets X No
D Interior floor drains and elevator shaft sump pumps X No
D Interior parking garages X No
D Need for future indoor & structural pest control X Yes
D Landscape/Outdoor Pesticide Use X Yes
D Pools, spas, ponds, decorative fountains, and other water features X No
D Food service X No
D Refuse areas X Yes
D Industrial processes X No
D Outdoor storage of equipment or materials X No
D Vehicle and Equipment Cleaning X No
D Vehicle/Equipment Repair and Maintenance X No
D Fuel Dispensing Areas X No
D Loading Docks X No
D Fire Sprinkler Test Water X No
D Miscellaneous Drain or Wash Water X No
D Plazas, sidewalks, and parking lots X Yes
For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers.
Refer to BMP Site plan in Attachment 4 section for reference to the additional BMPs for the items identified
as “Yes” above.
Per Appendix E.1 additional BMPS are:Biofiltration BF-1Efficient Irrigation SD-12Storm Drain Signage SD-13Building & Grounds Maintenance SC-41Non-Stormwater Discharges SC-10Street Sweeping and Vacuuming SE-7Parking Area Maintenance SC-43Velocity Dissipation Devices EC-10
E-36 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 (Volume 5 of City Engineering Standards) 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 X Yes I No I NIA
Discussion/justification if SD-1 not implemented:
SD-2 Conserve Natural Areas, Soils, and Vegetation I Yes I X No I N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize Impervious Area I X Yes I No I N/ADiscussion/justification if SD-3 not implemented:
SD-4 Minimize Soil Compaction I Yes I X No NIA
Discussion/justification if SD-4 not implemented:
As the site will be completely regraded, soil compaction of import soils will be required. Unfortunately, no native areas
will remain undisturbed.
SD-5 Impervious Area Dispersion I Yes I X No I NIA
Discussion/justification if SD-5 not implemented:
Source Control Requirement (continued)I Applied?
SD-6 Runoff Collection I Yes I No I X N/A
Discussion/justification if SD-6 not implemented:
SD-7 Landscaping with Native or Drought Tolerant Species I X Yes I No I NIA
Discussion/justification if SD-7 not implemented:
SD-8 Harvesting and Using Precipitation I Yes I X No I NIA
Discussion/justification if SD-8 not implemented:
See Form I-7 for calculation.
E-36 Revised 03/16
PDP Structural BMPs
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 pollution control measures and structural BMP’s have been implemented on site. The
proposed Bio-filtration Basins will treat onsite runoff, prior to discharge.
Hydromodification is exempt for this project therefore flow Control BMP is not required.
The bio-filtration basin has a high rating for removal of all likely pollutants from storm water.
[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.]
E-36 Revised 03/16
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMP]
Structural BMP ID No.
DWG 481-1A Sheet No. 4
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1)
✓ 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)
Detention pond or vault for hydromodification management
Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control
Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Discussion (as needed):
IMP #1
IMP #2
IMP #3
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
Sequence
Contents Checklist
Attachment 1a DMA Exhibit (Required)
See DMA Exhibit Checklist on the back
of this Attachment cover sheet.
(24”x36” Exhibit typically required)
Included
Attachment 1b Tabular Summary of DMAs Showing
DMA ID matching DMA Exhibit, DMA
Area, and DMA Type (Required)*
*Provide table in this Attachment OR
on DMA Exhibit in Attachment 1a
Included on DMA Exhibit in
Attachment 1a
Included as Attachment 1b,
separate from DMA Exhibit
Attachment 1c Form I-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 I-7.
Included
Not included because the entire
project will use infiltration BMPs
Attachment 1d Form I-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
I-8.
Included
Not included because the entire
project will use harvest and use
BMPs
Attachment 1e Pollutant Control BMP Design
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
Included
Appendix I: Forms and Checklists
I-2
Use this checklist to ensure the required information has been included on the DMA Exhibit:
The DMA 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). “See Course Sediment Exhibit.”
Existing topography and impervious areas
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
Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square footage or
acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating)
Structural BMPs (identify location and type of BMP)
O. 760.741.3570
www.masson-assoc.com
Planning Engineering Surveying
200 E. Washington Ave., Suite 200
Escondido, CA 92025
& A S S O C I A T E S , I N C .
