HomeMy WebLinkAboutCUP 260D; PALOMAR TRANSFER STATION; PRIORITY DEVELOPMENT PROJECT (PDP) SOTRM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2020-01-28CITY OF CARLSBAD
RECORD COPY
'D e/2.](1,3•
Initial
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
Palomar Transfer Station 6907
Project ID: CUP 260 (D)
GR 2018-0049
DWG No. 422-38
ENGINEER OF WORK:
Prepa~pervision of
Ricardo Garcia, P.E. No. 66957
PREPARED FOR:
PALOMAR TRANSFER STATION INC.
5960 EL Camino Real
Carlsbad, CA 92008
Phone No. (760) 603-0153
PREPARED BY:
DAVID EVANS AND ASSOCIATES INC.
25152 Springfield Court, Suite 350
Santa Clarita, CA 91355-1096
Phone No. (661) 284-7400
DATE
January 28, 2020
CE
TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1 : Backup for PDP Pollutant Control BMPs
Attachment 1 a: DMA Exhibit
Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1 c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment 1 e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 2: Backup for PDP Hydromodification Control Measures
Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas
Attachment 2c: Geomorphic Assessment of Receiving Channels
Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
CERTIFICATION PAGE
Project Name: Palomar Transfer Station 6907
Project ID: ID: CUP 260 (D) / GR2018-0049 I DWG 442-3B
I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs
for this project, and that I have exercised responsible charge over the design of the project as
defined in Section 6703 of the Business and Professions Code, and that the design is consistent
with the requirements of the BMP Design Manual, which is based on the requirements of
SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order.
I have read and understand that the City Engineer has adopted minimum requirements for
managing urban runoff, including storm water, from land development activities, as described in
the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability
and accurately reflects the project being proposed and the applicable source control and site
design BMPs proposed to minimize the potentially negative impacts of this project's land
development activities on water quality. I understand and acknowledge that the plan check
review of this SWQMP by the City Engineer is confined to a review and does not relieve me, as
the Engineer in Responsible Charge of design of storm water BMPs for this project, of my
responsibilities for project design.
Engineer of Work's Signature, PE Number & Expiration Date
Ricardo Garcia, P.E. No. 66957, Exp. 09-30-2020
Print Name
DAVID EVANS AND ASSOCIATES INC.
Company
01/28/2020
Date
PROJECT VICINITY MAP
CITY OF OCEANSIDE
PACIFIC
OCEAN
78
CITY OF ENCINITAS
VICINITY MAP
NOT TO SCALE
PROJECT
LOCATION
CITY OF VISTA
Y OF
N MARCOS
{'city of
Carlsbad
STORM WATER STANDARDS
QUESTIONNAIRE
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
E-34
I INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision , discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY
DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City
staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and signed questionnaire must be submitted with each development project application. Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECT INFORMATION
PROJECT NAME: PALOMAR TRANSFER STATION PROJECT ID: CUP 260(D)
ADDRESS: 5960 El Camino Real, Carlsbad CA 92008 APN: 760-166-84-00
The project is (check one): D New Development IB1 Redevelopment
The total proposed disturbed area is: 6700 ft2 ( 0.1 5 ) acres
The total proposed newly created and/or replaced impervious area is: 5916 ft2 ( 0.14 ) acres
If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
Project ID SWQMP#:
Then, go to Step 1 and follow the instructions. When completed , sign the form at the end and submit this with your
application to the city.
E-34 Page 1 of 4 REV 02/16
STEP1
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building □ 00 or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If you answered "no" to the above question, the project is a 'development project', go to Step 2.
STEP2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3}, please answer
the following questions:
Is your project LIMITED to one or more of the following :
YES NO
1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-
erodible permeable areas; □ 00 b) Designed and constructed to be hydraulically disconnected from paved streets or roads;
c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets guidance?
2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in □ 00 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? □ 00
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ... " and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
If you answered "no" to the above questions, your project is not exempt from PDP, go to Step 3.
E-34 Page 2 of 4 REV 04/17
STEP3
TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )):
YES NO
1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, □ Ix]
and public development projects on public or private land.
2. Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of
impervious surface collectively over the entire project site on an existing site of 10,000 square feet or ~ □ more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is
a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and □ [x]
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 □ [x]
development project includes development on any natural slope that is twenty-five percent or greater.
5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is ~ □ a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious street, road, highway, freeway or driveway surface collectively over the entire project □ Ix] site? A street, road, highway, freeway or driveway is any paved impervious surface used for the
transportation of automobiles, trucks, motorcycles, and other vehicles.
7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site, and discharges directly to an Environmentally
Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of Ix] □ 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).*
8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop? An automotive repair □ [x] shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.
9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes □ Ix] RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily
Traffic (ADT) of 100 or more vehicles per day.
10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land □ IX] 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 □ [x]
21.203.040)
If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... "
and complete applicant information.
If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the
second box stating "My project is a 'STANDARD PROJECT' ... " and complete applicant information.
E-34 Page 3 of 4 REV 04/17
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)):
YES NO
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
Existing impervious area (A) = 302,000 sq. ft. IZl □
Total proposed newly created or replaced impervious area (B) = 6,700 sq. ft.
Percent impervious area created or replaced (B/A)*100 = 2.2 %
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 BM P's required for PDP apply to the entire development. Go to step 5, check the
check the first box stating "My project is a PDP ... " and complete aoolicant information.
STEPS
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
Ix] 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: Ricardo Garci~D~vid Evans and Associates Applicant Title: Project Manager
Applicant Signature: M, Date: 01-28-2020
.. * Environmentally Sens1t1ve Areas include but are not limited to all Clean Water Act Section 303(d) 1mpa1red water bodies; areas designated as Areas of Special
Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and
amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat
Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Only
YES NO
City Concurrence: □ □
By:
Date:
Project ID:
E-34 Page 4 of 4 REV 04/17
SITE INFORMATION CHECKLIST
Proiect Summarv Information
Project Name Palomar Transfer Station 6907
Project ID Project ID: CUP 260 (D)
Project Address 5960 EL Camino Real
Carlsbad, CA 92008
Assessor's Parcel Number(s) (APN(s)) 760-166-84-00
Project Watershed (Hydrologic Unit) Carlsbad 904
Parcel Area *See Note Acres ( Sauare Feet)
Existing Impervious Area
0.06 Acres ( 2,400 Square Feet) (subset of Parcel Area)
Area to be disturbed by the project
0.15 Acres ( 61700 Square Feet) (Project Area)
Project Proposed Impervious Area 0.14 Acres ( 51916 Square Feet) (subset of Project Area)
Project Proposed Pervious Area
0.02 Acres ( 784 Square Feet) (subset of Project Area)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
*Note: Per Carlsbad Arc GIS MAP for APN
198.11 -Calculated Acreage -10.98 Assessed Acreage
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
!xi Existing development
□ Previously graded but not built out
D Agricultural or other non-impervious use
□ Vacant, undeveloped/natural
Description/ Additional Information:
The existing Palomar Transfer Station is a waste transfer station. The location of
the proposed addition area is currently vacant, with truck parking and storage
areas.
Existing Land Cover Includes (select all that apply):
□ Vegetative Cover
~ Non-Vegetated Pervious Areas
!xi Impervious Areas
Description/ Additional Information:
Existing AC pavement area and storage bins. An existing gravel and
non-vegetated slope exists adjacent to the northeast side of the building.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
D NRCS Type A
D NRCS Type B
D NRCS Type C
!xi NRCS Type D
Approximate Depth to Groundwater (GW):
D GW Depth < 5 feet
□ 5 feet < GW Depth < 1 0 feet
□ 10 feet < GW Depth < 20 feet
~ GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
□ Watercourses
□ Seeps
□ Springs
□Wetlands
!xi None
Description/ Additional Information:
Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from
the site? At a minimum, this description should answer (1) whether existing drainage
conveyance is natural or urban; (2) describe existing constructed storm water conveyance
systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]:
The existing Palomar Transfer Station is a waste transfer station. The location of
the proposed addition area is currently vacant with truck parking and storage
areas. The parking area is paved with asphalt and the storage area is bare with no
vegetation. Topography shows that the proposed addition area gently slopes to the
east, the runoff sheet flows southeasterly to an existing concrete curb and gutter
and then collected in to an existing catch basin (located in the north east corner of
the property). The existing catch basin is a CDS Model No. PMIU20_ 15 in-line
catch basin vortex separator, per as-built Grading Drawing 443-3A Sheet 2 of 5.
The CDS unit discharges to the southwest through an existing retaining wall and
daylights to an existing longitudinal gutter. The longitudinal gutter flows southwest
then to a curb opening in to native vegetation that is part of the Carlsbad Oaks
North Habitat Conservation Area (located near middle of southeast property line).
There is no off-site runoff conveyed through the site.
Description of Prooosed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The proposed addition will be a part of the existing Palomar Transfer Station
Bu il ding . The additional building area is about 5000 sf, and also associated with a
landscaped area.
LisUdescribe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
The proposed addition is a part of building. The runoff will come from the roof
which is 100% impervious. A small landscape area will be left adjacent to the
expansion
LisUdescribe proposed pervious features of the project (e.g ., landscape areas):
The proposed pervious area will be landscaped after the addition is completed
Does the project include grading and changes to site topography?
□Yes
~No
Description/ Additional Information:
The proposed addition is a part of building. The disturbed area will slightly
change the slope (flatten) of the existing grading pattern but the direction remains
the same.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
□Yes
~No
Description/ Additional Information:
The proposed disturbed area will consist of existing drainage pattern. There is no
change to the existing site drainage system.
Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
□ On-site storm drain inlets
□ Interior floor drains and elevator shaft sump pumps
□ Interior parking garages
□ Need for future indoor & structural pest control
ii Landscape/Outdoor Pesticide Use
□ Pools, spas, ponds, decorative fountains, and other water features
□ Food service
Ix Ref use areas
181 Industrial processes
15a Outdoor storage of equipment or materials
□ Vehicle and Equipment Cleaning
~ Vehicle/Equipment Repair and Maintenance
□ Fuel Dispensing Areas
IX Loading Docks
ii Fire Sprinkler Test Water
ii Miscellaneous Drain or Wash Water
□ Plazas, sidewalks, and parking lots
Identification of Receiving Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable):
N/A
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable}, identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Body Pollutant( s )/Stressor( s) TMDLs
Identification of Project Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
BMP Design Manual Appendix B.6):
Also a Receiving
Not Applicable to Anticipated from the Water Pollutant of
Pollutant the Project Site Project Site Concern
Sediment X
Nutrients X
Heavy Metals X
Organic Compounds X
Trash & Debris X
Oxygen Demanding n/a Substances
Oil & Grease X
Bacteria & Viruses X
Pesticides X
Hydromodification Manaaement Reauirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
!XI Yes, hydromodification management flow control structural BMPs required.
□ No, the project will discharge runoff directly to existing underground storm drains discharging
directly to water storage reservoirs, lakes, enclosed 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):
Hydromodification calculations have been included for the proposed planter box.
Hydromodification calculation is based on the 2018 Model BMP Design Manual, BMP
BMP Sizing Spreadsheet Version 3.1 -Projectcleanwater.org referenced and attached.
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification manaaement reauirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
□Yes
IX No, No critical coarse sediment yield areas to be protected based on WMAA maps
See CCSY A Map on following page.
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual
been performed?
□ 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
□ 6.2.2 Downstream Systems Sensitivity to Coarse Sediment
□ 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
□ No optional analyses performed, the project will avoid critical coarse sediment yield areas
identified based on WMAA maps
If optional analyses were performed, what is the final result?
□ No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
□ Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
□ Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas
are identified on the SWQMP Exhibit.
Discussion / Additional Information:
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CRITICAL COURSE SEDIMENT YIELD AREA (CCSYA) MAP
PALOMAR TRANSFER STATION
CARLSBAD,CA
.., Places
• T ~ My Places
► ./ EJ Sightseeing Tour
1 0 ADDITIONAL TOPO
• ' €SI Temporary Places
• 1 ~ WMAAData
► • EJ Legend
► ' EJ Watershed Boundaries
► ' EJ SD Regional WMAA Streams
► i EJ SD NHD Streams
► ,EJ nd
• i 61 Floodplains
► ' EJ FEMA Floodplain
► ' EJ Channel Structures
• i 61 Hydromod Exemptions
► ./ EJ Exempt ~ems
► ' EJ Exempt_Bodies
Get Directions History --
• ' 61 2015 R.!gional Potential Critical Coarse Sediment Yield Area Mapping ., "Yes
.., Lavers
• 11 ~ Primary Database
E:I Announcements
► ' f Borders and Labels
' QJ Places
► 11 !, Photos
i = Roads
► 11 t)i 3D Buildings
► 11 Ocean
► Q Weather
► * Gallery
► Global Awareness
► D More
' Terrain
-
Federal/State/Indian Lands
FEMA Roodpla ln
100-YR Floodway
100-YR Floodplain
500-YR Floodplain
• <all other values>
Struct_lyp
o Bridge
• Culvert
• Dam
Diversion
Drop Structure
0 _ Energy Dissipator
• Flood Management Basin
o Flood Wall
• Grade Control
Levee
Pipeline
• Weir
Exemption Category
Exempt Storm Water Conveyance System
--Exempt River Reach
Exempt_Bo dies
Flow Control for Post-Project Runoff"
-.Yhis Section onl ulred If h dromodlfication mana ement ulrements a
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see Section 6.3.1 ). For each POC, provide a POC identification name or number
correlating to the project's HMP Exhibit and a receiving channel identification name or number
correlating to the project's HMP Exhibit.
