HomeMy WebLinkAboutCT 16-10; HOME AVENUE; STORM WATER QUALITY MANAGEMENT PLAN; 2018-05-22CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
HOME AVENUE CONDOMINIUMS
CT 16-10, PUD 16-12
DWG 507-6A
SWQMP NO. GR2017-0057
ENGINEER OF WORK:
L\ 6 -1-JfJ
EXP 3-31-2019 DATE
PREPARED FOR:
PREPARED BY:
bl-IA, Inc
land planning, civil engineering, surveying
5115 AVENIDA ENCINAS, SUITE L
CARLSBAD, CA 92008-4387
(760) 931-8700
DATE:
May 22, 2018
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JN O 4 2C 8
W. 0 . 1026-1383-400 LA n OE VEL MENT
LI\JGINEERING
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TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1a: OMA 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: Structural BMP Maintenance Thresholds and Actions
Attachment 3: Single Sheet BMP (SSBMP) Exhibit
Attachment 4: Geotechnical Reference
2
CERTIFICATION PAC:iE
Project Name: Home Avenue Condominiums
Project ID: CT 16-10, PUD 16-12
I hereby declare that I am the Engineer in Responsible Chc1rge 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 OrdE!r.
I have read and understand that the City Engineer ha~. 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 bE!en 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 ne9ative 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.
R.C.E. 29271 Ex . 3/31/2019
k's Signature, PE Number & Expiration Date
Ronald Holloway
Print Name
bl-IA, Inc
land planning, civil engineering, surveying
May 22, 2018
Date
3
PROJECT VICINITY MAP
@
VICINITY 1v1AP
4
FORM E-34
5
{'ci~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 de·termining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering :;taff.
A completed and signed questionnaire must be submitted with eac:h development project application. Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECT INFORMATl~tN
PROJECT NAME: Home Avenue Condominiums PROJECT ID: CT 16-10/PUD 16-12
ADDRESS: Home Avenue, Carlsbad, CA 92008 APN: 203-202-03
The project is (check one): IZI New Development 0 Redevelopment
The total proposed disturbed area is: 18,097 ft2 ( 0.415 ) acres
The total proposed newly created and/or replaced impervious area is: 9,362 ft2(0.215 ) acres
If your project is covered by an approved SWQMP as part of a larger d1:lvelopment 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, si~In the form at the end and submit this with your
application to the city.
E-34 Page 1 of4 REV 02/16
STEP1
TO BE COMPLETED FOR ALL F~ROJECTS
To determine if your project is a "development project", please answer thei following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building □ Ill or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If you answered "no" to the above question, the project is a 'development project', go to Step 2.
STEP2 n
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-
erodible permeable areas; □ Ill b) Designed and constructed to be hydraulically disconnected from paved streets or roads;
c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets QUidance?
2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in □ Ill accordance with the USEPA Green Streets guidance?
3. Ground Mounted Solar Array that meets the criteria provided in sectkm 1.4.2 of the BMP manual? □ Ill
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ... " and complEite 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 vou answered "no" to the above auestions, vour proiect is not exempt from PDP, go to Step 3.
E-34 Page 2 of 4 REV02/16
STEP3
TO BE COMPLETED FOR ALL NEW OR REDE)fELOPMENT 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, □ 121
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 121 □ more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is
a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and □ Ill
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside □ IZI
development project includes development on any natural slope that is twenty-five percent or greater.
5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is □ Ill a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a street, road, highway □ IZI freeway or driveway? A street, road, highway, freeway or driveway is any paved impervious surface
used for the transportation of automobiles, trucks, motorcycles, and other vehicles.
7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site, and discharges directly to an Environmentally
□ IZI Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of
200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).*
8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop? An automotive repair □ IZI 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 □ IZI 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 dav.
1 O. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land □ IZI 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
□ IZI impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC
21.203.040)
If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... "
and complete applicant information.
If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the
second box statinQ "My project is a 'STANDARD PROJECT' .. ." and complete aoolicant information.
E-34 Page 3 of4 REV 02/16
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
YES NO
Existing impervious area (A}= ___________ sq. ft. D D
Total proposed newly created or replaced impervious area (8) = ___________ sq. ft.
Percent impervious area created or replaced (B/A)*100 = _____ %
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.
[l] 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.
0 My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Title: ........:c.::..~¢r::...~~,~---------
Applicant Signatur~====~:;:;:;::::::::::_ _ __:===== Date: _ __,,,,.,"'~;,t....,.L~~~/2c...L.J~"----------~ u e,r'
• envlronmentslly Sensitive Areas include but are n t limited to all Clean Water ct Section 303(d) Impaired water bodies: areas designated as Areas of Special
Biological Significance by the Stale Water Resources Control Board (Water Quality Control Plan fer 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 Cilv Use Onfv
YES NO
City Concurrence: D □
By:
Date:
Project ID:
E-34 Page 4 of 4 REV02/1S
SITE INFORMATION CHECKLIST
Project Summary Information
Project Name Home Avenue Condominiums
Project ID CT 16-10, PUD 16-12
Project Address Home Avenue, Carlsbad, CA 92008
Assessor's Parcel Number(s) (APN(s)) 203-202-03
Project Watershed (Hydrologic Unit) ISi Carlsbad 904
Project Hydrologic Unit Hydrologic Area Select One:
D Loma Alta 904.1
ISi Buena Vista Creek 904.2
□ Agua Hedionda 904.3
□ Encinas 904.4
□ San Marcos 904.5
□ Escondido Creek 904.6
Parcel Area
(total area of Assessor's Parcel(s) 0.415 Acres ( 18,097 Square Feet)
associated with the project)
Area to be disturbed by the project
(Project Area) 0.415 Acres ( 18,097 Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 0.214 Acres ( 9,305 Square Feet)
Project Proposed Pervious Area
(subset of Project Area) 0 .202 Acres ( 8,792 Square Feet)
Note: Proposed Impervious Area+ Proposed Pervious Area= Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
6
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
!SJ Existing development
!SJ Previously graded but not built out
D Agricultural or other non-impervious use
D Vacant, undeveloped/natural
Description / Additional Information:
The existing site is approximately 0.415 acres and has been previously graded. The site is
currently an impervious parking lot.
Existing Land Cover Includes (select all that apply):
D Vegetative Cover
D Non-Vegetated Pervious Areas
!SJ Impervious Areas
Description / Additional Information:
The site is currently a parking lot. The existing site is 100% impervious.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
□ NRCS Type A
!SJ NRCS Type B
□ NRCS Type C
□ NRCS Type D
The on-site soil classification is Type B from USGS Web Soil Survey.
Approximate Depth to Groundwater (GW):
□ GW Depth < 5 feet
D 5 feet < GW Depth < 10 feet
!SJ 10 feet < GW Depth < 20 feet
□ GW Depth > 20 feet
Approximate depth to groundwater is 16.5 ft. See Geotechnical Reference by Advanced
Geotechnical Solutions (Attachment 5).
7
Existing Natural Hydrologic Features (select all that apply):
D Watercourses
D Seeps
D Springs
D Wetlands
1SJ None
Description / Additional Information:
There are no existing natural hydrologic features.
8
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]:
Storm flows affecting the site are limited to the rainfall that lands directly on the property. Surface
runoff sheet flows west across the impervious parking lot to Home Street. Runoff that drains to
Home Street will be conveyed southwest via existing curb and gutter to the storm drain system
on Home Street. Approximately 100% of the existing site is impervious.
The on-site soil classification is Type B from USGS Web Soil Survey.
9
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The project proposes the development of five (5) condominiums, an amenity site, a driveway, and
surrounding landscape. Proposed drainage improvements consist of storm drain pipes and a
permeable pavement BMP (pollutant control) to provide stormwater treatment and maintain the
pre-developed runoff characteristics.
The units will be accessed by a 24-foot wide driveway within the interior of the property. The
proposed driveway will be designed as a retention BMP and will be comprised of permeable
pavement with additional detention storage below the surface.
Landscape areas in the back of the proposed residences will be designed with pervious area
dispersion as a site design BMP to minimize impervious area and provide additional stormwater
retention. The backyard areas are designed as Self-retaining DMAs. The project drains to one
(1) Point of Compliance (POC) located to the northwest corner of the project site.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
The proposed impervious features of the project include the five (5) proposed condominium
residences and impervious concrete areas surrounding the amenity site.
List/describe proposed pervious features of the project (e.g., landscape areas):
The proposed pervious features of the project include landscape areas surrounding the
proposed residences and the permeable pavement driveway.
Does the project include grading and changes to site topography?
ISi Yes
0 No
Description / Additional Information:
Project disturbance will occur on approximately 0.415 acres of the project site. Storm water flows
from impervious roof areas will be conveyed via roof drains to the permeable pavement BMP.
The BMP will include a permeable surface layer and an aggregate storage layer with an
underdrain. Yard drains located in pervious landscape areas will also convey runoff to the
project's point of discharge. The storm drain system will require excavation and installation of
underground storm drains. Post-development site flow will mimic existing drainage conditions,
and will discharge from the site at below historical flow rates. See the "Drainage Report for Home
Avenue Condominiums" by BHA, Inc. dated September 27, 2017 for post-development drainage
calculations. Impervious surfaces have been minimized where feasible. Project grading has
been minimized due to the previously level graded pad .
10
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
rs! Yes
0 No
Description / Additional Information:
Storm water runoff from the proposed project site is routed to three POCs, located along Home
Avenue (northerly boundary) of the project site. The proposed drainage pattern will be similar to
the existing drainage pattern with some modifications to incorporate Best Management Practices
(BMPs) into the project design to mimic the impacts on storm water runoff and quality. Runoff
from the developed project site is drained to one (1) onsite retention BMP (Water Quality-BMP or
WQ-BMP) for water quality purposes (the project is not subject to hydromodification
requirements). The project also includes site design BMPs for additional pollutant control and to
reduce runoff volumes. Once flows are routed via the proposed water quality and site design
BMPs, all flows are then conveyed via storm drain to the aforementioned POC.
The proposed driveway in the center of the project site will be designed as a retention BMP and
will provide storm water treatment and flow detention. The BMP will include a permeable
pavement surface layer and an infiltration storage layer below the surface to infiltrate runoff into
subgrade soils.
DMA-1 encompasses runoff from a portion of the proposed buildings and the proposed concrete
sidewalks and landscape areas of the amenity site. Roof drains will collect runoff from the
impervious roof surfaces and discharge onto the proposed permeable pavement driveway,
located in the center of the project site. Runoff from the proposed concrete sidewalks and
landscape areas of the amenity site will also surface flow onto the permeable pavement driveway.
The permeable pavement BMP will be designed as a retention BMP and will provide stormwater
treatment and flow detention. The BMP is designed with an infiltration storage volume equal to
the full DCV to infiltrate runoff into subgrade soils. An underdrain pipe will be provided within the
storage layer to convey high flows that exceed the infiltration capacity of the underlying soil. The
underdrain pipe will outlet over rip rap in a landscape area and flow northwest to POC-2 along
Home Avenue.
Roof runoff that is unable to flow to the permeable pavement BMP will be discharged to pervious
landscape areas in the back of the proposed residences. The landscape areas will consist of
native or drought tolerant landscape to promote water retention. Roof downspouts will discharge
over rip rap to the relatively flat pervious areas to facilitate sheet flows and minimize runoff
velocities, thereby improving storm water treatment. These areas are designed as Self-retaining
DMAs since their ratio of total drainage area (including impervious roof and surrounding
landscape) to area of pervious landscape is 1: 1 or less for Hydrologic Soil Group B. Therefore,
by utilizing impervious area dispersion as a site design BMP, these areas are considered
11
(Continued from previous page)
Self-retaining DMAs (SR-1 through SR-5) and are compliant with pollutant control obligations per
Section 5.2.3 of the BMP OM.
Runoff from the roof areas that are unable to drain to the retention BMP or back of the proposed
residences will be discharged to pervious landscape areas adjacent to Home Avenue. These
areas are also designed as Self-retaining DMAs since their ratio of total drainage area (including
impervious roof and surrounding landscape) to area of pervious landscape is 1: 1 or less for
Hydrologic Soil Group B. Therefore, by utilizing impervious area dispersion as a site design BMP,
these areas are considered Self-retaining DMAs (SR-6 and SR-7) and are compliant with pollutant
control obligations per Section 5.2.3 of the BMP OM.
Concrete sidewalk and patio areas adjacent to Home Avenue that are unable to gravity flow
toward pervious landscape area will flow directly to Home Avenue. These areas (DMIN-1 and
DMIN-2) are classified as De Minimis DMAs are not considered to be a significant contributor of
pollutants. The areas are also less than 250 square feet per Section 5.2.2 of the BMP OM.
The proposed drainage patterns will not alter the existing flow pattern and will discharge from
the site at the historic discharge points.
12
Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
IS] On-site storm drain inlets
D Interior floor drains and elevator shaft sump pumps
D Interior parking garages
IS] Need for future indoor & structural pest control
IS] Landscape/Outdoor Pesticide Use
IS] Pools, spas, ponds, decorative fountains, and other water features
D Food service
D Refuse areas
D Industrial processes
D Outdoor storage of equipment or materials
D Vehicle and Equipment Cleaning
D Vehicle/Equipment Repair and Maintenance
D Fuel Dispensing Areas
D Loading Docks
D Fire Sprinkler Test Water
D Miscellaneous Drain or Wash Water
IS] Plazas, sidewalks, and parking lots
13
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):
From the project site, runoff flows to the Buena Vista Lagoon and to the Pacific Ocean.
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d} Impaired Water Body Pollutant(s}/Stressor(s} TMDls
Indicator bacteria Bacteria (Est. TMDL
Buena Vista Lagoon (904.21) completion: 2008)
Nutrients Nutrients/ Eutrophication (Est.
TMDL completion: 2019)
Sedimentation/ Siltation Sedimentation/ Siltation (Est.
TMDL completion: 2019)
Identification of Project Site Pollutants
Identify pollutants expected from the project site based on all proposed use(s) of the site (see
BMP Design Manual Appendix B.6):
Not Applicable to the Expected from the Also a Receiving
Project Site Project Site Water Pollutant of
Pollutant Concern
Sediment □ IS] IS]
Nutrients □ IS] IS]
Heavy Metals □ IS] □
Organic Compounds □ IS] □
Trash & Debris □ IS] !SJ
Oxygen Demanding
Substances □ IS] IS]
Oil & Grease □ IS] u
Bacteria & Viruses □ IS] IS]
Pesticides □ IS] □
14
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
D Yes, hydromodification management flow control structural BMPs required.
D 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.
ISi 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.
D 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):
Storm water runoff from the project site flows southwest along Home Avenue and enters a
storm drain on Grand Ave, and ultimately discharges to the Buena Vista Lagoon. Based on
Section 1.6 of the City of Carlsbad BMP Design Manual, the City has the discretion to exempt a
PDP from hydromodification management requirements if discharge is conveyed via a concrete
lined system to an encased embayment (i.e. lagoon). Pursuant to the study approved by the
City of Carlsbad titled "Hydromodification Exemption Analyses for Select Carlsbad Watersheds"
dated September 17, 2015 prepared by Chang Consultants, the hydrologic and hydraulic
analyses performed showed that the hardened system downstream of the project draining to the
lagoon conveys the 10-year storm event, the discharge point has proper energy dissipation and
the outlet is within the 100-year flood limits.
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment yield
areas exist within the project drainage boundaries?
□Yes
ISi No, No critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual
been performed?
D 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
D 6.2.2 Downstream Systems Sensitivity to Coarse Sediment
D 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
D 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?
15
D No critical coarse sediment yield areas to be protected based on verification of GLUs
onsite
D Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
D 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:
Hydromodification requirements are not required for this project.
16
Flow Control for Post-Project Runofr
"'This Section only required if hydromodification management requirements apply
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see
Section 6.3.1 ). For each POC, provide a POC identification name or number correlating to the
project's HMP Exhibit and a receiving channel identification name or number correlating to the
project's HMP Exhibit.
Hydromodification requirements are not required for this project.
Has a geomorphic assessment been performed for the receiving channel(s)?
D No, the low flow threshold is 0.102 ( default low flow threshold)
D Yes, the result is the low flow threshold is 0.1O2
D Yes, the result is the low flow threshold is 0.3O2
D Yes, the result is the low flow threshold is 0.5O2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion/ Additional Information: (optional)
17
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
local codes governing minimum street width, sidewalk construction, allowable pavement
types, and drainage requirements.
Several factors are considered while assessing the feasibility and desirability of infiltration
related to geotechnical conditions. A review of the soil survey maps indicate Type-B soils at
the location of the project site. According to the NRCS web survey, Type-B soils are generally
rated for moderate infiltration capacity.
Additional field and laboratory investigations were performed by Advanced Geotechnical
Solutions, Inc. to further assess the geological impacts of storm water infiltration. The purpose
of the study was to evaluate the general infiltration rate of earth materials in the location of the
proposed stormwater facilities. Infiltration testing was performed using the borehole percolation
test method, in general conformance with City of Carlsbad BMP Design Manual Guidelines. An
analysis of the field test data is included in the Geotechnical Investigation and Foundation
Design Recommendations by Advanced Geotechnical Solutions, Inc., October 21, 2016
(Attachment 4 ).
Infiltration testing indicated that the soils located in the areas of the proposed BMPs have
relatively high infiltration rates when thoroughly wet, similar to typical Type B soils. The
geotechnical engineer has stated that partial or full infiltration of stormwater is feasible.
Based upon the proposed location of the pervious driveway, it is not anticipated that infiltration
of storm water will affect the proposed improvements. Therefore, the permeable pavement
BMP will not include an impermeable liner below the aggregate storage layer.
Optional Additional Information or Continuation of Previous Sections As Needed
Additionally, Home Avenue lacks an underground storm drain system. This requires the
proposed WQ-BMP and storm drain pipes to discharge flows onto Home Avenue. Because the
existing and proposed slope of the site is relatively flat, the depth of the storm drain system is
very limited.
18
FORM E-36
19
Ccityof
Carlsbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project Information
Project Name: Home Avenue Condominiums
Project ID:
DWG No. or Building Permit No.:
Source Control BMPs
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual for information to implement source control BMPs shown in this
checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 ~Yes □ No □ N/A
Discussion/justification if SC-1 not implemented:
Acknowledge that an illicit discharge is any discharge to the MS4 that is not composed entirely of wash water.
Provide educational materials to prevent illicit discharges as a component of the Operation and Maintenance Plan (O&M
Plan).
SC-2 Storm Drain Stenciling or Signage [ZI Yes □ No □ N/A
Discussion/justification if SC-2 not implemented:
No on-site storm drain inlets proposed. Pervious pavers will be stenciled or stamped with anti-dumping message. See
DMA Exhibit for location of anti-dumping message
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □Yes □ No [ZIN/A
Dispersal
Discussion/justification if SC-3 not implemented:
No outdoor materials storage areas proposed.
E-36 Page 1 of 4 Revised 03/16
Source Control Reaulrement (continued) ADDlled?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and □Yes 0 No 121 N/A Wind Dispersal
Discussion/justification if SC-4 not implemented:
No materials stored outdoors proposed.