M A S S O N F. 760.741.1786
Solved.
PROJECT
LOCATION
LEGEND
DATE: Oct 19, 20 12:27pm by:gwocker FILE: I:\16\16277\PROD\Reports\SWQMP\Exhibits\16277-DMA MAP- Final Eng.dwg
Appendix I: Forms and Checklists
I-
3333
3333
3999
3
February 2016
2016
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
Toilet and urinal flushing
Landscape irrigation
Other: None Provider
2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance
for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section
B.3.2.
[Provide a summary of calculations here]
Toilet Use (36 Hours use) = 22 Cubic-feet
Landscape Use (Over 36 Hours) = 6 Cubic-feet
Total anticipated Use (Over 36 Hour) = 29 Cubic-feet
25%*607.6=152 > 29 Cubic-feet
3. Calculate the DCV using worksheet B.2-1 .
DCV = 607.6 (cubic feet)
3a. Is the 36 hour demand greater
than or equal to the DCV?
Yes / No
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV?
Yes I No
3c. Is the 36 hour demand
less than 0.25DCV?
Yes
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.
Ha1vest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to determine
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.
Harvest and use is
considered to be
infeasible because of
the site design
constrain
Is hatvest and use feasible based on further evaluation?
D Yes, refer to Appendix E to select and size harvest and use BMPs.
No, select alternate BMPs.
Categorization of Infiltration Feasibility Condition Form I-8
Part 1 - Full Infiltration Feasibility Screening Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Note that it is not necessary to investigate each and every criterion in the worksheet if infiltration is precluded.
Instead a letter of justification from a geotechnical professional familiar with the local conditions
substantiating any geotechnical issues will be required.
Criteria Screening Question Yes No
1
Is the estimated reliable infiltration rate below proposed facility
locations greater than 0.5 inches per hour? The response to this
Screening Question must be based on a comprehensive evaluation of
the factors presented in Appendix C.2 and Appendix D.
X
Provide basis:
Three (3) separate percolation tests were completed within 50 feet of each proposed water quality basin
locations. The calculated infiltration rates at each location (with an applied factor of safety of 2) are 0.12,
0.12, & 0.15 inches per hour.
For reference refer to Geotechnical Investigation by Construction Testing & Engineering, Inc.
(CTE), dated May 31, 2017.
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 geotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot be
mitigated to an acceptable level? The response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.2.
X
Provide basis:
Basins can be constructed within the areas with favorable permeability (Figure 2) and with adequately set
back from proposed structural improvements; risk of geotechnical hazards will not be significantly
increased.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
Appendix I: Forms and Checklists
I-
3333
3333
3999
5
February 2016
2016
Form I-8 Page 2 of 4
Criteria Screening Question Yes No
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 level? The response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.3.
X
Provide basis:
According to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 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 must 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 Buena Vista Lagoon which is over 2,300 feet from the
site. Due to the significant distance to the lagoon it is unlikely to be impacted by infiltrating site water.
Due to the buildings footing and utility constrain, the basins will be lined.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
Part 1
Result
*
If all answers to rows 1 - 4 are “Yes” a full infiltration design is potentially feasible. The
feasibility screening category is Full Infiltration
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
Infiltration,
Proceed to Part 2
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings
Form I-8 Page 3 of 4
Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
5
Do soil and geologic conditions allow for infiltration in any
appreciable rate or volume? The response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.2 and Appendix D.
X
Provide basis:
Three (3) separate percolation tests were completed within 50 feet of each proposed water quality basin
locations, and the calculated infiltration rates at each location (with an applied factor of safety of 2) are
0.12, 0.12, & 0.15 inches per hour, which exceeds the 0.05 inches per hour.
For reference refer to Geotechnical Investigation by Construction Testing & Engineering, Inc.
(CTE), dated May 31, 2017.
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 geotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot
be mitigated to an acceptable level? The response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.2.
X
Provide basis:
Due to the buildings footing and utility constrain, the basins will be lined.
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.
I-
3333
3333
3999
7
February 2016
2016
Form I-8 Page 4 of 4
Criteria Screening Question Yes No
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 must be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
X
Provide basis:
According to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 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 and why it was not feasible to mitigate low infiltration rates.