The project site has a single POC located at the middle of the southeast property line. The POC
discharges to native vegetation that is part of the Carlsbad Oaks North Habitat Conservation Area
(CNLM No. S034). The proposed expansion will have its roof area treated through a means of
bio-filtration utilizing ( 4) planter box. The planter box has been sized to adequately manage
hydro-modification. Treated run-off and overflow from the planter boxes will follow the existing drainage
pattern and ultimately leave the site at the POC described above.
Has a geomorphic assessment been performed for the receiving channel(s)?
jl No, the low flow threshold is 0.102 (default low flow threshold)
D Yes, the result is the low flow threshold is 0.1 Q2
D Yes, the result is the low flow threshold is 0.302
□ Yes, the result is the low flow threshold is 0.502
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion/ Additional Information: (optional)
See following pages for Hydro-modification calculations. Calculations are based on the 2018 Model BMP
Design Manual.
BMP Sizing Spreadsheet V3.0 Project Name: Palomar Transfer Station 6907 Hydrologic Unit: 0 Project Applicant: Palomar Transfer Station Inc Rain Gauge: Oceanside Jurisdiction: Citv of Carlsbad Total Proiect Area: 6,700 Parcel IAPN): 760-166-84-00 Low Flow Threshold: 0.1Q2 8MP Name: Planter Boll. BMPType: Biofiltration BMP Native Soil Type: D BMP Infiltration Rate (in/hr): 0.025 Areas Draining to BMP HMP Sizing Factors Minimum BMP Size Area vveIgmea nuno11 DMA Pre Project Soil Post Project Factor Surface Area Surface Area l5F) Name Area !sf) Type Pre-Project Slope Surface Type !Table G.2-1)1 DMAl 2,830 D Moderate Roofs 1.0 0.07 198 DMA2 2,350 D Moderate Roofs 1.0 0.07 165 DMA3 600 D Moderate Concrete 1.0 0.07 42 0 0 BMP Tributary Area 5,780 Minimum BMP Size 405 Proposed BMP Size• 450 • Assumes standard configuration Surface Ponding Depth 12.00 in Bioretention Soil Media Depth 18.00 in Filter Coarse 6.00 in Gravel Storage Layer Depth 12 in Underdrain Offset 3.0 in Notes: 1. Runoff factors which are used for hydromodification management flow control (Table G.2-1) are different from the runoff factors used for pollutant control BMP sizing (Table B.1-1). Table references are taken from the San Diego Region Model BMP Design Mam Describe the BM P's in sufficient detail in your PDP SWQMP 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 BMP Sizing Spreadsheet has been updated in conformance with the San Diego Region Model BMP Design Manual, April 2018. For questions or concerns please contact the jurisdiction in which your project is located.
HYDROMODIFICATION -ORIFICE SIZING CALCULATION BMP Sizing Spreadsheet V3.0 Project Name: Palomar Transfer Station 6907 Hydrologic Unit: 0 Project Applicant: Palomar Transfer Station Inc Rain Gauge: Oceanside Jurisdiction: City of Carlsbad Total Project Area: 6,700 Parcel (APN): 760-166-84-00 Low Flow Threshold: 0.1Q2 BMP Name Planter Box BMPType: Biofiltration DMA Rain Gauge Pre-developed Condition Unit Runoff Ratio DMA Area (ac) Orifice Flow -%Q2 Orifice Area Name Soil Type Slope (cfs/ac) (cfs) (in2) DMAl Oceanside D Moderate 0.575 0.065 0.004 0.05 DMA2 Oceanside D Moderate 0.575 0.054 0.003 0.04 DMA3 Oceanside D Moderate 0.575 0.014 0.001 0.01 3.75 0.008 0.11 0.37 Max Tot. Allowable Max Tot. Allowable Max Orifice Max Orifice Head Orifice Flow Orifice Area Diameter (feet) (cfs) (in2) (in) 0.007 0.008 0.11 0.370 Average outflow during Max Orifice Outflow Actual Orifice Area Selected surface drawdown Orifice Diameter (cfs) (cfs) (in2) (in) Drawdown (Hrs) 17.8
Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or City
codes governing minimum street width, sidewalk construction, allowable pavement types, and
drainage requirements.
N/A
Ontional Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
{'city of
Carlsbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project lnfonnatlon
Project Name: Palomar Transfer Station
Project ID: CUP 260 (D)
DWG No. or Building Permit No.: 442-38
Source Control BMPs
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to
implement source control BMPs shown in this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 ~Yes □No D N/A
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage □Yes ~ No D N/A
Discussion/justification if SC-2 not implemented:
No catch basins in the redevelopment area.
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind ~Yes D No D N/A Dispersal
Discussion/justification if SC-3 not implemented:
E-36 Page 1 of 4 Revised 09/16
Source Control Raaulrement (continued) Annlled?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Ii] Yes □ No □ 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 li]Yes □ No □ N/A
Discussion/justification if SC-5 not implemented:
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Aooendix E.1 of BMP Manual for quidance).
□ On-site storm drain inlets □Yes lil No D N/A
□ Interior floor drains and elevator shaft sump pumps □Yes □ No lil N/A
□ Interior parking garages □Yes □ No lil N/A
□ Need for future indoor & structural pest control □Yes □ No lil N/A
□ Landscape/Outdoor Pesticide Use □ Yes □ No lil N/A
□ Pools, spas, ponds, decorative fountains, and other water features □ Yes □No lil N/A
□ Food service □ Yes □ No lil N/A
□ Refuse areas □Yes D No lil N/A
□ Industrial processes □Yes □ No lil N/A
□ Outdoor storage of equipment or materials □Yes □ No lil N/A
□ Vehicle and Equipment Cleaning □ Yes □ No lil N/A
□ Vehicle/Equipment Repair and Maintenance □Yes □ No lil N/A
□ Fuel Dispensing Areas □Yes □ No lil N/A
□ Loading Docks □Yes □ No lil N/A
□ Fire Sprinkler Test Water □ Yes □ No lil N/A
□ Miscellaneous Drain or Wash Water □ Yes □No Ii] NIA
D Plazas, sidewalks, and oarkina lots □Yes □No Iii NIA
For "Yes" answers, identify the additional BMP per Appendix E.1 . Provide justification for "No" answers.
No existing storm drain inlets within the project limits for the addition.
E-36 Page 2 of 4 Revised 09/16
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information
to implement site design BMPs shown in this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion / justification is not required.
• "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Site Design Requirement I Applied?
SD-1 Maintain Natural Drainage Pathways and Hydroloaic Features I Iii Yes I □ No I □ N/A
Discussion/justification if SD-1 not implemented:
Redevelopment area will keep existing drainage pattern.
SD-2 Conserve Natural Areas, Soils, and Vegetation I Iii Yes I □ No I □ N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize Impervious Area I □Yes I Iii No I □ NIA
Discussion/justification if SD-3 not implemented:
Bay addition is comprised of impervious roof. Downspouts will discharge to proposed planter box.
SD-4 Minimize Soil Compaction I Iii Yes I □ No I □ NIA
Discussion/justification if SD-4 not implemented:
landscaped area will not need soil compaction.
SD-5 Impervious Area Dispersion I Iii Yes I □ No I □ NIA
Discussion/justification if SD-5 not implemented:
Downspouts to discharge to proposed planter box.
E-36 Page 3 of 4 Revised 09/16
Site Design Reaulrement (continued) I Aoolled?
SD-6 Runoff Collection I □ Yes I □ No I Iii NIA
Discussion/justification if SD-6 not implemented:
Project area too small to collect runoff volume.
SD-7 Landscaping with Native or Drought Tolerant Species I Iii Yes I □ No I □ NIA
Discussion/justification if SD-7 not implemented:
Landscaped planters and hydroseed will be native and drought tolerant
SD-8 Harvesting and Using Precipitation I D Yes I □ No I Iii N/A
Discussion/justification if SD-8 not implemented:
Project area too small to justify a harvest and re-use system. Filtration through planter box will be
implemented.
E-36 Page4 of4 Revised 09/16
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).
The existing Palomar Transfer Station is a Waste Management Facility. The location of the
proposed addition area is currently vacant, with truck parking and storage areas. The
parking area is with asphalt pavement, the storage area is no pavement. Topography
shows that the proposed addition area from existing building is gently sloping to east, the
runoff sheets flow to an existing concrete curb & gutter then collected in to a existing catch
basin. The existing catch basin is a CDS Model No. PMIU20_ 15 in-line vortex separator.
The CDS unit discharges to the southwest through an existing retaining wall and daylights
to an existing longitudinal gutter. The longitudinal gutter flows southwest to a curb opening
in to native vegetation that is part of the Carlsbad Oaks North Habitat Conservation Area
(located near middle of southeast property line).There is no off-site runoff to the proposed
addition location. The proposed disturbed area will consist of existing drainage pattern.
There is no changes to the existing drainage system.
Since the project area is small and will result no increased runoff after the construction,
Biofiltration -Planter Box was selected as PDP structural BMPs of this project. One Planter
Box located at the downspouts were designed to treat the roof runoff by treatment media
and drainage rocks. A small landscaped area in this project also can be used as
stormwater quality control measure to self treat stormwater runoff. The methodology of
BMP's described in the city of Carlsbad BMPs manual is used to compute and designed in
this project. The BMPs location, sizing, analysis and details as shown in attachment 1 on
this report. The driveway to the proposed expansion will be covered by a roof overhang.
The roof overhang is sloped to a roof drain downspout that will discharge to the northerly
planter box. The portion of the driveway that Is not covered by the roof overhang will drain
to a proposed longitudinal gutter that will discharge to the planter box. The planter box has
been sized to accommodate the both the roof area and driveway. The planter box will be
at grade and partially buried and will be exposed as it continues south.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMP]
Structural BMP ID No. BIOFILTRATION TC-32 (Planter Box)
DWG 442-3B Sheet No. 3 4 6 of 9
Type of structural BMP:
□ Retention by harvest and use (HU-1)
□ Retention by infiltration basin (INF-1)
□ Retention by bioretention (INF-2)
□ Retention by permeable pavement (INF-3)
□ Partial retention by biofiltration with partial retention (PR-1)
~Biofiltration (BF-1)
□ Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
□ Detention pond or vault for hydromodification management
□ Other (describe in discussion section below)
Purpose:
□ Pollutant control only
□ Hydromodification control only
~ Combined pollutant control and hydromodification control
□ Pre-treatment/forebay for another structural BMP
□ Other (describe in discussion section below)
Discussion (as needed):
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment Contents Checklist
Seauence
Attachment 1 a DMA Exhibit (Required)
Attachment 1 b
Attachment 1 c
Attachment 1 d
See DMA Exhibit Checklist on the
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Tabular Summary of DMAs Showing
DMA ID matching DMA Exhibit, DMA
Area, and DMA Type (Required)*
*Provide table in this Attachment OR
on DMA Exhibit in Attachment 1 a
Form 1-7, Harvest and Use Feasibility
Screening Checklist (Required unless
the entire project will use infiltration
BMPs)
Refer to Appendix 8.3-1 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.