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal □Yes 0 No 121 N/A
Discussion/justification if SC-5 not implemented:
No trash storage areas proposed.
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 ouidance).
□ On-site storm drain inlets □Yes D No 121 N/A
□ Interior floor drains and elevator shaft sump pumps D Yes 0 No 121 N/A
D Interior parking garages □Yes □ No 121 N/A
□ Need for future indoor & structural pest control 121 Yes 0 No □ N/A
121 Landscape/Outdoor Pesticide Use 121 Yes 0 No 0 NIA
121 Pools, spas, ponds, decorative fountains, and other water features 121Yes 0 No 0 N/A
D Food service □Yes D No 121 NIA
D Refuse areas □Yes D No 121 N/A
□ Industrial processes □Yes 0 No 121 NIA
□ Outdoor storage of equipment or materials □Yes □ No 121 NIA
□ Vehicle and Equipment Cleaning D Yes D No 121 N/A
D Vehicle/Equipment Repair and Maintenance □Yes 0 No 121 N/A
□ Fuel Dispensing Areas □Yes □ No 121 N/A
□ Loading Docks D Yes 0 No 121 N/A
□ Fire Sprinkler Test Water □Yes D No 121 N/A
D Miscellaneous Drain or Wash Water □Yes D No 121 N/A
121 Plazas, sidewalks, and oarkina lots 121 Yes D No □ N/A
For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers.
• Plant pest-resistant or well-adapted plant varieties such as drought tolerant and/or native plants in landscape areas.
• Irrigation systems will be designed for the specific water requirements of each landscape area. Landscaping will be
designed to minimize irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of
fertilizers and pesticides that can contribute to storm water pollution.
• Acknowledgment that swimming pool water is chlorine and should never be discharged to the storm drain system. Pools
or fountains should be drained to the sanitary sewer if permitted to do so.
• Plazas, sidewalks, and parking lots must be swept regularly to prevent the accumulation of litter and debris. Debris from
pressure washing must be collected to prevent entry into the storm drain system.
E-36 Page 2 of 4 Revised 03/16
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual for information to implement site design BMPs shown in
this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion / justification is not required.
• "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Source Control Requirement I Applied?
SD-1 Maintain Natural DrainaQe Pathwavs and HvdroloQic Features I 1Z1 Yes I 0 No I □ NIA
Discussion/justification if SD-1 not implemented:
The project will maintain the overall cross lot drainage.
SD-2 Conserve Natural Areas, Soils, and VeQetation I □ Yes I □ No I IZI N/A
Discussion/justification if SD-2 not implemented:
The site is 100% impervious pre-development and 51 % impervious post-development. Although the project cannot
conserve natural areas, the project will create vegetated areas.
SD-3 Minimize Impervious Area l 1Z1 Yes I □ No I □ NIA
Discussion/justification if SD-3 not implemented:
Project will incorporate permeable pavements to minimize impervious area.
SD-4 Minimize Soil Comoaction I □ Yes I □ No I IZI NIA
Discussion/justification if SD-4 not implemented:
Project site has been previously graded.
SD-5 Impervious Area Dispersion l IZI Yes I □ No I □ N/A
Discussion/justification if SD-5 not implemented:
Runoff from the impervious rooftops and walkway areas of the amenity site will be directed onto the adjacent permeable
pavement driveway. The permeable pavement BMP will be designed to effectively receive, retain and treat runoff from
impervious areas prior to discharging to the MS4.
Roof runoff that is unable to drain to the permeable pavement BMP will be discharged onto adjacent pervious landscape
area before discharging off-site.
E-36 Page 3 of 4 Revised 03/16
Source Control Reaulrement (continued) l Applied?
50-6 Runoff Collection I '21 Yes I □ No I □ NIA
Discussion/justification if SD-6 not implemented:
Permeable pavement will be used as a retention BMP. Permeable pavement contains small voids to effectively receive
runoff and allow filtration, storage, and evaporation, prior to discharge to the storm drain system.
50-7 Landscaping with Native or Drouqht Tolerant Soecies I tzl Yes I □ No I □ NIA
Discussion/justification if SD-7 not implemented:
Landscape or pervious areas will incorporate native or drought tolerant landscape design. Final selection of plant material
needs to be made by a landscape architect experienced with LID techniques.
5D-8 Harvesting and Using Precipitation I □ Yes I □ No I tzl N/A
Discussion/justification if SD-8 not implemented:
Harvest and use is considered to be infeasible for the project site. Project will utilize other LID strategies such as
minimizing impervious area to reduce the overall DCV of the site. See Form 1-7 in Attachment 1c.
E-36 Page 4 of 4 Revised 03/16
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 local jurisdiction 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 local jurisdiction 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 (page 3 of this form) for each structural BMP within the project (copy
the BMP summary information page as many times as needed to provide summary information
for each individual structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information
must describe how the steps for selecting and designing storm water pollutant control BMPs
presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of
BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether
pollutant control and flow control BMPs are integrated or separate.
For the purpose of this SWQMP, the proposed site condition has been divided into ten (10)
Drainage Management Areas (DMAs): (1) Area Draining to a Permeable Pavement BMP, (7) Self-
retaining DMAs, and (2) De Minims DMAs. The DMAs have been delineated based on onsite
drainage patters and BMP locations.
A geotechnical investigation was provided by Advanced Geotechnical Solutions, Inc. to perform
infiltration testing and analyze storm water infiltration feasibility. Based on recommendations from
the geotechnical report, infiltration rates for the Home Ave site are greater than 0.5 in/hr.
Based upon the propcsed location of the pervious driveway, it is not anticipa~ed that storm water
infiltration will affect the proposed improvements. Therefore the permeable pavement driveway
will be designed as a retention BMP.
One (1) LID permeable pavement BMP {INF-3) is located within the project site and is responsible
for handling water quality requirements for a portion of the project draining to POC-1 . In developed
20
conditions, the permeable pavement will be designed with a uniform structural section and with
the surface sloping towards the northwest. Beneath the pavement's invert lies the infiltration
portion of the drainage facility. This portion of the permeable pavement is comprised of a 2-inch
bedding layer, a 2-inch choker layer, and a 12-inch reservoir layer of gravel for additional detention,
and to accommodate the French drain system. Below the underdrain pipe, the reservoir layer
includes a 3-inch infiltration storage layer of gravel to capture the full DCV. Flows will infiltrate
through the underground gravel layer to the underdrain pipe or infiltrate through the base of the
facility. The underdrain pipe will convey treated flows to the receiving storm drain system.
Structural BMPs are not required for the Self-retaining DMAs or De Minimis DMAs. Impervious
Area Dispersion (SD-6) is used as a site design BMP for SR-1 -SR-7. The Self-retaining DMAs
have a ratio of total drainage area to area of pervious landscape of 1: 1 or less for Hydrologic Soil
Group B. Therefore the self-retaining areas are compliant with pollutant control sizing criteria.
21
Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural
BMP)
Structural BMP ID No. BMP-1
DWG Sheet No. 2
Type of structural BMP:
D Retention by harvest and use (HU-1)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
1SJ Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1)
D Biofiltration (BF-1) D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements
(provide BMP type/description in discussion section below)
D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
D Flow-thru treatment control with alternative compliance (provide BMP type/description in
discussion section below)
D Detention pond or vault for hydromodification management
D Other (describe in discussion section below)
Purpose:
ISl Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control
D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Discussion (as needed):
Hydromodification requirements are not required for this project. The WQ-BMP is for pollutant
control only.
22
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 1 a OMA Exhibit (Required) IS] Included
Attachment 1 b
See OMA Exhibit Checklist on the
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Tabular Summary of DMAs Showing
OMA ID matching OMA Exhibit, OMA
Area, and OMA Type (Required)*
*Provide table in this Attachment OR
on OMA Exhibit in Attachment 1 a
□ Included on OMA Exhibit in
Attachment 1 a
IS] Included as Attachment 1 b,
separate from OMA Exhibit
Attachment 1c Form 1-7, Harvest and Use Feasibility IS] Included
Attachment 1 d
Screening Checklist (Required unless D Not included because the entire
the entire project will use infiltration project will use infiltration BMPs
BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required
unless the project will use harvest and
use BMPs)
Refer to Appendices C and D of the
BMP Design Manual to complete
Form 1-8.
IS] Included
D Not included because the entire
project will use harvest and use
BMPs
Attachment 1 e Pollutant Control BMP Design ~ Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
23
Attachment 1 a
DMA Exhibit
24
PERMEABLE
CONCRETE
PAVERS
2" BEDDING LA YER
AASHTO #B
12" RESERVOIR LA YER
AASHTO #2 or jJ
FIL 1ER LA YER
AASHTO #8
6" PERFORATED
PVC PIPE
JOINT
SUBGRADE
PERMEABLE PAVEMENT
BMP DETAIL
NOT TD SCALE
SELF-RETAINING DMAS:
,·
·. ;· : .. . .
~ .• ' . . .•
. .
CURB
ADJACBIT
MATERIAL
3" INF/L TRA TION
STORAGE LA YER
SELF-RETAINING DMAS AR E AREAS THAT ARE DESIGNED WITH THE SITE DESIGN BMPS TO RETAIN RUNOFF
TO A LEVEL EQUIVALENT TO THE PERVIOUS LAND. BMP FACT SHEETS FOR IMPERVIOUS AREA DISPERSION
(SD-5 IN APPENDIX E OF THE CITY OF CARLSBAD BMP DESIGN MANUAL) DESCRIBE THE DESIGN CRITERIA BY
WHICH BMPS CAN BE CONSIDERED SELF RETAINING.
SITE DESIGN BMPS SUCH AS IMPERVIOUS AREA DISPERSION IS USED TO REDUCE OR ELIMINATE RUNOFF.
A DMA IS CONSIDERED SELF-RETAINING IF THE IMPERVIOUS TO PERVIOUS RATIO IS 1:1 WHEN THE
PERVIOUS AREA IS COMPRISED OF HYDRO LOGIC SOIL GROUP B.
REDUCTIONS IN DCV REALIZED THROUGH SITE DESIGN BMPS ARE APPLICABLE TO TREATMENT CONTROL
ONLY.
DE MINIMIS DMAS:
DE MINIMIS DMAS ARE AREAS THAT ARE VERY SMALL, AND THEREFORE NOT CONSIDERED TO BE
SIGNIFICANT CONTRIBUTORS OF POLLUTANTS, AND ARE CONSIDERED NOT PRACTICAL TO DRAIN TO A BMP.
DE MINIMIS DMAS ARE AREAS ABUT THE PERIMETER OF THE DEVELOPMENT SITE.
THE PORTION OF THE SITE FALLING INTO THIS CATEGORY IS MINIMIZED THROUGH EFFECTIVE SITE DESIGN.
EACH DE MINIMIS DMA SHOULD BE LESS THAN 250 SQUARE FEET AND THE SUM OF ALL DE MINIMIS DMAS
SHOULD REPRESENT LESS THAN 2 PERCENT OF THE TOTAL ADDED OR REPLACED IMPERVIOUS SURFACE OF
THE PROJECT.
TWO DE MINIMIS DMAS CANNOT BE ADJACENT TO EACH OTHER AND HYDRAULICALLY CONNECTED.
(5) \ S:
O:s-
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L...L.
DRAINAGE MANAGEMENT AREA EXHIBIT
HOME A VENUE CONDOMINIUMS
(
SIDEWALK
UNDERDRAIN
--(W) --(~f_E __
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CT 16-10
PUD16-12
PROJECT CHARACTERISTICS
PARCEL AREA
DISTURBED AREA
PROPOSED IMPERVIOUS AREA
PROPOSED PERVIOUS AREA
SOIL TYPE
DEPTH TO GROUNDWATER
LEGEND
DMA NAME
DMA AREA (SQ FT)
DMA BOUNDARY
PROPERTY LINE
YARD DRAIN
STORM DRAIN DRAIN
POINT OF CONCENTRATION
SELF-RETAINING DMA
DE MINIMIS DMA
ROOF AREA
LANDSCAPE AREA, L
PROPOSED CONCRETE, PCC
RIP RAP ENERGY DISSIPATER
PROPOSED PERMEABLE PAVEMENT BMP
(POLLUTANT CONTROL)
LID AND SITE DESIGN:
0.415 ACRES
0.415 ACRES
0.214 ACRES
0.202 ACRES
B
16.5 FEET
SYMBOL
DMA-1
12,046 SF
---n---
---sn---
POC-1
SR-1
DMIN-1
R
1••••·•·•••••·•••••••••••••••·••••••••••1 ~
1:,:,:,:,:, :1
[ SD-1 MAINTAIN NATURAL DRAINAGE PATHWAYS AND HYDROLOGIC FEATURES.
[SD-3 MINIMIZE IMPERVIOUS AREA
[SD-5 IMPERVIOUS AREA DISPERSION
[ SD-6 RUNOFF COLLECTION
[SD-7 LANDSCAPING WITH NATIVE OR DROUGHT TOLERANT SPECIES
SOURCE CONTROL BMPS:
[ SC-1 [ PREVENTION OF ILLICIT DISCHARGES INTO THE MS4
[SC-2 [ STORM DRAIN STENCILING AND SIGNAGE
[SC-6 [ ADDITIONAL BMPS BASED ON POTENTIAL RUNOFF POLLUTANTS:
[A) ON-SITE STORM DRAIN INLETS
[[I NEED FOR FUTURE INDOOR & STRUCTURAL PEST CONTROL
(I] LANDSCAPE/OUTDOOR PESTICIDE USE
ITJ POOLS, SPAS, PONDS, DECORATIVE FOUNTAINS, AND OTHER WATER FEATURES
[QJ PLAZAS, SIDEWALKS, DRIVEWAYS, AND PARKING LOTS
1 o· 5' o· 1 o· 20· 30'
SCALE: 1" = 10'
I SH1ET I CITY OF CARLSBAD I SHlETS I
ENGINEERING DEPARTMENT
b~A,lnc.
land planning, cMI engineering, su1Veylng
5 115 A VEN ID A ENCINAS
SUITE "L"
CARLSBAD, CA. 92008-4387
(760) 931-8700
DMA EXHIBIT
HOME AVENUE
RECORD COPY
INITIAL DATE
CONDOMINIUMS
PROJECT NO.
CT 16-10 & PUD 16-12
I
DRAWING NO.
I XXX-XA
Attachment 1 b
Tabular Summary of DMAs and Design Capture Volume Calculations
~,"~~J~--wf 1:!':' :~1.::~~\"tj'!'-,~.._.,♦rt~tttt5>J._il \ ,',~••A .'..l°tt'\::t .. f~?;;:;'l·ff]t-'•"",.,.,.~.,,..._.,'"""•:, .. ,"',,.~, 'l c ... ; ' ,, '
UMA Si1rfacc Tabulaiior1 'to ,SuJ>j,o'rt Bio filtration 'of Design .DMA Name
~ (;,,. • ,1, ;.,;. • ' " " • ;•~'
~~aptu_re ~V9l_um~f(D~Y)J).~tero1jt!_a~ionj:::.:~.J,._.'. ~.,, .,·. ,·_,,. , -OMA-I 'f, '
DMA Impervious Area Tabulation
Surface Name Surface Type Area (ft)
Rl Roof and Patio 896
R2 Roof and Pa tio 1103
R3 Roof and Patio 1056
R4 Roof and Patio 1,084
RS Roof and Pa tio 902
PCCl Concrete 1,596
Total Impervious Area (ft) 6,637
DMA Pervious Area Tabulation
Surface Name Surface Type Area (ft)
L1 Landscape 1,536
T Bl T urf Block 1,084
PUPl Permeable Pavement 3,348
Total Pervious Area (ft) 5,968
Total DMA (A) 12,605
Total Impervious Area (ft1 /Total DMA (ft1 = Percent Impervious 53%
Soil Type B
DMA Runoff Factor "C" per Appendix B.1 and B.2 0.62
85th Percentile Rainfall (I) 0.6
Desien Capture Volume (DVQ = (C)(D(A) /12 388
25
~ ~m-rn~ ~r. .. ;3,~,_~fn.;<K~'t¥ AA ,§· m4:.?"ij m:sf@\~-. :£~!:1u e•v,r~'' " , t ''\t&~.,/,;\~ i1.hltii>n:o·f SclfRet:1in1ng DMAs,, mlJ:£,.~m'~,, il<'DM~A' ,N:1~,c _:sR-1 'i: .,, ;It;»'i --~~~ --~\l!~]f''!f £-~,/ '' ,,; ',,,, ''w/4''/<'fl ~ ~ ,j-c :,;< \°""" iii""'.,,:Ct':s L :R>';;x ;-&°'~
Runoff Factor Area x Runoff
Surface Name Surface Type Area (ft2) (Table B.1-1) Factor
R6 Roof 280 1.0 280
L4 Landscape 308 0.1 30.8
Adjusted Surface Drainioo: to Self-Re,~: .. ; .. v Area -(A) 310.8
Receiviru! Self-Retainioo: Surface Area -(B) 308
Self-Ret:ainirur Area Surface Tvoe Landscape
Ratio of (A) to ffi) 1.0: 1
Pond Depth within Self-Retainiru! Area 0.0 in
Total Area of DMA 588
ulation,of Self-::Ret OMA •%\!1\1J4'3Nil &it:l'/:'DMAtName -SR-2 · ,, ·:~~ IRIIIIIL~la II ~~ltl!til~i;; i :i. . . ::.~;,:: ,;::ti
Runoff Factor Area x Runoff
Surface Name Surface Tvoe Area (ft2) (Table B.1-1) Factor
R7 Roof 458 1.0 458
LS Landscape 493 0.1 49.3
Adjusted Surface Drainioo: to Self-Re.....;...;.."" Area -(A) 507.3
Receiving Self-Retainioo: Surface Area -IB) 493
Self-Retaininu Area Surface Tvoe Landscape
Ratio of (A) to IB1 1.0: 1
Pond Depth within Self-Retainiru! Area 0.0 in
Total Area of DMA 951
26
Surface Name Surface T e Area ft2
R8 Roof 411
L6 Landsca e 596
Pond De
Runoff Factor
able B.1-1
1.0
0.1
Surface Area -
Total Area of DMA
Area x Runoff
Factor
411
59.6
470.6
596
Landsca e
0.8: 1
0.0 in
1,007
t fil,,,; "'{fl~ g~t"f¾M"' ""'ML,,,ti§. P~W'!'J < ~ ~»,y, ""' ~,,i 1l;i'abula ·~ l"",};;,rJ,¾;,'ruillbDMA'liNaruc -SR.;:4 \, ,';;'•';"'f:'i'.,'; ·-·'k'tl\1:\,l,,4>M"L'1J!lt~,t---Wiu "'"'' , ,1 '~· w,,,';;;m Xit,I)W¥1\ lifilt~~g'1~.f' >»ti m ' t&~ '\t~tc<>?\' » ,~ * '~:~'"1tli
Runoff Factor Area x Runoff
Surface Name Surface Tvpe Area (ft2) (Table B.1-1) Factor
R9 Roof 425 1.0 425
L7 Landscape 452 0.1 45.2
Adiusted Surface Drainiru! to Self-Retainin2: Area -(A) 470.2
Receiving Self-Retainin2: Surface Area -IB) 452
Self-Rernininu Area Surface Type Landscape
Ratio of (A) to IB) 1.0 : 1
Pond Depth within Self-Re....:...:..~ Area 0.0 in
Total Area of DMA 877
27
-~f!"•1'!~1~'/l!'i'~~~~~ ~ljTI~'j!i~-~Tj!f•Ff'll;TY.fJ~'", •·' ;• •.'' > r,:" "'>':', 7 ~✓~/:i♦r2~ ,,. ! ,;_ t.•i:f\~ <w1&,,~ 1:~n ~~~;'.,)_,§ "! "-r .. Wbr\1!• ~--"'"_ .. ·:.-~ ' . ,._ ,,. t10n1ofSclf-Rctam111g DMAs f~N<r)tlt·~ ~,l;-z•.,DMA Name -SR-5 · · ·:: -l~~;.t?;'~f:~ii,"tftf.Ef-~:!!~ ~-~i!~-~J(: .Jth{it~ .. ~:;\\i;J~~~,: ,;,;;::\_' ~ •, "~.l ~ I ,. '~ •
Runoff Factor Area x Runoff
Surface Name Surface Type Area (ft2) (Table B.1-1) Factor
RlO Roof 314 1.0 314
L8 Landscape 341 0.1 34.1
Adjusted Surface Drainin2 to Self-Retainim? Area -(A) 348.1
Receiv:iru? Self-Retainim? Surface Area -(B) 341
Self-Retainim? Area Surface Type Landscape
Ratio of (A) to (B) 1.0: 1
Pond Depth within Self-Ret:aininQ' Area 0.0 in
Total Area of DMA 655
-~~4'.':lc,~~'!11'.:"'~J!l'~ ~rntt*,,,."""'"•Jc•, it' ~¥l!j-3tt;;ll\\'/i'm!:i ir~~~Jj!'!W"• ••111J!'~l1!WtfiJ, "Jrlffe' · ··• • • · · o•''" ••t• > 's'.!{1~ ~ ,.. ~""'••':.f>~~;,._. ,_,,._t< >d•j:"tv,~t: ,~:~~• .. .,..,. i ~-"I,~,-,"-'!{ it,'",£;'.i't•,;~:tt. '°•'<><"/~», '(' • ' " < •f.'i·;~Tabulation·of Sdf-Rctammg DMAs Jl>~: ~: :.,·, .. t: -;-r,, .. OMA .Name -SR-6 . -¾+~~-.-: ,.~ j'{ •,.,o:~f.jt.~" ... J~:-:N+4),.~~\t ~,{<'<:it'~!~'--"\,<<:»."-.,.'._.J, ~t'i%41B" ,·.,;1~";:, t ~, 1,, ',:-,,,;; ~ ~;,, _.· , -~-~a&"¼if2tB~,d0.¼¼-~1:!J.<t,~~'~1,th1l.;.,_'(p''.,;#{rAJ ~hit ~~-\it~~k~-,,ti!-~l~-t4ailt •. t\'q41-iA4~i;~i >l.,t>Z2t"x ' ",J " t
Runoff Factor Area x Runoff
Surface Name Surface Type Area (ft2) (Table B.1-1) Factor
R11 Roof 299 1.0 299
L9 Landscape 320 0.1 32
Adjusted Surface Drainin2 to Self-Retainim? Area -(A) 331
Receiv:iru? Self-Ret:a.ioiru? Surface Area -(B) 320
Self-Retainim? Area Surface Type Landscape
Ratio of (A) to (B) 1.0: 1
Pond Depth within Self-Re....:.....:..~ Area 0.0 in
Total Area o f DMA 619
28
Surface Name Surface T e Area n2
R12 Roof 290
LlO Landsca e 314
Pond De
Runoff Factor
able B.1-1
1.0
0.1
Surface Area -
Area Surface T
Total Area of DMA
Area x Runoff
Factor
290
31.4
321.4
314
Landsca e
1.0: 1
0.0 in
604
The locations and limits of all Surfaces Draining to Self-Retaining DMAs are delineated on the
DMA Exhibit.