8
Can infiltration be allowed without violating downstream water
rights? The response to this Screening Question must 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 Buena Vista Lagoon which is over 2,300 feet from the site. Due to
the significant distance to the lagoon 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 and why it was not feasible to mitigate low infiltration rates.
Part 2
Result*
If all answers from row 1-4 are yes then partial infiltration design is potentially feasible.
The feasibility screening category is Partial Infiltration.
If any answer from row 5-8 is no, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
No
Infiltration is
Feasible
*To be completed using gathered site information and best professional judgment considering the definition of MEP in the
MS4 Permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings.
Design Capture Volume (DCV)DMA - 2
1 85th percentile 24-hr storm depth d=0.590 inches
2 Area tributary to BMP (s)A=0.09 acres
3 Area Weighted runoff factor C=0.66 unitless
4 Rain Barrels volume reduction TCV=0 cubic-feet
5 Street trees volume reduction RCV=0 cubic-feet
6 Calculator DCV =
(3630 x C x d x A) - TCV - RCV DCV= 127.8 cubic-feet
Design Capture Volume (DCV)DMA - 2
1 85th percentile 24-hr storm depth d=0.590 inches
2 Area tributary to BMP (s)A=0.09 acres
3 Area Weighted runoff factor C=0.66 unitless
4 Rain Barrels volume reduction TCV=0 cubic-feet
5 Street trees volume reduction RCV=0 cubic-feet
6 Calculator DCV =
(3630 x C x d x A) - TCV - RCV DCV= 127.8 cubic-feet
Design Capture Volume (DCV)DMA - 3
1 85th percentile 24-hr storm depth d=0.590 inches
2 Area tributary to BMP (s)A=0.23 acres
3 Area Weighted runoff factor C=0.84 unitless
4 Rain Barrels volume reduction TCV=0 cubic-feet
5 Street trees volume reduction RCV=0 cubic-feet
6 Calculator DCV =
(3630 x C x d x A) - TCV - RCV DCV= 414.3 cubic-feet
I-
3333
3333
3999
9
February 2016
2016
Simple Sizing Method for Biofiltration BMPs-IMP#1 Worksheet B.5-1
1 Remaining DCV after implementing retention BMPs 130.2 cubic-
feet
Partial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0 in/hr.
3 Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated [Line 2 x Line 3]0 inches
5 Aggregate pore space 0.4 in/in
6 Required depth of gravel below the underdrain [Line 4/ Line 5]0 inches
7 Assumed surface area of the biofiltration BMP 44 sq-ft
8 Media retained pore space 0.1 in/in
9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Line 7 6.60 cubic-
feet
10 DCV that requires biofiltration [Line 1 – Line 9]123.61 cubic-
feet
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximum] 12 inches
12 Media Thickness [18 inches minimum]18 inches
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.
Baseline Calculations
16 Allowable Routing Time for sizing 6 hours
17 Depth filtered during storm [ Line 15 x Line 16]30 inches
18 Depth of Detention Storage
[Line 11 + (Line 12 x Line 14) + (Line13 x Line 5)]20.4 inches
19 Total Depth Treated [Line 17 + Line 18]50.4 inches
Option 1 – Biofilter 1.5 times the DCV
20 Required biofiltered volume [1.5 x Line 10]185 cubic-
feet
21 Required Footprint [Line 20/ Line 19] x 12 44 sq-ft
Option 2 - Store 0.75 of remaining DCV in pores and ponding
22 Required Storage (surface + pores) Volume [0.75 x Line 10]93 cubic-
feet
23 Required Footprint [Line 22/ Line 18] x 12 55 sq-ft
Footprint of the BMP
24 Area draining to the BMP 3724.24 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)0.68
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03]75 sq-ft
27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26)75 sq-ft
Simple Sizing Method for Biofiltration BMPs-IMP#2 Worksheet B.5-1
1 Remaining DCV after implementing retention BMPs 127.8 cubic-
feet
Partial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0.00 in/hr.
3 Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated [Line 2 x Line 3]0.00 inches
5 Aggregate pore space 0.4 in/in
6 Required depth of gravel below the underdrain [Line 4/ Line 5]0.0 inches
7 Assumed surface area of the biofiltration BMP 39 sq-ft
8 Media retained pore space 0.1 in/in
9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Line 7 5.85 cubic-
feet
10 DCV that requires biofiltration [Line 1 – Line 9]121.90 cubic-
feet
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximum] 6 inches
12 Media Thickness [18 inches minimum]18 inches
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.