ll!I Included
Ix Included on DMA Exhibit in
Attachment 1 a
□ Included as Attachment 1 b,
separate from DMA Exhibit
IX Included
□ Not included because the entire
project will use infiltration BMPs
ll!I Included
□ Not included because the entire
project will use harvest and use
BMPs
Attachment 1 e Pollutant Control BMP Design IX Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
Use this checklist to ensure the required information has been included on the DMA
Exhibit:
The OMA Exhibit must identify:
IXI Underlying hydrologic soil group
ii Approximate depth to groundwater
ii Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
□ Critical coarse sediment yield areas to be protected (if present)
l!!I Existing topography and impervious areas
ii Existing and proposed site drainage network and connections to drainage offsite
l!!I Proposed grading
Ix Proposed impervious features
~ Proposed design features and surface treatments used to minimize imperviousness
15G Drainage management area (OMA) boundaries, OMA ID numbers, and OMA areas (square
footage or acreage), and OMA type (i.e., drains to BMP, self-retaining, or self-mitigating)
~ Structural BMPs (identify location and type of BMP)
ATTACHMENT 1
1 a: OMA Exhibit and BM P's Summary Table
1 b: BM P's Design Worksheets / Calculations / BMP Details
1c: Form 1-7, Harvest and Use Feasibility Screening Checklist
1 d: Form 1-8, Categorization of Infiltration Feasibility Condition
1 e: Hydrology Information
1f: Soil Report
1 a: OMA Exhibit and BM P's Summary Table
~
------
/
/
310.48
310.98
FS
24.00
/
N ,,-,:: ,,,,--
,,,,--SI s1 ,,_,--,,_,--;:,--
~ ,,,,--
" ~ ------------s '---. ,,_,--_;...--
~ ,,,,--~ ------------~ ,,,,--1/ ----..._,
~ ,,,,--
------------s ,,,,--J5,, ---;:;: ,,,,--'\ ,,,,--<-------0 '\
'\ -----; ,,,,--'\ -------s ,,,,--J5,, \ -----; ,,,,--,,,,--~ s C,I ~ \ ,,,,--/
-----;-\ \ ,,,,--<--><\s
,,-,:: -\ s1--s\ \ _;s;;:----~ \
I SI -> \~ -% . . . . ·\ ~ \ \ 3\:5.5' COBBLE S"(ONE RIP RAP
,-, -S1 I \ \ ~ si -\ \ RUN DOWNSPOUT Ab.ONG ~ ~ ;:,---~, DOWNSPOUT' FACE OF BUILDING TO PLANTER
4' LONGITUDINAL LOCATION \
GUTTER TO CONVEY DMA-3
WATER TO PLANTER
SEE SHEET 3 AND 4 0.02
FOR DETAIL
""
\ \
BIOFIL TRA TION BMP
PLANTER BOX
L=83.70', W=5.5', H=4.25'
AREA= 450 SF
-TOP OF PLANTER WAC.L 306:87'
BOTTOM OF PLANTER 302.62' (301.19)
.,,--r~q-777"77-;">f-_ FS \
~~
EXISTING STRUCTURE
\
0 0 s,
\
\_
\
I
RUN DOWNSPOUT ALONG
FACE OF BUILDING\ TO PLANTER
I
6" DRAIN THROUGH CURB
INV: 300.73
DOWNSPOUT
LOCATION
\
PERMANENT WATER OUALITY
TREATMENT FACILITY
KEEP/NC OUR /11,,1 TER WA Y.S CLEAN
/,fA!NTAIN MTfl CARE -NO MOOIFICAT!O!IS WITHOUT ACENCY APPROVAL
OETAIL
WATER OVAL/TY S/CN-PLACEO AT
EACH 8/0RL 11?A 170N BASIN
NO TE· ALL BIORL TRA TION AREAS f/!!LL
HA VE A SIGN POSTED TO BE
VISIBLE AT ALL 11MES.
BMP Sizing Spreadsheet V3.0
OVERFLOW DRAIN JENSEN PRECAST MODEL 1212HDI
SQUARE GRATE INLET AT 12" ABOVE MULCH
DOWNSPOUT
COBBLE OR
SPLASH BLOC
PER PLAN
' ·' Project Name:
Project Applicant:
Palomar Transfer Station 6907 Hydrologic Unit: 0
Palomar Transfer Station Inc Rain Gauge: Oceanside
• Jurisdiction: City of Carlsbad Total Project Area: 6,700
6"TYP. 7 I
REINFORCED CMU BLOCK OR
Parcel (APN): 760-166-84-00 Low Flow Threshold: 0.1Q2
BMP Name Planter Box BMPType: Biofiltration
PRE-CAST CONCRETE WITH
\
3" MIN.
Freeboard WATERPROOF MEMBRANE THROUGHOUT
OMA ' Raln Gauge -.. Pfe-developed Condition -· tlnit Runoff Ratio OMA Area (ac) Orifice Flow -%Q2
6" OVERFLOW DRAIN TO DISCHARGE
THROUGH PROPOSED CURB FACE.
tn N .,;
12" PONDING
3"
mulch layer
15'
6" MIN.
12' Ml
2%TYP.
<l,· ••• • ,i : . . .,. -~
......
.
0
.... .... ' ..
INSTALL SCH 40 END CAP WITH
0
UNIFORM MIX OF SAND AND ORGANIC
MATERIAL (EX: COMPOST); MIN INFILTRATION
RATE OF 5 INCHES PER HOUR.
(DO NOT COMPACT)
NON-WOVEN GEOTEXTILE
MEMBRANE (OPTIONAL)
Project Name:
Project Applicant:
Jurisdiction:
Parcel (APN}:
BMP Name:
BMP Native Soil Type;
DMA
Name
DMAl
DMA2
DMA3
BMP Tributary Area
Name Soil Type Slope (cfs/ac) (els)
DMAl Oceanside D Moderate 0.575 0.065 0.004
DMA2 Oceanside D Moderate 0.575 0.054 0.003
DMA3 Oceanside D Moderate 0.575 0.014 0.001
' . ' •-OMA 4 IS 305 SF O 01 ACRES LANDSCAPED THEREFORE, IT IS SELF MITIGATING
BMP Sizing Spreadsheet V3.0
Palomar Transfer Station 6907 Hydrologic Unit: 0
Palomar Transfer Station Inc Rain Gauge: Oceanside
City of Carlsbad Total Project Area: 6,700
760·166-84-,-00 Low Flow Threshold: 0.102
Planter Box BMP Type: . Biofrltration
D .. BMP Infiltration Rate (in/hr): 0.02S
Areas Draining to BMP HMP Sizing Factors Minimum BMP Size
,..,rea .. e1gnte~ .. unorr
Pre Project Soil Post Project Factor Surface Area Surface Area (SF)
Area (sf} Type Pre-Project Slope Surface Type (Table G.2-1)1
2,830 D Moderate Roofs ' 1.D 0.07 198
2,350 0 Moderate Roofs 1.0 0.07 165
600 D Moderate Concrete 1.0 0.07 42
.· 0 0
5,780 Minimum BMP Size 405
0.37" ORIFICE DRILLED AT FLOWLINE
SEE ORIFICE DETAIL HEREON
LONGITUDINAL 6" DIA PERFORATED PVC PIPE
WRAPPED IN NON-WOVEN GEOTEXTILE MEMBRANE.
PLACED OVER 3" GRAVEL LAYER. Proposed BMP Size~ ' 450 * Assumes standard configuratio I
PAVEMENT
BIOFIL TRA TION
PLANTER BOX SECTION
NOTTO SCALE
Surface Ponding Depth
Bioretention Soil Media Depth
Filter Coarse
Gravel Storage Layer Depth
Underdrain Offset
12.00 lin
18.00 io
6.00 lin
12 io
3.0 io
'.;I l v
'
\
\
Orifice Area
(in')
0.05
0.04
0.01
DATE
10
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME: PALOMAR TRANSFER STATION 6907
ADDRESS: 5960 EL CAMINO REAL
CARLSBAD, CA 92008 ODRIGO HUERTERO OUTLET STRUCTURE WALL ~1-+--7 e )._/J,-;:./4.J-PHONE NO. (760) 603-0153
. / -GRAVEL STORAGE AREA
SCH 40 PVC MALE ADAPTER
PLAN PREPARED BY:
NAME: ---'-R""ICcc.Ac.RccDccO-=Gc.A~R~Cl~A~ __
COMPANY: DAVID EVANS AND ASSOCIATES INC.
ADDRESS 25152 SPRINGFIELD COURT,# 350
SANTA CLARITA, CA 91355-1096
PHONE NO. (661) 284-7400
SIGNATURE
BMP NOTES: CERTIFICATION ____ _
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
APPROVALFROMTHEGITYENGINEER
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 SWMP FOR ADDITIONAL INFORMATION.
BMP
BMP ID# BMPTYPE SYMBOL CASQA NO. QUANTITY
TREATMENT CONTROL
0 BIOFILTRATION 1·· ·· · ·1 TC-32 1 AREA ~::..:-·>i'.-</r:,:
* CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS
IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS:
ANNUAL
SEMI-ANNUALLY
QUARTERLY
BIMONTHLY
MONTHLY
EA
TABLE
DRAWING NO.
442-3B
0 0
3" MIN
SCH 40 PVC THREADED
END CAP
DRILL 0.37" ORIFICE HOLE
AT FLOWLINE OF END CAP
GRAVEL STORAGE AREA
SHEET NO.(S)
3,4,6
ORIFICE DETAIL
NOTTO SCALE
01-28-2020
INSPECTION * MAINTENANCE *
FREQUENCY FREQUENCY
SEMI-ANNUALLY ANNUALLY
NOTES:
PERMANENT WATER QUALITY TREA lMENT
FACILITY SIGN SHALL BE POSTED AT
PLANTER BOX WHERE IT IS VISIBLE
AS NEEDED
NONE
WEEKLY HYDROLOGY INFORMATION
1 TIME PER YEAR
2 TIMES PER YEAR
3 TIMES PER YEAR
4 TIMES PER YEAR
0 ' 10 20
SITE AREA, 6,700 SF
SOIL GROUP, D (PER SOR. REPORT)
IMPERVIOUS, 100% (ROOF AREA)
0% (LANDSCAPED AREA)
ISOHYETALS, 0.61" (85th PERCENTILE 24-HOURS)
GROUNDWATER DEPTH, 1 O' BGL (PER SOIL REPORT)
METHOD, CITY OF CARLSBAD BMP DESIGN MANUAL
LEGEND: ----DRAINAGE TRIBUTARY AREA BOUNDARY
scale 1"= 10' feet vvvv vvvv vvvv
3.75 0.008 0.11
Max Tot. Allowable Max Tot. Allowable Max Orifice Head Orifice Flow Orifice Area
(feet) (cfs) (in2)
0.007 0.008 0.11
Average outflow during Max Orifice Outflow A_~tual Orifice Area surface drawdown
(els) (els} (in')
I Drawdown (Hrs)
INITIAL DATE
0.37
Max Orifice
Diameter
(in)
0.370 .
Selected
Orifice Diameter
(in)
I 17.8 I
INITIAL DATE INITIAL
DMA-
xx.xx
I SHlET I CITY
PROPOSED ROOF AREA
EXISTING BUILDING
LANDSCAPED AREA
BIOFIL TRA llON-PLANTER BOX AREA
GRIND AND OVERLAY
COBBLE STONE RIP RAP
SLOPE OF THE ROOF
DRAINAGE MANAGEMENT AREA ID NO.
AREA ACREAGE (AC)
OF CARLSBAD
ENGINEERING DEPARTMENT
I SHlETS I
SINGLE SHEET BMP SITE PLAN
PALOMAR SINGLE SHEET BMP SITE PLAN
RECORD COPY PROJECT NO.
CUP260(D)
DRAWING NO.
ENGINEER OF WORK REVISION DESCRIPTION OTHER APPROVAL CITY APPROVAL INITIAL DATE I 442-3B I
1 b: BM P's Design Worksheets/ Calculations/ BMP Details
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing
Factors
and orifice detail on the plans.
Additional steps to use this BMP as a combined pollutant control and Bow control BMP:
The BMP sized using the sizing factors in Table G.2-5 meets both pollutant control and flow
control requirements except for surface drawdown requirements. Applicant must perform surface
drawdown calculations and if needed develop a vector management plan (Refer to Section 6.3.7) or
revise the BMP design to meet the drawdown requirements. If changes are made to the BMP design
applicants must perform site specific continuous simulation modeling (Refer to Appendix G).
Table G.2-5: Sizing Factors for Hydromodification Flow Control Biofiltration BMPs Designed Using
Sizing Factor Method
Lower Flow Soil Group Pre-Project Slope Rain Gauge A
Threshold
0.lQ2 A Flat Lindbergh 0.320
0.lQz A Moderate Lindbergh 0.300
0.lQ2 A Steep Lindbergh 0.285
0.tQz B Flat Lindbergh 0.105
0.lQ2 B Moderate Lindbergh 0.100
0.1Qz B Stc:cp Lindbergh 0.095
0.1Q2 C Flat Lindbergh 0.055
0.tQz C Moderate Lindbergh 0.050
0.1Q2 C Steep Lindbergh 0.050
0.lQz D Plat Lindbergh 0.050
0.lQ2 D Moderate Lindbergh 0.050
0.lQz D Stc:cp Lindbergh 0.050
O.lQ2 A Flat Oceanside 0.150
0.lQ2 A Moderate Oceanside 0.140
O.IQ2 A Steep Oceanside 0.135
0.JQ2 B Plat Oceanside 0.085
0.lQ2 B Moderate Oceanside 0.085
0.lQz B Steep Oceanside 0.085
G-45 May 2018
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing
Factors
Lower Flow Soil Group Pre-Project Slope Rain Gauge A Threshold
0.IQ2 C Flat Oceanside oms
0.1Q2 C Modmate OcC211sidc 0.075
0.lQ2 C Steep Oceanside oms -
0.lQz D Flat Oceanside e)
0.1Q2 D Moderate Oceanside
O.lQz D Steep OcC2llside
0.IQ2 A Flat L Wohlford
O.lQz A Modcnatc LWohlfotd
0.1Q2 A Steep L Wohlford
0.1Q2 B Flat LWohlford
0.IQ2 B Moderate LWohlford
0.1Q2 B Steep LWohlford
0.1Q2 C Flat L Wohlford
O.t(b C Moderate LWohlford
0.lQ2 C Steep L Wohlford
O.t(b D Flat LWohlford
0.1Q2 D Moderate L Wohlford
0.1Q2 D Steep LWohlford
Q2 = 2-year pre-project flow rate based upon partial duration analysis of long-term hourly rainfall records
flow control
A = Surface area (at surface of the BMP before any ponding occurs)) sizing factor for flow control
G-46
0.070
0.070
0.285
0.275
0.270
0.150
0.145
0.145
0.070
0.070
0.070
0.060
0.060
0.060
May 2018
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing
Factors
G.2.1 Unit Runoff Ratios and Low Flow Control Orifice Design
G.2.1.1 Unit Runoff Ratios
Table G.2-2 presents unit runoff ratios for calculating pre-development Q2, to be used when
applicable to determine the lower flow threshold for low flow control orifice sizing for biofiltration
with partial retention, biofiltration, or cistern BMPs. There is no low flow control orifice in the
infiltration BMP. The unit runoff ratios are updated from the previously reported BMP Sizing
Calculator methodology ratios to account for changes in modeling methodologies. Unit runoff ratios
for "urban" and "impervious" cover categories were not transferred to this manual due to the
requirement to control runoff to pre-development condition (see Chapter 6.3.3).
