HomeMy WebLinkAboutCD 2017-0003; KAISER CARLSBAD PARKING LOT EXPANSION; PRIORITY DEVELOPMENT PROJECT (PDP) AMENDED STORM WATER QUALITY MANAGEMENT PLAN (SWQMP);; 2019-01-14CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
AMENDED STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
KAISER CARLSBAD PARKING LOT EXPANSION
DWG 504-2A
CD 2017-0003 I GR2017-0030 I DEV2017-0024
ENGINEER OF WORK:
GREGP . LANG, P.E. RCE 68075
PASCO LARET SUITER & ASSOCIATES, INC.
535 N. HIGHWAY 101, SUITE A
SOLANA BEACH, CA 92075
PREPARED FOR:
KAISER PERMANENTE
6860 Avenida Encinas
Carlsbad, CA 92011
619-528-5000
PREPARED BY:
PASCO LARET SUITER
& ASSOCIATES
CIVIL ENGINEERING + LAND PLANNING+ LAND SURVEYING
535 N. HIGHWAY 101, SUITE A
SOLANA BEACH, CA 92075
858-259-8212
DATE:
JUNE 14, 2017
Updated: January 14, 2019
1-14-2019
EXP: 06-30-19
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STORM WATER QUALITY MANAGEMENT PLAN
TABLE OF CONTENTS
ENGINEER'S CERTIFICATION
PROJECT VICINITY MAP
STORM WATER STANDARD QUESTIONNAIRE
SITE INFORMATION
SUMMARY OF PDP STRUCTURAL BMPs
ATTACHMENT 1 -Backup for PDP Pollutant Control BMPs
JUNE 2017
Attachrnent la ......................................................................................................... DMA Exhibit
Attachment I b ............... Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1 c .................................................................. Harvest and Use Feasibility Screening
Attachment 1 d .............................................. Categorization of Infiltration Feasibility Condition
Attachment 1 e ................................... Pollutant Control BMP Design Worksheets / Calculations
ATTACHMENT 2 -Backup for PDP Hydromodification Control Measures
Attachment 2a ................................................................. Hydromodification Exemption Exhibit
Attachment 2b ....................................... Potential Critical Coarse Sediment Yield Areas Exhibit
Attachment 2c ................................................................................ Flow Control Facility Design
ATTACHMENT 3 -Structural BMP Maintenance Plan
Attachment 3a ...... Structural BMP Maintenance Thresholds and Actions and BMP Fact Sheets
Attachment 3b .............................................................................. Draft Maintenance Agreement
ATTACHMENT 4 -City of Carlsbad Standard Single Sheet BMP Exhibits
Attachment 4a ................................................................. Single Sheet BMP Exhibit
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
2
STORM WATER QUALITY MANAGEMENT PLAN
CERTIFICATION PAGE
Project Name: Kaiser Permanente Carlsbad -Parking Lot Expansion
Project ID:
JUNE 2017
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.
G~n~;'fa= RCE 68075
Pasco Laret Suiter & Associates
535 N. Highway 101 , Suite A
Solana Beach, CA 92075
KAISER PERMANENTE CARLSBAD
PAR.KING LOT EXPANSION
4
01/14/2019
Exp: 06-30-19 Date
STORM WATER QUALITY MANAGEMENT PLAN
CITY OF OCEANSIDE
PACIFIC
OCEAN
?a
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
CITY OF ENCINITAS
Figure 1 -Vicinity Map
4
JUNE 2017
CITY OF VISTA
VICINITY MAP
N.T.S.
{_ City of
Carlsbad
STORM WATER STANDARDS
QUESTIONNAIRE
Develo ment Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www .carlsbadca.gov
E-34
1 1NSTRUCTIONS:
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: Kaiser Carlsbad Parking Lot Expansion PROJECT ID: DWG 504-2A/U>'l-04?-ooo·
r ADDRESS: 6860 Avenida Encinas AP N: 214-450-19-00
The project is (check one): D New Development Ill Redevelopment I The total proposed disturbed area is: 20,962 ft2 ( 0.48 ) acres
The total proposed newly created and/or replaced impervious area is: 13,404 ft2 ( 0 31 ) acres
~If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
}'.Project ID CD2017-0003/Pw·~ ,;0 -t ,'-A SWQMP #: r Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
E-34 Page 1 of 4 REV 02/16
STEP1
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building
or stnir.turP. th;:it do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
YES NO
□ Ill
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):
STEP2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3}, please answer
the following questions:
Is your project LIMITED to one or more of the following:
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 uidance?
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?
YES NO
□
□ Ill
□
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ... " and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
If ou answered "no" to the above uestions, our ro·ect is not exem t from PDP
E-34 Page 2 of 4 REV 02/16
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )):
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 ublic develo ment ro ·ects on ublic or rivate 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
develo ment ro ·ects on ublic or rivate 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
develo ment ro·ect includes develo ment on an natural slo e that is twent -five ercent or reater.
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 trans ortation of automobiles, trucks, motorc cles, 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 ro ·ect to the ESA i.e. not commin led with flows from ad·acent 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.
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 er da .
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
YES NO
□ IZl
IZl □
□ IZl
□ [ZJ
Ill □
IZl □
□ [ZJ
□ IZl
□ IZl
□ [ZJ
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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 statin "M ro·ect is a 'STANDARD PROJECT' ... " and com lete a licant information.
E-34 Page 3 of 4 REV 02/16
STEP4
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)):
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) = ___ +_l-_9_1_, 1_8_7 _____ sq. ft.
Total proposed newly created or replaced impervious area (B) = ___ 13_,_4o_4 _______ sq. ft.
Percent impervious area created or replaced (B/A)*100 = _1_4_·_7 ___ %
YES NO
□
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 statin "M ro·ect is a PDP ... " and com lete a licant information.
STEPS
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
!ll My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
0 My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT'
stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project
Requirement Checklist 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.
D My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Name: Gregory W. Lang Applicant Title: _P_._E_., _P_ri_n_ci_p_al ________ _
Date: fll/lAf ( J
• Environmentally Sensitive Areas include b are not llmtted to all Cle , 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.
Th " B fl c ·t U O I IS ox or ny se mv
YES NO
City Concurrence: □ □
By:
Date:
Project ID:
E-34 Page 4 of 4 REV 02/16
STORM WATER QUALITY MANAGEMENT PLAN JU £ 2017
SITE INFORMATION CHECKLIST
Proiect Summarv Information
Project Name Kaiser Carlsbad Parking Lot Expansion
Project ID CD2017-0003
Project Address 6860 Avenida Encinas
Carlsbad, CA 92009
Assessor's Parcel Number(s) (APN(s)) 214-450-19-00
Hydrologic Unit: Carlsbad
Hydrologic Area: San Marcos
Hydrologic Sub-Area Name: Batiquitos
Project Watershed (Hydrologic Unit) Hydrologic Sub-Area#: 904.51
Watershed: San Marcos Creek-Frontal Gulf of
Santa Catalina
Subwatershed: San Marcos Creek
Parcel Area 3.16 Acres ( ±137,650 Square Feet)
Existing Impervious Area
±2.1 Acres ( ±91,187 Square Feet) (subset of Parcel Area)
Area to be disturbed by the project
0.56 Acres ( 24,594 Square Feet) (Project Area)
Project Proposed Impervious Area
0.31 Acres ( 13,543 Square Feet) (subset of Project Area)
Project Proposed Pervious Area (including
0.25 Acres ( 11 ,051 Square Feet) D.G., Deminimus, and Self-MitiQatinQ Area)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
5
STORM WATER QUALITY MANAGEMENT PLAN
Descrlntlon of Existing Site Condition and Dralnaae Patterns
Current Status of the Site (select all that apply):
[!I Existing development
D Previously graded but not built out
D Agricultural or other non-impervious use
D Vacant, undeveloped/natural
JUNE 2017
Description/ Additional Information:
The existing site is comprised of two (2) medical office buildings and an elevator/stair building,
with an interior courtyard between the buildings. To the north and south of the existing buildings
are patient and staff parking lots, respectively. The Avenida Encinas frontage of the site is
parkway landscaping with an open landscape area in front of building 'B.' (See further
discussion below on site topograghy and drainage).
Existing Land Cover Includes (select all that apply):
lg) Vegetative Cover
D Non-Vegetated Pervious Areas
[!I Impervious Areas
Description / Additional Information: See discussion above regarding the current status of the
site.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
D NRCS Type A
00 NRCS Type B (99.5% Per NRCS Custom Soil Resource Report for 6860 Avenida Encinas)
D NRCS Type C
[g)NRCS Type D (0.5% Per NRCS Custom Soil Resource Report for 6860 Avenida Encinas)
Approximate Depth to Groundwater (GW):
D GW Depth < 5 feet
□ 5 feet < GW Depth < 1 O feet
D 1 0 feet < GW Depth < 20 feet
[g)GW Depth > 20 feet (Groundwater not encountered during Geotechnical Investigation)
Existing Natural Hydrologic Features (select all that apply):
D Watercourses
□ Seeps
□ Springs
□Wetlands
~ None
Description/ Additional Information: N/A
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
6
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
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 existing site drainage conveyance for the project site is urban, with area drains located
throughout the site in landscape planter areas and in strategic parking lot locations to drain
hardscape areas. The northerly parking lot area on the site drains to the NW corner of the
parking lot and outlets via surface drainage to the Avenida Encinas right-of-way.
Offsite drainage from the Caltrans right-of-way to the directly east of the site is conveyed
through the project site via an underground 18" RCP storm drain. Just before reaching Avenida
Encinas the 18" RCP confluences at a Type A-4 Cleanout with a 12" PVC storm drain from the
southerly parking area and then continues to the west across Avenida Encinas.
Flow then continues north along Avenida Encinas for a short distance where the storm drain
then turns west into Poinsettia Properties, Planning Area 5 (Ref. C.O.C. DWG 378-9), and then
to Poinsettia Properties, Planning Areas 2, 3, &4 (Ref. C.O.C. DWG 396-7), via increasingly
larger storm drain piping until a 60" RCP outlets to an existing 72" RCP storm drain within the
San Diego Northern Railway right-of-way. This large main trunk line storm drain continues
southerly in the railroad right-of-way and then along N. Coast Hwy 101 for a total of
approximately 1 mile until its ultimate outlet via an 84" RCP storm drain to a rip-rap energy
dissipater at Batiquitos Lagoon. (Ref. C.O.C. DWGs 399-7 and 337-9).
KAISER PERMANENTE CARLSBAD
PARKJNG LOT EXPANSION
7
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
DescrlDtlon of ProDOSed Site Development and Drainage Patterns
Project Description I Proposed Land Use and/or Activities:
The project site is located at Latitude 33°06'27"N and Longitude 117°18'52"W and has a total
area of 3.16 acres. The surrounding area has been developed and is comprised of existing
commercial uses to the north and south. Interstate 5 is directly east of the project with Avenida
Encinas directly west of the site and existing residential just west of Avenida Encinas. The
project site land use will remain unchanged in the proposed condition.
For the proposed condition, portions of the existing landscape area will be removed and
replaced with asphalt parking area and a sidewalk connection added for pedestrian access to
the Avenida Encinas right-of-way sidewalk. Storm water from the newly created impervious
area will be treated via biofiltration BMPs along the project street frontage and be connected to
the existing site storm drain. Associated utilities for the site parking area will also be installed, as
necessary. Total disturbed area is 0.48 acres.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
For the proposed condition, portions of the existing landscape area will be removed and
replaced with asphalt parking area and a sidewalk connection added for pedestrian access to
the Avenida Encinas right-of-way sidewalk. The proposed project's drainage infrastructure will
not significantly alter the existing site's drainage patterns on-site or discharge points.