Baseline Calculations
16 Allowable Routing Time for sizing 6 hours
17 Depth filtered during storm [ Line 15 x Line 16]30 inches
18 Depth of Detention Storage
[Line 11 + (Line 12 x Line 14) + (Line13 x Line 5)]14.4 inches
19 Total Depth Treated [Line 17 + Line 18]44.4 inches
Option 1 – Biofilter 1.5 times the DCV
20 Required biofiltered volume [1.5 x Line 10]183 cubic-
feet
21 Required Footprint [Line 20/ Line 19] x 12 49 sq-ft
Option 2 - Store 0.75 of remaining DCV in pores and ponding
22 Required Storage (surface + pores) Volume [0.75 x Line 10]91 cubic-
feet
23 Required Footprint [Line 22/ Line 18] x 12 76 sq-ft
Footprint of the BMP
24 Area draining to the BMP 3676.18 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)0.66
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03]73 sq-ft
27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26)73 sq-ft
I-
3333
3333
3999
11
February 2016
2016
Simple Sizing Method for Biofiltration BMPs-IMP#3 Worksheet B.5-1
1 Remaining DCV after implementing retention BMPs 414.3 cubic-
feet
Partial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0 in/hr.
3 Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated [Line 2 x Line 3]0 inches
5 Aggregate pore space 0.4 in/in
6 Required depth of gravel below the underdrain [Line 4/ Line 5]0 inches
7 Assumed surface area of the biofiltration BMP 260 sq-ft
8 Media retained pore space 0.1 in/in
9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Line 7 39.00 cubic-
feet
10 DCV that requires biofiltration [Line 1 – Line 9]375.27 cubic-
feet
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximum] 6 inches
12 Media Thickness [18 inches minimum]18 inches
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.
Baseline Calculations
16 Allowable Routing Time for sizing 6 hours
17 Depth filtered during storm [ Line 15 x Line 16]30 inches
18 Depth of Detention Storage
[Line 11 + (Line 12 x Line 14) + (Line13 x Line 5)]14.4 inches
19 Total Depth Treated [Line 17 + Line 18]44.4 inches
Option 1 – Biofilter 1.5 times the DCV
20 Required biofiltered volume [1.5 x Line 10]563 cubic-
feet
21 Required Footprint [Line 20/ Line 19] x 12 152 sq-ft
Option 2 - Store 0.75 of remaining DCV in pores and ponding
22 Required Storage (surface + pores) Volume [0.75 x Line 10]281 cubic-
feet
23 Required Footprint [Line 22/ Line 18] x 12 235 sq-ft
Footprint of the BMP
24 Area draining to the BMP 9852.2 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)0.84
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03]249 sq-ft
27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26)249 sq-ft
ArcGIS • 85th percentile precipitation -San Diego County
[ [ii Details ] I 88 Basemap
0 I±]
Legend
No legend
Esri.com He!p Terms of Usl! Privacy Contact
Ei.ri Report Abus.i
Modify Map .:, Sign In
"'"' Share ~ Print I ~ Measure [ Find address or place ~-;~:..-_-_-_-_-_-----------~~
I-
3333
3333
3999
13
February 2016
2016
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
None required since this site will be exempt from
Hydromodification requirements.
Attachment
Sequence
Contents Checklist
Attachment 2a Hydromodification Management
Exhibit (Required)
Included
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of Critical Coarse
Sediment Yield Areas (WMAA Exhibit
is required, additional analyses are
optional)
See Section 6.2 of the BMP Design
Manual.
Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield
Area Map (Required)
Optional analyses for Critical Coarse
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
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
Not performed
Included
Attachment 2d Flow Control Facility Design and
Structural BMP Drawdown
Calculations (Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
Included
Use this checklist to ensure the required information has been included on the
Hydromodification Management Exhibit:
Not required since this site will be exempt from
Hydromodification requirements.