How to use the unit ru.nolEratios:
Obtain unit runoff ratio from Table G.2-2 based on the project's rainfall basin, hydrologic soil
group, and pre-development slope (for redevelopment projects, pre-development slope may be
considered if historic topographic information is available, otherwise use pre-project slope). Multiply
the area tributary to the structural BMP (A, acres) by the unit runoff ratio (Q2, cfs/acre) to
determine the pre-development Q2 to determine the lower flow threshold, to use for low flow
control orifice sizing.
Table G.2-2: Unit Runoff Ratios for Sizing Factor Method
Rain Gauge Soil Pre-Project Q 2 (cfs/ acre) Q 111 (cfs/acre) Slope
Lake Wohlford A Plat 0.256 0.518
Lake Wohlford A Moderate 0.275 0.528
Lake Wohlford A Steep 0.283 0.531
Lake Wohlford B Flat 0.371 0.624
Lake Wohlford B Moderate 0.389 0.631
Lake Wohlford B Steep 0.393 0.633
Lake Wohlford C Flat 0.490 0.729
Lake Wohlford C Moderate 0.495 0.733
Lalce Wohlford C Steep 0.496 0.735
Lake Wohlford D Flat 0.548 0.784
Lake Wohlford D Moderate 0.554 0.788
G-35 May 2018
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing
Factors
Rain Gauge Soil Pre-Project Q2 (cfs/ acre) Qiu (cfs/acre) Slope
Lake Wohlford D Steep 0.556 0.788
Oceanside A Flat 0.256 0.679
Oceanside A Moderate 0.277 0.694
Oceanside A Steep 0.285 0.700
Oceanside B Flat 0.377 0.875
Oceanside B Modctatc 0.391 0.879
Oceanside B Steep 0.395 0.881
Oceanside C Flat 0.488 0.981
Oceanside C Moderate 0.497 0.985
Oceanside C Steep 0.499 0.986
Oceanside D Flat 0.571 0.998
Oceanside D Moderate 0.575 0.999
Oceanside D Steep 0.576 0.999
Lindbergh A Flat 0.057 0.384
Lindbergh A Moderate 0.073 0.399
Lindbergh A Steep 0.082 0.403
Lindbergh B Flat 0.199 0.496
Lindbergh B Modctatc 0.220 0.509
Lindbergh B Steep 0.230 0.513
Lindbergh C Flat 0.335 0.601
Lindbergh C Moderate 0.349 0.610
Lindbergh C Steep 0.354 0.613
Lindbergh D Flat 0.429 0.751
Lindbergh D Moderate 0.437 0.753
Lindbergh D Steep 0.439 0.753
G-36 May2018
OVERFLOW DRAIN: JENSEN PRECAST MODEL 1212HDI
SQUARE GRATE INLET AT 12" ABOVE MULCH
6" OVERFLOW DRAIN TO DISCHARGE
THROUGH PROPOSED CURB FACE.
6"TYP. ----J I
Freeboard
12" PONOING
12" Ml
2% TYP.
DOWNSPOUT
REINFORCED CMU BLOCK OR PRE-CAST CONCRETE WITH
WATERPROOF MEMBRANE THROUGHOUT
UNIFORM MIX OF SAND AND ORGANIC MATERIAL (EX: COMPOST); MIN INFILTRATION
RA TE OF 5 INCHES PER HOUR
(DO NOT COMPACT)
NON-WOVEN GEOTEXTILE MEMBRANE (OPTIONAL)
LONGITUDINAL 6" DIA. PERFORATED PVC PIPE WRAPPED IN NON-WOVEN GEOTEXTILE MEMBRANE.
PLACED OVER 3" GRAVEL LAYER
PAVEMENT
BIOFIL TRA TION
PLANTER BOX SECTION
NOT TO SCALE
OUTLET STRUCTURE WALL
SCH 40 PVC MALE ADAPTER
GRAVEL STORAGE AREA
3'MIN
GRAVEL STORAGE AREA
ORIFICE DETAIL
NOTTO SCALE
STORMWATER PLANTER DETAILS
SCH 40 PVC THREADED
END CAP
DRILL 0.37' ORIFICE HOLE
AT FLOWLINE OF END CAP
BMP Sizing Spreadsheet V3.0 Project Name: Palomar Transfer Station 6907 Hydrologic Unit: 0 Project Applicant: Palomar Transfer Station Inc Rain GauRe: Oceanside Jurisdiction: Citv of Carlsbad Total Project Area: 6,700 Parcel (APN): 760-166-84-00 Low Flow Threshold: 0.1Q2 BMP Name: Planter Box BMP Tvoe: Biofiltration BMP Native Soil Type: D BMP Infiltration Rate (in/hr): 0.02S Areas Draining to BMP HMP Sizing Factors Minimum BMP Size Area vve1gmea l'\Unon OMA Pre Project Soil Post Project Factor Surface Area Surface Area (SF) Name Area (sf) Type Pre·Project Slope Surface Type (Table G.2-1)1 OMA 1 2,830 0 Moderate Roofs 1.0 0.07 198 OMA2 2,3S0 0 Moderate Roofs 1.0 0.07 16S OMA3 600 0 Moderate Concrete 1.0 0.07 42 0 0 BMP Tributary Area S,780 Minimum BMP Size 40S Proposed BMP Size• 4S0 • Assumes standard configuration Surface Ponding Depth 12.00 in Bioretention Soil Media Depth 18.00 in Filter Coarse 6.00 in Gravel Storage Layer Depth 12 in Underdrain Offset 3.0 in Notes: 1. Runoff factors which are used for hydromodification management flow control (Table G.2-1) are different from the runoff factors used for pollutant control BMP sizing (Table B.1-1). Table references are taken from the San Diego Region Model BMP Design Mam Describe the BM P's in sufficient detail in your PDP SWQMP 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 BMP Sizing Spreadsheet has been updated in conformance with the San Diego Region Model BMP Design Manual, April 2018. For questions or concerns please contact the jurisdiction in which your project is located.
HYDROMODIFICATION -ORIFICE SIZING CALCULATION BMP Sizing Spreadsheet V3.0 Project Name: Palomar Transfer Station 6907 Hydrologic Unit: 0 Project Applicant: Palomar Transfer Station Inc Rain Gauge: Oceanside Jurisdiction: City of Carlsbad Total Project Area: 6,700 Parcel (APN): 760-166-84-00 Low Flow Threshold: 0.1Q2 BMP Name Planter Box BMP Type: Biofiltration DMA Rain Gauge Pre-developed Condition Unit Runoff Ratio DMA Area (ac) Orifice Flow -%Q2 Orifice Area Name Soil Type Slope (cfs/ac) (cfs) (in2) DMAl Oceanside D Moderate 0.575 0.065 0.004 0.05 DMA2 Oceanside D Moderate 0.575 0.054 0.003 0.04 DMA3 Oceanside D Moderate 0.575 0.014 0.001 0.01 3.75 0.008 0.11 0.37 Max Orifice Head Max Tot. Allowable Max Tot. Allowable Max Orifice Orifice Flow 0 rifice Area Diameter (feet) (cfs) (in2) (in) 0.007 0.008 0.11 0.370 Average outflow during Max Orifice Outflow Actual Orifice Area Selected surface drawdown Orifice Diameter (cfs) (cfs) (in2) (in) Drawdown (Hrs) 17.8
1 c: Form 1-7, Harvest and Use Feasibility Screening Checklist
Appendix I: Forms and Checklists
Harvest and Use Feasibility Checklist Form 1-7
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
D Toilet and urinal flushing
Ix] Landscape irrigation
□ 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.
[Provide a summary of calculations here]
Landscape irrigation demand per 36 hours at wet season is 390 gal/ac = 52 cu-ft/ac,
landscaped area is 0.02 ac., the 36 hours at wet season irrigation water demand will be 52x0.02 = 1 cu-ft
3. Calculate the DCV using worksheet B-2.1.
DCV = __ 2_33 __ ( cubic feet) 0.25 DCV= 0.25x233 = 58.3 cu-ft.
3a. Is the 36 hour demand greater
than or equal to the DCV?
□ Yes / Ii No c::::>
-0-
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations
to confirm that DCV can be used
at an adequate rate to meet
drawdown criteria.
3b. Is the 36 hour demand greater than
0.25DCV but less than the full D CV?
□ Yes / [20 No c::::>
~
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.
Is harvest and use feasible based on further evaluation?
D Yes, refer to Appendix E to select and size harvest and use BMPs.
ll!I No, select alternate BMPs.
3c. Is the 36 hour demand
less than 0.25DCV?
Ii Yes
i
Harvest and use is
considered to be infeasible.
Note: 36-hour demand calculations are for feasibility analysis only. Once feasibility analysis is complete the
applicant may be allowed to use a different drawdown time provided they meet the 80% annual capture
standard (refer to B.4.2) and 96-hour vector control drawdown requirement.
1-26 May 2018
1 e: Hydrology Information
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods .\ \ \ \\ \ PROJECT~!!~ -.. -. I -~~ ( (( \\~ ~ 't-,"'-<.,.,.~ ~~ /~~~\\\ \ \ \\ ... "v. San Diego County 85th Pe~enllle lsoplu,L,ls ~ ~ :(( \\ \\\\\\\J~ ,~,,\ l '-. '--l"""'"" -!151rl~VTil,l.eoaw'Nil.. _]-,.,.., ... n,.,...,_,...••24t-•_..lbU :.:=~,:.::=:~!: . ......... ., ... N +·-~ ~' ' """""""'"' ~ 1\\ 4\ ~ ~~~<-: -----==-~-====~ ~.• __. W= -Pigwe B.1-1: 85th Percentile 24-hour lsopluvial Map B-6 May 2018
·"~ Project Location ~ 0 25 5 Miles 10 Figure C.1 Soils San Diego County, Calfornia ~---HydricSois Hydrologic Soils Group -A -B -C D -~· ~~ ~ ~, •, ~ { 'l;, ,,-~· >.;.. • 'i-t ·-:..::_~ ~ ~ County "~. l'i\atf·~~:~--~ -• of San Diego ... ~\ ..,.._ ---...... -~~ .._ ., > • J>
1 f: Soil Report
I
I
I
PERCOLATION TESTING REPORT
PALOMAR TRANSFER STATION
5960 EL CAMINO REAL
CARLSBAD, CALIFORNIA
NOVEMBER 2019
PREPARED FOR:
Republic Services, Inc.
8514 Mast Blvd
Santee, California 92071
PREPARED BY:
Geo-Logic Associates
11415 West Bernardo Court, Suite 200
San Diego, California 92127
{858) 451-1136
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
1. INTRODUCTION
1.1 GENERAL
This report presents the results of geotechnical investigation, field percolation testing, and
geotechnical evaluation of subsurface material to evaluate the feasibility of onsite soil
percolation of stormwater at 5960 El Camino Real in Carlsbad, CA, (see Site Plan, Figure 1).
This report presents GLA's planning-level geotechnical recommendations for site infiltration .
These recommendations are based on subsurface information collected during GLA
investigation. The conclusions and recommendations in this report should not be extrapolated
to other areas or used for other projects without our review .
1.2 PROJECT UNDERSTANDING
GLA understands that the project involves the feasibility of onsite stormwater. Based on
conversations with representatives of Republic, shallow percolation beds/trenches or deeper
gallery-type vaults may be considered for the northern (re-fueling) parking lot and/or the
southern "employee" parking lot. The general site conditions are presented in Figure 1.
1.3 INFORMATION PROVIDED
The approximate limits of each parking lot were provided to us by representatives of Republic
Services and are approximately shown on Figure 1.
1.4 PURPOSE AND SCOPE OF SERVICES
The purpose of this investigation was to evaluate subsurface conditions at the site to develop
planning-level geotechnical recommendations for the design of the proposed infiltration
facilities .
The following work was performed .
• Review of information provided by Republic and a site reconnaissance to observe
surface site conditions at the locations for each site delineated by Republic.
• Utility location clearance by Underground Service Alert (USA) and our third-party
geophysical underground utility locating subcontractor (South West Geophysics) .