29
l"'ril'i;'fi'I; ,;'l!'l;•Nt~,~.:ru•r~~-~~.,f!~lr~~e"S~"i-"Z!l1t'J;'lt(·t~~;p;w;i~w.~-,,.~ FY/:,:•,,>¥:,"J'!i •. · " ' •. ~· ;il Hi)'.',"', .,,,-~tr,,.-•~ 1Jt.l--f' ..:.i:{l :.( ~;,,...._t ''i,:-_-t,.~ .. ,"~~ .. ~._ .. .,. . "/.,-":''"" " "W--«• , '«) ""-·•:.". ,Tabulatmn""ofDe"Mmums OMA l'• w··• -~,DMA Name -DMJN-1 l!f!! ~~\~ f.if''tt',l,:,;; ;.;;;_:,,:~~ ,"<):...; .~ ~ ji••",{{l;j ! ,-~~-~ ~...-r-,; ~l': ~""~':"' ,\ ;!:i<,-" ~ ~ :,. , _, "', ,,. .~ J~ ~~2ttt1~t-sllifr:.N.(1Jt,J48-m " ~@k&G 2ist::.ifi&i.bl> "'~~F.tt.½'..u~-,rLJi7;,rkf'"'.:-,.m.,1 l~h"'>L~.i! :r,s;;;, , _ . __ .. t ...,
Surface Name Surface Type Area (ft2)
PCC2 Conventional Asphalt 93
Subtototal De Minimis Areas 93
Comment Proposed concrete sidewalk will flow onto Home Ave. This area is
considered a De Minimis DMA per Chapter 5 Section 5.2.2 of the County of San
Diego BMP Design Manual.
''Wt"t1!1,r,;}<~<M:k,'<C'!"""-/,'"~'"1b""!~f''t"f:~t .. ~,i"]f;/1R:'"l:.(-'f"'-'/'~•••,::~'\"'1'f;i_~~,:;t•~..,_~~: l'W,.-'™',l"<)~J\"'"•'!-h:.1,'0 '"" •~~ M. >e'-''t ' }t•s_;;. •,, *"'/~,.::s1."'"'~~T,,}$L,3f·· .. ,,,-t;."''""r;•*~!:/1?/!:,\<,'~}-h,i1, i ..... , G/.4,\
iF'< . ·T~b~_la)j,<>,~.-~f!:>.~:¥~~.i~, P.,~ : >· •. : DMA Name -DMIN-2
~•:, u';s ~ .. ~"\:,~11..,:itfui\AJ.,,.~~.St1,:;~:;:¥t-. .. i:'~':%....J.i:m~cut.t ... ,tfk,:. »\itl;z~.rt¼. !t ! . w _;'l'l'ft th 'x [' <,. 4 , , i, ,.:
Surface Name Surface Type Area (ft2)
PCC3 Conventional Asphalt 98
Subtototal De Minimis Areas 98
Comment Proposed concrete sidewalk will flow onto Home Ave. This area is
considered a De Minim.is DMA per Chapter 5 Section 5.2.2 of the County of San
Diego BMP Design Manual
30
DMA Classification
Self-Mi· a DMAs 0
Self-Re .. DMAs 7 5,301 0.12
HU -1: Cistern 0 0 0
INF-1: Infiltration Basins 0 0 0
INF-2: Bioretention 0 0 0
INF-3: Permeable Pavement ollutant Contra 1 12,605 0.29
PR-1: Bio filtration with Partial Retention 0 0 0
BF-1: Bio filtration 0 0 0
BF-2: Nutrient Sensitive Media Des· n 0 0 0
BF-3: Pro rie Bio filtration 0 0 0
FT-1: Ve etated Swales 0 0 0
FT-2: Media Filters 0 0 0
FT-3: Sand Filters 0 0 0
Extended Detention Basin 0 0 0
FT-5: Pro Flow-thru Treatment Control 0 0 0
De Minims DMAs 2 191 0.00
Total Pro·ect DMA 10 18,097 0.42
Total Parcel Area 18,097 0.42
Comment:
31
Attachment 1 c
Form 1-7, Harvest and Use Feasibility Screening Checklist
"
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?
[SJ Toilet and urinal flushing
[SJ Landscape irrigation
0 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.
Modified ETWU = ETowerX [(I(PF x HA)/IE) + SLA] x 0.015
Using an average value for HA over the 14 lots and Low Plant Water Use (per Table B.3-2);
Modified ETWU = 2.7 x [[(0.2 x 5,444)/0.9) + OJ x 0.015
Modified ETWU= 49
Note: Total Landscape Area= 5,444 sf
3. Calculate the DCV using worksheet B-2.1.
D CV = ___.3=8=8 ___ (cubic feet)
3a. Is the 36 hour demand greater
than or equal to the DCV?
0 Yes I ISJ No
~ c:>
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations to
confirm that DCV can be used at an
adequate rate to meet drawdown
criteria.
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV?
0 Yes I ISJ No
~ c:>
3c. Is the 36 hour demand
less than 0.25D CV?
ISJ Yes
~
Harvest and use may be feasible. Harvest and use is considered
Conduct more detailed evaluation and to be infeasible.
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.
32
Is harvest and use feasible based on further evaluation?
D Yes, refer to Appendix E to select and size harvest and use BMPs.
ISi No, select alternate BMPs
Harvest and use BMPs are considered infeasible. Drought tolerant landscape, as proposed in SD-7 in Form E-36,
requires low plant water use. Project will implement other LID strategies such as minimizing impervious area and
impervious area dispersion. The full DCV can be treated and detained in the proposed permeable pavement BMP.
33
Attachment 1 d
Form 1-8, Categorization of Infiltration Feasibility Condition
Form 1-8 consists of an excerpt taken from the below cited report. For the full report, see
Attachment 4.
Geotechnical Investigation and Foundation Design Recommendations for Proposed Residential
Multi-Family Podium Structure (Grand Ave) and Single Family (Home Ave) by Advanced
Geotechnical Solutions, Inc. October 21, 2016.
34
,,, ' , i
C~tegorizatiou of Irifiltratio~ Feasibility Conditio'n-Home Ave Worksheet C.4-1
;<> .,j '", 1~ ,,_ "'
"' ,, i 1
Part t -Full Infiltration FeasibilitY Screenina Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria
1
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
□
One (1) borehole percolation tests was performed in proposed/possible BMP location. One was conducted for
Home Ave single family detached (HS-3); and two were conducted for the 800 Grand condominium portion Pl
and P2 . Testing was performed in general conformance wi th Appendix D, Section D.3.3.2 of the recently adopted
BMP Design Manual. The stabilized percolation rates were then converted to infiltration rates using the "Porchet
Method". The observed infiltration rates were calculated to be 0.77 inches/hour in test hole HSP-3 (Home Ave)
and 2.0 inches/hour in test hole P-land 2.83 inches/hour in test hole P-2 on the Grand Ave. portion. Using a factor
of safety of 2 for feasibility screening purposes yielded design infiltration rates of 0.39(Home Ave). Using a
factor of safety of 2 for feasibility screening purposes yielded design infiltration rates of 1.00 in/hr and 1.42 in/hr.
and 0.38in/hr. It is our opinion that an average infiltration rate of 0.93 in/hr should be used for both sites given the
similar soils and geology.
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:
□
Yes an infiltration rate of 0.93in/lu· can be used for the design of possible infiltration on the Home Avenue
portion of the project. Tbis opinion is based upon: the similarity of the soils exposed in the 3 percolation
test borings; the lower rate found in HS-1 is likely related to the near surface compaction as a result of the
original parking lot and drive isle construction activities. 1be types of soils and the blow counts within the
upper soils are relatively uniform. Accordingly, once the proposed infiltration section is cut to the design
grade (18 to 24 inches) it is conservatively estimated that the average rate presented herein can be utilized for
design.
Based upon the proposed location in the drive aisles/parking areas it is not anticipated that this will
adversely affect the proposed improvements provided the building slabs are adequately waterproofed with a
suitable moisture barrier and the buried utility lines are located outside of the pervious pavement or
adequately backfilled with a sand cement slurry where they intercept the permeable pavement.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
" ;
' ·.: · , . Worksheet C.4-1 Page 2 of4-Home Ave.
>i\ " > ~ a ~ ' -' sc I
Criteria
3
Sct:eening 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
□
No known contamination exists at the site and the c losest know site with contamination issues is located
approximately 0.1 miles southeast of the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface
waters? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
Provide basis:
□
The design infilu·ation rates at the Home Ave portion of the project are suitable provided they do not infiltrate
into the buried utilities and that they are a minimum of 25 to 30 feet horizontally away from the Grand Ave
podium structure and drain in a south to north direction. Per Section C.4.4 of the BMP Design Manual, final
determination should be made by the project design engineer.
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
*To be completed using gathered site information and best professional judgment considering the definition of MEP
in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate findings
if'';J' I ' ~ w 1!'\ ~ ! l, t '· · Worksheet_ C.4-1 Page 3 of4-Home Ave
''$ ' ~ ¼" '
Part 2 -Partial Infiltration vs. No Infiltration Feasibilitv 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
AppendixD.
Provide basis:
Yes No
□
Site specific infiltration testing yielded infiltration rates of greater than 0.5 inches/hour. The sandy nature of the
subsurface materials beneath the site, allow for infiltration in an appreciable rate or volume. It is anticipated that
over the lifetime of the development the infiltrati on rates will fmther diminish. The BMP Design Manual utilizes
the subjective terminology of 'appreciable' :md fai ls to define a lower bound infiltration rate. It is our current
understanding that an 'appreciable' infiltration rate is interpreted to be any perceptible amount of infiltration.
Therefore, in consideration of the current interpretation, the soil and geologic conditions at the project site allow
for infiltration in an 'appreciable' rate or volume.
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:
□
Partial Infiltration can be allowed in the proposed BMP basin/Permeable pavement locations without
significantly increasing the risk of geotechnical hazards provided appropriate mitigation/remedial grading
measures are performed during site development/basin construction. The infiltration surface for the proposed
BMPs have not been finalized at this time, however, it is expected that they will be within the native material at
the site (Old Paralic Deposits) As encountered, the Old Paralic Deposits beneath the site, consist predominantly
of sand and silty sand, in a dense to very dense condition. Some gravely sand was observed at the bottom of the
Old Paralic Deposits. Below the Old Paralic Deposits, a less permeable silty claystone was encountered and
assigned to the Santiago Formation. More detailed recommendations should be provided when final design
plans become available. For the "Home" Avenue portion of the development it is our opinion that infiltration
within the proposed driveways and pa.txing lots is suitable.
Criteria
7
:Worksheet C.4:1,Pag~ 4 of4 Home Ave
,-' '' ' "
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.
Provide basis:
Yes No
ISi □
The proposed basin location has adequate separation (>IO feet) to seasonal high groundwater. There are no
known water supply wells within I 00 feet of the project site. According to the State Water Board's Geotracker
website, the closest site with contamination issues is located 0.1 miles from the site. That site is reported as a
LUST cleanup, and the case has been closed. Land use in the project vicinity is predominantly multi-family
residential with locally interspersed commercial/retail. There are no known contamination risks from current land
use activities. As such, we do not anticipate that construction of the proposed BMP basin will adversely impact
receiving channels in the project vicinity.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
□
The project site is graded and is located in a developed neighborhood with impermeable surfaces where surface
waters are controlled and directed to storm drain inlets. There is no apparent evidence that construction of BMP
basins would divert or otherwise preclude flow to downstream water bodies. Per Section C.4.4 of the BMP
Design Manual, final determination should be made by the project design engineer.
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.
If any answer from row 5-8 is "No", then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
*To be completed using gathered site information and best professional judgment considering the definition of
MEP in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate
findings
3
4
5
Attachment 1e
Pollutant Control BMP Design Worksheets/ Calculations
BMP-1
orksheet D .S-1 Kdesi =
Available BMP surface area ABM P=
Avera effective de th in the BM P foo CV/ABMP DAVG=
D rawdown time, T AVG *12/Kdes· T=
0.39
3,348 fr2
0.11 ft
3.49 hr
6
BMP ensures that the D CV is fully retained, and the stored effective depth draws down no longer than
36 hours.
PERMEABLE
CONCRETE
PAVERS
2• BEDDING LA YER
AASHTO /8
12• RESERVOIR LA YER
AASHTO #2 or /3
FIL TER LA YER
AASHTO /8
5• PERFORATED
PVC PIPE
SUBGRAOE
PERMEABLE PAVEMENT
BMP DETAIL
NOT TD SCALE
35
. : -~ ... : ~~-. . ... . ·· /~· --.: :.-~~ ~·~ . ..
CURB
ADJACENT
MATER/Al
3• INFIL TRA noN
STORAGE LA YER
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
Project is not subject to Hydromodification requirements.
36
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:
ts] 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:
ts] 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)
ts] How to access the structural BMP(s) to inspect and perform maintenance
ts] 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)
ts] Manufacturer and part number for proprietary parts of structural BMP(s) when
applicable
ts] 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.)
1SJ Recommended equipment to perform maintenance
ts] When applicable, necessary special training or certification requirements for
inspection and maintenance personnel such as confined space entry or
hazardous waste management
37
Draft Maintenance Agreement
I. Purpose and Scope
This section was prepared based on the Chapter 7 of City of Carlsbad BMP Design Manual. The
goal is to insure that the Project proponent accepts responsibility for all facilities maintenance,
repair, and replacement from the time they are constructed until the ownership and maintenance
responsibilities is formally transferred to the new owner. Facilities shall be maintained in perpetuity
and comply with the City's self-inspection, reporting, and verification requirements.
II. Inspection, Maintenance Log and Self-Verification Forms
Fill the forms on the following pages for each BMP using the maintenance schedule here and the
inspection-maintenance checklists. These forms shall be signed by the responsible party and
retained for at least (5) years. Use the OMA Exhibit for the location of BMPs. (Make duplicate
copies of these forms and fill out those, not the original ones.)
Ill. Updates, Revisions and Errata
This maintenance plan is a living document and based on the changes made by maintenance
personnel, such as replacement of mechanical equipments, addition maintenance procedure
shall be added and maintenance plan shall be kept up to date.
Please add the revisions and updates to the maintenance plan to this section if any, these
revisions maybe transmitted to the City at any time. However, at a minimum, updates to the
maintenance plan must accompany the annual inspection report.
IV. Introduction
The Home Avenue Condominiums project is a 0.415-acre project that includes the development
of five condominiums, an amenity site, a driveway, and surrounding landscape. The project is
located at Home Avenue in the City of Carlsbad, west of the Interstate 5 freeway. The project
site is bounded on the east by Hope Avenue and on the west by Jefferson Street.
Storm flows affecting the site are limited to the rainfall that lands directly on the property. The
project site drains to one Point of Compliance (POC), located at the northwest of the project site
on Home Avenue.