List/describe proposed pervious features of the project (e.g., landscape areas):
Pervious areas of the proposed improvements include the addition of parking area trees and
landscaping along the project frontage, including the addition of required BMPs for stormwater
quality as presented in this report.
Does the project include grading and changes to site topography?
l!I Yes
□ No
Description / Additional Information:
The project will include precise grading for placement of pavement for parking, driveways and
pedestrian access throughout the site.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
8
STORAf WATER QUA LITY MANAGEMENT PLAN
Does the project include changes to site drainage (e.g ., installation of new storm water
conveyance systems)?
~ Yes
□ No
Description / Additional Information:
JUNE 201 7
Storm water from the newly created impervious area will be treated via biofiltration BMPs along
the project street frontage and be connected to the existing site storm drain on site. Runoff from
the new impervious area will drain via sheet flow to one of two (2) BMPs located along the
project frontage. The new parking area and sidewalk areas (OMA 1) will drain via overland flow
(gutters, and concrete swale) to the larger BMP. And at the southerly end of the parking lot,
where the new parking area entrance and 2 parking stalls are proposed (OMA 2), a trench drain
has been added to capture flow from these areas and direct it to the smaller BMP at the project
frontage. The outlet of the larger BMP will be an 18" RCP, connecting to a proposed re-built
cleanout, while the smaller BMP will outlet to an 8" PVC pipe and connect to the existing 12"
PVC storm drain from the parking lot.
Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
l!l On-site storm drain inlets
□ Interior floor drains and elevator shaft sump pumps
□ Interior parking garages
□ Need for future indoor & structural pest control
00 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
00 Plazas, sidewalks, and parking lots
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
9
STORM WATER QUALITY MANAGEMENT PLAN JUNE2017
Identification of Recelvlna Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable):
The outlet of the larger BMP will be an 8" PVC, connecting to a proposed re-built cleanout, while
the smaller BMP will outlet to an 8" PVC pipe and connect to the existing 12" PVC storm drain
from the southern parking lot confluencing at the Type A-4 Cleanout with a 12" PVC storm drain
from the southerly parking area and then continues to the west across Avenida Encinas via 18"
RCP storm drain. Flow then continues north along Avenida Encinas for a short distance where
the storm drain then turns west into Poinsettia Properties, Planning Area 5 (Ref. C.O.C. DWG
378-9), and then to Poinsettia Properties, Planning Areas 2, 3, &4 (Ref. C.O.C. DWG 396-7), via
increasingly larger storm drain piping until a 60" RCP outlets to an existing 72" RCP storm drain
within the San Diego Northern Railway right-of-way. This large main trunk line storm drain
continues southerly in the railroad right-of-way and then along N. Coast Hwy 101 for a total of
approximately 1 mile until its ultimate outlet via an 84" RCP storm drain to a rip-rap energy
dissipater at Batiquitos Lagoon. (Ref. C.O.C. DWGs 399-7 and 337-9).
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)lstressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Body Pollutant( s )/Stressor( s) TMDLs
None
Identification of Project Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
BMP Design Manual Aooendix B.6):
Not Applicable to
Pollutant the Proiect Site
Sediment
Nutrients
Heavy Metals
Organic Compounds X
Trash & Debris
Oxygen Demanding
Substances
Oil & Grease
Bacteria & Viruses X
Pesticides
KAISER PERMANENTE CARLSBAD
PARKJNG LOT EXPANSION
Also a Receiving
Anticipated from the Water Pollutant of
Proiect Site Concern
X NIA
X NIA
X N/A
X NIA
X NIA
X NIA
X NIA
10
STORJvf WATER QUA LITY MANAGEMENT PLAN JUNE 2017
Hvdromodlflcatlon Manaaement Raaulrementa
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
D Yes, hydromodification management flow control structural BMPs required.
00 No, the project will discharge runoff directly to existing underground storm drains discharging
directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
□ No, the project will discharge runoff directly to conveyance channels whose bed and bank are
concrete-lined all the way from the point of discharge to water storage reservoirs, lakes,
enclosed embayments, or the Pacific Ocean.
□ No, the project will discharge runoff directly to an area identified as appropriate for an
exemption by the WMAA for the watershed in which the project resides.
Description / Additional Information (to be provided if a 'No' answer has been selected above):
The drainage from this project site is conveyed via underground storm drain pipe from the point
of discharge until it outlets at Batiquitos Lagoon, an enclosed embayment, which is included in
the Carlsbad Watershed Management Area Water Quality Improvement Plan (WQIP), dated
June 2016, as an exempt water body. Within the Carlsbad WQIP, reference Appendix F
entitled, "Hydromodification Exemption Analyses for Select Carlsbad Watersheds" by Chang
Consultants dated September 17, 2015. The HMP Exemption Exhibit from this report is
included as Attachment 2a for reference, and highlights the project site shown within the HMP
exemption area.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
11
STORM WATER QUALITY MANAGEMENT PLAN JUNE 201 7
~his Section onl ulrements a
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
□ Yes (See discussion below)
00 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 28 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:
See Attachment 2b for a Potential Critical Coarse Sediment Yield GIS overlay of the project
area and surrounding areas.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
12
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
Flow Control for Post-Project Runofr
~hi• Section onlv raaulred If hvdrornodlflcatlon manaaement reaulrements annlv
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.
*Hydromodification management requirements do not apply. See discussion on page 11 .
Has a geomorphic assessment been performed for the receiving channel(s)?
□ No, the low flow threshold is 0.1 Q2 (default low flow threshold)
□ Yes, the result is the low flow threshold is 0.1 Q2
□ Yes, the result is the low flow threshold is 0.3Q2
o 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)
KA ISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
13
STORM WATER QUALITY MA NAGEMENT PLAN JUNE 2017
Other Site Raaulrements 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.
ODtlonal Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
14
STORM WATER QUALITY MANAGEMENT PLAN
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
JUNE 201 7
15
( City of
Carlsbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project lnfonnatlon
Project Name: Kaiser Carlsbad Parking Lot Expansion
Project ID: CD20 17-0003
DWG No. or Building Permit No.: DWG 504-2A
Source Control BMP•
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www .carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual for information to implement source control BMPs shown in this
checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "NIA" 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 Applled?
SC-1 Prevention of Illicit Discharges into the MS4 ~ Yes □ No □ NIA
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage ~Yes □ No □ NIA
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind ~ Yes □ No □ NIA Dispersal
Discussion/j ustification if SC-3 not implemented:
E-36 Page 1 of 4 Revised 03/16
Source Control Reaulrement (continued) lnnlled?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and 121Yes D No D N/A Wind Dispersal
Discussion/justification if SC-4 not implemented:
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal 121Yes D No D 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 Aooendix E.1 of BMP Manual for guidance).
121 On-site storm drain inlets 121Yes D No D N/A
D Interior floor drains and elevator shaft sump pumps □Yes D No 121 N/A
□ Interior parking garages D Yes D No 121 N/A
D Need for future indoor & structural pest control □Yes D No 121 N/A
121 Landscape/Outdoor Pesticide Use 121Yes D No D NIA
□ Pools, spas, ponds, decorative fountains, and other water features □ Yes D No 121 N/A
D Food service D Yes D No 121 N/A
D Refuse areas D Yes D No 121 N/A
D Industrial processes D Yes D No 121 N/A
□ Outdoor storage of equipment or materials D Yes D No l2l N/A
□ Vehicle and Equipment Cleaning □ Yes D No l2l N/A
□ Vehicle/Equipment Repair and Maintenance D Yes D No l2l N/A
D Fuel Dispensing Areas □Yes D No 121 N/A
□ Loading Docks D Yes D No 121 N/A
□ Fire Sprinkler Test Water □Yes O No 121 N/A
□ Miscellaneous Drain or Wash Water □ Yes D No 121 N/A
121 Plazas, sidewalks, and parkinQ lots '2]Yes 0 No 0 N/A
For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers.
Storm Drain Inlets:
*Mark all inlets with the words, "No Dumping! Flows to Ocean I"
See attached sheet for continuation of "Yes" answers
E-36 Page 2 of 4 Revised 03/16
Standard Project Requirement Checklist E-36
Continuation of SC-6:
Landscape/Outdoor Pesticide Use:
*For Landscape/Outdoor Pesticide use, final landscape plans will: 1) Preserve existing drought tolerant
trees, shrubs, and ground cover to the maximum extent possible, 2) Design landscaping to minimize
irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of
fertilizers and pesticides that can contribute to storm water pollution, 3) Specify plants that are tolerant of
periodic saturated soil conditions where landscape areas are used to retain or detain storm water, 4) Use
pest resistant plans adjacent to hardscape, and 5) Select plants appropriate to site soils, slopes, climate,
sun, wind, rain, land use, air movement, ecological consistency, and plant interactions.
Plazas, sidewalks, and parking lots:
*Plazas, sidewalks, and parking lots shall be swept regularly to prevent the accumulation of litter and
debris.
*Debris from pressure washing shall be collected to prevent entry into the storm drain system.
Washwater containing any cleaning agent or degreaser shall be collected and discharged to the sanitary
sewer and not discharged to a storm drain.
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual for information to implement site design BMPs shown in
this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion / justification is not required.
• "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Source Control Requirement I Applied?
SD-1 Maintain Natural Drainage Pathwavs and Hydrologic Features I D Yes I 0 No I 0 NIA
Discussion/justification if SD-1 not implemented:
No existing natural drainage pathways exist onsite.
SD-2 Conserve Natural Areas, Soils, and Vegetation I 0 Yes I D No I D N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize lmoervious Area I 0 Yes I D No ID N/A
Discussion/justification if SD-3 not implemented:
Only impervious areas required to gain additional parking were added to the site along with pedestrian walkway
connections.
SD-4 Minimize Soil Compaction I 0 Yes I D No ID N/A
Discussion/justification if SD-4 not implemented:
SD-5 Impervious Area Dispersion I 0Yes I 0 No I D N/A
Discussion/justification if SD-5 not implemented:
E-36 Page 3 of 4 Revised 03/16
Source Control Raoulrement (continued) I Annlled?
SD-6 Runoff Collection I 0 Yes l □ No I □ N/A
Discussion/justification if SD-6 not implemented:
SD-7 LandscaoinCI with Native or DrouC1ht Tolerant Species I 0 Yes I □ No I □ N/A
Discussion/justification if SD-7 not implemented:
SD-8 HarvestinCI and UsinCI Precioitation I □ Yes 1 0 No I □ N/A
Discussion/justification if SD-8 not implemented:
Harvesting precipitation and using precipitation is not planned for the project. Proper BMP implementation will treat storm
water runoff, as required. (See completed Form 1-7 in Attachment 1c)
E-36 Page 4 of 4 Revised 03/16
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
SUMMARY OF PDP STRUCTURAL BMPS
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).
KA ISER PERMANENTE CA RLSBAD
PARKING LOT EXPANSION
17
STORM WATER QUAl/TY MANAGEMENT PLAN JUNE20l7
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.