• Coordination of our subsurface exploration with onsite representatives of the Transfer
Station .
• Subsurface exploration by means of two exploratory borings and six in-situ percolation
tests, as discussed in Section 2.2 of this report. Obtain representative soil samples from
the borings.
• Engineering evaluations and preparation of this percolation report .
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
2. SITE INVESTIGATION
2.1 GENERAL
Field investigation consisted of a site reconnaissance (including utility location clearance) and a
subsurface exploration. The subsurface exploration is discussed below. The interpretation of
encountered subsurface conditions is presented in Section 3.1.
2.2 SUBSURFACE EXPLORATION
Our subsurface exploration program included advancement of two borings across the site (B-2
and B-6) for soil sampling and six percolation borings (P-1 through P-6) for the performance of
percolation testing. The approximate locations of borings and percolation test holes are shown
in Figure 2 .
The borings were advanced using a truck-mounted drill rig and a 7-inch diameter hollow-stem
auger. The borings were advanced from 6 to 20 feet below the existing ground surface .
Representative soil samples were recovered by driving a Standard Penetration Test (SPT} soil
sampler up to 18 inches into the soil by means of a 140-pound automatic hammer falling 30
inches. The number of blows required to drive the samplers was recorded for each 6-inch
penetration interval. The number of blows required to drive the sampler for the last 12 inches
of penetration is presented as blows per foot (i.e., blow count) on the borehole log.
Visual classification of soil encountered in B-2 and B-6 was performed by our field personnel in
accordance with the Unified Soil Classification System (ASTM D 2487 and D 2488). A Key to Soil
Classification is included in Appendix A along with the boring logs.
The borings were backfilled prior to our representative leaving the site .
The percolation test holes were left open overnight and covered with orange construction
cones for the required testing pre-soaking .
2.3 GEOTECHNICAL LABORATORY TESTING
Geotechnical samples were obtained from the two soil borings on the site. Since the soil
conditions are mostly fine-grained clay, geotechnical laboratory tests were not deemed to be
necessary at this time, but will be retained for 60 days for future testing, if necessary .
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
3. FINDINGS
3.1 SUBSURFACE CONDITIONS
Northern Re-Fueling Parking Lot: Boring B-2 was advanced in the southern portion of the
northern parking lot and encountered a surficial layer of 2 to 4 inch diameter gravel underlain
by 5 feet of Fill soils consisting of stiff, silty clay with trace of sand and some medium angular to
sub-angular to 3 inches in diameter extending to a depth of 5 feet below the existing ground
surface. At a depth of 5 feet, the Pt. Loma Formation (Kennedy and Tan, 2005) was
encountered to the total depth explored of 20 feet. The Pt. Loma Formation was described as
slightly weathered, slightly cemented, grey-brown, sandy to clayey siltstone to silty claystone
with iron-staining and caliche stringers.
Southern Employee Parking Lot: Boring B-6 was advanced in the southern portion of the
southern employee parking lot and encountered a surficial layer of 2 to 4 inch diameter gravel
underlain by 3 feet of Fill soils consisting of stiff, silty clay to clayey silt with a trace of fine sand
and coarse angular gravel to 2 to 10+ inches in diameter. At a depth of 3 feet, the Lusardi
Formation (Kennedy and Tan, 2005) was encountered to the total depth explored of 6 feet. At
depth of 6 feet, practical refusal on large boulders was encountered. Three separate attempts
were needed to advance the borehole to a depth of 6 feet. The Lusardi Formation was
described as slightly weathered, slightly cemented, brown, sandy to silty claystone with angular
gravel and cobbles ranging in size from 4 to 12+ inches .
Soil Survey: Review of the USDA Web Soil Survey indicates the site is underlain by the Las
Flores loamy fine sand generally consisting of a surficial layer (upper 12-14 inches) of loamy fine
sand overlying sandy clay to clay. The Hydrological Soil Group is "D" with a capacity to transmit
water ranging from very low to moderately low (0.00 to 0.06 inches per hour). Group D soils
typically have very slow percolation rates when thoroughly wet. They are clays that have a high
shrink-swell potential, soils that have a high permanent water table, soils that have a clay layer
at or near the surface, or soils that are shallow over nearly impervious material. The rate of
water transmission for group D soils is very slow (San Diego County, 2016).
3.2 GROUNDWATER
Groundwater was not encountered at a depth of 20 feet below the existing ground surface in
Boring B-2 and at a depth of 6 feet in Boring B-6. Based on boring logs near the site
(Geotracker, 2018), groundwater below the site is on the order of 50 + feet below the ground
surface across the site .
3.3 VARIATIONS IN SUBSURFACE CONDITIONS
Our interpretations of subsurface and groundwater conditions, as described in this report, are
based on data obtained from this investigation. Our conclusions and geotechnical
recommendations are based on interpretation of this data. Careful observations should be
made during construction to verify our interpretation. Should variations from our
interpretations be found, GLA should be notified to evaluate whether any revisions should be
made to the recommendations herein.
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
4. PERCOLATION TESTING
4.1 SOIL PERCOLATION TESTING
Six borings were advanced to facilitate percolation testing in the approximate locations and
depths directed by representatives of site, our experience with similar sites, and
vehicle/underground utility constraints to estimate the infiltration rate across the two parking
lots at various depths. The borings were advanced on November 9, 2018 and the percolation
testing was performed on November 10, 2018 after the required pre-soaking due to clayey
soils. The approximate locations of the percolation tests (P-1 through P-6) are presented on
Figure 2. The conditions encountered at each of the testing locations follow:
Table 1 -Percolation Test Summary
Test Soil Conditions Encountered as Measured Below Existing Depth to Bottom of
Percolation Test From Number Ground Surface, ft Existing Ground Surface, ft
P-1 Stiff, dry to moist, silty clay with some fine sand and small 4.0' gravel to 3 inches in diameter, moderately plastic (CL)
P-2 Stiff, dry to moist, silty clay with trace fine sand and small 3.0' gravel to 2 inches in diameter, moderately plastic (CL)
P-3 Stiff, dry to moist, silty clay with trace fine sand and small 5.0' gravel to 2 inches in diameter, moderately plastic (CL)
P-4 Stiff, dry to moist, silty clay with trace fine sand and small 3.0' gravel to 3 inches in diameter, moderately plastic (CL)
P-5 Medium stiff to stiff, dry, clayey silt with trace of sand and 3.0' gravel to 4+ inches in diameter (ML)
P-6 Medium stiff to stiff, dry, clayey silt with some fine to 4.0' coarse sand and gravel to 8+ inches in diameter (ML)
Note: Depth measured below existing ground surface .
Percolation testing was performed in all six percolation borings in accordance with the
recommendations set forth by the County of San Diego "Model BMP Design Manual, San Diego
Region", dated February 2016, Appendix C and D using the borehole percolation test method
(as described in Appendix D, Section D.3.3.2) .
A reduction factor was applied to the field percolation rate to calculate the raw (vertical)
infiltration rate which is corrected for non-vertical flow in accordance with the procedures
described in the "County of Los Angeles Department of Public Works, Geotechnical and
Materials Engineering Division, Guidelines for Geotechnical Investigation and Reporting, Low
Impact Development Stormwater Infiltration, Administrative Manual GS200.2", dated 6/30/17,
Page 9 of 17.
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The raw (vertical) infiltration rates are reported for each test location in the table below. The
raw infiltration rate is converted into the Design Infiltration Rate using an applied safety factor
of 4 (to account for "site suitability" and system "design" in accordance with Appendix D,
Worksheet D.5-1 of the "San Diego County Model BMP Design Manual") in the table below .
Table 2 -Design Infiltration Rates from Percolation Testing
Percolation Test Raw Vertical Infiltration Rate, Design Infiltration Rate (with Safety
Number (Figure 2) (inches/hour) Factor=4), (inches/hour)
P-1 0.47 0.1
P-2 0.04 0.01
P-3 0.019 0.005
P-4 0.03 0.008
P-5 0.3 0.07
P-6 0.4 0.1
Note: Depth measured below existing ground surface, safety factor from Form 1-9.
The results of the percolation testing across the site indicate that the upper five feet (below
existing grades) is comprised of clayey silt to silty clay soils above the weathered bedrock for
both the north (re-fueling) parking lot and the south (employee) parking lot. The boring on the
north parking lot (B-2) encountered Pt. Loma/Santiago Formation comprised of sandy to silty
claystone with gravel at a depth of 5 feet below the existing ground surface. The boring on the
south parking lot (B-6) encountered Lusardi Formation comprised of sandy to silty claystone
and clayey siltstone at a depth of 3 feet below the existing ground surface. Practical drilling
refusal was encountered in Boring B-6 at a depth of 6 feet below the existing ground surface .
Since the County of San Diego Low Impact Development Handbook, 2014 (Appendix A, Table
A.1-1} recommends underdrains in areas where the design infiltration rate is less than 0.5
inches per hour, the test results indicate that all the six tested locations (P-1 through P-6) are
not suitable for direct onsite water infiltration .
Additional design guidelines for infiltration feasibility (San Diego, 2016) are presented below:
• The ability to infiltrate stormwater is limited in areas with a high groundwater table. A 10-
foot separation distance is required from the bottom of the infiltration facility to the
seasonal high groundwater level.
• Native soils that are Hydrologic Soil Group (HSG) A or B are suitable for infiltration
without amendments. Other concerns with regard to infiltration of stormwater to soils are
the potential for liquefaction during earthquakes, expansion of clay soils, or compression
of fill or alluvium. All of these conditions can cause damage to structures and
pavements.
• Stormwater infiltration is not recommended on hillsides (slopes of 20 percent or more)
because of the risk of downhill seepage that creates surficial slope instability (increased
potential of erosion, slumps, or slides).
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• Stormwater should not be infiltrated in areas adjacent to improvements that could be
damaged by the presence of groundwater. Infiltration facilities should be set back 10-25
feet from building foundations, basements, footings, and retaining walls to prevent the
zone of saturation from undermining structures .
• Infiltration is not appropriate within 100 feet of water supply wells .
• Infiltrating practices might also be restricted in stormwater hotspots such as industrial
and high-traffic .
Infiltration (San Diego, 2016) is typically not permitted if:
• Soil contamination is expected or is present.
• Runoff could unintentionally be received from a stormwater hotspot.
• The groundwater table is within 1 0 feet of the proposed subgrade .
• The site is within 100 feet of a water supply well or septic drain field .
• The site is within 1 0 feet of a structure or foundation.
• Infiltrated water could interfere with utilities.
• Underlying geology presents risks for sinkholes or liquefaction.
• The site is within 50 feet of a steep, sensitive slope .
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
5. CONCLUSIONS
Based on the very poor site infiltration rates and considering the shallow depth to dense,
relatively impermeable formational materials across both the north and south parking areas, it
appears that the use of this site for onsite stormwater infiltration into the (un-amended) onsite
clayey soils is relatively impractical. See County of San Diego Form 1-8 in Appendix C for more
information.
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6. LIMITATIONS
In preparing the findings and professional opinions presented in this report, Geo-Logic
Associates (GLA) has endeavored to follow generally accepted principles and practices of the
engineering geologic and geotechnical engineering professions in the area and at the time our
services were performed. No warranty, express or implied, is provided .
The conclusions and recommendations contained in this report are based, in part, on
information that has been provided to us. In the event that the general development concept
or general location are modified, our conclusions and recommendations shall not be considered
valid unless we are retained to review such changes and to make any necessary additions or
changes to our recommendations.
Subsurface exploration is necessarily confined to selected locations and conditions may, and
often do, vary between these locations. Should conditions different from those described in
this report be encountered during project development, GLA should be consulted to review the
conditions and determine whether our recommendations are still valid. Additional exploration,
testing, and analysis may be required for such evaluation.
Should persons concerned with this project observe geotechnical features or conditions at the
site or surrounding areas which are different from those described in this report, those
observations should be reported immediately to GLA for evaluation.
It is important that the information in this report be made known to the design professionals
involved with the project, that our recommendations be incorporated into project drawings
and documents, and that the recommendations be carried out during construction by the
contractor and subcontractors. It is not the responsibility of GLA to notify the design
professionals and the project contractors and subcontractors.
The findings, conclusions and recommendations presented in this report are applicable only to
the specific project development on this specific site. These data should not be used for other
projects, sites or purposes unless they are reviewed by GLA or a qualified geotechnical
professiona I .
Report prepared by,
Geo-Logic Associates
(Jose G.F~
ervising Geotechnical Engineer
REAR OF TEXT
Vicinity Map Figure 1
Figure 2
Appendix A
Appendix B
Boring/Percolation Testing Location Map
Boring Logs
County of San Diego Forms 1-8 and 1-9
Project SO18.1210
November 2019
8 Geo-Logic Associates
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Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
7. REFERENCES
Cal Vada Surveying, 2016, Topographic Survey, 5960 El Camino Real, Carlsbad, CA, 4 Sheets,
dated March 23, 2016.
County of Los Angeles, Department of Public Works, 2014, GS200.1, Administrative Manual,
Geotechnical and Materials Engineering Division Guidelines for Design, Investigation, and
Reporting Low Impact Development Stormwater Infiltration, dated June 2014.