Runoff from the developed project site is drained to one (1) onsite retention BMP (Water Quality-
BMP or WQ-BMP) for water quality purposes (the project is not subject to hydromodification
requirements). The project also includes site design BMPs for additional pollutant control and to
reduce runoff volumes. Once flows are routed via the proposed water quality and site design
BMPs, all flows are then conveyed via storm drain to the aforementioned POC.
All drainage into and out of the treatment facilities is gravity fed.
38
V. Responsibility for Maintenance
A. General
McKellar McGowan will enter into a Stormwater Facilities Maintenance Agreement (SWFMA)
with the City of Carlsbad to maintain designated facilities herein this section for the Home
Avenue Condominiums Project.
The SWFMA will serve as the mechanism to ensure that proper inspection and maintenance
is done in an efficient and timely manner.
Responsible Party
McKellar McGowan
888 Prospect Street, Suite 330
La Jolla, CA 92037
858-342-9725
McKellar McGowan will have the direct responsibility for maintenance of stormwater controls.
A Home Owner's Association (HOA) shall be formed, or establish another mechanism to the
satisfaction of the City. Funding for the maintenance activities shall be provided by McKellar
McGowan, the HOA, or other mechanism to the satisfaction of the City.
Whenever the property is sold and whenever designated individual change, immediately the
updated contact information must be provided to the City of Carlsbad.
B. Staff Training Program
Staff training and education program shall be carried out twice a year, once prior to the rainy
season (October 1st) and once during the early dry seasqn (April 30th).
The inspection and maintenance training program consists of the operation and function of
the biofiltration basins. Please refer to the following pages for fact sheets and checklists.
It is the responsibility of McKellar McGowan to convey the maintenance and inspection
information to the employees. Maintenance personnel must be qualified to properly maintain
stormwater management facilities. Inadequately trained personnel can cause additional
problems resulting in additional maintenance costs.
C. Records
McKellar McGowan shall retain education, inspection, and maintenance forms and documents
for at least five (5) years.
39
D. Safety
Keep safety considerations at the forefront of inspection procedures at all times. Likely
hazards should be anticipated and avoided. Never enter a confined space (outlet structure,
manhole, etc) without proper training or equipment. A confined space should never be
entered without at least one additional person present.
If a toxic or flammable substance is discovered, leave the immediate area and contact the
local Sheriff at 911 .
Potentially dangerous (e.g., fuel, chemicals, hazardous materials) substances found in the
areas must be referred to the local Sheriff's Office immediately for response by the Hazardous
Materials Unit. The emergency contact number is 911.
Vertical drops may be encountered in areas located within and around the facility. Avoid
walking on top of retaining walls or other structures that have a significant vertical drop. If a
vertical drop is identified within the pond that is greater than 48" in height, make the
appropriate note/comment on the maintenance inspection form .
VI. Summary of Drainage Areas and Stormwater Facilities
A. Drainage Areas
The project has been divided into (10) Drainage Management Areas (DMAs): (1) Area
Draining to a Permeable Pavement BMP, (7) Self-Retaining Areas, and (2) De Minimis DMAs.
The DMAs have been delineated based on onsite drainage patters and BMP locations.
DMA-1 encompasses runoff from a portion of the proposed buildings and the proposed
concrete sidewalks and landscape areas of the amenity site. Roof drains will collect runoff
from the impervious roof surfaces and discharge onto the proposed permeable pavement
driveway, located in the center of the project site. Runoff from the proposed concrete
sidewalks and landscape areas of the amenity site will also surface flow onto the permeable
pavement driveway. The permeable pavement BMP will provide stormwater treatment and
flow detention.
Roof runoff that is unable to flow to the permeable pavement driveway will be directed to
pervious landscape areas in the back of the proposed residences. The landscape areas will
consist of native or drought tolerant landscape to promote water retention. Roof downsoouts
will discharge over rip rap to the relatively flat pervious areas to facilitate sheet flows and
minimize runoff velocities, thereby improving storm water treatment. These areas are
designed as Self-retaining DMAs (SR-1 though SR-5) by utilizing impervious area dispersion
as a site design BMP.
40
Runoff from the roof areas that are unable to drain to the retention BMP or back of the
proposed residences will be discharged to pervious landscape areas adjacent to Home
Avenue. These areas are also designed as Self-retaining DMAs (SR-6 and SR-7) by utilizing
impervious area dispersion as a site design BMP.
Concrete sidewalk and patio areas adjacent to Home Avenue that are unable to gravity flow
toward pervious landscape areas will flow directly to Home Avenue. These areas are
classified as De Minimis DMAs (DMIN-1 and DMIN-2) are not considered to be a significant
contributor of pollutants.
B. Treatment and Flow-Control Facilities
One (1) LID permeable pavement BMP (INF-3) is located within the project site and is
responsible for handling water quality requirements for a portion of the project draining to
POC-1. In developed conditions, the permeable pavement will be designed with a uniform
structural section and with the surface sloping towards the northwest. Beneath the
pavement's invert lies the infiltration portion of the drainage facility. This portion of the
permeable pavement is comprised of a 2-inch bedding layer, a 2-inch choker layer, and a 12-
inch reservoir layer of gravel for additional detention, and to accommodate the French drain
system. Below the underdrain pipe, the reservoir layer includes a 3-inch infiltration storage
layer of gravel to capture the full DCV. Flows will infiltrate through the underground gravel
layer to the underdrain pipe or infiltrate through the base of the facility. The underdrain pipe
will convey high flows that exceed the infiltration capacity of the underlying soil. Discharges
from the underdrain pipe will outlet over rip rap in a landscape area and flow northwest to the
project's point of discharge at POC-1.
See the OMA Exhibit for the location of the treatment facility.
The permeable pavement is designed to allow percolation through void spaces in the
pavement surface and subsurface layers. The subsurface layers are designed to provide
storage of storm water runoff so that outflows, primarily via infiltration into subgrade soils or
rel~ase to the downstream conveyance system, can be at controlled rates. The permeable
pavement is designed with a uniform structural section and with the surface sloping towards
the northwest. The bottom of the permeable pavement will be unlined. The permeable
pavement for this project has been designed as a retention BMP for storm water pollutant
control, based on the City of Carlsbad BMP Design Manual.
VII. Facility Documentation
Please see the following pages regarding BMP details and maintenance fact sheets.
VIII. Maintenance Schedule and Checklist
Fill out the checklists in the following pages for each BMP. The required maintenance activities
are at the end of this section. At the discretion of the Project proponent, a qualified Stormwater
41
company may be hired to perform the required inspection and maintenance and provide
necessary reports.
42
INF-3
Permeable Pavement as Structural BMP
BMP MAINTENANCE FACT SHEET
FOR
STRUCTURAL BMP INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP
Permeable pavement is pavement that allows for percolation through void spaces in the pavement surface into
subsurface layers. The subsurface layers are designed to provide storage of storm water runoff so that outflows,
primarily via infiltration into subgrade soils or release to the downstream conveyance system, can be at controlled
rates. Permeable pavement as structural BMP usually receives runoff from a larger tributary area than permeable
pavement as site design BMP (see SD-68 for permeable pavement as site design BMP). Pollutant control is
provided via infiltration (retention). Flow control is provided by infiltration and/or an outlet control structure.
Typical permeable pavement components include:
Permeable surface layer
Bedding layer for permeable surface
Aggregate storage layer with optional underdrain(s)
Optional final filter course layer over uncompacted existing subgrade
Uncompacted native soils at the bottom of the facility
Optional subsurface check dams at regular intervals when pavement is sloped (more closely spaced on
steeper slopes)
• Optional outflow control structure for runoff released via underdrain(s)
Normal Expected Maintenance
Routine maintenance of permeable pavement includes: removal of materials such as trash and debris accumulated
on the paving surface; vacuuming of the paving surface to prevent clogging; and flushing paving and subsurface
gravel to remove fine sediment. If the BMP includes underdrains and/or an outflow control structure, check and
clear these features. A summary table of standard inspection and maintenance indicators is provided within this
Fact Sheet.
Non-Standard Maintenance or BMP Failure
If the permeable pavement area is not drained between storm events, or if runoff sheet flows across the
permeable pavement area and flows off the permeable pavement area during storm events, the BMP is not
performing as intended to protect downstream waterways from pollution and/or erosion. During storm events up
to the 85th percentile storm event (approximately 0.5 to 1 inch of rainfall in San Diego County), runoff should not
flow off the permeable pavement area. The permeable pavement area is expected to have adequate hydraulic
conductivity and storage such that rainfall landing on the permeable pavement and runoff from the surrounding
drainage area will go directly into the pavement without ponding or overflow (in properly designed systems, the
surrounding drainage area is not more than half as large as the permeable pavement area). Following the storm
event, there should be no standing water (puddles) on the permeable pavement area.
If storm water is flowing off the permeable pavement during a storm event, or if there is standing water on the
permeable pavement surface following a storm event, this is an indicator of clogging somewhere within the
system. Poor drainage can result from clogging of the permeable surface layer, any of the subsurface components,
or the subgrade soils. The specific cause of the drainage issue must be determined and corrected. Surface or
subsurface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito)
breeding. Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP
INF-3
Permeable Pavement as Structural BMP
type will be required. If poor drainage persists after flushing of the paving, subsurface gravel, and/or underdrain(s)
when applicable, or if it is determined that the underlying soils do not have the infiltration capacity expected, the
[City Engineer) shall be contacted prior to any additional repairs or reconstruction.
Other Special Considerations
The runoff storage and infiltration surface area in this BMP are not readily accessible because they are subsurface.
This means that clogging and poor drainage are not easily corrected. If the tributary area draining to the BMP
includes unpaved areas, the sediment load from the tributary drainage area can be too high, reducing BMP
function or clogging the BMP. All unpaved areas within t he tributary drainage area should be stabilized with
vegetation. Other pretreatment components to prevent transport of sediment to the paving surface, such as grass
buffer strips, will extend the life of the subsurface components and infiltration surface. Along with proper
stabilization measures and pretreatment within the tributary area, routine maintenance, including preventive
vacuum/regenerative air street sweeping. is key to preventing clogging.
INF-3
Permeable Pavement as Structural BMP
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an
agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently.
Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see
when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31
and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and
maintenance frequency can be determined based on the results of the first year inspections.
Threshold/Indicator Maintenance Action Typical Maintenance Frequency Comments
Preventive vacuum/regenerative air street Pavement should be swept with a vacuum • Schedule/perform this preventive action
sweeping power or regenerative air street sweeper to at least twice per year.
maintain infiltration through paving surface
Accumulation of sediment, litter, or debris Remove and properly dispose of • Inspect monthly and after every 0.5-inch The most common tools for maintenance
on permeable pavement surface accumulated materials. Inspect tributary or larger storm event. are vacuums, street sweepers and hand
area for exposed soil or other sources of • Remove any accumulated materials tools to remove built up sediment and
sediment and apply stabilization measures found at each inspection. debris on the pavement surface.
to sediment source areas. Apply source
control measures as applicable to sources of
litter or debris.
Weeds growing on/through the permeable Remove weeds and add features as • Inspect monthly.
pavement surface necessary to prevent weed intrusion. Use • Remove any weeds found at each
non-chemical methods (e.g., instead of inspection.
pesticides, control weeds using mechanical
removal, physical barriers, and/or physical
changes in the surrounding area adjacent to
pavement that will preclude weed intrusion
into the pavement).
INF-3
Permeable Pavement as Structural BMP
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP
Threshold/Indicator Maintenance Action Typical Maintenance Frequency Comments
Standing water in permeable paving area This condition requires investigation of why • Inspect monthly and after every 0.5-inch
or subsurface infiltration gallery for longer infiltration is not occurring. If feasible, or larger storm event. If standing water is
than 24-96 hours following a storm event corrective action shall be taken to restore observed, increase inspection frequency
infiltration (e.g., pavement should be swept to after every 0.1-inch or larger storm
with a vacuum power or regenerative air event.
street sweeper to restore infiltration rates, • Maintenance when needed.
clear underdrains if underdrains are present).
BMP may require retrofit if infiltration cannot
be restored. The [City Engineer] shall be
contacted prior to any repairs or
reconstruction.
Presence of mosquitos/larvae If mosquitos/larvae are observed: first, • Inspect monthly and after every 0.5-inch
immediately remove any standing water by or larger storm event. If mosquitos are
For images of egg rafts, larva, pupa, and dispersing to nearby landscaping; second, observed, increase inspection frequency
adult mosquitos, see make corrective measures as applicable to to after every 0.1-inch or larger storm
httQ:L{_www.mosguito.orgLbiolog~ restore BMP drainage to prevent standing event.
water. • Maintenance when needed.
If mosquitos persist following corrective
measures to remove standing water, or if the
BMP design does not meet the 96-hour
drawdown criteria because the underlying
native soils have been compacted or do not
have the infiltration capacity expected, the
[City Engineer] shall be contacted to
determine a solution. A different BMP type,
or a Vector Management Plan prepared with
concurrence from the County of San Diego
Department of Environmental Health, may be
required.
INF-3
Permeable Pavement as Structural BMP
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP
Threshold/Indicator Maintenance Action
Obstructed underdrain or outlet structure Clear blockage.
(when the BMP includes outflow control
structure for runoff released from
subsurface storage via underdrain(s))
Damage to structural components of Repair or replace as applicable.
subsurface infiltration gallery such as weirs
or outlet structures
Damage to permeable paving surface Repair or replace damaged surface as
(e.g., cracks, settlement, misaligned paver appropriate.
blocks, void spaces between paver blocks
need fill materials replenished)
References
American Mosquito Control Association.
http://www.mosguito.org/
Typical Maintenance Frequency
• Inspect if standing water is observed for
longer than 24-96 hours following a storm
event.
• Maintenance when needed.
• Inspect annually.
• Maintenance when needed.
• Inspect annually.
• Maintenance when needed.
California Storm Water Quality Association (CASQA). 2003. Municipal BMP Handbook.
https://www.casqa.org/resources/bmp-handbooks/municipal-bmp-handbook
County of San Diego. 2014. Low Impact Development Handbook.
http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html
San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet INF-3.
http://www.projectcleanwater.org/index.php?option=com content&view=article&id=250&Itemid-220
Comments
Grated lids on catch basins can be
removed for clearing underdrains. The
most common tool for cleaning
underdrains/flow restrictors is a truck with
a tank, vacuum hose, and a jet hose (e.g.
Vactor truck) to flush sediment and debris
from the pipes. If inspection and
maintenance requires entering a catch
basin, it should be conducted by an
individual trained and certified to work in
confined spaces.
INF-3
----------------. Permeable Pavement as Structural BMP
Date: Inspector: I BMP ID No.:
Permit No.: APN(s):
Property/ Development Name: Responsible Party Name and Phone Number:
Property Address of BMP: Responsible Party Address:
INSPECTION AND MAINTENANCE CHECKLIST FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP PAGE 1 of 4
Threshold/Indicator
Accumulation of sediment, litter, or debris on
permeable pavement surface
Maintenance Needed?
DvEs
□NO
□N/A
Weeds growing on/through the permeable
pavement surface
Maintenance Needed?
DvEs
□No
□N/A
Maintenance Recommendation
□Remove and properly dispose of
accumulated materials
D1nspect tributary area for exposed soil or
other sources of sediment and apply
stabilization measures to sediment source
areas. Apply source control measures as
applicable to sources of litter or debris
Dother / Comments:
□Remove weeds and add features as
necessary to prevent weed intrusion
Duse non-chemical methods (e.g., instead
of pesticides, control weeds using
mechanical removal, physical barriers,
and/or physical changes in the surrounding
area adjacent to pavement that will
preclude weed intrusion into the
pavement).
Dother / Comments:
Date Description of Maintenance Conducted
Date: Inspector:
Permit No.: APN(s):
INF-3
Permeable Pavement as Structural BMP
BMP ID No.:
INSPECTION AND MAINTENANCE CHECKLIST FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP PAGE 2 of 4
Threshold/Indicator
Standing water in permeable paving area or
subsurface infiltration gallery for longer than
2496 hours following a storm event•
Maintenance Needed?
DvEs
□NO
□N/A
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosguito.org/biology
Maintenance Needed?
DvEs
□No
□N/A
Maintenance Recommendation
D1f feasible, take corrective action to
restore infiltration (e.g., sweep pavement
with a vacuum power or regenerative air
street sweeper to restore infiltration rates,
clear underdrains if underdrains are
present). BMP may require retrofit if
infiltration cannot be restored. The [City
Engineer] shall be contacted prior to any
repairs or reconstruction.
Dather / Comments:
□Apply corrective measures to remove
standing water in BMP when standing
water occurs for longer than 24-96 hours
following a storm event.**
Dother / Comments:
Date Description of Maintenance Conducted
*Surface or subsurface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the
permeable surface layer, any of the subsurface components, or the underlying native soils. The specific cause of the drainage issue must be determined and corrected. If poor
drainage persists after flushing of the paving, subsurface gravel, and/or underdrain(s) when applicable, or if it is determined that the underlying native soils have been compacted or
do not have the infiltration capacity expected, the [City Engineer) shall be contacted prior to any additional repairs or reconstruction.
**If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria because the underlying native soils
have been compacted or do not have the infiltration capacity expected, the [City Engineer) shall be contacted to determine a solution. A different BMP type, or a Vector Management
Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required.
Date: Inspector:
Permit No.: APN(s):
INF-3
Permeable Pavement as Structural BMP
BMP ID No.:
INSPECTION AND MAINTENANCE CHECKLIST FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP PAGE 3 of 4
Threshold/Indicator
Obstructed underdrain or outlec structure
(when the BMP includes outflow control
structure for runoff released from subsurface
storage via underdrain(s))
Maintenance Needed?
□YES
□NO
□N/A
Damage to structural components of subsurface
infiltration gallery such as weirs or outlet
structures
Maintenance Needed?
□YES
□NO
□N/A
Damage to permeable paving surface (e.g.,
cracks, settlement, misaligned paver blocks, void
spaces between paver blocks need fill materials
replenished)
Maintenance Needed?
□YES
□No
□N/A
Maintenance Recommendation
Dclear blockage
Dother / Comments:
□Repair or replace as applicable
Dother / Comments:
□Repair or replace damaged su-rface as
appropriate
Dother / Comments:
Date Description of Maintenance Conducted
Date: l 1nspector:
Permit No.: I APN(s):
INF-3
Permeable Pavement as Structural BMP
I BMP ID No.: I
INSPECTION AND MAINTENANCE CHECKLIST FOR INF-3 PERMEABLE PAVEMENT AS STRUCTURAL BMP PAGE 4 of 4
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Preventive vacuum/regenerative air street □Pavement should be swept with a
sweeping vacuum power or regenerative air street
Maintenance Needed? sweeper to maintain infiltration through
DvEs
paving surface.