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)
Appendix I: Forms and Checklists
I-
3333
3333
3999
15
February 2016
2016
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:
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).
o The indicators of required maintenance include the failure of any of the BMP’s. Failure of the BMP could include clogging of an
inlet as indicated by failure to drain or slow draining of the bio Basin. The Basin should drain in a 72 hour period and be free
debris.
How to access the structural BMP(s) to inspect and perform maintenance.
o Maintenance of the BMP can easily be accessed from the projects common open space. Permeable pavers have been provided
on the access pathway for equipment should it be necessary to maintain the bio-filtration BMP. Access to clean out the pipe
can be done via removable catch basin grate inlet.
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)
o The access corridor to the Structural BMP’s has been overlain with concrete pavers, insuring permanent access to the Bio
Retention Basin, headwall and spillway.
Manufacturer and part number for proprietary parts of structural BMP(s) when applicable.
o No specific proprietary parts or part numbers
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.)
o Please see inspection and fact sheets on the following pages.
Recommended equipment to perform maintenance.
o Routine maintenance can be accomplished with hand tools. Should major maintenance (such as replacement of amended soil
or gravel) be required, it is anticipated that a small backhoe will be needed.
When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as
confined space entry or hazardous waste management.
o No special training or certification is required.
Appendix E: BMP Design Fact Sheets
E-66 February 2016
E.12 BF-1 Biofiltration
Location: 43rd Street and Logan Avenue, San Diego, California
Description
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
MS4 Permit Category
Biofiltration
Manual Category
Biofiltration
Applicable Performance
Standard
Pollutant Control
Flow Control
Primary Benefits
Treatment
Volume Reduction (Incidental)
Peak Flow Attenuation (Optional)
Appendix E: BMP Design Fact Sheets
E-67 February 2016
Overflow structure
Typical plan and Section view of a Biofiltration BMP
Appendix E: BMP Design Fact Sheets
E-68 February 2016
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 Intent/Rationale
□
Placement observes geotechnical
recommendations regarding potential hazards
(e.g., slope stability, landslides, liquefaction
zones) and setbacks (e.g., slopes, foundations,
utilities).
Must not negatively impact existing site
geotechnical concerns.
□
An impermeable liner or other hydraulic
restriction layer is included if site constraints
indicate that infiltration or lateral flows should
not be allowed.
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.
□ Contributing tributary area shall be ≤ 5 acres
(≤ 1 acre preferred).
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
minimizing short circuiting of flows in
Appendix E: BMP Design Fact Sheets
E-69 February 2016
Siting and Design Intent/Rationale
the BMP and 2) incorporate additional
design features requested by the City
Engineer for proper performance of the
regional BMP.
□ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and
channelization within the facility.
Surface Ponding
□ Surface ponding is limited to a 24-hour
drawdown time.
Surface ponding limited to 24 hours for
plant health. Surface ponding drawdown
time greater than 24-hours but less than
96 hours may be allowed at the
discretion of the City Engineer if
certified by a landscape architect or
agronomist.
□ Surface ponding depth is ≥ 6 and ≤ 12 inches.
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 time 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.
□ A minimum of 2 inches of freeboard is
provided.
Freeboard provides room for head over
overflow structures and minimizes risk
of uncontrolled surface discharge.
□ Side slopes are stabilized with vegetation and
are = 3H:1V or shallower.
Gentler side slopes are safer, less prone
to erosion, able to establish vegetation
more quickly and easier to maintain.
Vegetation
Appendix E: BMP Design Fact Sheets
E-70 February 2016
Siting and Design Intent/Rationale
□ Plantings are suitable for the climate and
expected ponding depth. A plant list to aid in
selection can be found in Appendix E.20.
Plants suited to the climate and ponding
depth are more likely to survive.
□ An irrigation system with a connection to
water supply should be provided as needed.
Seasonal irrigation might be needed to
keep plants healthy.
Mulch (Optional)
□ A minimum of 3 inches of well-aged, shredded
hardwood mulch that has been stockpiled or
stored for at least 12 months is provided.
Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch
kills pathogens and weed seeds and
allows the beneficial microbes to
multiply.
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.
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.
□
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) or County of San
Diego Low Impact Development Handbook:
Appendix G -Bioretention Soil Specification
(June 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 of
San Diego Storm Water Standards or County
LID Manual, the media meets the pollutant
treatment performance criteria in Section F.1.
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.