County of Los Angeles, Department of Public Works, 2011, GS200.1, Administrative Manual,
Geotechnical and Materials Engineering Division, Low Impact Development Best
Management Practice Guideline For Design, Investigation, and Reporting, dated June 2011
Geotracker, 2018, State of California Water Resources Control Board website:
https://geotracker. waterboa rds.ca.gov /
Kennedy, M. P. and Siang S. Tan, 2005, Geologic Map of the Oceanside 30' X 60' Quadrangle,
California, Compiled by: Kelly R. Bovard, Rachel M. Alvarez and Michael J. Watson
Los Angeles County, 2009, Low Impact Development Standards Manual, dated January 2009.
Los Angeles County, Department of Public Works, Geotechnical and Materials Engineering
Division, Guidelines for Geotechnical Investigation and Reporting, Low Impact Development
Stormwater Infiltration, Administrative Manual GS200.2, dated 6/30/17.
Peabody, A.W., 2001, Control of Pipeline Corrosion, NACE International-The Corrosion Society,
edited by Ronald Bianchetti.
San Diego County, 2016, County of San Diego Model BMP Design Manual San Diego Region,
February 2016.
San Diego County, 2014, County of San Diego Low Impact Development Handbook, July 2014.
USDA, 2018, We Soil Survey, https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
Project SO18.1210
November 2019
9 Geo-Logic Associates
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EXPLANATION
S ■ SPILL KIT
.,_ DRAINAGE FLOW DIRECTION
Ill STORM DRAIN INLET
= TRENCH DRAIN
--------CURB
----STORM DRAIN PIPE
• • • • • • • • OVERFLOW TRENCH DRAIN
=---==--=o DRAINAGE AREA
NON-INDUSTRIAL DISCHARGE AREAS
~ IMPERVIOUS AREA
SW-1 ♦ SAMPLE LOCATION
---)(-FENCE
PROPERTY BOUNDARY
(((((((((((( DRAINAGE DITCH
-,-,-,-WIND FENCE
* DRAINAGE AREA DISCHARGE LOCATION
♦ CNG FUEL STATION
Brown-,. caldwell· PALOMAR TRANSFER STATION
5960 EL CAMINO REAL
CARLSBAD, CALIFORNIA
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Reference: Google Earth, 2018. B~ LEGEND 0 Approximate Location of Exploratory Boring
Draft: JGF Date: NOV. 2018 Project No.18.1201.00
P-6 ■ Approximate Location of Percolation Test
BORING/PERCOLATION TEST LOCATION MAP
PALOMAR TRANSFER STATION, CARLSBAD, CA FIGURE 2
Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
APPENDIX A
BORING LOGS
Geo-Logic Associates
UNIFIED SOIL CLASSIFICATION
LAIIORATORY CLASSll'ICATION CRITERIA
GW and SW: CU • O. ID1e greater than 4 for GW, greater than 6 for SW
Cc• 0.2,0. x D11 between 1 and 3
~ GP and SP: Clean gravel or sand not meeting requkements for GW and SW
~ 40---+--+--t---"4f-l--+--~+--+--i GM and SM: Attert>erg Lanlts below •A• LINE and Pl lea than 4
~ GC and SC: Atterberg Lanils above •A• LINE and Pl greater than 7
0 ~ 2Q---t--A---t-:9'11-+t-t-+-+--+---t
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Classlfication of ,arth materials is b~ on field lnsoection and should not be construed to lmpiy laboratory analysis unless so stafed
UOUIDLIMIT
MATERIAL SYMBOLS
Asphalt G±E· Calcaerous Sandstone
Concrete ~ Marl
Conglomerate ~ Lmestone
Sandstone § Dotostone
Silty Sandstone ~ Breccia
Clayey Sandstone rn Volcanic Ash/Tuff
SIitstone -Metamorphic Rock
Sandy SIitstone [ill Quartzite
CIIYeY Siltstone /Sill'f Claystone
Claystone/Shale
t~ ~ ~j ExtrusMI ~neous R
~ Intrusive ~neous R
Blows / Foot• Granular Blows / FOCX-Cohesive
0-5 Very loose 0-2 Very Soft
6-10 loose 2-4 Soft
11 -30 iumDe 4-8 Medium Stiff
31 -50 Dense 8-15 Stiff
50 Very Dense 15-30 Very Stiff
>30 Hard
• using 1-40-lb. hammer with 30" drop • 350 ft-b'blow
LEGEND OF BORING
Bulk Sample
_ U~rmh --.
Water Level Yl..
"NSR• lndlcatn NO SAMPLE RECOVERY
JOB NO.:
SITE LOCATION:
DRIWNG METHOD:
CONTRACTOR:
LOGGED BY:
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Boring
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Log
BORING NO.:
PAGE:
8-2
1 Of 1
S018.1210.00
PALOMAR TRANSFER STATION 7" Ill HOLLOW STEM AUGER
PACIFlC DRIWNG
JGF
~....,. .---.. w 0 w ~t N.---.. (/) t;: a:: iii~ z z . ::::i.---.. w w::, I-~ 0 !z w :i:::
Cl~ ...Ju ...J \!l ........ ...J ::::i a.. ~~ 0 mo a.. z ::Ii 2-::Ii ~ ~ ........ ~ Cl .....,
10 1.4
25 1.4 2
22 1.4 3
12 1.4 4
15 1.4 5
DATE STARTED:
DATE FlNISHED:
11/9/2018
11/9/2018
GW DEPTH: N/A
CAVING DEPTH: N/A
TOTAL DEPTH: 20 FEET ELEVATION:
LATITUDE:
313 FT MSL {CAL VADA, 2016)
33.135438" NOTES: 140 POUND
AUTO-HAMMER LONGITUDE: 117.26781S
~
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=-== = = ~ -= =-=
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15
-=-=
-----
--_--
=-= ~ = == --=-== = --=-== = =-= --=-==
VISUAL FIELD DESCRIPTION
CL FILL: 2 TO 4 INCHES OF CRUSHED GRAVEL, OVER
BROWN, DRY TO SLIGHTLY MOIST, STIFF, SILTY CLAY WITH
TRACE OF FlNE SAND, ROOTLETS, SOME MEDIUM ANGULAR TO
SUB-ANGULAR GRAVEL TO 3 INCHES IN DIAMETER.
PT. LOMA FORMATION: GRAY-BROWN, MOIST, SANDY TO
CLAYEY SILTSTONE TO SILTY CLAYSTONE, IRON-STAINED,
CAUCHE STRINGERS, MODERATELY WEATHERED, SLIGHTLY
CEMENTED.
12 INCH VOID ENCOUNTERED IN FORMATION AT 15.5 FEET.
--= 20h':.......,1--=+-...,6y-=-=-==i---t--------'\\.,,,----------------1
--
----7 ---
2' --
30
35
4'
50
---~a ---------9 ---------10 ---------11 ---------12 _----
-----
---------15 ---------16 --
NOTES:
1. TOTAL DEPTH = 20 FEET.
2. NO GROUNDWATER ENCOUNTERED AT TIME OF DRILLING.
3. NO CAVING DURING DRIWNG.
4. BORING BACKFILLED WITH BORING CUTTINGS ON 11/9/18.
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring
and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time.
JOB NO.:
SITE LOCATION:
DRIWNG METHOD:
CONTRACTOR:
LOGGED BY:
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Boring Log
BORING NO.: 8-6
PAGE: 1 OF 1
S018.1210.00
PALOMAR TRANSFER STATION
7" If HOLLOW STEM AUGER
PACIFIC DRIWNG
JGF
~--:-
,,...._ LoJ ci LoJ ~t N,,...... V) t;: ~ iii~ z
z . => ,,...._ LoJ LoJ::, I-~ g !z LoJ :i:::
0~ -' u -' !!l-..., Q. ~~ 0 m => Q. z ::E 0 ::E-::E 8-;,j '-' cJi 0-...,
10 1.4
100+ 1.4 2
DATE STARTED: 11/9/2018
DATE FINISHED: 11/9/2018
GW DEPTH: N/A
CAVING DEPTH: N/A
TOTAL DEPTH: 6 FEET ELEVATION: 304.5 FT MSL (CAL YN:JA, 2016)
LATITUDE: 33.134696" NOTES: 140 POUND
AUTO-HAMMER LONGITUDE: 117.267485°
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VISUAL FIELD DESCRIPTION
::,
-= -[L 6~~ iR6~/ ci~~Hi~ ~~G~~;HJi1s~~~~. o~~ CLAY TO
--CLAYEY SILT, WITH TRACE OF FINE SAND, SOME MEDIUM TO
--1 ----:::. COARSE ANGULAR GRAVEL TO 2 TO 1 Ot INCHES IN -= ~ '1-'D""IAM=ETE='-'R"--. ----------------i 5 --~ LUSARDI FORMATION: BROWN, MOIST, HARD SANDY TO SILTY
CLAYSTONE WITH ANGULAR GRAVEL TO 1 INCH IN SAMPLER,
SLIGHTLY WEATHERED, SLIGHTLY CEMENTED, COBBLES FROM 4
TO 12+ INCHES IN DIAMETER. PRACTICAL DRIWNG REFUSAL
ON LARGE ROCK AT 6 FEET.
--2 -------
3 ---
---15 ------5 ---
------'r-7 ---
25 --
----9 30 ---------10 ---35 -:=
----11 ----
--------
---45 -
---14 -------------15
-------->--16
_____,,\~-v
NOTES:
1. TOTAL DEPTH = 6 FEET, PRACTICAL DRIWNG REFUSAL.
AUGER GRINDING ON LARGE ROCKS IN FIRST TWO AffiMPTS
TO ADVANCE HOLE AT FIRST TWO LOCATIONS.
2. NO GROUNDWATER ENCOUNTERED AT TIME OF DRIWNG.
3. NO CAVING DURING DRIWNG.
4. BORING BACKFILLED WITH BORING CUTTINGS ON 11/9/18.
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring
and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time.
Percolation Testing Report, Palomar Transfer Station, Carlsbad, CA
APPENDIX B
CATEGORIZATION OF INFILTRATION FEASIBILITY CONDITION (FORM 1-8)
AND SAFETY FACTOR CALCULATION (FORM 1-9)
Geo-Logic Associates
Appendix I: Forms and Checklists
Categorization of Infiltration Feasibility Form 1-8
Condition
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
Six percolation tests were completed across the site. The calculated infiltration rates (with an
applied factor of safety of 4) ranged from 0.005 to 0.1 inches per hour.
The results of the testing indicate that full on-site percolation of storm water is not feasible.
Please note: although the infiltration rates referenced are of nearby areas, the results may apply to
the proposed BMP site locations based on the comprehensive geotechnical evaluation.
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
Infiltration galleries in the site soils would likely cause groundwater mounding and/or surface seepage
causing other geotechnical issues and site erosion. Based on the comprehensive geotechnical
evaluation, full site infiltration is not feasible due to the nature of the site soils and the relatively low
infiltration rates encountered in our testing.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
1-3 February 2016
Appendix I: Forms and Checklists
Criteri
a
3
Form 1-8 Page 2 of 4
Screening Question
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
Infiltration rates greater than 0.5 inches per hour cannot be accomplished on this site and therefore,
the question is hypothetical. However, since there is no shallow groundwater table at the site, the
risk of groundwater contamination is low.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed
without causing potential water balance issues such as change
of seasonality of ephemeral streams or increased discharge of
contaminated groundwater to surface waters? The response to
this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
X
Provide basis:
Infiltration rates greater than 0.5 inches per hour cannot be accomplished on this site and therefore,
the question is hypothetical. However, infiltration at the site is not anticipated to cause potential
water balance issues and not anticipated to change the seasonality of ephemeral streams since
there are no ephemeral streams in the site area.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
Part 1
Result
*
If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible.
The feasibility screening category is Full Infiltration
If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
No full infiltration
*To be completed usmg gathered site mformatlon and best professional Judgment cons1denng the definition of MEP m
the MS4 Permit. Additional testing and/ or studies may be required by the City to substantiate findings.
1-4 February 2016
Appendix I: Forms and Checklists
Form 1-8 Page 3 of 4
Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria
5
Screening Question
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
According to Appendix C the lower limit of partial infiltration is 0.05 inches/hour. The average of
the infiltration rates determined by testing on the site is less than 0.05 inches per hour, therefore
partial infiltration is not considered feasible.
Please note: although the infiltration rates referenced are of nearby areas, the results may apply
to the proposed BMP site locations based on the comprehensive geotechnical evaluation.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed
without increasing risk of geotechnical hazards (slope
stability, groundwater mounding, utilities, or other factors)
that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.2.
Provide basis:
X
Infiltration rates greater than 0.05 inches per hour cannot be accomplished on this site and such, the
question is hypothetical. As such, partial infiltration into the site soils will likely cause local
groundwater mounding and may daylight as seepage causing other geotechnical concerns and site
erosion. Based on the comprehensive geotechnical evaluation, partial infiltration is not feasible due to
the nature of the site soils and the relatively low infiltration rates encountered in our testing.