□Schedule/perform this preventive action □NO at least twice per year. □N/A Dother / Comments:
ATTACHMENT 3
City standard Single Sheet BMP (SSBMP) Exhibit
43
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~--------\---'----"-+/c _____ _ / ·,
GRAPHIC SCALE
0 10 20
SWMP NO. ____ _
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME MCKELLAR MCGOWAN
ADDRESS 888 PROSPECT STREET
SUITE 330 CONTACT CHRISTOPHER MCKELLAR
LA JOLLA CA 92037
PHONE NO. (858) 342-9725
PLAN PREPARED BY:
NAME RON HOLLOWAY
COMPANY-B~H~A~IN=C=·------
ADDRESS 5115AVENIDA ENCINAS
SUITE L
CARLSBAD CA 92008
PHONE NO. (760} 931-8700
BMPNOTES: CERTIFICATION ____ _
1. THESE BMPS ARE MANDATORYTO 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
BMPID# BMPTYPE SYMBOL CASQA NO. QUANTITY
TREATMENT CONTROL
CD PERVIOUS !Im SD-20 --3,348._ SF. PAVEMENT
LOW IMPACT DESIGN (L.1.D.)
0-@ ROOF DRAIN TO • SD-11 9EA. LANDSCAPING
®-@ ND DUMPING STENCILS DRAINS TO SD-13
OCEAN
* CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS
IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS:
1"=10'
ANNUAL
SEMI-ANNUALLY
QUARTERLY
BIMONTHLY
MONTHLY
AS NEEDED
NONE
WEEKLY
1 TIME PER YEAR
2 TIMES PER YEAR
3 TIMES PER YEAR
4 TIMES PER YEAR
30
TABLE
DRAWING NO. SHEET NO.(S) INSPECTION * MAINTENANCE *
FREQUENCY FREQUENCY
507-6A 4 SEMI-ANNUALLY ANNUALLY
507-6A 4 ANNUALLY ANNUALLY
I SH1ET I CITY OF CARLSBAD I SH1ETS I
ENGINEERING DEPARTMENT
SINGLE SHEET BMP SITE PLAN
HOME A VENUE CONDOMINIUMS
RECORD COPY PROJECT NO.
CT 16-10 & PUD 16-12
DAlE INillAL DAlE INITIAL I
DRAWING NO.
I REVISION DESCRIPTION OlHER APPROVAL CITY APPROVAL INITIAL DATE 507-6A
Attachment 4
Geotechnical Study
44
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, California 92029
Telephone: (619) 867-0487 Fax: (714) 409-3287
ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES
(714) 786-5661 (619) 867-0487 (619) 867-0487
McKellar McGowan December 28, 2017
888 Prospect St. #330 P/W 1607-03
La Jolla CA 92037 Report No. 1607-03-B-2R
Attention: Mr. Chris McKellar
Subject: Second Revised Geotechnical Investigation and Foundation Design
Recommendations for Proposed Residential Multi-Family Podium Structure (800
Grand Ave.) and Single Family (Home Ave.), 800 Grand Project, Carlsbad,
California
Reference: See Appendix
Gentlemen,
In accordance with your request, presented herein is Advanced Geotechnical Solutions, Inc.'s (AGS) 2ND
Revised Geotechnical Investigation and Foundation Design Recommendations for the proposed residential
structures to be located at 800 Grand Avenue, Carlsbad, California. Specifically, this report has been revised
in response to comments from the Land Development Engineering Department of the City of Carlsbad. As
we understand the project the site will be separated into two pieces: the Home Avenue portion (5 unit single
family residential) and the 800 Grand portion (partially subterranean podium structure).
The recommendations presented in the following report are based on a limited subsurface investigation
performed by AGS and associated laboratory testing. It is AGS's opinion, from a geotechnical standpoint,
the subject site is suitable for construction of the proposed residences, provided the recommendations
presented in this report are incorporated into the design, planning and construction phases of site
development. Included in this report are: 1) engineering characteristics of the onsite soils; 2) unsuitable
soil removal recommendations; 3) grading recommendations; 4) foundation design recommendations; and
5) storm water infiltration feasibility analysis.
Advanced Geotechnical Solutions, Inc., appreciates the opportunity to provide you with geotechnical
consulting services and professional opinions. If you have any questions, please contact the undersigned
at (619) 867-0487.
Respectfully Submitted,
Advanced Geotechnical Solutions, Inc.
_________________________________ _______________________________
JEFFREY A. CHANEY, President PAUL DERISI, Vice President
GE 2314, Reg. Exp. 6-30-19 CEG 2536, Reg. Exp. 5-31-19
Distribution: (3) Addressee
Attachments: Figure 1 – Site Location Map;
Figure 2 – Geologic Map and Exploration Plan;
Plate 1 – Site Geologic Map; Plate 2 – Cross-Sections;
Appendix A – Field and Laboratory Data;
Appendix B – General Earthwork Specifications & Grading Guidelines;
Appendix C – Homeowner Maintenance Recommendations;
Appendix D – Preliminary Storm Water Infiltration Feasibility Analysis
REVISED GEOTECHNICAL INVESTIGATION AND FOUNDATION
DESIGN RECOMMENDATIONS FOR PROPOSED RESIDENTIAL MULTI-
FAMILY PODIUM STRUCTURE (Grand Ave.) and SINGLE FAMILY (Home
Ave.)
800 GRAND PROJECT
CARLSBAD, CALIFORNIA
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
1.0 SCOPE OF SERVICES
This revised study is aimed at providing geotechnical information as it relates to: 1) existing site soil conditions;
2) discussion of the geologic units onsite; 3) seismic hazard analysis; 4) engineering characteristics of the onsite
soils; 5) excavation characteristics of earth materials; 6) seismic design parameters for use in the structural design
of the proposed single-family residences; 7) foundation design parameters for the proposed conventional shallow
foundation systems; and 8) storm water infiltration onsite.
The scope of our study included the following tasks:
Review of pertinent published and unpublished geologic and geotechnical literature, maps, and aerial
photographs.
Excavate, log, and sample: two (2) exploratory borings (TB-1 and TB-2) with a limited access tripod
drill rig and four Hollowstem Auger Borings (HS-1 thru HS-4) excavated with a truck mounted drill rig
CME 55 (Appendix A).
Laboratory testing of representative bulk and “undisturbed” ring samples including moisture content and
density, maximum density and optimum moisture content, shear strength, and chemical/resistivity
analysis. (Appendix A)
Excavate three (3) percolation test borings with tripod rig or with a truck mounted Hollowstem Auger
to conduct infiltration testing in accordance with Appendix D of the final Model BMP Design Manual
for the San Diego Region, adopted by the City of Carlsbad.
Conduct a geotechnical engineering and geologic hazard analysis of the site.
Conduct a limited seismicity analysis.
Determine the site-specific seismic design parameters for use in the structural design.
Determine design parameters of onsite soils as a foundation medium including bearing and friction
values for foundation soils.
Preparation of a geotechnical foundation investigation report with exhibits summarizing our findings.
This report would be suitable for design, contractor bidding, and regulatory review.
2.0 GEOTECHNICAL STUDY LIMITATIONS
The conclusions and recommendations in this report are professional opinions based on our field investigation,
associated lab testing, review of referenced geotechnical maps, and our experience in the area.
The materials immediately adjacent to or beneath those observed may have different characteristics than those
observed. No representations are made as to the quality or extent of materials not observed. Any evaluation
regarding the presence or absence of hazardous material is beyond the scope of this firm's services.
3.0 SITE LOCATION AND DESCRIPTION
The “L” shaped 1.38 acre site is located at 800 Grand Avenue, Carlsbad, California (Figure 1, Site Location
Map). The site is bounded by Grand Avenue to the south, commercial and apartment building to the east and
west and to the north by an apartment building and Home Avenue. The larger southerly portion (Parcel A- called
the Grand Avenue portion) is occupied by three older slab-on-grade, two story wood framed office buildings.
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The northerly portion of the site (Parcel B-called the Home Avenue portion) consists of an asphaltic concrete
parking lot with minor areas of landscaping. The existing driveways and parking areas consist of approximately
5 to 6 inches of concrete pavement. Based upon our review of Google Earth imagery the elevations onsite range
from a high of 64MSL at the northeastern property corner, to a low of 57 MSL at the northwest corner of the
site.
4.0 PROPOSED DEVELOPMENT
As AGS understand the project, it is anticipated that the existing commercial structures will be demolished and
the lots will be re-graded to two separate developments. The larger “Parcel A” called the 800 Grand portion lot
will support a Multi-Family Podium structure. The proposed podium will consist of a partially subterranean
garage imbedded approximately 4 to 6 feet from existing grade (See Cross-Sections, Plate 2). Above the partially
subterranean garage will be a three story of condominium podium. The condominiums will be wood frame
construction with access via the garage entryways at street level with both elevators and stairs.
The “Parcel B” called the Home Avenue portion is located in the smaller northern “panhandle” portion of the
site. It will consist of 5 single family, wood frame two-story single-family residential structures supported by
conventional or post-tensioned slab-on-grade foundation systems.
Grading on both parcels is anticipated to consist of cuts and fills of two to 9 feet, or less.
5.0 FIELD AND LABORATORY INVESTIGATION
5.1. Subsurface Exploration
AGS conducted a limited subsurface exploration at the subject site on September 10, 2016 to evaluate
the onsite soil conditions. Five exploratory borings were excavated to depths ranging from 6 to 21.5
feet bgs with a truck mounted Hollowstem Auger rig (HS-1 through HS-4) and with a limited access
tripod drill rig (TB-1 and TB-2). The approximate locations of the exploratory borings are shown on
Plate 1 with boring logs presented in Appendix A.
5.2. Laboratory Investigation
Representative “undisturbed” ring samples, and bulk samples were obtained from the borings for
laboratory testing to determine: in-situ moisture content and density; shear strengths; maximum density
and optimum moisture content; soluble sulfate/chloride content; and resistivity. Results of laboratory
testing are presented in Appendix A.
5.3. Infiltration Testing
Two additional borings were excavated adjacent to soil borings TB-1 and TB-2 to depths of
approximately 9 feet and 5 feet below existing grade. A total of three infiltration tests were conducted
(two adjacent to Grand Avenue and one in the Home Ave portion of the development). Infiltration
testing was conducted in accordance with the Borehole Percolation Testing Method described in
Appendix D of the San Diego Region BMP Design Manual and Riverside County Percolation Test
Methods (2011). Preliminary infiltration rates were calculated utilizing the Porchet Method. A more
detailed discussion of the site specific infiltration testing along with supporting worksheets, field data
and calculations are presented in Appendix D. Test locations are shown on Plate 1.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B, Escondido Ca, 920925
Telephone: (619) 726-1046 Fax: (714) 409-3287
P/W 1607-03 Report No. 1607-03-B-2
N
SITE LOCATION MAP
800 GRAND AVE
CARLSBAD, CALIFORNIA
Site
SOURCE MAP(S): TOPOGRAPHIC MAP OF THE
SAN LUIS REY 7.5 MINUTE QUADRANGLE
SAN DIEGO COUNTY, CALIFRONIA
FIGURE 1
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6.0 ENGINEERING GEOLOGY
6.1. Geologic and Geomorphic Setting
The subject site is situated within the Peninsular Ranges Geomorphic Province. The Peninsular Ranges
province occupies the southwestern portion of California and extends southward to the southern tip of
Baja California. In general the province consists of young, steeply sloped, northwest trending mountain
ranges underlain by metamorphosed Late Jurassic to Early Cretaceous-aged extrusive volcanic rock and
Cretaceous-aged igneous plutonic rock of the Peninsular Ranges Batholith. The westernmost portion of
the province is predominantly underlain by younger marine and non-marine sedimentary rocks. The
Peninsular Ranges’ dominant structural feature is northwest-southeast trending crustal blocks bounded
by active faults of the San Andreas transform system.
6.2. Subsurface Conditions
A brief description of the earth materials encountered on this site is presented in the following sections.
More detailed descriptions of these materials are provided in the boring logs included in Appendix A.
Based on our site reconnaissance, subsurface excavations, and review of the referenced geologic map,
the site is underlain to the depths explored by old paralic deposits (marine terrace deposits) which are
locally overlain by a relatively thin veneer of undocumented fill soils. A site geologic map is presented
in Figure 2.
6.2.1. Artificial Fill- Undocumented (afu)
Undocumented fill soils were encountered in the onsite excavations and observed to overlie the
old paralic deposits. As encountered in our limited subsurface investigation, the undocumented
fill soils were approximately one foot thick, it is anticipated that thicker sequences (4 to 6 feet)
may be present onsite within the existing utility lines. As encountered, these materials generally
consisted of brown, dry to slightly most, fine-grained sand with some silt in a loose condition.
6.2.2. Old Paralic Deposits (Map symbol Qop6)
The site is underlain to maximum depth explored by old paralic deposits. These materials can
generally be described as orange brown to light brownish gray, slightly moist to moist, medium
dense to dense, fine-grained sand. At the contact between the old paralic deposits and the
underlying Santiago formation was a coarse grained sandy to gravelly lag deposit which was
found to be approximately six to twelve inches thick and saturated.
6.2.3. Santiago Formation (Tsa)
The bedrock unit underlying the site is assigned to the Eocene-aged Santiago Formation. The
unit is composed predominately of a relatively massive grey green sandy silt stone that is fine-
to coarse-grained to a silty claystone. Subunits of sandy siltstone and silty claystone are
common throughout.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate drive, Suite B, Escondido Ca, 92025
Telephone: (619) 726-1046 Fax: (714) 409-3287
P/W 1607-03 Report No. 1607-03-B-2
N
SITE GEOLOGIC MAP
800 GRAND AVE.
CARLSBAD, CALIFORNIA
SOURCE MAP(S): GEOLOGIC MAP OF THE
OCEANSIDE, 30x60 QUADRANGLE
CALIFORNIA, KENNEDY AND TAN, 2005
FIGURE 2
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6.3. Groundwater/Saturated Soils
Groundwater/saturated soils were encountered in exploratory soil borings on site. Groundwater was
found to vary from 14fbg (southeast corner of the site) adjacent to Grand Street to 16.5 fbg feet from
existing grade in the northwest portion of the site adjacent to Home Avenue. It is our opinion that the
groundwater is collecting in the coarser lag deposits on top of the Santiago formation and is generally
draining in a northwesterly direction towards Buena Vista Lagoon. It should be noted that the
groundwater level may vary, due to fluctuations in precipitation, irrigation practices, infiltration water
from adjacent properties, or factors not evident at the time of our field explorations.
6.4. Non-seismic Geologic Hazards
6.4.1. Mass Wasting
Given the flat nature of the site no evidence of mass wasting was observed onsite nor was any
noted on the reviewed maps.
6.4.2. Flooding
According to available FEMA maps, the site is not in a FEMA identified flood hazard area.
6.4.3. Subsidence/Ground Fissuring
Due to the presence of the relatively dense underlying materials and the removals proposed
herein, the potential for subsidence and ground fissuring due to settlement is unlikely.
6.5. Seismic Hazards
The site is located in the tectonically active Southern California area, and will therefore likely experience
shaking effects from earthquakes. The type and severity of seismic hazards affecting the site are to a
large degree dependent upon the distance to the causative fault, the intensity of the seismic event, and
the underlying soil characteristics. The seismic hazard may be primary, such as surface rupture and/or
ground shaking, or secondary, such as liquefaction or dynamic settlement. The following is a site-
specific discussion of ground motion parameters, earthquake-induced landslide hazards, settlement, and
liquefaction. The purpose of this analysis is to identify potential seismic hazards and propose
mitigations, if necessary, to reduce the hazard to an acceptable level of risk. The following seismic
hazards discussion is guided by the California Building Code (2016), CDMG (2008), and Martin and
Lew (1998).
6.5.1. Surface Fault Rupture
No known active faults have been mapped at or near the subject site. The nearest known active
surface fault is the Oceanside section of the Newport-Inglewood-Rose Canyon fault zone which
is approximately 4.7 miles west of the subject site. Accordingly, the potential for fault surface
rupture on the subject site is considered to be low to remote. This conclusion is based on
literature review and aerial photograph analysis.
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6.5.2. Seismicity
As noted, the site is within the tectonically active southern California area, and is approximately
4.7 miles from an active fault, the Oceanside section of the Newport-Inglewood-Rose Canyon
fault zone. The potential exists for strong ground motion that may affect future improvements.
At this point in time, non-critical structures (commercial, residential, and industrial) are usually
designed according to the California Building Code (2016) and that of the controlling local
agency. However, liquefaction/seismic slope stability analyses, critical structures, water tanks
and unusual structural designs will likely require site specific ground motion input.
6.5.3. Liquefaction
In consideration of the proposed remedial grading recommendations presented herein and the
relatively dense nature and age (middle to late Pleistocene) of the deeper underlying old paralic
deposits at the project site, the potential for seismically induced liquefaction is considered low.
6.5.4. Dynamic Settlement
Dynamic settlement occurs in response to an earthquake event in loose sandy earth materials.
This potential of dynamic settlement at the subject site is considered low due to the presence of
the old paralic deposits and the proposed removals of loose, sandy soils.
6.5.5. Seismically Induced Landsliding
The topography on site is flat. As such, the potential for landsliding on site is considered nil.
6.5.6. Tsunamis
Our review of the 2009 Tsunami Inundation Map for Emergency Planning, Point Loma
Quadrangle, prepared by CalEMA, indicates the project site is not located within the tsunami
inundation line. This line represents the maximum considered tsunami run-up from a number of
local and distant tsunami sources. The suite of tsunami source events selected for modeling
represent possible but extreme and rare events. As such, no information about the probability
of any tsunami affecting any area within a specific period of time is provided. In addition, the
map does not represent inundation from a single scenario event. Rather, it was created by
combining inundation results for an ensemble of source events affecting a region.
Recent studies indicate that significant run-up heights in the Carlsbad area due to distant tsunami
source events are highly unlikely in consideration of the offshore topography and presence of
islands along the southern California borderlands. In addition, the protected shoreline in the
project vicinity will further inhibit significant run-up heights during a tsunami event.
Accordingly, it is our opinion that tsunamis are not a significant risk at the project site.
7.0 GEOTECHNICAL ENGINEERING
Presented herein is a general discussion of the geotechnical properties of the various soil types and the analytic
methods used in this report.
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7.1. Material Properties
7.1.1. Excavation Characteristics
Based on our previous experience with similar projects near the subject site and the information
gathered in preparing this report, it is our opinion that the undocumented fill soils and Old
Paralic Deposits are readily excavatable with conventional grading equipment. However, it
should be anticipated that well cemented zones could be encountered within the old paralic
deposits that may be difficult to excavate. Specialized grading equipment (large excavators
and/or bull dozers) may be necessary to efficiently excavate portions of the old paralic deposits.
7.1.2. Compressibility
The near surface undocumented fill soils and the weathered one to two feet of the Old Paralic
deposits are considered to be moderately compressible in their present condition.
Compressibility of the unweathered old paralic deposits is not a geotechnical design concern for
the proposed structures.
7.1.3. Collapse Potential/Hydro-Consolidation
Given the relatively thin veneer of undocumented fill soils on top of the generally dense
formational materials, and the removals proposed herein, the potential for hydro-consolidation
is considered remote at the subject site.
7.1.4. Expansion Potential
Based on our previous experience in the area with similar materials, the onsite soils exposed
within the upper 10 to 15 feet will likely exhibit a “very low to low” expansion potential.