BIOFILTRATION (BF-1)
Using section 5.1 of the City of Carlsbad BMP Design Manual (Fi gure 5-1 and 5-2) Biofiltration was
selected as the treatment control BMP for the project and integrated as storm water flow control (HMP
s izing) and w ill include outlet contro l at the downstream outlet of the facilities. With infiltration
infeasible at the project location, the facilities will be lined in order for surface waters to discharge via
underdrain or overflow to the downstream conveyance system.
Per C ity of Carlsbad Fact Sheet BF-I, "Biofiltration (Bioretention with underdrain) facilities are
vegetated surface water systems that fi lter 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 s ite 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."
Biofiltration systems are effective at removing sediments and pollutants which are associated with fine
particles by fi ltration through surface vegetation and underly ing engineered soil media. These systems
can also delay runoff peaks by providing detention and/or retention capacity in the media layer and
ponding area through the controlled release of treated runoff. The addition of vegetation not only
increases the aesthetic value of these areas, but also enhances the fi ltration component of the system
through plant uptake and helps maintain the porosity of the engineered soil layer. Biofiltration systems
can be constructed as either large or small scale devices with native or amended soils. Biofiltration
systems, like the systems designed for this project, collect storm water from impervious areas (roof areas
and other impervious surfaces) through the site's grading design.
The biofiltration systems for this project have been integrated into the drainage design to meet poll utant
control requirements for the site by minimizing directly connected impervious areas. The proposed
parking lots, building roof areas, and hardscape associated with the project drain to the proposed
biofiltration planter systems through the use of roof drain downspouts or piping, which allow runoff to
flow directly into the biofiltration areas for water quality treatment. Rip rap energy dissipaters will be
located at points where concentrated flow enters the biofiltration basins from roof drain downspouts or
pipe outfalls to minimize erosion from occurring.
Biofiltration systems are designed to allow ponding to occur. A soil layer, gravel layer, under drain
system, and impermeable liner was designed for the systems due to the poor infiltration rates of the in situ
soil and the systems' close proximity to t he proposed improvements and building foundations.
(Continued on next page)
KAISER PERMANENTE CARLSBAD
PARKJNG LOT EXPANSION
18
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
Biofiltration systems function by allowing ponded runoff to infiltrate down through the mulch layer,
amended soil layer, and the gravel layer; ultimately discharging to the private storm drain system through
the system's perforated under drain. The biofiltration system areas will be landscaped with a combination
of ground covers, shrubs and/or trees as selected by the project's landscape architect.
The biofiltration systems w ill provide water quality treatment for the calculated DCV for each DMA. The
project is exempt from hydromodification management requirements. (See discussion of
Hydromodification Management Requirements on page 11 ).
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
19
STORM WATER QUALITY MANAGEMENT PLAN
Structural BMP Summary Information
Structural BMP ID No.: 1 (OMA 1)
DWG 504-2A Sheet No. 3, 5, & 7
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) (BMP ID No. 1)
□ Flow-thru treatment control included as pre-treatment/forebay
biofiltration BMP (provide BMP type/description and indicate
biofiltration BMP it serves in discussion section below)
□ Detention pond or vault for hydromodification management
□ Other (describe in discussion section below)
Purpose:
l!l 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):
Biofiltration BMP for treatment of DCV with 36-hour drawdown.
KAISER PERMANENTE CA RLSBAD
PARKING LOT t.,-XPANSION
20
JUNE 201 7
for an onsite retention or
which onsite retention or
STORM WATER QUALITY MANAGEMENT PLAN
Structural BMP Summary Information
Structural BMP ID No.: 2 (OMA 2)
DWG 504-2A Sheet No. 3, 6, & 7
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)
o Partial retention by biofiltration with partial retention (PR-1)
~ Biofiltration (BF-1) (BMP ID No. 2)
JUNE 20/7
□ Flow-thru treatment control included as pre-treatmenUforebay 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):
Biofiltration BMP for treatment of DCV with 36-hour drawdown.
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
21
STORM WATER QUALITY MANAGEMENT PLAN JUNE 2017
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
Attachment Contents
Sequence
Attachment 1 a OMA Exhibit (Required)
See OMA Exhibit Checklist on the
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Checklist
00 Included
Attachment 1 b Tabular Summary of DMAs Showing 00 Included as Attachment 1 b
OMA ID matching OMA Exhibit, OMA separate from OMA Exhibit
Attachment 1 c
Attachment 1 d
Area, and OMA Type (Required)*
*Provide table in this Attachment OR
on OMA Exhibit in Attachment 1 a
Form 1-7, Harvest and Use Feasibility
Screening Checklist (Required unless
the entire project will use infiltration
BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)
Refer to Appendices C and D of the
BMP Design Manual to complete
Form 1-8.
00 Included
□ Not included because the entire
project will use infiltration BMPs
00 Included
□ Not included because the entire
project will use harvest and use
BMPs
Attachment 1e Pollutant Control BMP Design 00 Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
KA ISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
22
DMAExhibit
\
\
LOT13 I
MAP10899 <::!.
11.:
I
-
20· 1 o· o 20· 40• 1~~1----1_~1
SCALE: 1" = 20'
s
@
I
BUILD/NGA
I
I
I
I
_ (EX/STING 2-STORY I MEDICAL OFFICE)
,o ~~=~ -=~-::_~-~~-~-~ ~
r;:0 J-.;~o/=(,:__".:'.~_']~=~-~= LOT 12 --~ . ~ I _ MAP 10899 '--~../'+-'\
I
)
s ' EXISTING
DRIVEWAY
RJW~'
EXISTING CURB
EXISTING PARKING TO REMAIN
LOT TO REMAIN
•• ,o
I • , f ,
0
@
,.,.-;.=r:.XIST/NG PARKING
---__..-"-../ LOT TO REMAIN
EXISTING RIBBON
0
GUTTER TO REMA/
0 ---0
(
\Zl
--~+r-
1~
\
•@
u
EXJS11NG
ELEVATOR
AND
STAIRS
--·
LINED BIOF'/L TRA TION BMP
(360 SF') 64,0 F'G ;':' !
~II
BUILDINGS
(EX/STING 2-STORY
MEDICAL OFFICE)
AVENIDA 111 ENCINAS
s s ~ -s
-tr---c/L
ii i
PLAN VIEW -OMA AREAS
SCALE: 1" = 20'
WIDTH VARIES PER PLAN
s
BIO-FIL TRAT/ON BASIN WITH IMPERMEABLE LINER DETAIL
NOT TO SCALE
j
• I
I I I
"'"""' I I I
I I I
I I I
/
LOT11
MAP10899
7
/
I
\
I I
I I
I I
I I
I I
I I
I I
I I
I I
I I I I#,,===""
I I
I I I \ I I _
1/ / V EXISTING PARKING '
LOT TO REMAIN
I \ i I I I
11:,,__-----=::::-t.J-l-EXISTING CURB \ TO REMAIN
\
PROPOSED
TRENCH DRAIN
I
\
EXISTING STORM
DRAIN INLET
\
I
I
I
"' \
EXISTING
DRIVEWAY
1 "'0
BF
LINED 8/0F'IL TRA TION BMP
( 45 SF') 63. 9 F'G
-~"' "'"'=r-----------0 I I
I I I
I I I
I t
I
Know what's below.
Call before you dig.
LEGEND
PROPOSED STORM DRAIN =---so_== -
PROPOSED HARDSCAPE/ IMPERVIOUS
AREA
PROPOSED LANDSCAPING/ PERVIOUS AREA
DRAINAGE MANAGEMENT
AREA (DMA) BOUNDARY
TREATMENT CONTROL BMP NUMBER
FLOW DIRECTION ARROW
TREATMENT CONTROL BMPS
BIOFIL TRA TION WITH
IMPERMEABLE LINER
SELF-MmGA TING DMA
DE MINIMIS DMA
SOURCE CONTROL BMPS
INLET STENCILING 0
SOIL INFORMATION
80/L: TYPE B
SITE INFORMATION:
IMPERVIOUS AREA:
PERVIOUS AREA=
TOTAL DISTURBED AREA:
85TH PERCENTILE STORM DEPTH=
0.31AC
0.17 AC
0.48AC
0.57in
OMA SUMMARY
DRAINAGE IMPERVIOUS MANAGEMENT BMP TYPE AREA (AC) AREA (OMA)
1 8/0FIL TRA TION 0.28
2 8/0FIL TRA TION 0.03
3* SELF-MIT/GA TING 0.00
4 SELF-MIT/GA TING 0.00
5 DE MIN/MIS 0.00
6 SELF-MIT/GA TING 0.00
PERVIOUS
AREA (AC)
0.05
0.02
0.09
0.01
0.00
0.09
TOTAL
AREA
(ACRES)
0.33
0.05
0.09
0.01
0.00
0.09
*LANDSCAPING TO 8£ REPLACED WITH NON-INVASIVE DROUGHT TOLERANT SPECIES PER
SECTION 5.2.1 OF' TH£ CITY OF' CARLSBAD BMP DESIGN MANUAL.
BIOFIL TRATION BMP SUMMARY
BMP ID BMP TYPE REQUIRED BMP PROVID ED BMP
AREA (SF) AREA (SF)
1 BIOFIL TRA TION 337 360
2 8/0FIL TRA TION 36 45
PASCO LARET SUITER
& ASSOC I ATES
KAISER PERMANENTE -CARLSBAD
PARKING LOT EXPANSION
SWQMP OMA EXHIBIT
CIVI L ENGINEER IN G + LAND PLANNI NG+ LAN D SUR VEYIN G
535 North Highway 101 , Suite A Solana Beach, CA 92075
ph 858.259.8212 I fx 858.259.4812 I plsaengineering.com
CARLSBAD, CALIFORNIA
PROJECT NUMBER: PE 2512
SCALE: 1" = 20'
DATE: JANUARY 2019
SHEET 1 OF 1
DMASummary
I
I
I
I
PASCO LARET SUITER
& ASSOCIATES
CIVIL ENGINEERING + LAND PLANNING+ LAND SURVEY NG
DMA DCV Summary
Kaiser Carlsbad Parking Lot Expansion
May 2017
Where:
C = Runoff factor (unitless)
d = 85th percentile, 24-hr storm event rainfall depth (inches), refer to section B.1 .3.
A= Tributary area draining to the BMP
BASIN AREAS (SF)
Impervious Pervious D.G. Total
1 12,128 2,289 0 14,417
2 1,313 740 0 2,053
*DCV = 3630 x C(ocvJ x d (inches) x A (acres)
AREAS (acre)
Impervious Pervious D.G.
0.28 0.05 0.00
0.03 0.02 0.00
DCV Surface Runoff Factors* Proposed Biofiltration BMP Section
Impervious Area 0.9 Section Thickness (in) Porosity Volume/sf
Pervious Area/Landscape 0.10 Ponding 10 1.0 0.83
Decomposed Granite 0.30 Engineered Soil 18 0.1 0.15
*See Table 8.1-1 Gravel 12 0.4 0.40
Total Volume/SF 1.38
d
Total (In)
0.33 0.57
0.05 0.57
DCV Area Sizing
C Design Capture
(DCV) Volume (DCV)*
(no unit) (cf)
0.78 533
0.58 60
Project: Kaiser Carlsbad
Job No.: PE 2512-01
Cale. By: RT Date: May 2017
Checked: RT Date: May 2017
Sheet: 1._of 1
~ __ Harv~t and Use Feasibili!Y (Form 1-7)
PASCO LARET SUITER
& ASSOCIATES
CIVIL ENGINEERING+ LAND PLANNING + LAND SURVEYING
Kaiser Permanente Carlsbad Parking Lot Expansion
Harvested Water Demand
Toilet and Urinal Flushing
Land Use Type: Commercial/Parking
Per Capita Use Total Usage Demand
# of Employees per Day* per Day 36-hour Demand
N/A ---
*Gallons per employee per day for office land use type (See Table B.3-1)
Landscape Irrigation
Landscape Area 36-hour TOTAL Irrigation
Demand (Gal lons/36 (Acres) Demand** hour)
0.17 1470 249.9
Project: Kaiser Carlsbaed
Job No.: PE 2512
Cale. By: RT Date: May 2017
Checked:RT Date: May 2017
Sheet: 1 of 1
**Gallons per irrigated acre per 36-hour period (See Table B.3-3, Hydrozone -Moderate Plant Water Use)
-.