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.
1-5 February 2016
Criteria
7
Appendix I: Forms and Checklists
Form 1-8 Page 4 of 4
Screening Question
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.
Yes No
X
Provide basis:
Infiltration rates greater than 0.05 inches per hour cannot be accomplished on this site and therefore,
the question is hypothetical. However, since there is no shallow groundwater table at the site, the
risk of groundwater contamination from partial infiltration is low.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
8
Can infiltration be allowed without violating downstream
water rights? The response to this Screening Question shall be
based on a comprehensive evaluation of the factors presented in
Appendix C.3.
X
Provide basis:
Infiltration at the site is not recommended due to the low infiltration rates. If allowed, partial infiltration
is not anticipated to change the seasonality of ephemeral streams since there are no ephemeral
streams in the site area.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
Part 2
Result*
If all answers from row 5-8 are yes then partial infiltration design is potentially feasible.
The feasibility screening category is Partial Infiltration. No infiltration
is
If any answer from row 5-8 is no, then infiltration of any volume is considered to be recommended
infeasible within the drainage area. The feasibility screening category is!No Infiltration.I
*To be completed usmg gathered site 1nformat1on and best professional Judgment cons1dermg the defirunon of MEP m
the MS4 Permit. Additional testing and/or studies may be required by the City to substantiate findings.
1-6 February 2016
Appendix I: Forms and Checklists
Factor of Safety and Design Infiltration Rate
Worksheet Form 1-9
Factor Description Assigned Factor Product (p)
Factor Category Weight (w) Value (v) p =wxv
Soil assessment methods 0.25 2 0.5
Predominant soil texture 0.25 2 0.5
Suitability Site soil variability 0.25 2 0.5 A Assessment Depth to groundwater / impervious 0.25 2 0.5 layer
Suitability Assessment Safety Factor, SA = :Ep 2.0
Level of pretreatment/ expected
sediment loads 0.5 2 1
B Design Redundancy/ resiliency 0.25 2 0.5
Compaction during construction 0.25 2 0.5
Design Safety Factor, SB = :Ep 2.0
Combined Safety Factor, S,0121= S,1 x Sa 4.0
Observed Infiltration Rate, inch/hr, Kobscrvcd
(corrected for test-specific bias) see table in text
Design Infiltration Rate, in/hr, ~c,;g,, = Kobscrvcd / S,01al see table in text
Supporting Data
Briefly describe infiltration test and provide reference to test forms:
Testing performed in accordance with San Diego County Guidelines, all holes
were pre-soaked overnight with testing performed on second day.
Reference: San Diego County, 2016, County of San Diego Model BMP Design Manual San Diego
Region, February 2016, Appendix I.
1-31 February 2016
Converse Consultants
Geotechnical Engineering, Environmental & Groundwater Science, Inspection & Testing Services
November 14, 2019
Mr. DJ Dean
Principal Architect
KPG
3131 Elliott Avenue, Suite 400
Seattle, Washington 98121
Subject: Proposed Palomar Transfer Station Project
Orion Street and Faraday Avenue
Carlsbad, California
Converse Project No. 06-32-110-05
Dear Mr. Dean:
In accordance with your request and approval, Converse Consultants (Converse) has prepared
this percolation test review letter for the subject project. To prepare this letter, we have reviewed
the following:
• Converse Consultants, Geotechnical Investigation Report, Improvements to Palomar
Station, Orion Street and Faraday Avenue, Carlsbad, California, dated April 5, 2006,
Converse Project No. 06-32-110-01 .
• The project grading, foundation and improvement plans for Proposed Palomar Transfer
Station Project.
• Percolation Testing Report, Palomar Transfer Station, 5960 El Camino real, Carlsbad,
California, prepared by Geologic Associates, dated November 2018.
Based on our review, the boring locations BH-1, BH-2 and BH-3 which were performed by
Converse are in the proposed biofiltration area. The borings BH~1. BH-2 and BH-3 show very
dense materials up to five (5) feet below ground level and shallow bedrock materials from five (5)
feet below ground level. Dense and bedrock materials have low percolations rates and not
feasible to infiltration systems. Therefore, the proposed location is not feasible for infiltration
systems. Proposed biofiltration location with soil borings and boring logs are attached with this
letter.
The opportunity to be of service is highly appreciated. If you have any questions or require
additional information, please call the undersigned at (626) 930-1275.
Sincerely,
CONVERSE CONSULTANTS
. -===:::-#--
___ , • v ~ ~
Siva K. Ivathasan, PhD, PE, GE, DGE, QSD, F. ASCE
Senior Vice President/ Principal Engineer
Dist: 2/Addressee
Attachments
PA/SKS:jjl
717 South Myrtle Avenue, Monrovia, California 91016
Telephone: (626) 930-1200 • Facsimile: (626) 930-1212 ♦ www.converseconsultants.com
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C0IA8C1AL EXIT r -I
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LEGEND
BH-2 INDICATES NUMBER AND
~ APPROXIMATE LOCATION
OF BORING
'!1CIN(TY MAP
N.T.&
Base Plan· Provtded: by. Riha. Construction Co.
SITE AN~BORlf'.IIG COCATtQN. PLAN,
ro11ct No.
IMPROVEMENTS:TO'THEP-ALOMAR TRANSFER.STATION.
Cltyrof"Cartsba¢.0Jifomla 0S-32..11 Q;;.Q1
.CotweBe <!:atts1.dtants ~ E!,giNing.
;ind ~ Sciences
Flgut• No.
·. 1'
Log of BH-1
Dates Drilled: ------------3/9/2006 Logged by: _____ C_K_L __ Checked By: KN
Equipment: 8" HOLLOW STEM AUGER
Ground Surface Elevation (ft)_: ___ N_/A __ _
Driving Weight and Drop: 140 lbs / 30 in
Depth to Water (ft): NOT ENCOUNTERED
SUMMARY OF SUBSURFACE CONDITIONS
This log is part of the report prepared by Converse for this project
and should be read together with the report. This summary applies g only at the location of the boring and at the time of drilling. (..)
.s:::. :c Subsurface conditions may differ at other locations and may change Q_ Q_ ro O> at this location with the passage of time. The data presented is a Q) ...._ 0 0 (9~ simplification of actual conditions encountered.
4" ASPHALT CONCRETE OVER 8" AGGREGATE
BASE
FILL:
SIL TY SAND (SM): fine-to coarse-grained, olive gray.
5 BEDROCK FORMATION:
SANDSTONE: broken into silty sand, fine-to
coarse-grained, cemented clasts, olive gray.
10 -rocks and cobbles
End of bori ng at 10.5 feet due to refusal of bedrock.
Groundwater not encountered at the time of drilling.
Boring backfilled with bentonite chips and soil cuttings.
~ Converse Consultants
Project Name
Improvements to Palomar Transfer Station
Carlsbad, California For: Riha Construction Co.
SAMPLES I-~ 0
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0 CD
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50-4" 11 .5
50-6" 14.5
50-4" 10.5
(50-2")
Project No.
06-32110-01
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LU :::, I->-c CD a::: (J :5 o-9;
110
99 ds, wa
106
Drawing No.
A-2
n
Log of BH-2
Dates Drilled: ------------3/9/2006 Logged by: _____ C_K_L _____ Checked By: KN
Equipment: 8" HOLLOW STEM AUGER
Ground Surface Elevation (ft)_: __ N_/_A __ _
Driving Weight and Drop: 140 lbs I 30 in
Depth to Water (ft): NOT ENCOUNTERED
g .!:2 .c .c a. 0.
<1l Ol QJ .... 0 0 C, ....J
5
10
15
20
SUMMARY OF SUBSURFACE CONDITIONS
This log is part of the report prepared by Converse for this project
and should be read together with the report. This summary applies
only at the location of the boring and at the time of drilling.
Subsurface conditions may differ at other locations and may change
at this location with the passage of time. The data presented is a
simplification of actual conditions encountered.
FILL:
SIL TY SAND (SM): fi ne-to coarse-grained, some fine
gravel, brown.
BEDROCK FORMATION:
SANDSTONE: broken into silty sand, fine-to
coarse-grained, some broken cobbles, cemented,
elastic sedimentary rocks and cobbles, reddish brown.
-gray, rocks and cobbles
-rocks and cobbles
-some fi ne gravel, olive gray
-rocks and cobbles
End of boring at 24.5 feet due to refusal of bedrock.
Groundwater not encountered at the time of drilling.
Boring backfilled with soil cuttings.
~ Converse Consultants
Project Name
Improvements to Palomar Transfer Station
Carlsbad, California For: Riha Construction Co.
SAMPLES
LU :::.::: > ii: ....J :::> 0 CD
I-0 0 u. ---en s: 0 ....J co
50-6"
50-6"
50-4"
(50-4")
(50-2")
(96-11")
(50-6")
Project No.
06-32110-01
....... ~ ~ 0
~
LU en a::: I-I-z en :::> LU I-:::> I-(/) >-c 6 co 0::: u <{ ~ o-3: ....J
max.ma
9.5 118
16 109.5
10 dist.
Drawing No.
A-3
Log of BH-3
Dates Drilled: ------------3/9/2006 . Checked By: _ Logged by: _____ C_K_L ___ _
Equipment: 8" HOLLOW STEM AUGER
Ground Surface Elevation (ft): ___ N_/_A __ _
Driving Weight and Drop: 140 lbs/ 30 in
Depth to Water (ft): NOT ENCOUNTERED
g
.c a.
Q)
0
5
10
15
20
-~ .c a. CO Ol .... 0 (!) _J
X XXX
)( X X )(
X X X X
X X )( X
X X X X
X X X X
X X X X
X X X X
>< X X X
X X X X
X X X X
X X )( X
X X X X
X X X X
X X X X
X X X X
X )( X X
SUMMARY OF SUBSURFACE CONDITIONS
This log is part of the report prepared by Converse for this project
and should be read together with the report. This summary applies
only at the location of the boring and at the time of drilling.
Subsurface conditions may differ at other locations and may change
at this location with the passage of time. The data presented is a
simplification of actual conditions encountered.
FILL:
SIL TY SAND (SM): fine-to coarse-grained, some fine
gravel, brown.
BEDROCK FORMATION:
SANDSTONE: broken into silty sand, some fine gravel,
cemented, elastic sedimentary rocks and cobbles,
brown.
-gray
CLAYSTONE: broken into clay, cemented, gray brown.
End of boring at 22.0 feet due to refusal of bedrock.
Groundwater not encountered at the time of drilling.
Boring backfilled with soil cuttings.
~
SAMPLES f-~ g 0 e......
0 UJ
LL. a:: t:: --Cl) ::> z w ~ ~ I-::> > (/) a: _J 0 0 >-c ::, _J a::(.)
0 en co ~ oS
50-4" 12.5 108
50-6" 8 115.5
(50-6")
50-4" 10 107
50-6" 25 92
50-6" 18.5 103
KN
Cl)
f-Cl) w f-
co :5
~ Converse Consultants
Project Name Project No.
06-32110-01
Drawing No.
Improvements to Palomar Transfer Station Carlsbad, Callfornla
For: Riha Construction Co.
A-4
Log of BH-4
Dates Drilled: 3/9/2006 Logged by: ______ C_K_L _____ Checked By: _ KN _
Equipment: 8" HOLLOW STEM AUGER Driving Weight and Drop: 140 lbs / 30 in
Ground Surface Elevation (ft): NIA Depth to Water (ft): NOT ENCOUNTERED
SUMMARY OF SUBSURFACE CONDITIONS SAMP LES f-0 This log is part of the report prepared by Converse for this project 0 and should be read together with the report. This summary applies u.. g .2 only at the location of the boring and at the time of drilling. en ..c ..c Subsurface conditions may differ at other locations and may change w ~ s: a. a. ~ C1l Ol at this location with the passage of time. The data presented is a _J 0 Q) ... 0 a:: ::) _J
0 (.!) _J simplification of actual conditions encountered. 0 co co
4" ASPHALT CONCRETE OVER 8" AGGREGATE
BASE r :8 ~ FILL: ■ X
SIL TY SAND (SM): fine-to medium-grained, some fine 50-2"
gravel, light brown. ~ 5 X --
-rocks [>( (50-6")
End of boring at 6.5 feet.
Groundwater not encountered at the time of drilling.
Boring backfilled with soil cuttings.
~ Converse Consultants
Project Name
Improvements to Palomar Transfer Station
Carlsbad, California
For: Riha Construction Co.
Project No.
06-32110-01
,....._ ::,e_ g 0 ~ w Cl) a:: t: f-Cl) ::) z w f-::) f-Cl)
0 >-c co a:: u ::i ~ 0..$
6.5 dist.
Drawing No.
A-5
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 2a Hydromodification Management ~ Included
Exhibit (Required)
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of"Critical Coarse ~ Exhibit showing project drainage
Sediment Yield Areas (WMAA Exhibit boundaries marked on WMAA
is required, additional analyses are Critical Coarse Sediment Yield
optional) Area Map (Required)
See Section 6.2 of the BMP Design Optional analyses for Critical Coarse
Manual. Sediment Yield Area Determination
□ 6.2.1 Verification of Geomorphic
Landscape Units Onsite
□ 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
□ 6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
Attachment 2c Geomorphic Assessment of Receiving Dil Not performed
Channels (Optional) □ Included
See Section 6.3.4 of the BMP Design
Manual.