7.1.5. Shear Strength
Based upon our laboratory testing and our previous experience in the area with similar soils, the
following are proposed shear strengths for compacted fill and old paralic deposits.
TABLE 7.1.5
SHEAR STRENGTHS
Material Cohesion
(psf)
Friction Angle
(degrees)
Compacted Fill 150 34
Old Paralic Deposits 250 35
7.1.6. Chemical/Resistivity Test Results
Preliminary soluble sulfate and chloride, and resistivity testing was conducted on a
representative bulk sample obtained during subsurface exploration (Appendix A). Based upon
the test results and our previous experience in the area it is anticipated that the onsite soil will
exhibit "negligible" sulfate concentrations when classified in accordance with ACI 318-05 Table
4.3.1 (per 2016 CBC).
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Testing reveals that soil on site has a “low” corrosion potential to metal construction materials
in direct contact to the onsite soils.
7.1.7. Earthwork Adjustments
It is anticipated that the onsite fill soils and weathered old paralic deposits will shrink on the
order of 5 to 10 percent when re-compacted. The fresher, old paralic deposits are anticipated to
bulk on the order of 4 to 8 percent when used to make compacted fill.
7.1.8. Pavement Support Characteristics
It is anticipated that the onsite soils will have good to moderate support characteristics.
Depending upon the final distribution of site soils, pavement support characteristics could vary.
If structural pavements are to be constructed (concrete or asphaltic concrete), an "R"-value of
35 can be utilized for the preliminary design of pavements. Final design should be based upon
representative sampling of the as-graded soils.
7.1.9. Infiltration Potential
AGS conducted three borehole percolation tests (P-1 and P-2) in the southern portion of the site
(Grand Avenue) and one test (HSP-3) in the northern portion of the site (Home Avenue), in
accordance with the testing methods described in Appendix D of the BMP Design Manual.
Based on the results of our subsurface investigation, it is anticipated that the dense upper
portions of the sandy Old Paralic deposits onsite possess relatively high to moderate infiltration
rates. Infiltration rates were calculated using the Porchet method. Measured infiltration rates
varied from between 0.77 in/hr and 2.83 in/hr.
8.0 CONCLUSIONS AND RECOMMENDATIONS
Construction of the proposed “Podium” structure (Grand Avenue) and the single family residential structures
(Home Avenue) and associated improvements are considered feasible, from a geotechnical standpoint, provided
that the conclusions and recommendations presented herein are incorporated into the design and construction of
the project. Presented below are specific issues identified by this study as possibly affecting site development.
Recommendations to mitigate these issues are presented in the text of this report.
8.1. Grading Recommendations
8.1.1. Unsuitable Soil Removals
In areas to receive settlement sensitive structures, all undocumented fill soils and highly
weathered formational materials should be removed. It is anticipated that the upper 1 to 3 feet
of the onsite soils will require removal and recompaction for the support of settlement sensitive
structures. Localized areas may require deeper removals. Minimally the removals should extend
a lateral distance of at least 5 feet beyond the limits of settlement sensitive structures. If deeper
removals are performed, the removals should extend a lateral distance equal to the depth of
removal beyond the improvement limits. Removal bottoms should expose competent
formational materials in a firm and unyielding condition. The resulting removal bottoms should
be observed by a representative of AGS to verify that adequate removal of unsuitable materials
have been conducted prior to fill placement. In general, soils removed during remedial grading
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
will be suitable for reuse in compacted fills, provided they are properly moisture conditioned
and do not contain deleterious materials. Grading shall be accomplished under the observation
and testing of the project soils engineer and engineering geologist or their authorized
representative in accordance with the recommendations contained herein, the current grading
ordinance of the City of Carlsbad.
8.2. Earthwork Considerations
8.2.1. Compaction Standards
Fill and processed natural ground shall be compacted to a minimum relative compaction of 90
percent as determined by ASTM Test Method: D 1557. All fill to be placed below subdrains
should be compacted to at least 93 percent of maximum dry density. Compaction shall be
achieved at slightly above the optimum moisture content, and as generally discussed in the
attached Earthwork Specifications (Appendix E).
8.2.2. Benching
Where the natural slope is steeper than 5-horizontal to 1-vertical and where determined by the
project Geotechnical Engineer or Engineering Geologist, compacted fill material shall be keyed
and benched into competent materials.
8.2.3. Mixing and Moisture Control
In order to prevent layering of different soil types and/or different moisture contents, mixing
and moisture control of materials may be necessary. The preparation of the earth materials
through mixing and moisture control should be accomplished prior to and as part of the
compaction of each fill lift. Water trucks or other water delivery means may be necessary for
moisture control. Discing may be required when either excessively dry or wet materials are
encountered.
8.2.4. Haul Roads
All haul roads, ramp fills, and tailing areas shall be removed prior to engineered fill placement.
8.2.5. Import Soils
Import soils, if required, should consist of clean, structural quality, compactable materials
similar to the on-site soils and should be free of trash, debris or other objectionable materials.
Import soils should be tested and approved by the geotechnical consultant prior to importing. At
least three working days should be allowed in order for the geotechnical consultant to sample
and test the potential import material.
8.2.6. Utility Trench Excavation and Backfill
All utility trenches should be shored or laid back in accordance with applicable Cal/OSHA
standards. Excavations in bedrock areas should be made in consideration of underlying geologic
structure. The geotechnical consultant should be consulted on these issues during construction.
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Mainline and lateral utility trench backfill should be compacted to at least 90 percent of
maximum dry density as determined by ASTM D 1557. Onsite soils will not be suitable for use
as bedding material but will be suitable for use in backfill, provided oversized materials are
removed. No surcharge loads should be imposed above excavations. This includes spoil piles,
lumber, concrete trucks or other construction materials and equipment. Drainage above
excavations should be directed away from the banks. Care should be taken to avoid saturation
of the soils.
Compaction should be accomplished by mechanical means. Jetting of native soils will not be
acceptable.
To reduce moisture penetration beneath the slab-on-grade areas, shallow utility trenches should
be backfilled with lean concrete or concrete slurry where they intercept the foundation
perimeter. As an alternative, such excavations can be backfilled with native soils, moisture-
conditioned to over optimum, and compacted to a minimum of 90 percent relative compaction.
8.3. Design Recommendations
The following design recommendations have been separated due to the different building types. Grand
Avenue will consist of a “Podium” structure with a partially subterranean structure and Home Avenue
with will be conventional slab-on-grade wood frame structures.
8.3.1. Grand Avenue-Podium Structure
It is our understanding that the proposed Grand Avenue condominium building will consist of a
“Podium” with a partially subterranean “Mat” slab-on-grade foundation system. The podium
will support the three-story wood-frame residential structure. It is anticipated that the foundation
systems will likely be a “Mat” system with CMU basement walls. In addition to the structures,
associated driveways, hardscape and landscape areas are proposed. From a geotechnical
perspective these proposed improvements are feasible provided that the following
recommendations are incorporated into the design and construction.
8.3.1.1. Foundation Design Criteria Podium Structure –Grand Avenue
The residential condominium podium structure can be supported on a shallow “mat”
foundation system. For preliminary design, the expansion potential of the underlying
soils can be considered “Very Low” to "Low". The following values may be used in
the foundation design.
Allowable Bearing: 3000 lbs./sq.ft.
Lateral Bearing: 350 lbs./sq.ft. at a depth of 12 inches plus
200 lbs./sq.ft. for each additional 12 inches
embedment to a maximum of 5000 lbs./sq.ft.
Sliding Coefficient: 0.37
Settlement: Total = 3/4 inch
Differential: 3/8 inch in 20 feet
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The above values may be increased as allowed by Code to resist transient loads such as
wind or seismic. Building Code and structural design considerations may govern. Depth
and reinforcement requirements should be evaluated by the Structural Engineer.
Based upon the onsite soil conditions and information supplied by the 2016 CBC,
conventional foundation systems should be designed in accordance with Section 8.2.1.1
and the following recommendations.
Continuous Footings-
Depth- Minimum of 24 inches
Width-Minimum of 18 inches
Reinforcement- Minimum four No.5 rebar’s, two top and two bottom
Isolated Spread Footings- Minimum of 24 inches wide and 24 inches deep
(Reinforcement per structural engineer)
Garage Slab-Minimum of 5 inches thick with # 3 rebar on 15 inch centers
both ways. Consideration should be given to underlay the garage slab with a
moisture barrier.
Garage Slab Entrance- A grade beam reinforced continuously with the
garage footings shall be constructed across the garage entrances, tying
together the ends of the perimeter footings and between individual spread
footings. This grade beam should be embedded a minimum of 18 inches. A
thickened slab, separated by a cold joint from the garage beam, should be
provided at the garage entrance. Minimum dimensions of the thickened edge
shall be six (6) inches deep. Footing depth, width and reinforcement should
be the same as the structure. Slab thickness, reinforcement and under-slab
treatment should be the same as the structure.
8.3.2. Home Avenue-Conventional Slab-On-Grade
The conventional slab-on-grade residential one to two story structures can be supported on
conventional shallow foundation and slab-on-grade systems. For preliminary design, the
expansion potential of the underlying soils can be considered “Very Low” to "Low". The
following values may be used in the foundation design.
Allowable Bearing: 2000 lbs./sq.ft.
Lateral Bearing: 300 lbs./sq.ft. at a depth of 12 inches plus
200 lbs./sq.ft. for each additional 12 inches
embedment to a maximum of 2000 lbs./sq.ft.
Sliding Coefficient: 0.40
Settlement: Total = 3/4 inch
Differential: 3/8 inch in 20 feet
The above values may be increased as allowed by Code to resist transient loads such as wind or
seismic. Building Code and structural design considerations may govern. Depth and
reinforcement requirements should be evaluated by the Structural Engineer. Based upon the
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onsite soil conditions and information supplied by the 2013 CBC, conventional foundation
systems should be designed in accordance with Section 8.2.1 and the following
recommendations.
Interior and exterior footings for one-story structures should be a minimum of
12 inches wide and extend to a depth of at least 12 inches below lowest adjacent
grade. Footing reinforcement should minimally consist of four No. 4
reinforcing bars, two top and two bottom or two No. 5 reinforcing bars, one top
and one bottom.
Interior and exterior footings for two-story structures should be a minimum of
15 inches wide and extend to a depth of at least 18 inches below lowest adjacent
grade. Footing reinforcement should minimally consist of four No. 4
reinforcing bars, two top and two bottom or two No. 5 reinforcing bars, one top
and one bottom.
Interior and exterior footings for three-story structures should be a minimum of
18 inches wide and extend to a depth of at least 24 inches below lowest adjacent
grade. Footing reinforcement should minimally consist of four No. 4
reinforcing bars, two top and two bottom or two No. 5 reinforcing bars, one top
and one bottom.
Conventional, slab-on-grade floors, underlain by “low” expansive soil, should
be five or more inches thick and be reinforced with No. 3 or larger reinforcing
bars spaced 18 inches on center each way. The slab reinforcement and
expansion joint spacing should be designed by the Structural Engineer.
If exterior footings adjacent to drainage swales are to exist within five feet
horizontally of the swale, the footing should be embedded sufficiently to assure
embedment below the swale bottom is maintained. Footings adjacent to slopes
should be embedded such that a least seven feet are provided horizontally from
edge of the footing to the face of the slope.
Isolated spread footings outside the footprint of the proposed structures should
be tied with grade beams to the structure in two orthogonal directions.
A grade beam reinforced continuously with the garage footings shall be
constructed across the garage entrance, tying together the ends of the perimeter
footings and between individual spread footings. This grade beam should be
embedded at the same depth as the adjacent perimeter footings. A thickened
slab, separated by a cold joint from the garage beam, should be provided at the
garage entrance. Minimum dimensions of the thickened edge shall be six (6)
inches deep. Footing depth, width and reinforcement should be the same as the
structure. Slab thickness, reinforcement and under-slab treatment should be the
same as the structure.
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8.4 Seismic Design Parameters
The following seismic design parameters are presented to be code compliant to the California Building
Code (2016). The subject parcels have been identified to be Site Class "C" in accordance with CBC,
2013, Section 1613.3.2 and ASCE 7, Chapter 20. The lots are located at Latitude 33.1633°N, and
Longitude 117.3462° W. Utilizing this information, the United States Geological Survey (USGS) web
tool (http://earthquake.usgs.gov/hazards/designmaps/) and ASCE 7 criterion, the mapped seismic
acceleration parameters SS, for 0.2 seconds and S1, for 1.0 second period (CBC, 2016, 1613.3.1) for
Risk-Targeted Maximum Considered Earthquake (MCER) can be determined. The mapped acceleration
parameters are provided for Site Class “B”. Adjustments for other Site Classes are made, as needed, by
utilizing Site Coefficients Fa and Fv for determination of MCER spectral response acceleration
parameters SMS for short periods and SM1 for 1.0 second period (CBC, 2016 1613.3.3). Five-percent
damped design spectral response acceleration parameters SDS for short periods and SD1 for 1.0 second
period can be determined from the equations in CBC, 2013, Section 1613.3.4.
TABLE 8.4
SEISMIC DESIGN CRITERIA
Mapped Spectral Acceleration (0.2 sec Period), SS 1.147g
Mapped Spectral Acceleration (1.0 sec Period), S1 0.440g
Site Coefficient, Fa 1.000
Site Coefficient, Fv 1.360
MCE Spectral Response Acceleration (0.2 sec Period), SMS 1.147g
MCE Spectral Response Acceleration (1.0 sec Period), SM1 0.598g
Design Spectral Response Acceleration (0.2 sec Period), SDS 0.764g
Design Spectral Response Acceleration (1.0 sec Period), SD1 0.399g
Using the United States Geological Survey (USGS) web-based ground motion calculator, the site class
modified PGAM (FPGA*PGA) was determined to be 0.454g.
8.5 Deepened Footings and Structural Setbacks
It is generally recognized that improvements constructed in proximity to natural slopes or properly
constructed, manufactured slopes can, over a period of time, be affected by natural processes including
gravity forces, weathering of surficial soils and long-term (secondary) settlement. Most building codes,
including the California Building Code (CBC), require that structures be set back or footings deepened,
where subject to the influence of these natural processes.
Grading plans for the subject site were not available for review at the time of this report, but as AGS
understands the project, no slopes greater than 5 feet are planned. If foundations for residential structures
December 28, 2017 Page 13
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
are to exist in proximity to slopes, the footings should be embedded to satisfy the requirements presented
in Figure 4.
FIGURE 4
H
TOP OF SLOPE
FACE OF FOOTING
TOE OF SLOPE
FACE OF
STRUCTURE H/3 BUT NEED NOT EXCEED 40 FT. MAX.
H/2 BUT NEED NOT
EXCEED 15 FT. MAX.
8.6 Under Slab
Prior to concrete placement the subgrade soils should be moisture conditioned to optimum moisture
content.
A moisture and vapor retarding system should be placed below the slabs-on-grade in portions of the
structure considered to be moisture sensitive. The retarder should be of suitable composition, thickness,
strength and low permeance to effectively prevent the migration of water and reduce the transmission of
water vapor to acceptable levels. Historically, a 10-mil plastic membrane, such as Visqueen, placed
between one to four inches of clean sand, has been used for this purpose. More recently Stego® Wrap
or similar underlayments have been used to lower permeance to effectively prevent the migration of
water and reduce the transmission of water vapor to acceptable levels. The use of this system or other
systems, materials or techniques can be considered, at the discretion of the designer, provided the system
reduces the vapor transmission rates to acceptable levels.
8.7 Concrete Design
Laboratory testing and our previous experience in the general area indicates onsite soils likely exhibit a
“negligible” sulfate exposure when classified in accordance with ACI 318-11 Table 4.2.1. Final
determination will be based upon testing of near surface soils obtained at the conclusion of grading.
However, some fertilizers have been known to leach sulfates into soils otherwise containing "negligible"
sulfate concentrations and increase the sulfate concentrations to potentially detrimental levels. It is
incumbent upon the owner to determine whether additional protective measures are warranted to
mitigate the potential for increased sulfate concentrations to onsite soils as a result of the future
homeowner’s actions.
8.8 Corrosion
Resistivity tests performed indicate that the onsite soils possess a “low” corrosion potential to buried
metallic materials. It is our understanding that only the last ten feet of the domestic and fire waterlines
December 28, 2017 Page 14
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
will be metallic, with the remainder of these lines being non-metallic. Further, the proposed plumbing
for each structure will not be located under slab but will be located in the walls and roofs. Provided that
all metallic piping is wrapped with a suitable corrosion inhibiting material (foam, plastic sleeve, tape, or
similar products) and that non-aggressive backfill (sand) soils are placed around all metallic pipe, no
other requirements are deemed necessary to address the “moderately” corrosive soils found onsite.
8.9 Retaining Walls
At the time of this report, grading plans were not available for our review. As AGS understands the
project, no buried structures or retaining walls are anticipated. The following earth pressures are
recommended for design if retaining walls are proposed onsite. At rest earth pressures should be used in
the design of restrained basement walls.
Static Case
Compacted Fill/Old Paralic Deposits (34° at 125pcf):
Rankine Equivalent Fluid
Level Backfill Coefficients Pressure (psf/lin.ft.)
Coefficient of Active Pressure: Ka = 0.28 35
Coefficient of Passive Pressure: Kp = 3.54 442
Coefficient of At Rest Pressure: Ko = 0.44 55
Seismic Case
In addition to the above static pressures, unrestrained retaining walls should be designed to resist seismic
loading. In order to be considered unrestrained, retaining walls should be allowed to rotate a minimum
of roughly 0.004 times the wall height. The seismic load can be modeled as a thrust load applied at a
point 0.6H above the base of the wall, where H is equal to the height of the wall. This seismic load (in
pounds per lineal foot of wall) is represented by the following equation:
Pe = ⅜ *γ*H2 *kh
Where:
H = Height of the wall (feet)
γ = soil density = 125 pounds per cubic foot (pcf)
kh = ½ * peak horizontal ground acceleration = ½ * 0.537g
Walls should be designed to resist the combined effects of static pressures and the above seismic
thrust load.
A bearing value of 3,000 psf may be used for design of basement walls. A value of 0.40 may be used to
model the frictional between the soil and concrete. For sliding passive pressure both passive and friction
can be combined to a maximum of 2/3 the total.
Retaining wall footings should be designed to resist the lateral forces by passive soil resistance and/or
base friction as recommended for foundation lateral resistance. To relieve the potential for hydrostatic
pressure wall backfill should consist of a free draining backfill (sand equivalent “SE” >20) and a heel
drain should be constructed. The heel drain should be place at the heel of the wall and should consist of
a 4-inch diameter perforated pipe (SDR35 or SCHD 40) surrounded by 4 cubic feet of crushed rock (3/4-
inch) per lineal foot, wrapped in filter fabric (Mirafi® 140N or equivalent).