Harvest and'Usc Feasibility Screening Form 1-7
-~ ~ ~ -' ..
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably
present during the wet season?
Demand for harvested water is present at the project site and currently in use for site
irrigation by way of existing retention basins (water hazards) on the golf course.
D Toilet and urinal flushing
~ Landscape irrigation
D Other: ________ _
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.
33.4 cubic feet (250 gallons)
/
2. Calculate the DCV using worksheet B.2.1
593 cubic feet (4,436 gallons)
3a. Is the 36-hour demand greater
than or equal to the DCV?
No
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.
36. Is the 36-hour demand greater than
0.25DCV but less than the full DCV?
No
Harvest 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.
3c. Is the 36-hour demand
less than 0.25DCV?
Yes
New harvest and
use is considered
to be infeasible.
Attachment 1 d
________ Infiltration Feasibility
f' · -··· -.,-... ,,, -,., i .----·;-. ':.~j' '• .~· '1::..:--.-~. -.. -.-..c ._ ~ ., ~
Catcgorizatior' of,_Jnfil~r.*i.01~-Fcis}bility f.:ori~i_t\on ) .. : . ' F~nn 1-8 ' ,
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?
Criteria Screening Question
Is the estimated reliable infiltration rate below proposed facility locations greater than
0.5 inches per hour? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D.
Provide basis:
Yes No
X
Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factor of safety the
klesign infiltration rates would be 0.0 in/hr to 0.32in/hr. This form is included with site infiltration report prepared b)'
IIU,1A Group. (Ref. Preliminary Soil Infi ltration Testing and Pavement Structural Section Report, Kaiser Carlsbad
Parking Lot Expansion, dated May 10, 2017 by RMA Group, RMA Project No. 17-0497-0 1 ).
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 shall be based on a comprehensive evaluation of the factors presented in
Appendix C.2.
Provide basis:
X
!Not applicable. Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factot
k>f safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr.
Infiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite an
!medium dense to dense silty sand and sand ,vith silt and are not subject to hydrocollapse or consolidation based upo1
\SPT blow counts, are non-expansive and not subject to liquefaction. Groundwater mounding would not be expectec
lbased on the separation between the bottom of the proposed basins being greater than 10 feet and the slow infiluat:ior
rates obtained in our testing.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
• I", • ..., ...., ~. --
Form f {Page 2 of 4 · ·
• • • \ ' • .. > ' ~
Criteria Screening Question
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of
groundwater contamination (shallow water table, storm water pollutants or other
factors) that cannot be mitigated to an acceptable level? The response to this Screening
Question shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Yes No
X
Not applicable. Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factoi
of safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr.
Ground water beneath the site was not encountered in or exploratory borings that extended to a depth of 16.5 feet
below the existing ground surface.
According to the Geotracker website (http://geotracker.warerboards.ca.gov), groundwater was encountered in a
monitoring well located approximately 1 mile nortl1west of the site was at a depth of 28 feet in 2005.
Due to the slow infiltration rate and the separation between the groundwater level and the proposed basin bottom
levation and the proposed use as vehicle parking, an increased risk of groundwater contamination is considered very
ow.
Summarize fu1dings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing potential
water balance issues such as change of seasonality of ephemeral streams or increased
discharge of contaminated groundwater to surface waters? The response to this
Screening Question shall be based on a comprehensive evaluation of the factors
presented in Appendix C.3.
Provide basis:
X
Not applicable. Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. Witl1 application of the mininium factot
of safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr.
Due to the slow infiltration rate and the separation between the groundwater level and the proposed basin bottom
elevation and the proposed use as vehicle parking, and increase potential water balance issues such as change of
seasonality of ephemeral stream s or increased discharge of contaminated groundwater to surface waters is considered
very low. No ephemeral streams are located onsite or nearby and the Geotracker website does not indicate a source of
known contamination within a mile of the site.
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
See Part
2
*To be completed using gathered site information and best professional judgment considering the definition of:tvIEP in
the MS4 Permit. Additional testing and/or studies may be required by City Engineer to substantiate findings.
r. ,, --~~,,._... \.t-.4'...._,,,._ ·-,,_ -. -\;;• 11.· 11
< ; , Form'l,-8 P1g~ 3·of1 _ ; . _ ·, ·
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
5
Do soil and geologic conditions allow for infiltration in any appreciable rate or volume?
The response to this Screening Question shall be based on a comprehensive evaluation
of the factors presented in Appendix C.2 and Appendix D .
Provide basis:
Yes No
X
Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factor of safety the
design infiltration rates would be 0.0 in/hr to 0.32in/hr. This form is included with site infiltration report prepared by
RMA Group. (Ref. Preliminary Soil Infiltration Testing and Pavement Structural Section Report, Kaiser Carlsbad
Parking Lot Expansion, dated May I 0, 2017 by RMA Group, RMA Project No. 17-0497-0 I).
Swnmarize 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 shall be based on a comprehensive evaluation of the factors presented in
Appendix C.2.
Provide basis:
X
nfiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite are
n edium dense to dense silty sand and sand with silt and are not subject to hydrocollapse or consolidation based upon
SPT blow counts, are non-expansive and not subject to liquefaction. Groundwater mounding would not be expected
based on the separation between the bottom of the proposed basins being greater than 10 feet and the slow infiltration
rates obtained in our testing. Would increase risk to existing undergrow1d utilities (particularly to electrical and
telephone utilities) servicing the existing Medical Office Building.
S=arize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
kliscussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
f'" ' ; I .-f --.~ : -~--; .. ,.-;, • •~r~-ti .• _,. •--y -1, i -:T-;t:
, · . Fo~·I;.S;Page,4 of 4 ~~• • b },...._,.; .. ~ ,,, ... ., ,._ " I
Criteria Screening Question
7
Can Infiltration in any appreciable quantity be allowed without posing significant risk
for groundwater related concerns (shallow water table, storm water pollutants or other
factors)? The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Yes No
X
Infiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite are dense
silty sand and sand with silt and are not subject to hydrocollapse or consolidation based upon SPT blow counts, are
1non-expansive and not subject to liquefaction. Grow1dwater mounding would not be expected based on the separation
oetween the bottom of the proposed basins being greater than 10 feet and the slow infiltration rates obtained in ow
testing.
Swnmarize 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 shall be based on a comprehensive evaluation of the factors
presented in Appendix C.3.
Provide basis:
X
The site is not up gradient from a stream course and is located about ½ mile from the ocean. Also, no known watet
wells are located within a 1/2 from the site. Evaluation of downstream water rights is outside of the purview ol
geotechnical engineering.
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-I'
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 volwne is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
Infiltration
"To be completed using gathered site information and best professional judgment considering the definition of i'v1EP 111
the MS4 Permit Additional testing and/or studies may be required by City Engineer to substantiate findings.
,____ ______ B_MP Des~ Worksheets
Kaiser Carlsbad Parking Lot Expansion
PE 2512-01
5/6/2017 DMAl
W orks heet 8 .5-1: Simple Sizing Method for Biofiltration BMPs
1 Remaining DCV After implementing retention BMPs 533.0
Partial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0.00
3 Allowable drawdown time for aggregate storage below the underdrain 36
4 Depth of runoff that can be infiltrated (Line 2 x Line 3] 0.00
5 Aggregate pore space 0.40
6 Required depth of gravel below the underdrain [Line 4 / Line 5] 0.00
7 Assumed surface area of the biofiltration BMP 360.0
8 Media retained pore storage 0.1
9 Volume retained pore storage 54.00
10 DCV that requires biofiltration (Line 1 -Line 9] 479.0
BMP Parameters
11 Surface Poding (6 inch minimum, 12 inch maximum] 10
12 Media Thickness (18 in Min], also add mulch layer thicknes to this line 18
13
Aggregate Storage above underdrain inver (12 inches typical) -Use O inches for 12 sizing if the aggregate is not over the entire bottom surface area
14 Freely drained pore storage 0.4
Media filtration rate to be used tor sizing (5 in/hr. with no outlet control; if the
15 filtration rate is controlled by the outlet, use the outlet controlled rate which will 5
be less than 5 in/hr.)
Baseline Calculations
16 Allowable Routing Time for sizing 6
17 Depth filtered during storm [Line 15 x Line 16] 30
Depth of Detention Storage 22.00
18 [Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)]
19 Total Depth Treated [Line 17 + Line 18] 52.00
Option 1 -Biofilter 1.5 times t he DCV
20 Required biofiltered volume (1.5 x Line 10] 719
21 Required Footprint [Line 20 / Line 19] x 12 165.8
Option 2 -Store 0.75 of remaining DCV in pores and poding
22 Required Storage (surface+ pores) Volume (0. 75 x Line 10] 359
23 Required Footprint (Line 22 / Line 18] x 12 196
Footprint of the BMP
24 Area draining to the BMP 14417.0
Adjusted Runoff Factor for drainage area (Refer 0.78
25 to Appendix B.1 and B.2)
26 BMP Footprint Sizing Factor (Default 0.03 or an alternative minimum footprint 0.03
sizing factor from Worksheet B.5-2, Line 11)
27 Minimum BMP Footprint (Line 24 x Line 25 x Line 26] 337
28 Footprint of the BMP = Maximum (Minimum(Line 21, Line 23), Line 27) 337
Check for Volume Reduction [Not applicable for No Infiltration Condition]
~ GalE1:1late tl=le fFaEtiaA af QGV FetaiAea iA tl=le 8MP (biAe 9 I-biAe 1l ~
~ MiAiFAl:IFA FeE!l:liFea fFaEtiaA af QGV FetaiAea faF 13aFtial iAfiltFatiaA E8Aaiti8A5 ~
Is tl=le ~etaiAea QGV::. Q.371if If tl=le aAs1,1,1eF is Ra iAEFease tl=le faat13FiAt sii!iAg ~
3-1 faEtaF iA biAe ;!G 1:1Atil tl=le aAs1,..,eF is •;es faF tl=lis EFiteFiaA.
cu-ft
in/hr
hours
inches
in/in
inches
sq-ft
in/in
cu-ft
cu-ft
inches
inches
inches
in/in
in/hr
hours
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inches
inches
cu-ft
sq-ft
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sq-ft
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~
J:\Active Jobs\2512 KAISER CARLSBAD\CIVIL\REPORTS\SWQMP-Final\Appendices\Appendix le-BMP Design
Worksheets\2512_Worksheet B.5-l_Biofiltration BMP Sizing
Kaiser Carlsbad Parking Lot Expansion
PE 2512-01
5/6/2017 DMA2
Works heet B.5-1: Simple Sizing Method for Biofiltration BMPs
1 Remaining DCV After implementing retention BMPs 60.0
Partial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0.00
3 Allowable drawdown time for aggregate storage below the underdrain 36
4 Depth of runoff that can be infiltrated [Line 2 x Line 3) 0.00
5 Aggregate pore space 0.40
6 Required depth of gravel below the underdrain [Line 4 / Line SJ 0.00
7 Assumed surface area of the biofiltration BMP 46.0
8 Media retained pore storage 0.1
9 Volume retained pore storage 6.90
10 DCV that requires biofiltration [Line 1 -Line 9) 53.1
BMP Parameters
11 Surface Poding (6 inch minimum, 12 inch maximum) 10
12 Media Thickness (18 in Min], also add mulch layer thicknes to this line 18
13
Aggregate Storage above underdrain inver {12 inches typical) -Use O inches for 12 sizing if the aggregate is not over the entire bottom surface area
14 Freely drained pore storage 0.4
Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the
15 filtration rate is controlled by the outlet, use the outlet controlled rate which will 5
be less than 5 in/hr.)