Attachment 2d Flow Control Facility Design and ~ Included
Structural BMP Drawdown Used 2018 Model BMP Design
Calculations (Required) Manual, with permission from City of
Carlsbad , using the tables and
See Chapter 6 and Appendix G of the worksheets under Appendix G.2 of
BMP DesiQn Manual the Model BMPDM.
Use this checklist to ensure the required information has been included on the
Hydromodification Management Exhibit:
The Hydromodification Management Exhibit must identify:
1)(1 Underlying hydrologic soil group
D!l Approximate depth to groundwater
ll<I Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)
[}jl Critical coarse sediment yield areas to be protected (if present)
ll<I Existing topography
ll<I Existing and proposed site drainage network and connections to drainage offsite
1)(1 Proposed grading
ll<I Proposed impervious features
!}ii Proposed design features and surface treatments used to minimize imperviousness
[}jl Point(s) of Compliance (POC) for Hydromodification Management
ll<I Existing and proposed drainage boundary and drainage area to each POC (when necessary,
create separate exhibits for pre-development and post-project conditions)
~ Structural BMPs for hydromodification management (identify location, type of BMP, and
size/detail)
ATTACHMENT 3
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural
BMP Maintenance Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
□ Typical maintenance indicators and actions for proposed structural BMP(s) based
on Section 7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
□ Specific maintenance indicators and actions for proposed structural BMP(s). This
shall be based on Section 7.7 of the BMP Design Manual and enhanced to reflect
actual proposed components of the structural BMP(s)
□ How to access the structural BMP(s) to inspect and perform maintenance
□ Features that are provided to facilitate inspection (e.g., observation ports,
cleanouts, silt posts, or other features that allow the inspector to view necessary
components of the structural BMP and compare to maintenance thresholds)
□ Manufacturer and part number for proprietary parts of structural BMP(s) when
applicable
□ Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level
posts or other markings shall be included in all BMP components that will trap and
store sediment, trash, and/or debris, so that the inspector may determine how full
the BMP is, and the maintenance personnel may determine where the bottom of
the BMP is . If required, posts or other markings shall be indicated and described
on structural BMP plans.)
□ Recommended equipment to perform maintenance
□ When applicable, necessary special training or certification requirements for
inspection and maintenance personnel such as confined space entry or
hazardous waste management
Stormwater Management BMPs Schedule &
Maintenance Activates
MAINTENAN Record
BMP's Reponsibl O&M CE SCHEDULE Keeping
e Party(s) PROCESS & ACTIVITIES &
INSPECTION
Inspect the planter Box, maintain landscape
Bio-filtration vegetaions, remove accumulated materials, Annually, Required
Property Replace clogged surface soi ls, Revove and System Owner properly dispose filter midia soils. Check and after
(Planter Box) overflow drain and repair or replace as heavy rains
applicable.
Maintain landscape area vegetation, slope
Landscape Property protection and grades, adjacent to hardscape Weekly Required
Maintenance Owner and prevent discharges of landscape
maintenance waste into storm drains
Property Vacuum sweep drive aisles and parking areas Weekly/ Required Litter Control to remove potential stormwater contamination Owner before anticipated storm events Monthly
Check and repair the irrigation system. Verify
there are no leaks or runoff from landscape
Irrigation Property areas. Adjust irrigation heads and system run Required
System Owner times as necessary to prevent overwatering of Weekly
vegetation, overspray or run-off from
landscape areas and to ensure the health and
aesthetic quality of the landscape
Empty trash receptacles. Clean the areas
Trash Property around enclosures by sweeping and /or Weekly Enclosures mopping to provent discharges of cleanup Required Owner water.
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
I
~
----310.48
-------FS
310.98
FS
24.00
0 0 s
\
\__
RUN DOWNSPOUT ALONG
FACE OF BUILDING\ TO PLANTER \
6" DRAIN THROUGH CURB
INV: 300.73
DOWNSPOUT
LOCATION
\
PERMANENT WATER (}UAL/TY
\
-------
EXISTING STRUCTURE
/
/
OVERFLOW DRAIN: JENSEN PRECAST MODEL 1212HDI
SQUARE GRATE INLET AT 12" ABOVE MULCH
DOWNSPOUT
COBBLE OR
SPLASHBLOCK
6" OVERFLOW DRAIN TO DISCHARGE
THROUGH PROPOSED CURB FACE.
PAVEMENT
•·
-.. : .
12"
6" TYP. 7
3" MIN.
Freeboard
PONDING
3"
mulch layer
15"
6"MIN.
'
~'
"·. .
·' . . ..
PER PLAN
r REINFORCED CMU BLOCK OR PRE-CAST CONCRETE WITH
WATERPROOF MEMBRANE THROUGHOUT
UNIFORM MIX OF SAND AND ORGANIC
MATERIAL (EX: COMPOST); MIN INFILTRATION
RATE OF 5 INCHES PER HOUR.
(DO NOT COMPACT)
NON-WOVEN GEOTEXTILE
MEMBRANE (OPTIONAL)
Project Name:
Project Applicant:
12" Ml
2% TYP.
0 0
Jurisdiction:
'" WASHED GRAVEL 4
U'-"\J.'-"\__('-"\J.'-'\J.
Parcel (APN):
BMP Name:
INSTALL SCH 40 END CAP WITH 0.37'' ORIFICE DRILLED AT FLOWLINE
SEE ORIFICE DETAIL HEREON
'
LONGITUDINAL 6" DIA. PERFORATED PVC PIPE
WRAPPED IN NON-WOVEN GEOTEXTILE MEMBRANE.
PLACED OVER 3" GRAVEL LAYER.
BIOFIL TRA TION
PLANTER BOX SECTION
NOTTO SCALE
BMP Native Soil Type:
OMA
Name
DMAl
DMA2
DMA3
BMP Tributary Area
0
Project Name:
Project Applicant:
Jurisdiction:
Parcel (APN):
BMP Name
----DMA -
Name
DMAl
DMA2
DMA3
Palomar Transfer Station 6907
Palomar Transfer Station Inc
City of Carlsbad
760-166-84-DO
Planter Box
TREATMENT FACILITY
KEEP/NC OUR WATER WAYS CLEAN
MAINTAIN MTH CARE -110 M00JFJCA110NS Y.1THOUT AGENCY APPR0WL
DETAIL
WATER (}UAL/TY S/CN-PLACED AT
EACH 8/0RL lRA TION BASIN
Hydrologic Unit:
Rain Gauge:
Total Project Area:
NOTE: ALL BIOFIL TRA T/ON AREAS llfLL
HA VE A SICN POSTED TO BE
VISIBLE AT ALL TIMES.
BMP Sizing Spreadsheet V3.0
Low Flow Threshold:
BMPType:
D
Oceanside
6,700
0.1Q2
Biofiltration
-Rain Gauge----- --Pre:cdevelope·d Condition -------·unit Runoff Ratio OMA Area (ac) Orifice Flow~ %Q2
Soil Type Slope (cfs/ac) (els)
Oceanside D Moderate 0.575 0.065 0.004
Oceanside D Moderate 0.575 0.054 0.003
Oceanside D Moderate 0.575 0.014 0.001
' ' ' ' •· OMA 4 IS 305 Sf O 01 ACRES LANDSCAPED THEREFORE IT IS SELF MITIGATING
BMP Sizing Spreadsheet V3.0
PalornarTransfer Station 6907 Hydrologic Unit: 0
Palomar Transfer Station Inc Rain Gauge: Oceanside
City of Carlsbad Total Project Area: 6,700
760-166-84-00 Low Flow Threshold: 0.1Q2
Planter Box BMP Type: Bio filtration
D -' BMP Infiltration Rate (in/hr): 0.025
Areas Draining to BMP HMP Sizing Factors Minimum BMP Size
i 1-1rea we1g .. teu I\UllOu I Pre Project Soil Post Project Factor Surface Area Surface Area (SF)
{Table G.2-1)1 Area (sf) Type Pre-Project Slope Surface Type
2,830 D . Moderate Roofs 1.0 0.07 198
2,350 D Moderate Roofs 1.0 0.07 165
600 D Moderate ·concrete 1.0 0.07 42
. . 0 0
5,780 Minimum BMP Size 405
Proposed BMP Size* 450 * Assumes standard configuratio
Surface Ponding Depth 12.00 ic
Bioretention Soil Media Depth 18.00 m
Filter Coarse 6.00 lin
Gravel Storage Layer Depth 12 ic
underdrain Offset 3.0 !in
I
r
\
\
Orifice Area
{in2)
0.05
0.04
0.01
DATE
10
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME: PALOMAR TRANSFER STATION 6907
ADDRESS: 5960 EL CAMINO REAL
CARLSBAD, CA 92008 CONTACT RODRIGO HU RTER OUTLET STRUCTURE WALL
~z,' ~ PHONE NO. (760) 603-0153 J . / GRAVEL STORAGE AREA
SCH 40 PVC MALE ADAPTER
PLAN PREPARED BY:
NAME: RICARDO GARCIA
COMPANY: DAVID EVANS AND ASSOCIATES INC.
ADDRESS 25152 SPRINGFIELD COURT,# 350
SANTA CLARITA, CA 91355-1096
PHONE NO. (661) 284-7400
SIGNATURE
BMP NOTES: CERTIFICATION ____ _
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 SWMP FOR ADDITIONAL INFORMATION.
BMP
BMP ID# BMPTYPE SYMBOL CASQA NO. QUANTITY
TREATMENT CONTROL
CD BIOFILTRATION rs>~·:'•''I TC-32 1 AREA :·:~ ,'., ·, : .. ,,.:
* CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS
IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS:
ANNUAL
SEMI-ANNUALLY
QUARTERLY
BIMONTHLY
MONTHLY
EA
TABLE
DRAWING NO.
442-3B
0
3" MIN
"'-...Laa"---"""4----1,>""----'j{}]f 1
GRAVEL STORAGE AREA
}}}ti·
ORIFICE DETAIL
NOTTO SCALE
01-28-2020
SCH 40 PVC THREADED
END CAP
DRILL 0.37" ORIFICE HOLE
AT FLOWLINE OF END CAP
SHEET NO.(S) INSPECTION * MAINTENANCE *
FREQUENCY FREQUENCY
3,4,6 SEMI-ANNUALLY ANNUALLY
NOTES:
CD PERMANENT WATER QUALITY TREATMENT
FACILITY SIGN SHALL BE POSTED AT
PLANTER BOX WHERE IT IS VISIBLE
AS NEEDED
NONE
WEEKL"Y HYDROLOGY INFORMATION
1 TIME PER YEAR
2 TIMES PER YEAR
3 TIMES PER YEAR
4 TIMES PER YEAR
0 ' 10 20
SITE AREA, 6,700 SF
SOIL GROUP, D (PER SOIL REPORT)
IMPERVIOUS, 100% (ROOF AREA)
0% (LANDSCAPED AREA)
ISOHYETALS, 0.61" (85th PERCENTILE 24-HOURS)
GROUNDWATER DEPTH, l O' BGL (PER SOIL REPORT)
METHOD, CITY OF CARLSBAD BMP DESIGN MANUAL
LEGEND: ----DRAINAGE TRIBUTARY AREA BOUNDARY
scale feet vvvv vvvv vvvv
3.75 0.008 0.11 0.37
Max Tot. Allowable Max Tot. Allowable Max Orifice Max Orifice Head Orifice Flow Orifice Area Diameter
(feet) {els) {in2) (in)
0.007 0.008 0.11 0.370
Average outflow during Selected Max Orifice Outflow Actual Orifice Area surface drawdown ------~ -~----elrifice·D@meter
{els) (els) (in2) (in)
I Drawdown (Hrs) I 17.8
INlllAL DATE INlllAL DATE
I
I::::::=:=:=:=:=:=:::=: ::=:l :-: . :-:-:.:. :-:-:-:-:-:.:. ..•.. · ... · ... ·.· .·. · ... · ..
I:\ ::: ::::I
PROPOSED ROOF AREA
EXISTING BUILDING
LANDSCAPED AREA
BIOFILTRATION-PLANTER BOX AREA
----ff)Z?Z]
~~dA
GRIND AND OVERLAY
COBBLE STONE RIP RAP
SLOPE OF THE ROOF
INlllAL
1: 12
DMA-1
XX,XX
CITY
DRAINAGE MANAGEMENT AREA ID NO.
AREA ACREAGE (AC)
OF CARLSBAD I SHlET I
ENGINEERING DEPARTMENT
I SHlETS I
SINGLE SHEET BMP SITE PLAN
PALOMAR SINGLE SHEET BMP SITE PLAN
RECORD COPY PROJECT NO.
CUP260(D)
DRAWING NO.
ENGINEER OF WORK REVISION DESCRIPTION OTHER APPROVAL CITY APPROVAL INITIAL DATE I 442-3B I