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Proper drainage devices should be installed along the top of the wall backfill, which should be properly
sloped to prevent surface water ponding adjacent to the wall. In addition to the wall drainage system, for
building perimeter walls extending below the finished grade, the wall should be waterproofed and/or
damp-proofed to effectively seal the wall from moisture infiltration through the wall section to the
interior wall face. Retaining wall backfill and drains should be constructed in general conformance to
RTW-A. Final design of the waterproofing should be determined by the Architect.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
RETAINING WALL
ALT. A - SELECT BACKFILL
VER 1.0 NTS
WATERPROOFING
MEMBRANE
PROVIDEDRAINAGE
SWALE D E SI GN GR A D E
1:1 (H:V) OR FLATTER
H BACKCUTH/2
min.
SELECT
BACKFILL(EI 20 &SE 20)
<>
NATIVEBACKFILL(EI 50)<
DRAIN (1)
NOTES: DRAIN: (1) 4-INCH PERFORATED ABS OR PVC PIPE OR APPROVED EQUIVALENT SUBSTITUTE PLACED PERFORATIONS DOWN AND SURROUNDED BY A MINIMUM OF 1 CUBIC FEET OF 3/4 INCH ROCK OR APPROVED EQUIVALEN T SUBSTITUTE AND WRAPPED IN MIRAFI 140 FILTER FABRIC OR APPROVED EQUIVALENT SUBSTITUTE
12 in.
min.
December 28, 2017 Page 16
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
The retaining walls should be backfilled with granular soils placed in loose lifts no greater than
8-inches thick, at or near optimum moisture content, and mechanically compacted to a minimum
90 percent relative compaction as determined by ASTM Test Method D1557. Flooding or
jetting of backfill materials generally do not result in the required degree and uniformity of
compaction and, therefore, is not recommended. The soils engineer or his representative should
observe the retaining wall footings, backdrain installation and be present during placement of
the wall backfill to confirm that the walls are properly backfilled and compacted.
8.10 Utility Trench Excavation
All utility trenches should be shored or laid back in accordance with applicable CAL/OSHA standards.
Excavations in bedrock areas should be made in consideration of underlying geologic structure. AGS
should be consulted on these issues during construction.
8.11 Utility Trench Backfill
Mainline and lateral utility trench backfill should be compacted to at least 90 percent of maximum dry
density as determined by ASTM D 1557. Onsite soils will not be suitable for use as bedding material
but will be suitable for use in backfill, provided oversized materials are removed. No surcharge loads
should be imposed above excavations. This includes spoil piles, lumber, concrete trucks or other
construction materials and equipment. Drainage above excavations should be directed away from the
banks. Care should be taken to avoid saturation of the soils. Compaction should be accomplished by
mechanical means. Jetting of native soils will not be acceptable.
8.12 Exterior Slabs and Walkways
Subgrade Compaction
The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be compacted to
a minimum of 90 percent relative compaction as determined by ASTM D 1557.
Subgrade Moisture
The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be moisture
conditioned to a minimum of 110 percent of optimum moisture content prior to concrete
placement.
Slab Thickness
Concrete flatwork and driveways should be designed utilizing four-inch minimum thickness.
Control Joints
Weakened plane joints should be installed on walkways at intervals of approximately eight to
ten feet. Exterior slabs should be designed to withstand shrinkage of the concrete.
Flatwork Reinforcement
Consideration should be given to reinforcing any exterior flatwork.
December 28, 2017 Page 17
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Thickened Edge
Consideration should be given to construct a thickened edge (scoop footing) at the perimeter
of slabs and walkways adjacent to landscape areas to minimize moisture variation below these
improvements. The thickened edge (scoop footing) should extend approximately eight inches
below concrete slabs and should be a minimum of six inches wide.
9.0 BMP DESIGN
AGS conducted site specific percolation testing to determine preliminary infiltration rates and evaluate
feasibility for storm water infiltration at the project site. Testing was completed in general accordance
with the new 2016 San Diego Region BMP Design Manual. Worksheet C-4.1 and supporting documents
are presented in Appendix D.
Based on the results of our preliminary testing, Full to Partial Infiltration design for BMPs is potentially
feasible for the Home Avenue portion of the site. For the Grand Avenue portion of the site AGS does
not recommend full or partial infiltration as this portion of the development will be supported by a
partially subterranean garage “Podium” structure. From a geotechnical perspective the addition of
shallow groundwater from infiltration near the podium structure is highly unpredictable. In some
instances infiltration below and adjacent to these types of structures has resulted in: additional hydraulic
forces on basement walls; increase the likelihood for unwanted seepage into the basement; caused
differential settlement across the basement floor; and created mounding of infiltration water due to the
disruption of the horizontal conductivity of the flat lying deposits found in the Old Paralic deposits.
10.0 PLAN REVIEW
Once grading and foundation design plans become available, they should be reviewed by AGS to verify
that the design recommendations presented are consistent with the proposed construction.
11.0 GEOTECHNICAL REVIEW
As is the case in any grading project, multiple working hypotheses are established utilizing the available
data, and the most probable model is used for the analysis. Information collected during the grading and
construction operations is intended to evaluate these hypotheses, and some of the assumptions
summarized herein may need to be changed as more information becomes available. Some modification
of the grading and construction recommendations may become necessary, should the conditions
encountered in the field differ significantly than those hypothesized to exist.
AGS should review the pertinent plans and sections of the project specifications, to evaluate
conformance with the intent of the recommendations contained in this report.
If the project description or final design varies from that described in this report, AGS must be consulted
regarding the applicability of, and the necessity for, any revisions to the recommendations presented
herein. AGS accepts no liability for any use of its recommendations if the project description or final
design varies and AGS is not consulted regarding the changes.
12.0 SLOPE AND LOT MAINTENANCE
Maintenance of improvements is essential to the long-term performance of structures and slopes. Although the
design and construction during mass grading is planned to create slopes that are both grossly and surficially
December 28, 2017 Page 18
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
stable, certain factors are beyond the control of the soil engineer and geologist. The homeowners must
implement certain maintenance procedures.
The following recommendations should be implemented.
12.1. Lot Drainage
Roof, pad and lot drainage should be collected and directed away from structures and slopes and toward
approved disposal areas. Design fine-grade elevations should be maintained through the life of the
structure or if design fine grade elevations are altered, adequate area drains should be installed in order
to provide rapid discharge of water, away from structures and slopes. Residents should be made aware
that they are responsible for maintenance and cleaning of all drainage terraces, down drains and other
devices that have been installed to promote structure and slope stability.
12.2. Irrigation
The resident, homeowner and Homeowner Association should be advised of their responsibility to
maintain irrigation systems. Leaks should be repaired immediately. Sprinklers should be adjusted to
provide maximum uniform coverage with a minimum of water usage and overlap.
Overwatering with consequent wasteful run-off and ground saturation should be avoided. If automatic
sprinkler systems are installed, their use must be adjusted to account for natural rainfall conditions.
12.3. Burrowing Animals
Residents or homeowners should undertake a program for the elimination of burrowing animals. This
should be an ongoing program in order to maintain slope stability.
13.0 LIMITATIONS
This report is based on the project as described and the information obtained from the excavations at the
approximate locations indicated on Plate 1. The findings are based on the results of the field, laboratory, and
office investigations combined with an interpolation and extrapolation of conditions between and beyond the
excavation locations. The results reflect an interpretation of the direct evidence obtained. Services performed
by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by
members of the profession currently practicing in the same locality under similar conditions. No other
representation, either expressed or implied, and no warranty or guarantee is included or intended.
The recommendations presented in this report are based on the assumption that an appropriate level of field
review will be provided by geotechnical engineers and engineering geologists who are familiar with the design
and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic
conditions exposed during grading are consistent with the geologic representations and corresponding
recommendations presented in this report. AGS should be notified of any pertinent changes in the project plans
or if subsurface conditions are found to vary from those described herein. Such changes or variations may
require a re-evaluation of the recommendations contained in this report.
The data, opinions, and recommendations of this report are applicable to the specific design of this project as
discussed in this report. They have no applicability to any other project or to any other location, and any and all
subsequent users accept any and all liability resulting from any use or reuse of the data, opinions, and
recommendations without the prior written consent of AGS.
December 28, 2017 Page 19
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
AGS has no responsibility for construction means, methods, techniques, sequences, or procedures, or for safety
precautions or programs in connection with the construction, for the acts or omissions of the CONTRACTOR,
or any other person performing any of the construction, or for the failure of any of them to carry out the
construction in accordance with the final design drawings and specifications.
December 28, 2017 Page 20
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
REFERENCES
Advanced Geotechnical Solutions, Inc. (2017), Revised Geotechnical Investigation and Foundation Design
Recommendations for Proposed Residential Multi-Family Podium Structure (800 Grand Ave.) and
Single Family (Home Ave.), 800 Grand Project, Carlsbad, California(Report No. 1607-03-B-2R dated
11/21/17)
Advanced Geotechnical Solutions, Inc. (2017), Geotechnical Investigation and Foundation Design
Recommendations for Proposed Residential Multi-Family Podium Structure (Grand Ave.) and Single
Family (Home Ave.), 800 Grand Project, Carlsbad, California (Report No. 1607-03-B-2 dated
10/21/17)
American Concrete Institute, 2002, Building Code Requirements for Structural Concrete (ACI318M-02) and
Commentary (ACI 318RM-02), ACI International, Farmington Hills, Michigan.
American Society for Testing and Materials (2008), Annual Book of ASTM Standards, Section 4, Construction,
Volume 04.08, Soil and Rock (I), ASTM International, West Conshohocken, Pennsylvania.
California Code of Regulation, Title 24, 2013 California Building Code, 3 Volumes.
California Emergency Management Agency, 2009, Tsunami Inundation Map for Emergency Planning, Point
Loma Quadrangle, County of San Diego, California, Scale 1:24,000.
Gouvis Engineering 2017, 849 Home Avenue, Foundation Plans, Sheets SN-1,S1.1, S2.1, S3.1 & SD-1, City
of Carlsbad, California dated November 22, 2017 (Job No. 64516)
Jennings, C.W., and Bryant, W.A., 2010, Fault Activity Map of California: California Geological Survey,
California Geologic Data Map No. 6, Scale 1:750,000.
Kennedy, M.P., and Tan, S.S., 2008, Geologic Map of the San Diego 30’ x 60’ Quadrangle, California Regional
Geologic Map Series, Scale 1:100,000, Map No. 3, Sheet 1 of 2.
San Diego Region, Model BMP Design Manual for Permanent Site Design, Storm Water Treatment and Hydro-
modification Management, February 2016.
United States Geological Survey, 2010 Ground Motion Parameter Calculator v. 5.1.0., World Wide Web,
http://earthquake.usgs.gov/designmaps/us/application.php.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX A
FIELD AND LABORATORY DATA
ADVANCED GEOTECHNICAL SOLUTIONS, INC., 2016
Shear,RemoldedConsol, EI
Shear,RemoldedConsol
5.086
BU
MCMC
SPT
SPT
SPT
Artifical fill undocumented (afu), AC approximately 2 inch,
with 3 inch of base
@ 0.5 ft, Old Paralic Deposits (Qop6), SILTYSANDSTONE, medium to fine grained, red brown, dry
@ 2.5 ft, slightly moist, freshening@ 3.0 ft, SILTY SANDSTONE, medium to fine grained,slightly moist, moderately hard
@ 5.0 ft, SANDSTONE , medium to coarse grained, red tobrown, slightly moist, moderately hard to hard
@ 7.0 ft SANDSTONE, medium grained, light tan,
freshening
@ 14.0 ft SANDSTONE, medium to coarse grained, tan to
light brown, slightly moist, moderately hard, gravel 3/8th inchto 1/2 inch
@ 16.5 ft SANDSTONE, becoming saturated, interbedded
CLAY, very moist to saturated, hard
@ 19.0 ft, Santiago Formation (Tsa), CLAYSTONE, gray,moist, moderately hard
@ 19.5 ft, CLAYSTONE, gray, moist to saturated, soft
Total Depth = 19.75 FeetNo Groundwater EncounteredBackfilled with Cement and Bentonite Grout per San Diego
County
36/3"50/3"
15-18-21(39)
20-21-38(59)
21-32-5(37)
NOTES
GROUND ELEVATION 62 ft
LOGGED BY JAC
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8 inch
DRILLING CONTRACTOR Baja Exploration GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5
10
15 FINES CONTENT(%)ELEVATION(ft)60
55
50
45 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER HS-1
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Shear,RemoldedConsol
31
103
99
4.3
22.8
18.9
119
103
108
MC
SPT
MC
MC
MC
Artificial Fill Undocumented (afu), 0-4 inch CONCRETE
@ 4 inch, Old Paralic Deposits (Qop6), SANDSTONE,medium to coarse grained, red brown, slightly moist, soft tomoderately hard
@ 3.0 ft SILTY SAND, medium to coarse grained, redbrown, slightly moist, dense@ 5.0 ft, SANDSTONE, medium to coarse grained, red
brown, moist, hard@ 7.5 ft, medium to coarse grained, light tan, slightly moist,hard
@ 8.5 ft, CLAYSTONE, coarse grained, moist to very moist,soft to moderately hard
@ 10.0 ft, SILTY SANDSTONE, medium to fine grained, tan
to red brown, moist to very moist, moderately hard@ 12.0 ft, SILTY SANDSTONE, medium to fine grained,medium brown, moist to very moist, hard to very hard, (Tight
Drilling)
@ 17.5 ft, SILTY SANDSTONE, medium to fine grained, tan
to gray, moist to very moist, hard@18.0 ft, LAG DEPOSIT, coarse grained, very moist tosaturated, firm
@ 20 ft, Santiago Formation (Tsa), CLAYSTONE, dark
green, very moist to saturated, hard
Total Depth = 21.5 FeetNo Groundwater Encountered
Backfilled with Cement and Bentonite Grout per San DiegoCounty
SM
SC
21-31-39(70)
12-14-14(28)
15-28
50/3"
50/5"
NOTES
GROUND ELEVATION 64 ft
LOGGED BY JAC
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8 inch
DRILLING CONTRACTOR Baja Exploration GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5
10
15
20 FINES CONTENT(%)ELEVATION(ft)60
55
50
45 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER HS-2
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Artificial Fill Undocumented (afu), 3 inch AC
@ 0.5 ft, Old Paralic Deposits (Qop6), SILTYSANDSTONE, medium to dark brown, slightly moist,moderately hard
@ 1.0 ft SANDSTONE, medium to fine grained, red brown,moist, moderately hard
Total Depth = 6.0 FeetNo Groundwater Encountered
Backfilled with Cement and Bentonite Grout per San DiegoCounty
SM
NOTES
GROUND ELEVATION 60 ft
LOGGED BY JAC
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8 inch
DRILLING CONTRACTOR Baja Exploration GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5 FINES CONTENT(%)ELEVATION(ft)60
55 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER HS-3
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Sieve
51
108
7.6
20.5
117
109
SPT
MC
SPT
MCMC
Artifical Fill Undocumented (afu), 3 inches AC over 3
inches base@ 0.25 ft SILTY SAND, medium to fine grained, tan to redbrown, slightly moist, dense
@ 0.5 ft Old Paralic Deposit (Qop6) SANDSTONE,medium to fine grained, red brown, slightly moist,moderately hard
@ 5.0 ft SANDSTONE, medium to coarse grained, light tanto red brown, slightly moist, hard@ 6.0 ft SANDSTONE, medium to fine grained, light tan,
slightly moist, moderately hard
@ 10.0 ft SANDSTONE, medium grained, dark brown,
slightly moist, soft@ 12.0 ft SANDSTONE, medium to fine grained, brown todark brown, moist, moderately hard to hard
(hard drilling)@ 13.0 ft occasional 4 inch gravel
@ 15.0 ft Interbedded SAND, medium to fine grained, tan to
gray brown, saturated, dense@ 17.5 ft LAG Deposit, 3/8th-3/4th inch diameter
@ 18.0 ft, Santiago Formation (Tsa), SANDSTONE,
medium to coarse grained, saturated, very hard
Total Depth = 20.0 Feet
No Groundwater EncounteredBackfilled with Cement and Bentonite Grout per San DiegoCounty
SM
23
12-11-12(23)
23-47-50(97)
12-12-20(32)
2450/2"
NOTES
GROUND ELEVATION 61 ft
LOGGED BY JAC
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8 inch
DRILLING CONTRACTOR Baja Exploration GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5
10
15
20 FINES CONTENT(%)ELEVATION(ft)60
55
50
45 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER HS-4
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Shear,RemoldedConsol
49
45
72
101
6.0
8.3
9.6
19.6
123
110
120
108
MC
MC
MC
MC
MC
MC
MC
Artificial Fill Undocumented (afu), SILTY SAND, medium
grained, brown, dry, loose, some rootlets
@ 1 ft Old Paralic Deposits (Qop6), CLAYEYSANDSTONE, fine grained, reddish brown, slightly moist,
moderately soft, some silt
@ 4 ft SILTY SANDSTONE, fine grained, reddish brown,
moist to slightly moist, soft, trace olive mottling, trace clay
@ 5.0 ft CLAYEY SANDSTONE, fine grained, reddish
yellow and light yellowish brown, slightly moist to moist,moderately hard, some olive mottling@ 8.0 ft CLAYEY SANDSTONE, fine grained, pale olive,
moist, moderately hard, some silt
@ 14.0 ft SANDSTONE, fine to coarse grained, yellowish
brown and light olive, saturated, moderately soft, friable,trace silt
Total Depth = 16.0 Feet
Saturated at 14.0 ftBackfilled with Cement and Bentonite Grout per San DiegoCounty
SM
18-32
30/4"
8-11-14(25)
22-33
30/3"
22-33
50/5"
NOTES
GROUND ELEVATION 66 ft
LOGGED BY FE
DRILLING METHOD Tripod
HOLE SIZE 6 inch
DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5
10
15 FINES CONTENT(%)ELEVATION(ft)65
60
55
50 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER TB-1
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Shear,RemoldedConsol, Consol
31
25
23
5.3
4.9
4.5
112
108
108
MC
MC
MC
TOPSOIL, SILTY SAND, fine grained, brown, slightly
moist, loose, abundant roots
@ 0.5 ft Old Paralic Deposits (Qop6), SILTYSANDSTONE, yellowish red, slightly moist, soft, moderately
weathered, roots to 3 ft@ 3.5 ft moderately hard, less weathered
@ 4.0 ft SILTY SANDSTONE, fine grained, reddish brown,
slightly moist, moderately hard, trace clay, roots to 6ft@ 5.0 ft SANDSTONE, fine grained, light yellowish brown toreddish yellow, dry to slightly moist, moderately hard, some
silt, friable
Total Depth = 11.0 FeetNo Groundwater Encountered
Backfilled with Cement and Bentonite Grout per San DiegoCounty
SM
10-15-22
(37)
15-21-22(43)
13-18-22(40)
NOTES
GROUND ELEVATION 61 ft
LOGGED BY FE
DRILLING METHOD Tripod
HOLE SIZE 6 inch
DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS:
CHECKED BY JAC
DATE STARTED 9/10/16 COMPLETED 9/10/16
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---OTHER TESTSSATURATION (%)MOISTURECONTENT (%)DRY UNIT WT.(pcf)SAMPLE TYPENUMBERMATERIAL DESCRIPTION
USCSGRAPHICLOGDEPTH(ft)0
5
10 FINES CONTENT(%)ELEVATION(ft)60
55
50 BLOWCOUNTS(N VALUE)PAGE 1 OF 1
BORING NUMBER TB-2
AGS BORING LOG V3 9.30.2014 - GINT STD US LAB.GDT - 10/21/16 14:22 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\1607-03 800 GRAND CARLSBAD.GPJCLIENT McKellar McGowan
PROJECT NUMBER 1607-03
PROJECT NAME 800 Grand Carlsbad
PROJECT LOCATION Carlsbad
Advanced Geotechnical Solutions, Inc.PROJECT 800 Grand
FILE NO.1607-03
MOISTURE CONTENT / DRY DENSITY ( INTACT SAMPLES )
D-2216, D1557 BY H-M DATE 9/12/2016
EXCAVATION TB-1 TB-1 TB-1 TB-1 TB-2 TB-2 TB-2
DEPTH 2 '5 '10 '15 '2 '5 '10 '
SOIL Redish Redish Redish Light Redish Redish Medium
Brown Brown Brown Brown Brown Brown Brown
Silty Sand Silty Sand Silty Sand Fine to Silty Fine Silty Fine Sand
Coarse Sand Sand
Sand
LENGTH 6 5 5 5 4 5 6
TUBE+W. SOIL 1222.7 945.2 1025.9 1007.5 752.9 915.3 1090.0
TUBE 267.9 223.3 223.3 223.3 178.6 223.3 267.9
W. SOIL 954.8 721.9 802.6 784.2 574.3 692.0 822.1
FACTOR 0.01609 0.01341 0.01341 0.01341 0.01073 0.01341 0.01609
W. DENSITY 130.71 118.57 131.83 128.81 117.91 113.66 112.54
CUP NO.75 68 86 71 3 71 86
CUP+W. SOIL 326.64 279.67 251.38 285.15 260.80 123.45 275.21
CUP+D. SOIL 308.61 258.92 230.03 239.69 248.15 118.10 263.72
MOIST. LOSS 18.03 20.75 21.35 45.46 12.65 5.35 11.49
CUP 8.26 8.40 8.24 8.01 8.03 8.03 8.34
D. SOIL 300.35 250.52 221.79 231.68 240.12 110.07 255.38
MOIST. CONT.6.00 8.28 9.63 19.62 5.27 4.86 4.50
DRY DENSITY 123.31 109.50 120.25 107.68 112.01 108.40 107.70
DEG. SATUR.44 42 65 94 28 24 22
EXCAVATION HS-1 HS-2 HS-2 HS-2 HS-4 HS-4
DEPTH 5 '5 '15 '20 '10 '18.5 '
SOIL Redish Redish Light to Light Gray Dark Olive Gray
Brown Brown Dark Gray Silty Fine Brown Sand Some
Silty Fine Silty Fine Sand Sand Silty Sand Silt Stone
Sand Sand
LENGTH 4 6 6 6 6 6
TUBE+W. SOIL 774.7 1175.2 1193.3 1209.3 1186.9 1225.1
TUBE 223.3 267.9 267.9 267.9 267.9 267.9
W. SOIL 551.4 907.3 925.4 941.4 919.0 957.2
FACTOR 0.01341 0.01609 0.01609 0.01609 0.01609 0.01609
W. DENSITY 90.57 124.20 126.68 128.87 125.81 131.04
CUP NO.68 75 88 76 93 4
CUP+W. SOIL 199.56 322.25 305.39 180.32 290.57 322.45
CUP+D. SOIL 190.49 309.40 250.24 152.96 270.66 269.02
MOIST. LOSS 9.07 12.85 55.15 27.36 19.91 53.43
CUP 8.48 8.34 8.13 8.06 8.24 8.18
D. SOIL 182.01 301.06 242.11 144.90 262.42 260.84
MOIST. CONT.4.98 4.27 22.78 18.88 7.59 20.48
DRY DENSITY 86.27 119.12 103.18 108.40 116.93 108.76
DEG. SATUR.14 28 97 92 46 101
Project Name: 800 Grand Excavation: TB-2
Location: Depth: 5 '
Project No: 1607-03 Description: Silty Fine Sand
Date: 9/13/2016 By: HM
Test Description:
Before Test After Test
Water Content, w 4.9% 17.5%
Void Ratio, e 0.65 0.60
Saturation, S 20% 78%
Dry Density (pcf) 102.3 105.0
Wet Density (pcf) 107.2 123.4
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
CONSOLIDATION - ASTM D2435
-7
-6
-5
-4
-3
-2
-1
0
1
0.1 1 10 100
Consolidation (%)Normal Pressure (ksf)
Consolidation-Pressure Curve
ADVACED GEOTECHNICAL SOLUTION . INC .