Appendix E: BMP Design Fact Sheets
E-71 February 2016
Siting and Design Intent/Rationale
□ Media surface area is 3% of contributing area
times adjusted runoff factor or greater.
Greater surface area to tributary area
ratios: a) maximizes volume retention as
required by the MS4 Permit and b)
decrease loading rates per square foot
and therefore increase longevity.
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.
□
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).
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.
Migration of media can cause clogging of
the aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to
clog.
□ Filter course is washed and free of fines.
Washing aggregate will help eliminate
fines that could clog the facility and
impede infiltration.
□ Filter course calculations assessing suitability
for particle migration prevention have been
completed.
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.
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
Washing aggregate will help eliminate
fines that could clog the aggregate
storage layer void spaces or subgrade.
Appendix E: BMP Design Fact Sheets
E-72 February 2016
Siting and Design Intent/Rationale
filter course layer at the top of the crushed
rock is required.
□
The depth of aggregate provided (12-inch
typical) and storage layer configuration is
adequate for providing conveyance for
underdrain flows to the outlet structure.
Proper storage layer configuration and
underdrain placement will minimize
facility drawdown time.
Inflow, Underdrain, and Outflow Structures
□ Inflow, underdrains and outflow structures are
accessible for inspection and maintenance.
Maintenance will prevent clogging and
ensure proper operation of the flow
control structures.
□ Inflow velocities are limited to 3 ft/s or less or
use energy dissipation methods. (e.g., riprap,
level spreader) for concentrated inflows.
High inflow velocities can cause erosion,
scour and/or channeling.
□ Curb cut inlets are at least 12 inches wide, have
a 4-6 inch reveal (drop) and an apron and
energy dissipation as needed.
Inlets must not restrict flow and apron
prevents blockage from vegetation as it
grows in. Energy dissipation prevents
erosion.
□ Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.
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.
□ Minimum underdrain diameter is 6 inches. Smaller diameter underdrains are prone
to clogging.
□
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent or
corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.
Slotted underdrains provide greater
intake capacity, clog resistant drainage,
and reduced entrance velocity into the
pipe, thereby reducing the chances of
solids migration.
□
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.
Properly spaced cleanouts will facilitate
underdrain maintenance.
□ Overflow is safely conveyed to a downstream
storm drain system or discharge point Size
overflow structure to pass 100-year peak flow
Planning for overflow lessens the risk of
property damage due to flooding.
Appendix E: BMP Design Fact Sheets
E-73 February 2016
Siting and Design Intent/Rationale
for on-line infiltration basins and water quality
peak flow for off-line basins.
Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only
To design bioretention with underdrain 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 Applicable
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 underdrain 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 underdrain 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.
BF-1
Biofiltration
BMP MAINTENANCE FACT SHEET
FOR
STRUCTURAL BMP 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 dissipators, 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
BF-1
Biofiltration
Other Special Considerations
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,
without damage to the vegetation or compaction of the
media layer.
• Inspect monthly. If the BMP is 25% full* or more in
one month, increase inspection frequency to monthly
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
outlet structures
Repair or replace as applicable • Inspect annually.
• Maintenance when needed.
Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original
plans.
• Inspect monthly.
• Maintenance when needed.
Dead or diseased vegetation Remove dead or diseased vegetation, re-seed, re-plant,
or re-establish vegetation per original plans.
• Inspect monthly.
• 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
removed
Remove decomposed fraction and top off with fresh
mulch to a total depth of 3 inches.
• Inspect monthly.
• Replenish mulch annually, or more frequently when
needed based on inspection.
*“25% full” is defined as ¼ 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
BF-1
Biofiltration
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION (Continued from previous page)
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the
irrigation system. • Inspect monthly.
• Maintenance when needed.
Erosion due to concentrated storm water runoff flow 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.
• 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.
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
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.
• 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.
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
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.
• 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.
Underdrain clogged Clear blockage. • Inspect if standing water is observed for longer than
24-96 hours following a storm event.
• Maintenance when needed.