Baseline Calculations
16 Allowable Routing Time for sizing 6
17 Depth filtered during storm [Line 15 x Line 16) 30
Depth of Detention Storage 22.00
18 [Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5))
19 Total Depth Treated [Line 17 + Line 18) 52.00
Option 1 -Biofilter 1.5 times the DCV
20 Required biofiltered volume [1.5 x Line 10) 80
21 Required Footprint [Line 20 / Line 19) x 12 18.4
Option 2 -Store 0.75 of remaining DCV in pores and poding
22 Required Storage (surface+ pores) Volume [0.75 x Line 10) 40
23 Required Footprint [Line 22 / Line 18) x 12 22
Footprint of the BMP
24 Area draining to the BMP 2053.0
Adjusted Runoff Factor for drainage area (Refer 0.58
25 to Appendix 8.1 and 8.2)
26 8MP Footprint Sizing Factor (Default 0.03 or an alternative minimum footprint 0.03
sizing factor from Worksheet 8.5-2, Line 11)
27 Minimum BMP Footprint [Line 24 x Line 25 x Line 26) 36
28 Footprint of the 8MP = Maximum (Minimum(Line 21, Line 23), Line 27) 36
Check for Volume Reduction [Not applicable for No Infiltration Condition]
~ Galeulate tl:le fFaetieA ef QGV FetaiAeel iA tl:le 8MP fbiAe 9 ./-biAe :J:l ~
~
~ Mi Ai FA UFA Fe~uiFeel fFaetieR ef QGV FetaiReel feF J'laFtial iRfiltFatieR eeAelitieAs
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~ faeteF iR biRe ;!6 uRtil tl:le aRsweF is •,es feF tRis eFiteFieR.
cu-ft
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inches
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inches
sq-ft
in/in
cu-ft
cu-ft
inches
inches
inches
in/in
in/hr
hours
inches
inches
inches
cu-ft
sq-ft
cu-ft
sq-ft
sq-ft
sq-ft
sq-ft
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AA
J:\Active Jobs\2512 KAISER CARLS8AD\CIVIL\REPORTS\SWQMP-Final\Appendices\Appendix le-8MP Design
Worksheets\2512_Worksheet 8.5-l_Biofiltration BMP Sizing
STORM WATER QUALITY MANAGEMENT PLAN JUNE2017
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
Attachment Contents
Sequence
Attachment 2a Hydromodification Management
Exhibit (Required)
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.
Attachment 2c Geomorphic Assessment of Receiving
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
Attachment 2d Flow Control Facility Design and
Structural BMP Drawdown
Calculations (Required)
See Chapter 6 and Appendix G of the
BMP Desion Manual
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
23
Checklist
00 Included {Project is exempt from
Hydromodification Control
Requirements)
00 Exhibit showing project
drainage boundaries marked on
WMAA Critical Coarse
Sediment Yield Area Map
(Required)
Optional analyses for Critical Coarse
Sediment Yield Area Determination
D 6.2.1 Verification of Geomorphic
Landscape Units Onsite
D 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
D 6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
00 Not performed
□ Included
00 Included
.______~Hydromodification Exem tion Exhibit
r •• , .. ·.
HMP
LEGEND: --•••••
V//21
WJ1
EXEMPTION
GRAPHIC SCALE
500 1000
I I
1 INCH = 500 FEET
MAJOR DRAINAGE BASIN BOUNDARY
NATURAL FLOW PATH
HYDROMODIFICA TION EXEMPT AREA
HYDROMODIFICATION EXEMPT AREA IF FUTURE
DRAINAGE IM PROVEMENTS ARE CONSTRUCTED
EXHIBIT *Exhibit take from the, "Hydromodification
Exemption Analyses for Select Carlsbad
Watersheds" by Chang Consultants dated
September 17, 2015
Attachment 2b
Potential Critical Course Sedimen
Yield Areas Exhibit
-----~i
: l=P otential Criti~I Coarse
. Sediment Yield Area* ·-------·... ---, __ _ [Source: Project Clean Water Watershed
t;,1 anagement Area Analysis 2015
~egional Potential Critical Coarse
e ediment Yield Area Mapping
NWW.projectcleanwater.org) ____ 11
Attachment 2c
Flow Control and
BMP Drawdown Calculations
PASCO LARET SUITER
& ASSOCIATES
CIVIL ENGINE[RING + LAND PLANNING+ LAND SURVEYING
Flow Control Facility Design and Structural BMP Drawdown Calculations
The following BMP Sizing and Orifice outflow calculations are intended to show only that the
orifice outflow meets the requirements of the BMP Design Manual. The BMP design
worksheets provided in Attachment 1 match the surface volume for biofiltration BMP areas (1 O"
ponding) for the respective DMAs, however these calculations are not intended to show the or
subsurface (HMP) storage volume for biofiltration (shown as flow-through planter) areas in the
spreadsheets. Note, the project is HMP Exempt.
535 N Coast Highway IOI Ste A Solana Beach, California 92075 [ ph 858.259.82 12 [ fx 858.259.4812[
plsaengineering.com
BMP Sizing Spreadsheet Vl.04
Project Name: Kaiser Parking Lot Expansion
Project Applicant: Kaiser Foundation Health Plan, Inc.
Jurisdiction: City of Carlsbad
Parcel (APN): 214-450-19-00
Hydrologic Unit: 904.51
Rain Gauge: Lindbergh
Total Project Area (sf): 20,962
Channel Susceptibility: Low
The BMP Sizing Spreadsheet user should attempt to account for all elements of a project
site through the definition of Drainage Management Areas {DMAs) and BMPs. The total
area of the DMAs and BMPs should be equal to the total site area. Including all areas -
even those portions of the project site that will not be developed -will help the plan
reviewer assess the completeness of the BMP sizing effort in the project application.
This BMP Sizing Spreadsheet has been developed in accordance with the
San Diego BMP Sizing Calculator Methodology
Directions to User:
1. Fill out project information on this sheet . Rain gauge information can be found at
http://bit.ly/ln HsW Je
2. Map and measure DMA's. Include a copy of the map with your submittal.
3. The entire site shall be divided into separate drainage management areas {DMAs), with
each area identified as one of the following: self-treating, self-retaining, draining to a self-
retaining area, or draining to a BMP. Each area should be clearly marked with a unique
identifier.
4. For each BMP within your project, copy the BMP and Orifice tabs simultaneously. Both
tabs must be copied together for linked formulas to work properly.
5. On the BMP tab, select BMP type and list all DMA's draining to the BMP.
6. Enter the information for each OMA.
7. Open the orifice tab and enter the exiting condition information for each OMA.
8. Enter a proposed orifice size.
9. Return to BMP tab and confirm selected BMP depth.
10. Return to orifice tab and confirm adequacy of drawdown time.
11. Make sure the BMP on your plans, specifications, and details match the proposed BMP
dimensions.
Frequently Asked Questions
1. When sizing the orifice, it does not seem to account for existing impervious area.
On the orifice tab, existing impervious areas are accounted for by selecting "Impervious"
for the soil type and "N/ A" for the cover.
2. What does it mean when the drawdown time is blank?
This means that additional user information is need. The most common cause is a lacks
of input for the proposed vault or cistern volume on the BMP tab.
BMP Sizing Spreadsheet Vl.04
Project Name: Kaiser Parking Lot Expansion Hydrologic Unit: 904.51
Project Applicant: Kaiser Foundation Health Plan, Inc Rain Gauge: Lindbergh
Jurisdiction: City of Carlsbad Total Project Area: 20962
Parcel (APN): 214-450-19-00 Low Flow Threshold: 0.SQ2
BMP Name: 1 (DMAl) BMPType: Flow-Through Planter
BMP Native Soil Type: N/A -Impervious liner BMP Infiltration Rate (in/hr): N/A
Areas Draining to BMP HMP Sizing Factors
OMA Post Project Runoff Factor
Name Area (sf) Soil Type Slope Surface Type (Table 4-2) Surface Area Surface Volume Subsurface Volume Surface Area (sf)
1 -Landscape 2289 B Flat Landscape 0.1 N/A N/A N/A N/A
1 -Impervious 12128 B Flat Impervious 0.9 N/A N/A N/A N/A
Total BMP Area 14417 Minimum BMP Size
Proposed BMP Size' 360
Soil Matrix Depth
Minimum Ponding Depth
Maximum Ponding Depth
Selected Ponding Depth
Describe the BM P's in sufficient detail in your SWMP to demonstrate the area, volume, and other criteria can be met within the constraints of the site.
BM P's must be adapted and applied to the conditions specific to the development project such as unstable slopes or the lack of available head.
Designated Staff have final review and approval authority over the project design.
This Sizing Calculator has been developed in compliance with the Countywide Model SUSMP. For questions or concerns please contact the jurisdiction in which your project is located.
Minimum BMP Size
Surface Volume Subsurface Volume
(cf) (cf)
N/A N/A
N/A N/A
300 216
18.00 in
in
S928.43 in
10.00 in
BMP Sizing Spreadsheet Vl.04
Project Name: iser Parking Lot Expansi Hydrologic Unit: 904.51
Project Applicant: Foundation Health Pia Rain Gauge: Lindbergh
Jurisdiction: City of Carlsbad Total Project Area: 20962
Parcel (APN): 214-450-19-00 Low Flow Threshold: 0.SQ2
BMP Name 1 (OMA 1) BMPType: Flow-Through Planter
OMA Rain Gauge Existing Condition Q2 Sizing Factor OMA Area (ac)
Name Soil Type Cover Slope (ds/ac)
1 -Landscape Lindbergh B Scrub Flat 0.011 0.053
1 -Impervious Lindbergh B Scrub Flat 0.011 0.278
Orifice Flow -%Q2
(cfs)
0.000
0.002
0.002
Tot. Allowable
Orifice Flow
(cfs)
0.515
Actual Orifice Flow
(cfs)
Orifice Area (in2)
0.01
0.04
0.04 0.24
Tot. Allowable Max Orifice
Orifice Area Diameter
(in2) (in)
12.57 4.00
Actual Orifice Area Selected
Orifice Diameter
(in2) (in)
Drawdown (Hrs) 0.2
BMP Drawdown time < 36 hours
with no orifice control, therefore, OK.
BMP Sizing Spreadsheet Vl.04
Project Name: Kaiser Parking Lot Expansion Hydrologic Unit: 904.51
Project Applicant: l(aiser Foundation Health Plan, Inc Rain Gauge: Lindbergh
Jurisdiction: City of Carlsbad Total Project Area: 20962
Parcel (APN): 214-450-19-00 Low Flow Threshold: 0.SQ2
BMPName: 2(0MA2) BMPType: flow-Through Planter
BMP Native Soil Type: N/A -Impervious Liner BMP Infiltration Rate (in/hr): N/A
Areas Draining to BM P HMP Sizing Factors
OMA Post Project Runoff Factor
Name Area (sf) Soil Type Slope Surface Type (Table 4-2) Surface Area Surface Volume Subsurface Volume Surface Area (sf)
2 -Landscape 740 B Flat Landscape 0.1 N/A N/A N/A N/A
2 -Impervious 1313 B Flat Impervious 0.9 N/A N/A N/A N/A
Total BMP Area 2053 Minimum BMP Size
Proposed BMP Size• 3319
Soil Matrix Depth
Minimum Ponding Depth
Maximum Ponding Depth
Selected Ponding Depth
Describe the BM P's in sufficient detail in your SWMP to demonstrate the area, volume, and other criteria can be met within the constraints of the site.
BM P's must be adapted and applied to the conditions specific to the development project such as unstable slopes or the lack of available head.
Designated Staff have final review and approval authority over the project design.
This Sizing Calculator has been developed in compliance with the Countywide Model SUSMP. For questions or concerns please contact the jurisdiction in which your project is located.
Minimum BMP Size
Surface Volume Subsurface Volume
(cf) (cf)
N/A N/A
N/A N/A
2766 1991
18.00 in
in
643.04 in
10.00 in
BMP Sizing Spreadsheet Vl.04
Project Name: iser Parking Lot Expansi Hydrologic Unit: 904.51
Project Applicant: Foundation Health Pia Rain Gauge: Lindbergh
Jurisdiction: City of Carlsbad Total Project Area: 20962
Parcel (APN): 214-450-19-00 Low Flow Threshold: O.SQ2
BMP Name 2 (DMA2) BMPType: Flow-Through Planter
OMA Rain Gauge Existing Condition Q2 Sizing Factor OMA Area (ac)
Name Soil Type Cover Slope (cfs/ac)
2 -Landscape Lindbergh D Scrub Flat 0.05 0.017
2 -Impervious Lindbergh D Scrub Flat 0.05 0.030
Orifice Flow -%Q2
(cfs)
0.000
0.001
0.001
Tot. Allowable
Orifice Flow
(cfs)
0.515
Actual Orifice Flow
(cfs)
Orifice Area (in2)
0.01
0.02
0.03 0.19
Tot. Allowable Max Orifice
Orifice Area Diameter
(in2) (in)
12.57 4.00
Actual Orifice Area Selected
Orifice Diameter
(in2) (in)
I Drawdown (Hrs) 1.5
BMP Drawdown time < 36 hours
with no orifice control, therefore, OK.
I
Attachment 3a
BMP Maintenance Thr~holds
and BMP Fact Sheets
STORM WATER QUALITY MA NAGEMENT PLAN JUNE 2017
ATTACHMENT 3
Structural BMP Maintenance Information
OWNERSHIP AND MAINTENANCE FOR STRUCTURAL BMPs
The operations and maintenance of the treatment control BMPs will be the responsibility of the
owner. The current contact information for the responsible party is:
Kaiser Permanente
6860 Avenida Encinas
Carlsbad, CA 92011
(619) 528-5000
A training program will be administered and implemented by Kaiser Permanente and shall occur
at a minimum of once annually. The training program shall consist of, at a minimum: the
disbursement of the brochures and flyers included in this SWQMP and a copy of the
maintenance plan to all operation and maintenance staff associated with the project. A training
log shall be filled out at each training session and kept for a minimum of five (5) years.
Kaiser Permanente will complete and maintain operation and maintenance forms to adequately
document all maintenance performed on the project's treatment control BMPs. These records
should be kept on file for a minimum of five (5) years and shall be made accessible to the City of
Carlsbad, the State Water Resources Control Board or any other authority regulating storm
water discharges for inspection upon request at any time.
All waste generated from the Kaiser Permanente Parking Lot Expansion project site is ultimately
the responsibility of Kaiser Permanente Disposal of sediment, debris, and trash will comply with
applicable local, county, state, and federal waste control programs. Suspected hazardous
waste will be analyzed to determine proper disposal methods.
The following Operation and Maintenance Plan has been developed for each type of pollutant
control BMP used on this project. These are minimum requirements only. Their frequency
and/or scope may be increased, if necessary, to meet and/or maintain the level of storm water
quality treatment required of this project.
All costs associated with the operation and maintenance of the pollutant control BMPs will be
funded by Kaiser Permanente in perpetuity or until the project is sold to another entity where the
responsibility would transfer with the sale of the property or an individual parcel.
The project's owner, Kaiser Permanente, will enter into a Stormwater Facility Maintenance
Agreement as required by the City of Carlsbad, which will be executed prior to grading permit
issuance.
KA ISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
24
STORM WATER QUALITY MANAGEMENT PLAN
Biofiltration System Inspection Activities
Inspect biofiltration system
Inspect soil and repair eroded areas
Inspect for erosion or damage to vegetation, preferably at the end of the wet
season to schedule dry season maintenance and before major wet season runoff
to be sure the areas are ready for the wet season. However, additional inspection
after periods of heavy runoff is recommended.
Inspect to ensure grasses, ground covers, vegetation is well established. If not,
either prepare soil and reseed or replant with appropriate alternative species.
Install erosion control blankets if necessary.
C heck for debris and litter, areas of sediment accumulation
Inspect health of trees and shrubs and vegetation
Inspect system cleanouts and outfall structures
Inspect for standing water and vectors
Biofiltration System Maintenance Activities
Remove litter and debris in conjunction with regularly scheduled landscape
maintenance
Irrigate biofiltration area(s) during dry season (April through October) and as
necessary to maintain vegetation during the rainy season.
Physically remove weeds
Remove sediment
Apply mulch to areas devoid of mulch, especially prior to the wet season
Replace damaged or diseased trees and shrubs
Mow turf areas, if any
Repair erosion at inflow points
Unclog under drain system
Remove and replace dead and diseased vegetation
Replace tree stakes and wires, if any
Mulch should be replaced every 2 to 3 years or when bare spots appear
Rototill or cultivate the surface if the system does not draw down in 48 hours
KAISER PERMANENTE CARLSBAD
PARKING LOT EXPANSION
25
JUNE 2017
Recommended
Frequency
-Before/after rainy
season
-Bi-weekly during
the rainy season
-After a rainfall
event of 0.5'' or more
Monthly
Prior to rainy season
& every other month
Every other month
Every other month
Every other month
Every other month
Every other month
Recommended
Frequency
As part of routine,
regular landscape
maintenance
Every 2-3 years, or as
needed
As needed
E.12 BF-1 Biofiltration
Location: 43rd Street and Logan Avenue, San Diego, California
Description
Appendix E: BMP Design Fact Sheets
MS4 Permit Category
Biofiltration
Manual Category
Bio filtration
Applicable Performance
Standard
Pollutant Control
Flow Control
Primary Benefits
Treatment
Volume Reduction (Incidental)
Peak Flow Attenuation (Optional)
Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter
water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow
to the downstream conveyance system. Bioretention with underdrain facilities are commonly
incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because
these types of facilities have limited or no infiltration, they are typically designed to provide enough
hydraulic head to move flows through the underdrain connection to the storm drain system.
Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant
uptake.
Typical bioretention with underdrain components include:
• Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips)
• Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap)
• Shallow surface ponding for captured flows
• Side slope and basin bottom vegetation selected based on expected climate and ponding depth
• Non-floating mulch layer (Optional)
• Media layer (planting mix or engineered media) capable of supporting vegetation growth
• Filter course layer consisting o f aggregate to prevent the migration of fines into uncompacted
native soils or the aggregate storage layer
• Aggregate storage layer with underdrain(s)
• Impermeable liner or uncompacted native soils at the bottom of the facility
E-66 February 2016
• Overflow structure
CURB
· .. · .. · .. · .. ~
APRON FOR ENERGY
• •DISSIPATION
♦ + ♦ + .. ..
,.3H:1V (MIN.) ..
• ·:~ ~; : • • + + : ~·-·· .. :I/f :::::•:·
♦ + • +
+ + + +
PLAN
NOTTO SCALE
4-6" DROP FROM CURB CUT TO APRON
APRON FOR ENERGY DISSIPATION
6" MIN. TO 12" MAX.
SURFACE PONDING
CURB CUT CLEANOUT
. ,
Appendix E : BMP Design Fact Sheets
• ... + +
MAINTENANCE •
ACCESS
SAS ~EEpED) +
+ ... + ...
.. +
.. +
MEDIA SURFACE AREA
2" MIN. FREEBOARD
3" WELL-AGED, SHREDDED
HARDWOOD MULCH
(OPTIONAL) MAINTENANCE
ACCESS
(AS NEEDED)
EXISTING UNCOMPACTED SOILS
SECTION A-A'
NOTTO SCALE
Typical plan and Section view of a Biofiltration BMP
E-67 February 2016
Appendix E: BMP Design Fact Sheets
Design Adaptations for Project Goals
Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined
to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered
runoff. This configuration is considered to provide biofiltration treatment via flow through the media
layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is
considered included in the biofiltration treatment volume. Saturated storage within the aggregate
storage layer can be added to this design by raising the underdrain above the bottom of the aggregate
storage layer or via an internal weir structure designed to maintain a specific water level elevation.
Integrated storm water flow control and pollutant control configuration. The system can be
designed to provide flow rate and duration control by primarily providing increased surface ponding
and/ or having a deeper aggregate storage layer above the underdrain. This will allow for significant
detention storage, which can be controlled via inclusion of an outlet structure at the downstream end
of the underdrain.
Design Criteria and Considerations
Bioretention with underdrain must meet the following design criteria. Deviations from the below
criteria may be approved at the discretion of the City E ngineer if it is determined to be appropriate:
Siting and Design
□
□
□
Placement observes geotechnical
recommendations regarding potential hazards
(e.g., slope stability, landslides, liquefaction
zones) and setbacks (e.g., slopes, foundations,
utilities).
An impermeable liner or other hydraulic
restriction layer is included if site constraints
indicate that infiltration or lateral flows should
not be allowed.
Contributing tributary area shall be :S 5 acres
(:S 1 acre preferred).
E-68
Intent/Rationale
Must not negatively impact existing site
geotechnical concerns.
Lining prevents storm water from
impacting groundwater and/ or sensitive
environmental or geotechnical features.
Incidental infiltration, when allowable,
can aid in pollutant removal and
groundwater recharge.
Bigger BMPs require additional design
features for proper performance.
Contributing tributary area greater than 5
acres may be allowed at the discretion of
the City Engineer if the following
conditions are met: 1) incorporate design
features (e.g. flow spreaders) to
minimizing short circuiting of flows in
February 2016
Siting and Design
□ Finish grade of the facility is :S 2%.
Surface Ponding
□
□
□
□
Surface ponding is limited to a 24-hour
drawdown time.
Surface ponding depth is 2: 6 and :S 12 inches.
A minimum of 2 inches of freeboard is
provided.
Side slopes are stabilized with vegetation and
are = 3H:1 V or shallower.