BF-1 Page 4 of 11
January 12, 2017
BF-1
Biofiltration
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
BF-1
Biofiltration
Page Intentionally Blank for Double-Sided Printing
BF-1 Page 6 of 11
January 12, 2017
BF-1
Biofiltration
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
Property / Development Name:
Responsible Party Name and Phone Number:
Property Address of BMP:
Responsible Party Address:
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 1 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Accumulation of sediment, litter, or debris
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ 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:
Poor vegetation establishment
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Re-seed, re-plant, or re-establish
vegetation per original plans
☐ Other / Comments:
*“25% full” is defined as ¼ 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
BF-1
Biofiltration
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 2 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Dead or diseased vegetation
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Remove dead or diseased vegetation, re-
seed, re-plant, or re-establish vegetation
per original plans
☐ Other / Comments:
Overgrown vegetation
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Mow or trim as appropriate
☐ Other / Comments:
2/3 of mulch has decomposed, or mulch has
been removed
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ 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
BF-1
Biofiltration
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 3 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Erosion due to concentrated irrigation flow
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Repair/re-seed/re-plant eroded areas and
adjust the irrigation system
☐ Other / Comments:
Erosion due to concentrated storm water runoff
flow
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ 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
BF-1
Biofiltration
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 4 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Obstructed inlet or outlet structure
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Clear blockage
☐ Other / Comments:
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
☐ Clear blockage
☐ Other / Comments:
Damage to structural components such as weirs,
inlet or outlet structures
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Repair or replace as applicable
☐ Other / Comments:
BF-1 Page 10 of 11
January 12, 2017
BF-1
Biofiltration
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 5 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
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?
☐ YES
☐ NO
☐ N/A
☐ 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
☐ Other / Comments:
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Apply corrective measures to remove
standing water in BMP when standing
water occurs for longer than 24-96
hours following a storm event.**
☐ Other / Comments:
*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
Appendix I: Forms and Checklists
I-
3333
February 2016
2016
TABLE 7-3. Maintenance Indicators and Actions for Vegetated BMPs
Typical Maintenance Indicator(s)
for Vegetated BMPs Maintenance Actions
Accumulation of sediment, litter, or
debris
Remove and properly dispose of accumulated materials, without
damage to the vegetation.
Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans.
Overgrown vegetation Mow or trim as appropriate, but not less than the design height of the
vegetation per original plans when applicable (e.g. a vegetated swale
may require a minimum vegetation height).
Erosion due to concentrated irrigation
flow
Repair/re-seed/re-plant eroded areas and adjust the irrigation system.
Erosion due to concentrated storm
water runoff flow
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 County must
be contacted prior to any additional repairs or reconstruction.
Standing water in vegetated swales Make appropriate corrective measures such as adjusting irrigation
system, removing obstructions of debris or invasive vegetation,
loosening or replacing top soil to allow for better infiltration, or minor
re-grading for proper drainage. If the issue is not corrected by
restoring the BMP to the original plan and grade, County staff in the
Watershed Protection Program must be contacted prior to any
additional repairs or reconstruction.
Standing water in bioretention,
biofiltration with partial retention, or
biofiltration areas, or flow-through
planter boxes for longer than 96 hours
following a storm event*
Make appropriate corrective measures such as adjusting irrigation
system, removing obstructions of debris or invasive vegetation,
clearing underdrains (where applicable), or repairing/replacing
clogged or compacted soils.
Obstructed inlet or outlet structure Clear obstructions.
Damage to structural components such as
weirs, inlet or outlet structures
Repair or replace as applicable.
*These BMPs typically include a surface ponding layer as part of their function which may take 96 hours to drain
following a storm event.
Appendix I: Forms and Checklists
I-
3333
3333
3999
17
February 2016
2016
TABLE 7-3. Maintenance Indicators and Actions for Vegetated BMPs
Typical Maintenance Indicator(s)
for Vegetated BMPs Maintenance Actions
Accumulation of sediment, litter, or
debris
Remove and properly dispose of accumulated materials, without
damage to the vegetation.
Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans.
Overgrown vegetation Mow or trim as appropriate, but not less than the design height of the
vegetation per original plans when applicable (e.g. a vegetated swale
may require a minimum vegetation height).
Erosion due to concentrated irrigation
flow
Repair/re-seed/re-plant eroded areas and adjust the irrigation system.
Erosion due to concentrated storm
water runoff flow
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 County must
be contacted prior to any additional repairs or reconstruction.