Vegetation
E-69
Appendix E: BMP Design Fact Sheets
Intent/Rationale
the BMP and 2) incorporate additional
design features requested by the City
Engineer for proper performance of the
regional BMP.
Flatter surfaces reduce erosion and
channelization within the facility.
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 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.
Freeboard provides room for head over
overflow structures and minimizes risk
of uncontrolled surface discharge.
Gentler side slopes are safer, less prone
to erosion, able to establish vegetation
more quickly and easier to maintain.
February 2016
Appendix E: BMP Design Fact Sheets
Siting and Design Intent/Rationale
Plantings are suitable for the climate and
□
Plants suited to the climate and ponding
expected ponding depth. A plant list to aid in depth are more likely to survive.
selection can be found in Appendix E.20.
□
An irrigation system with a connection to
water supply should be provided as needed.
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.
Media Layer
□
□
Media maintains a minimum filtration rate of 5
in/hr over lifetime of facility. An initial
filtration rate of 8 to 12 in/hr is recommended
to allow for clogging over time; the initial
filtration rate should not exceed 12 inches per
hour.
Media is a minimum 18 inches deep, meeting
either of these two media specifications:
City of San Diego Storm Water Standards
Appendix F (February 2016, unless superseded
by more recent edition) or County of San
Diego Low Impact Development Handbook:
Appendix G -Bioretention Soil Specification
Qune 2014, unless superseded by m ore 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.
E-70
Seasonal irrigation might be needed to
keep plants healthy.
Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch
kills pathogens and weed seeds and
allows the beneficial microbes to
multiply.
A filtration rate of at least 5 inches per
hour allows soil to drain between events.
The initial rate should be higher than
long term target rate to account for
clogging over time. H owever an
excessively high initial rate can have a
negative impact on treatment
performance, therefore an upper limit is
needed.
A deep media layer provides additional
filtration and supports plants with deeper
roots.
Standard specifications shall be followed.
For non-standard or proprietary designs,
compliance with F.1 ensures that
adequate treatment performance will be
provided.
February 2016
Siting and Design
□
□
Media surface area is 3% of contributing area
times adjusted runoff factor or greater.
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).
Filter Course Layer
□
□
□
A filter course is used to prevent migration of
fines tluough layers of the facility. Filter fabric
is not used.
Filter course is washed and free of fines.
Filter course calculations assessing suitability
for particle migration prevention have been
completed.
Aggregate Storage Layer
□
Class 2 Permeable per Caltrans specification
68-1.025 is recommended for the storage layer.
Washed, open-graded crushed rock may be
__ u_sed, however a 4-6 inch washed pea grave_] __
E-71
Appendix E: BMP Design Fact Sheets
Intent/Rationale
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.
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.
Migration of media can cause clogging of
the aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to
clog.
Washing aggregate will help eliminate
fines that could clog tl1e facility and
impede infiltration.
Gradation relationship between layers
can evaluate factors (e.g., bridging,
permeability, and uniformity) to
determine if particle sizing is appropriate
or if an intermediate layer is needed.
Washing aggregate will help eliminate
fines that could clog the aggregate
storage layer void spaces or subgrade.
February 2016
Siting and Design
□
fil ter 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.
Inflow, Underdrain, and Out.iow Structures
□
□
□
□
□
□
□
□
Inflow, underdrains and outflow structures are
accessible for inspection and maintenance.
Inflow velocities are limited to 3 ft/ s or less or
use energy dissipation m ethods. (e.g., riprap,
level spreader) for concentrated inflows.
Curb cut inlets are at least 12 inches wide, have
a 4-6 inch reveal (drop) and an apron and
energy dissipation as needed.
Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.
Minimum underdrain diameter is 6 inches.
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent or
corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.
Ao underdrain cleaoout with a minimum 6-
inch diameter and lockable cap is placed every
250 to 300 feet as required based on
underdrain length.
Overflow is safely conveyed to a downstream
storm drain system or discharge point Size
overflow structure to pass 100-year peak flow ------
E-72
Appendix E: BMP Design Fact Sheets
Intent/Rationale
Proper storage layer configuration and
underdrain placement will minimize
facility drawdown time.
Maintenance will prevent clogging and
ensure proper operation of the flow
control structures.
High inflow velocities can cause erosion,
scour and/ or channeling.
Inlets must not restrict flow and apron
prevents blockage from vegetation as it
grows in. Energy dissipation prevents
erosion.
A minimal separation from subgrade or
the liner lessens the risk of fines entering
the underdrain and can improve
hydraulic performance by allowing
perforations to remain unblocked.
Smaller diameter underdrains are prone
to clogging.
Slotted underdrains provide greater
intake capacity, clog resistant drainage,
and reduced entrance velocity into the
pipe, thereby reducing the chances of
solids migration.
Properly spaced cleanouts will facilitate
underdrain maintenance.
Planning for overflow lessens the risk of
property damage due to flooding.
February 2016
Siting and D esign
for on-line infiltration basins and water quality
peak flow for off-line basins.
Appendix E: BMP Design Fact Sheets
Intent/Rationale
---~-----~-
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 D CV 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
o f 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 tl1e full range of flows.
3. If bioretention with underdrain cannot fully provide tlle 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.
E-73 February 2016
Appendix E: BMP Design Fact Sheets
E.13 BF-2 Nutrient Sensitive Media Design
Some studies of bioretention with underdrains have observed export of nutrients, particularly
inorganic nitrogen (nitrate and nitrite) and dissolved phosphorus. This has been observed to be a
short-lived phenomenon in some studies or a long term issue in some studies. The composition of
the soil media, including the chemistry of individual elements is believed to be an important factor in
the potential for nutrient export. Organic amendments, often compost, have been identified as the
most likely source of nutrient export. The quality and stability of organic amendments can vary widely.
The biofiltration media specifications contained in the County of San Diego Low Impact
Development Handbook: Appendix G -Bioretention Soil Specification CTune 2014, unless superseded
by more recent edition) and the City of San Diego Low Impact Development Design Manual (page
B-18) CTuly 2011, unless superseded by more recent edition) were developed with consideration of the
potential for nutrient export. These specifications include criteria for individual component
characteristics and quality in order to control the overall quality of the blended mixes. As of the
publication of this manual, the June 2014 County of San Diego specifications provide more detail
regarding mix design and quality control.
The City and County specifications noted above were developed for general purposes to meet
permeability and treatment goals. In cases where the BMP discharges to receiving waters with nutrient
impairments or nutrient TMDLs, the biofiltration media should be designed with the specific goal of
minimizing the potential for export of nutrients from the media. Therefore, in addition to adhering to
the City or County media specifications, the following guidelines should be followed:
1. Select plant palette to minimize plant nutrient needs
A landscape architect or agronomist should be consulted to select a plant palette that minimizes
nutrient needs. Utilizing plants with low nutrient needs results in less need to enrich the biofiltration
soil mix. If nutrient quantity is then tailored to plants with lower nutrient needs, these plants will
generally have less competition from weeds, which typically need higher nutrient content. The
following practices are recommended to minimize nutrient needs of the plant palette:
• Utilize native, drought-tolerant plants and g rasses where possible. Native plants
generally have a broader tolerance for nutrient content, and can be longer lived in
leaner/lower nutrient soils.
• Start plants from smaller starts or seed. Younger plants are generally m ore tolerant o f
lower nutrient levels and tend to help develop soil structure as they grow. Given the lower
cost o f smaller plants, the project should be able to accept a plant mortality rate that is
somewhat higher than starting from larger plants and providing high organic content.
2. Minimize excess nutrients in media mix
Once the low-nutrient plant palette is established (item 1), the landscape architect and/ or agronomist
should be consulted to assist in the design of a biofiltration media to balance the interests of plant
E -74 February 2016
Appendix E: BMP Design Fact Sheets
establishment, water retention capacity (irrigation demand), and the potential for nutrient export. T he
following guidelines should be followed:
• The mix should not exceed the nutrient needs of plants. In conventional landscape
design, the nutrient needs of plants are often exceeded intentionally in order to provide a
factor of safety for plant survival. This practice must be avoided in biofiltration media as excess
nutrients will increase the chance of export. The mix designer should keep in mind that
nutrients can be added later (through mulching, tilling of amendments into the surface), but it
is not possible to remove nutrients, once added.
• The actual nutrient content and organic content of the selected organic amendment
source should be determined when specifying mix proportions. utrient content (i.e.,
C:N ratio; plant extractable nutrients) and organic content (i.e, % organic material) are
relatively inexpensive to measure via standard agronomic methods and can provide important
information about mix design. If mix design relies on approximate assumption about
nutrient/ organic content and this is n ot confirmed with testing ( or the results o f prior
representative testing), it is possible that the mix could contain much more nutrien t than
intended.
• Nutrients are better retained in soils with higher cation exchange capacity. Cation
exchange capacity can be increased through selection of organic material with naturally high
cation exchange capacity, such as peat or coconut coir pith, and/ or selection of inorganic
material with high cation exchange capacity such as some sands or engineered minerals (e.g.,
low P-index sands, zeolites, rhyolites, etc). Including higher cation exchange capacity materials
would tend to reduce the net export of nutrients. Natural silty materials also provide cation
exchange capacity; however potential impacts to permeability need to be considered.
• Focus on soil s tructure as well as nutrient content. Soil structure is loosely defined as the
ability of the soil to conduct and store water and nutrients as well as the degree of aeration of
the soil. Soil structure can be more important than nutrient content in plant survival and
biologic health of the system. If a good soil structure can be created with very low amounts of
organic amendment, plants survivability should still be provided. While soil structure generally
develops with time, bio filtration media can be designed to promote earlier development of
soil structure. Soil structure is enhanced by the use of amendments with high humus content
(as found in well-aged organic material). In addition, soil structure can be enhanced through
the use of organic material with a distribution o f particle sizes (i.e., a more heterogeneous mix).
• Consider alternatives to compost. Compost, by nature, is a material that is continually
evolving and decaying. It can be challenging co determine whether tests previously done on a
given compost stock are still representative. It can also be challenging to determine how the
properties of the compost will change once placed in the media bed. More stable materials
such as aged coco coir pith, peat, biochar, shredded bark, and/ or other amendments should
be considered.
With these considerations, it is anticipated that less than 10 percent organic amendment by volume
E-75 February 2016
Appendix E: BMP Design Fact Sheets
could be used, while still balancing plant survivability and water retention. If compost is used,
designers should strongly consider utilizing less than 10 percent by volume.
3. Design with partial retention and/ or internal water storage
An internal water storage zone, as described in Fact Sheet PR-1 is believed to improve retention of
nutrients. For lined systems, an internal water storage zone worked by providing a zone that fluctuates
between aerobic and anaerobic conditions, resulting in nitrification/ denitrification. In soils that will
allow infiltration, a partial retention design (PR-1) allows significant volume reduction and can also
promote nitrification/ denitrification.
Acknowledgment: This fact sheet has been adapted from the Orange County Technical Guidance
Document (May 2011). It was originally developed based on input from: Deborah Deets. City of Los
Angeles Bureau of Sanitation. Drew Ready. Center for Watershed Health, Rick Fisher. ASLA. City of
Los Angeles Bureau of Engineering. Dr. Garn Wallace. Wallace Laboratories. Glen Dake. GDML.
and Jason Schmidt, Tree People. The guidance provided herein does not reflect the individual opinions
of any individual listed above and should not be cited or otherwise attributed to those listed.
E-76 February 2016
Appendix E: BMP Design Fact Sheets
E.14 BF-3 Proprietary Biofiltration Systems
The purpose of this fact sheet is to help explain the potential role of proprietary BMPs in meeting
biofiltration requirements, when full retention of the DCV is not feasible. The fact sheet does not
describe design criteria like the other fact sheets in this appendix because this information varies by
BMP product model.
Criteria for Use of a Proprietary BMP as a Blofiltratlon BMP
A proprietary BMP may be acceptable as a "biofiltration BMP" under the following conditions:
(1) The BMP meets the minimum design criteria listed in Appendix F, including the pollutant
treatment performance standard in Appendi'C F.1;
(2) The BMP is designed and maintained in a manner consistent with its performance
certifications (See explanation in Appendix F.2); and
(3) T he BMP is acceptable at the discretion of the City Engineer. In determining the
acceptability of a BMP, the City Engineer should consider, as applicable, (a) the data
submitted; (b) representativeness of the data submitted; (c) consistency of the BMP
performance claims with pollutant control objectives; certainty of the BMP performance
claims; (d) for projects within the public right of way and/ or public projects: maintenance
requirements, cost of maintenance activities, relevant previous city experience with operation
and maintenance of the BMP type, ability to continue to operate the system in event that the
vending company is no longer o perating as a business; and (e) other relevant factors.
Guidance for Sizing a Proprietary BMP as a Biofiltration BMP
Proprietary biofiltration BMPs must meet the same sizing guidance as non-proprietary BMPs. Sizing
is typically based on capturing and treating 1.50 times the DCV not reliably retained. Guidance for
sizing biofiltration BMPs to comply with requirements of this manual is provided in Appendix F.2.
E-77 February 2016
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€1) TREATMENT CONTROL BMP
VERIFICATION FORM
. Pursuant to CMC 15.12.100 -
GENERAL INFORMATION
Owner Name
Owner Address City and Zip
Contact Name Contact Phone
New Contact New Phone
BMP INFORMATION
BMPType BMPID# I Prioritv I
BMP Description Manufacturer
BMP Location BMP
Address
BMP Approval Date I Last Inspection Date Maintenance Freauencv I
Comments
BMP VERIFICATION AND MAINTENANCE
en 0 !:"" 3: ~ w zo
>-z Oz z 0 ~
BMP ACTIVITY COMMENTS
Has the BMP been installed?
Has the BMP been removed?
Is the BMP ooeratina orooerlv?
Has the BMP been reolaced? If so when?
Is BMP covered under a maintenance agreement?
Is the BMP on a reaular maintenance schedule?
Has trash or other debris accumulated in or around BMP?
Has the BMP been insoected durina the last vear?
Has the BMP been maintained or cleaned durina the last vear?
Are discharae ooints free of litter and debris?
Has it rained since the last time the BMP was maintained?
D Leaking Vehicles
D Erosion/Sediments D Trash and Debris
What are the sources of pollution that could impact the BMP? D Over Irrigation D Improvement Projects (paint,
concrete wash, landscaping, etc.)
□ Pet/Animal Waste □ Lawn clippings and yard waste
□ Other
Certification Statement
"I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in
accordance with a system to assure that the responsible party gathered and evaluated the information submitted. Based on
my inquiry of the person or person who managed the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate and complete, I am aware that
there are sianificant oenalties for submittina false information inc/udina the possibilitv of fines and other enforcement actions."
PRINT NAME: SIGNATURE
Please return the completed and signed form to the
City of Carlsbad
CMI -Storm Water Compliance
5950 El Camino Real
Carlsbad, CA 92008
760-602-2780 or FAX 760-438-7178
DATE
.,.~ ....
Attachment 3b
_Draft Stormwater Maintenance Agreement
EXHIBIT "A "
PR
PROPERTY
LEGAL DESCRIPTION
LOTS 11, 12 AND 13 OF CARLSBAD TRACT NO. 81-5, IN THE CITY OF CARLSBAD, COUNTY
OF SAN DIEGO, STA TE OF CALIFORNIA, MAP NO. 10899, RECORDED , APRIL 11, 1984.
PAUL E. GOEBEL, PLS 8548
5/8/17 -------------------------------DATE:
PASCO LAREY SUITER
------n ASSOCIATES PH. 858.259.8212 I PLSAENGINEERING.COM PLSA JOB NO. 2512
KAISER M.O.8.-PARKING LOT EXPANSION
STORM WATER MANAGEMENT AGREEMENT
SHEET 1 OF 1
EXHIBIT "B"
PR
CITY OF OCEANSIDE
NOT TO
SCALE
la
SITE
CITY OF ENCINITAS ~ VICINITY MAP
NO SCALE
NOTE OWNER/APPLICANT
REFER TO DWG NO. ______ ON KAISER FOUNDATION HEAL TH PLAN, INC.
8010 PARKWAY DRIVE FILE WITH THE CITY OF CARLSBAD
FOR ADDITIONAL DETAILS. LA MESA, CA 91942
-------------------------------PAUL E. GOEBEL, PLS 8548
5/8/17 -------------------------------DATE:
CITY OF VISTA
PASCO LAREY SUITER KAISER M.O.B.-PARKING LOT EXPANSION
STORM WATER MANAGEMENT AGREEMENT
n ASSOCIATES
PH. 858.259.8212 I PLSAENGINEERING.C0M PLSA JOB NO. 2512 SHEET 1 OF 3
~ EXHIBIT
PR
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SCALE: 1 "=40'
40' 20· 0 40' 80' 120·
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GRAPHIC SCALE: 1''=40'
PASCO LARET SUITER
-----■ & ASSOCIATES
PH. 858.259.8212 I PLSAENGINEERING.COM PLSA JOB NO. 2512
,, B,,
BU/LDINGA ,,,, \ (EXISTING
2-STORY
MEDICAL OFFICE)
BUILDINGS
(EXISTING
2-STORY
MEDICAL OFFICE)
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------.-!.------------------,, ---\
_,,,,. -
KAISER M.O.8.-PARKING LOT EXPANSION
STORM WATER MANAGEMENT AGREEMENT
SHEET 2 OF 3
EXHIBIT "B"
PR
I~,
~c%'11(cs 100-YR PONDING 0~JscS DEPTH (VARIES)
WIDTH VARIES PER PLAN
2% Ml!i. --
EXTEND P~~ ~ ---
LINER UP T~ I I I I -
PONDING DEP7tf 1
I
l-rrili-!rnlllml--Uia--=----18-INCH THICK LA YER
OF BIORETENTION SOIL
MEDIA. SANDY LOAM,
POROSITY=0.4
11
8 11-THICK
STORAGE
LAYER OF
#57 STONE
4" PERFORATED
SUBDRAIN
3"-THICK
STORAGE LA YER
OF #57 STONE,
BELOW OUTLET
FIELD CAPACITY=0.2
WILTING POINT=0.1
CONDUCTIVITY=5IN/HR
I
-4"-THICK LA YER OF
"BIRDSEYE" WASHED
PEA GRAVEL-CHOKER
STONE LAYER
BROOKS BOX INLET
STRUCTURE SIZED PER
PLANS. TOP OF GRATE
AND INVERT ELEVATIONS
VARY PER PLANS.
BIO-FILTRATION BASIN WITH IMPERMEABLE LINER DETAIL
NOT TO SCALE
PASCO LAREY SUITER
------n ASSOCIATES PH. 858.259.8212 I PLSAENGINEERING.COM PLSA JOB NO. 2512
KAISER M.O.B.-PARKING LOT EXPANSION
STORM WATER MANAGEMENT AGREEMENT
SHEET 3 OF 3
Attachment 4
,______ City Standard Single Sheet BMP Exhibit
@ I \
\ \
I LOT13
MAP10899 ~ IL
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-
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EXISTING
DRIVEWAY
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VAULT
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(EXJST1NG 2-STORY
MEDICAL OFFICE)
----
LOT 12 --~
MAP10899
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---
LINED BIOFIL TRA TION
BMP (360 SF)
AVENIDA
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BUILDINGS
(EXJST1NG 2-STORY
MEDICAL OFFICE)
-0-
~-LANDSCAPING----,'/----''>:"
o -
+ + +
~II~
Ill
~
ENCINAS
_111 -C/L
1'1
PLAN VIEW
SCALE: 1" = 20'
j
• I /
LOT11
MAP10899
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PROPOSED
TRENCH DRAIN
I
\
EXISTING STORM
DRAIN INLET
LINED BIOFIL TRA T/ON
BMP (46 SF)
IL
'
PASCO LARET SUITER
& ASSOCIATES
CIVIL ENGINEERING + LAND PLANNING + LAND SURVEYING
535 North Highway 101, Ste A, Solana Beach, CA 92075
ph 858.259.8212 I fx 858.259.4812 I plsaengineering.com
GR2017-0030 I CD2017-0003
PARTY RESPONSIBLE FOR MAINTENANCE:
KAISER FOUNDATION HEAL TH PLAN, INC,
8010 PARKWAY DRIVE
LA MESA, CA 91942
(619) 315-9316
CONTACT: KATH ERINE CLARK
PLAN PREPARED BY:
PASCO LARET SUITER & ASSOCIATES
535 N. HWY 101, SUITE A
SOLANA BEACH, CA 92075
(858~259-8212
BMPNOTES:
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S
RECOMMENDATIONS OR THESE PLANS,
2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR
APPROVAL FROM THE CITY ENGINEER
3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES
WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER
4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF
HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION
AND INSTALLATION.
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
6. SEE PROJECT SWQMP FOR ADDITIONAL INFORMATION.
BMP TABLE
BMP ID# BMPTYPE SYM BOL CASQA NO. QUANTITY DRAWING NO. SHEET NO.(S) INSPECTION
FREQUENCY
TREATMENT CONTROL (PROJ ECT IS EXEMPT FROM HYDROMODIFICAITON REQUIREMENTS)
G)&(I) BIORETENTION (~) TC-32 406 SF. 504-2A 5&6 QUARTERLY AREA
SOURCE CONTROL
@-® STENCILS NO DUMPING SD-13 ANNUALLY DRAJ NS TO OCEAN -----
@) SITE DESIGN
AND LANDSCAPE -SD-10 11,051 SF. 504-2A 5&6 QUARTERLY
PLANNING
20' 10· 0
I ~
SCALE:
MAINTENANCE
FREQUENCY
SEMI-ANNUALLY
AS-NEEDED
'\
SEMI-ANNUALLY <
/
20' 40'
I I
1,, = 20'
~ CITY OF CARLSBAD I SHEETS -1 l----+----+----------------+-------11-----+--+-----t L_l_J ENGI NEERING DEPARTMENT f
1----+----+----------------+-------11-----+--+-----t
SINGLE SHEET BMP SITE PLAN
KAISER PERMANENTE M.O.B.
(PARKING LOT EXPANSION )
RECORD COPY PROJECT NO,
Ii\ REPLACES DWG 504-2SW APPROVED ON 11-08-2018 CD2017-0003
ADDEO SITE DESIGN AND LANDSCAPE PLANNING AREA
DATE IN ITIAL
ENGINEER OF WORK REVISION DESCRIPTION f--D_ATE_~IN_IT_IA_L-+-_D_ATE_~IN_ITI_A_L_. '----C..C..C.--=-----~~-~ I 50DRt:1N2GSNWO, I
OTHER APPROVAL CITY APPROVAL INlllAL DA TE _ "+ _