Standing water in vegetated swales Make appropriate corrective measures such as adjusting irrigation
system, removing obstructions of debris or invasive vegetation,
loosening or replacing top soil to allow for better infiltration, or minor
re-grading for proper drainage. If the issue is not corrected by
restoring the BMP to the original plan and grade, County staff in the
Watershed Protection Program must be contacted prior to any
additional repairs or reconstruction.
Standing water in bioretention,
biofiltration with partial retention, or
biofiltration areas, or flow-through
planter boxes for longer than 96 hours
following a storm event*
Make appropriate corrective measures such as adjusting irrigation
system, removing obstructions of debris or invasive vegetation,
clearing underdrains (where applicable), or repairing/replacing
clogged or compacted soils.
Obstructed inlet or outlet structure Clear obstructions.
Damage to structural components such as
weirs, inlet or outlet structures
Repair or replace as applicable.
*These BMPs typically include a surface ponding layer as part of their function which may take 96 hours to drain
following a storm event.
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City’s standard Single Sheet BMP Plan.]
BMP TYPEBMP ID #SYMBOL CASQA NO.DRAWING NO.SHEET NO.(S)MAINTENANCEFREQUENCY
BMP TABLE
INSPECTION FREQUENCYQUANTITY
TREATMENT CONTROL AND 100-YR ATTENUATION FACILITY
LOW IMPACT DESIGN (L.I.D.)
SOURCE CONTROL
HYDROMODIFICATION & TREATMENT CONTROL
HYDROMODIFICATION
BIOFILTRATION TC-32 426 S.F.MONTHLY MONTHLY-2, 4, 5
N/ASD-12N/A AS-NEEDEDMONTHLYSMARTIRRIGATION
1
N/A
N/A
7
8
9
10
NEED FOR FUTUREINDOOR/STRUCTURALPEST CONTROL
LANDSCAPE/OUTDOORPESTICIDE USE:PROVIDE IMP
ROOFTOP DRAIN TOPERVIOUS LANDSCAPEAREA, AVOID USE OFUNPROTECTEDMETALS
PLAZAS, SIDEWALKS,AND PARKING LOTS:SWEEP REGULARLY,COLLECT DEBRIS,COLLECTWASTEWATER ANDDISCHARGE TOSANITARY SEWER
SC-41
SC-41
SC-10
SE-7SC-43
--
BMP NOTES:
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME
ADDRESS
PHONE NO.
CONTACT
PLAN PREPARED BY:
NAME
ADDRESS
PHONE NO.CERTIFICATION
COMPANY
SIGNATURE
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PERMANUFACTURER'S RECOMMENDATIONS OR THESE PLANS.
2.NO CHANGES TO THE PROPOSED BMPS ON THIS SHEETWITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER.
3.NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTINGTYPES WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER.
4.NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTIONSTAFF HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMPCONSTRUCTION AND INSTALLATION.
5.REFER TO MAINTENANCE AGREEMENT DOCUMENT.
6.SEE PROJECT SWMP FOR ADDITIONAL INFORMATION.
* CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS:
ANNUAL MONTHLY 1 TIME PER YEAR
11
12
COBBLE SWALES
CHECK AND MAINTENANCE(PUMP/VAULT)
2, 4, 5
2, 4, 5
2, 4, 5
2, 4, 5
2, 4, 5
2, 4, 5
EC-10 BIOMONTHLY
AS-NEEDED
AS-NEEDED
AS-NEEDED
AS-NEEDEDAS-NEEDED
AS-NEEDED
AS-NEEDED
BIOMONTHLY
AS-NEEDED
-
-
-
-
1 --
-
-
-
-
N/A
N/A
N/A
N/A
N/A
BIOMONTHLYBIOMONTHLY
-
6 WATER QUALITYSIGNAGE SD-13 2, 4, 5 NANA-3 EA -DATE: Dec 08, 20 12:09pm by:dmasson FILE: I:\16\16277\PROD\Reports\SWQMP\Exhibits\16277-SS BMP-Final Eng.dwgO. 760.741.3570
www.masson-assoc.com
Planning Engineering Surveying
200 E. Washington Ave., Suite 200
Escondido, CA 92025
& A S S O C I A T E S , I N C .
M A S S O N F. 760.741.1786
Solved.
LEGEND