EXPANSION INDEX TEST ASTM (D4829)
Project Name:800 Grand Excavation:HS-1
Location: Depth:2-5 '
File No:1607-03 Description: Silty Sand
Date
SAMPLE PREPARATION By: H-M
PARAMETER FORMULA UNITS DATA
Ring Volume A cf 0.007268
Specific Surcharge psf 144
2-lb Sample Moist B % 7.3
Wt. Ring C g 194.4
Wt. Ring + Wet Soil D g 619.4
Wt. Wet Soil E = D - C g 425
Dry Density F pcf 120.04
Initial Saturation G = (B x 2.7 x F) / (2.7 x 62.4 - F) % 49
FINAL SAMPLE INFORMATION
Wt. Ring + Tare + Wet Soil H g 733.5
Wt. Ring + Tare + Dry Soil I g 677.2
Tare J no. 19
Wt. Tare K g 98.8
Wt. Moisture Loss L = H - I g 56.3
Wt. Dry Soil M = I - C - K g 384
Final Moisture Content N = 100 x (L / M) % 14.7
Final Saturation O = (N x 2.7 x F) / (2.7 x 62.4 - F) % 98.09
Ring Volume After Test P = (R - S + 1) x 0.08722 / 12 cf 0.00735
TEST INFORMATION
PROPOSED READINGS FORMULA DATE TIME UNITS
LOAD APPLIED
0 minute Q 9/15/2016 12.30 PM 0.5431
10 minute R 9/15/2016 12.40 PM 0.5409
11 minute WATER ADDED
S 9/16/2016 1.00 PM 0.5527
EXPANSION INDEX EI = 1000 x (S - R)12 Low
INITIAL INITIAL INITIAL FINAL FINAL FINAL
DRY MOISTURE SATURA- SWELL EXPANSION DRY MOISTURE SATURA-
DENSITY CONTENT TION (%) INDEX DENSITY CONTENT TION
F (pcf) B (%) G (%) EI /10 (EI)
(E/P/454)/
(100+N)x10
0
N (%) O (%)
120.04 7.3 48.8 1.2 12 118.63 14.7 98.1
Advanced Geotechnical Solutions, Inc.
MAXIMUM DENSITY
ASTM D-1557
Project Name:800 Grand Excavation:HS-1
Location:Depth 2-5 '
File No:1607-03 Description:Dark Brown Silty Sand
Date:9/17/2016
Sieve Size 4
Mold Size 4"% Retained None
No. of Layers 5 Method A By:H-M
Test point number 1 2 3 4
Wt. wet soil + mold g 3986.3 4053.1 4072.7 4051.2
Wt. wet soil + mold lbs 8.78 8.93 8.97 8.92
Wt. of mold lbs 4.10 4.10 4.10 4.10
Wt. wet of soil lbs 4.68 4.83 4.87 4.82
Wet density pcf 140.41 144.83 146.12 144.70
Dry density pcf 132.24 134.79 134.44 130.50
Moisture Determination (Oven)
Container number 12 71 8 3
Wt. wet of soil+tare g 264.5 282.3 266.3 285.4
Dry wt. soil+tare g 249.61 263.3 245.7 258.2
Tare wt.g 8.62 8.24 8.55 8.24
Wt. of moisture g 14.89 19.00 20.60 27.20
Dry wt. of soil g 240.99 255.06 237.15 249.96
Moisture Content g 6.18 7.45 8.69 10.88
Maximum Density 135.0 pcf Optimum Moisture 8.0 %
100.0
105.0
110.0
115.0
120.0
125.0
130.0
135.0
140.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0Dry Density (pcf)Moisture %
Max Density
SG=2.8
SG=2.7
SG=2.6Zero Air VoidsCurves
Samples Tested 1 2 3 Peak Ultim.
Boring ID HS-1 HS-1 HS-1 Friction Angle, phi (Deg)35 36
Depth (in/ft.)2-5'2-5'2-5'Cohesion (psf)400 200
Initial Dry Density (pcf)121.5 121.5 121.5
Initial Moisture Content (%)8.00 8.00 8.00 Sample Type:
Normal Stress (psf)1000 2000 4000
Maximum Shear Stress (psf)1087 1802 3169
Ultimate Shear Stress (psf)963 1647 3169
ASTM D3080 Strain Rate (in/min):0.005
Normal
1000
2000
4000
PEAK
0.692417
0.7
34.69939
35
ULTIMATE
0.739022
0.7
36.46522
36
F.N.:1607-03 Plate
ADVANCED GEOTECHNICAL SOLUTION, INC.Date:Sep 2016
DIRECT SHEAR TEST RESULTS
0
800 Grand, Remolded
Remolded
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Deformation (in)Displacement (in)
Vertical Deformation v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress (psf)Displacement (in)
Shear Stress v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000Shear Stress (psf)Normal Stress (psf)
Shear Stress
Peak
Ultimate
Samples Tested 1 2 3 Peak Ultim.
Boring ID HS-1 HS-1 HS-1 Friction Angle, phi (Deg)38 38
Depth (in/ft.)5 '5 '5 'Cohesion (psf)230 230
Initial Dry Density (pcf)99.74 98.86 105.13
Initial Moisture Content (%)4.98 4.98 4.98 Sample Type:
Normal Stress (psf)1000 2000 4000
Maximum Shear Stress (psf)901 1957 3293
Ultimate Shear Stress (psf)901 1957 3293
ASTM D3080 Strain Rate (in/min):0.005
Normal
1000
2000
4000
PEAK
0.778969
0.8
37.9175
38
ULTIMATE
0.778969
0.8
37.9175
38
F.N.:1607-03 Plate
ADVANCED GEOTECHNICAL SOLUTION, INC.Date:Sep 2016
DIRECT SHEAR TEST RESULTS
0
800 Grand, Intact
Remolded
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Deformation (in)Displacement (in)
Vertical Deformation v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress (psf)Displacement (in)
Shear Stress v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000Shear Stress (psf)Normal Stress (psf)
Shear Stress
Peak
Ultimate
Samples Tested 1 2 3 Peak Ultim.
Boring ID HS-2 HS-2 HS-2 Friction Angle, phi (Deg)36 36
Depth (in/ft.)20 '20 '20 'Cohesion (psf)280 150
Initial Dry Density (pcf)99.09 105.9 98.51
Initial Moisture Content (%)18.88 18.88 18.88 Sample Type:
Normal Stress (psf)1000 2000 4000
Maximum Shear Stress (psf)994 1740 3169
Ultimate Shear Stress (psf)963 1554 3169
ASTM D3080 Strain Rate (in/min):0.005
Normal
1000
2000
4000
PEAK
0.723487
0.7
35.88525
36
ULTIMATE
0.74568
0.7
36.71116
36
F.N.:1607-03 Plate
ADVANCED GEOTECHNICAL SOLUTION, INC.Date:Sep 2016
DIRECT SHEAR TEST RESULTS
0
800 Grand, Intact
Remolded
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Deformation (in)Displacement (in)
Vertical Deformation v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress (psf)Displacement (in)
Shear Stress v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000Shear Stress (psf)Normal Stress (psf)
Shear Stress
Peak
Ultimate
Samples Tested 1 2 3 Peak Ultim.
Boring ID TB-1 TB-1 TB-1 Friction Angle, phi (Deg)23 32
Depth (in/ft.)10 '10 '10 'Cohesion (psf)1490 140
Initial Dry Density (pcf)109.29 127.88 112.5
Initial Moisture Content (%)9.63 9.63 9.63 Sample Type:
Normal Stress (psf)1000 2000 4000
Maximum Shear Stress (psf)1181 3418 2796
Ultimate Shear Stress (psf)621 1616 2579
ASTM D3080 Strain Rate (in/min):0.005
Normal
1000
2000
4000
PEAK
0.417226
0.4
22.64715
23
ULTIMATE
0.628058
0.6
32.1312
32
F.N.:1607-03 Plate
ADVANCED GEOTECHNICAL SOLUTION, INC.Date:Sep 2016
DIRECT SHEAR TEST RESULTS
0
800 Grand, Intact
Remolded
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Deformation (in)Displacement (in)
Vertical Deformation v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress (psf)Displacement (in)
Shear Stress v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000Shear Stress (psf)Normal Stress (psf)
Shear Stress
Peak
Ultimate
Samples Tested 1 2 3 Peak Ultim.
Boring ID TB-2 TB-2 TB-2 Friction Angle, phi (Deg)32 34
Depth (in/ft.)5 '5 '5 'Cohesion (psf)500 215
Initial Dry Density (pcf)102.95 101 105.76
Initial Moisture Content (%)4.86 4.86 4.86 Sample Type:
Normal Stress (psf)1000 2000 4000
Maximum Shear Stress (psf)994 1926 2921
Ultimate Shear Stress (psf)777 1771 2890
ASTM D3080 Strain Rate (in/min):0.005
Normal
1000
2000
4000
PEAK
0.6214
0.6
31.85682
32
ULTIMATE
0.68354
0.7
34.35417
34
F.N.:1607-03 Plate
ADVANCED GEOTECHNICAL SOLUTION, INC.Date:Sep 2016
DIRECT SHEAR TEST RESULTS
0
800 Grand, Intact
Remolded
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Deformation (in)Displacement (in)
Vertical Deformation v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress (psf)Displacement (in)
Shear Stress v. Displacement
1000
2000
4000
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000Shear Stress (psf)Normal Stress (psf)
Shear Stress
Peak
Ultimate
Project Name:800 Grand Excavation:HS-4
Location:0 Depth:5 '
Project No.:1607-03 By:H M
Date:6/17/16
Grain Size
(in/#)
Grain Size
(mm)
Amount
Passing (%)
3 "76.20 % Gravel =0.0
2 1/2 "63.50 % Sand =76.8
2 "50.80 % Fines =23.2
1 1/2 "38.10 Sum =100.0
1 "25.40
3/4 "19.05
1/2 "12.70 LL=
3/8 "9.53 PL=
# 4 4.75 PI=
# 10 2.00 100.00
# 20 0.85 #N/A
# 30 0.60 #N/A Soil Type:
# 40 0.425 81.86
# 50 0.30 #N/A
# 60 0.212 #N/A
# 100 0.15 31.85
# 200 0.075 23.21
Hydro 0.0319 18.68
Hydro 0.0204 17.34
Hydro 0.0100 16.01
Hydro 0.0084 14.67
Hydro 0.0060 12.01
Hydro 0.0030 10.67
Hydro 0.0013 9.34
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
PARTICLE SIZE ANALYSIS - ASTM D422
Summary
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.11101001000Percent Passing (%)Grain Size (mm)
C.Gravel F.Gravel C. Sand Md. Sand F. Sand Silt ClayCobbles
L A B O R A T O R Y R E P O R T
Telephone (619) 425-1993 Fax 425-7917 Established 1928
C L A R K S O N L A B O R A T O R Y A N D S U P P L Y I N C.
350 Trousdale Dr. Chula Vista, Ca. 91910 www.clarksonlab.com
A N A L Y T I C A L A N D C O N S U L T I N G C H E M I S T S
Date: September 30, 2016
Purchase Order Number: 1607-03
Sales Order Number: 32907
Account Number: ADVG
To:
*-------------------------------------------------*
Advance Geotechnical Solutions Inc
9707 Waples Street Ste. 150
San Diego, CA 92121
Attention: Paul Deresi
Laboratory Number: SO6150 Customers Phone: 850-3980
Sample Designation:
*-------------------------------------------------*
One soil sample received on 09/23/16 at 1:05pm,
from Project# 1607-03 marked as HS-1 @ 2-3 ft.
Analysis By California Test 643, 1999, Department of Transportation
Division of Construction, Method for Estimating the Service Life of
Steel Culverts.
pH 7.5
Water Added (ml) Resistivity (ohm-cm)
10 5700
5 2800
5 2100
5 1800
5 1700
5 1700
5 1600
5 1900
5 2200
37 years to perforation for a 16 gauge metal culvert.
48 years to perforation for a 14 gauge metal culvert.
67 years to perforation for a 12 gauge metal culvert.
85 years to perforation for a 10 gauge metal culvert.
104 years to perforation for a 8 gauge metal culvert.
Water Soluble Sulfate Calif. Test 417 0.003% (30ppm)
Water Soluble Chloride Calif. Test 422 0.010% (96ppm)
____________________Rosa M. Bernal
RMB/ilv
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX B
GENERAL EARTHWORK SPECIFICATIONS
AND GRADING GUIDELINES
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
GENERAL EARTHWORK SPECIFICATIONS
I. General
A. General procedures and requirements for earthwork and grading are presented herein. The earthwork
and grading recommendations provided in the geotechnical report are considered part of these
specifications, and where the general specifications provided herein conflict with those provided in the
geotechnical report, the recommendations in the geotechnical report shall govern. Recommendations
provided herein and in the geotechnical report may need to be modified depending on the conditions
encountered during grading.
B. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the
project plans, specifications, applicable building codes, and local governing agency requirements. Where
these requirements conflict, the stricter requirements shall govern.
C. It is the contractor’s responsibility to read and understand the guidelines presented herein and in the
geotechnical report as well as the project plans and specifications. Information presented in the
geotechnical report is subject to verification during grading. The information presented on the exploration
logs depicts conditions at the particular time of excavation and at the location of the excavation.
Subsurface conditions present at other locations may differ, and the passage of time may result in
different subsurface conditions being encountered at the locations of the exploratory excavations. The
contractor shall perform an independent investigation and evaluate the nature of the surface and
subsurface conditions to be encountered and the procedures and equipment to be used in performing his
work.
D. The contractor shall have the responsibility to provide adequate equipment and procedures to
accomplish the earthwork in accordance with applicable requirements. When the quality of work is less
than that required, the Geotechnical Consultant may reject the work and may recommend that the
operations be suspended until the conditions are corrected.
E. Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe
grading procedures and provide testing of the fills for conformance with the project specifications,
approved grading plan, and guidelines presented herein. All remedial removals, clean-outs, removal
bottoms, keyways, and subdrain installations should be observed and documented by the Geotechnical
Consultant prior to placing fill. It is the contractor’s responsibility to apprise the Geotechnical Consultant
of their schedules and notify the Geotechnical Consultant when those areas are ready for observation.
F. The contractor is responsible for providing a safe environment for the Geotechnical Consultant to
observe grading and conduct tests.
II. Site Preparation
A. Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently
removed as required by the Geotechnical Consultant, and such materials shall be properly disposed of
offsite in a method acceptable to the owner and governing agencies. Where applicable, the contractor may
obtain permission from the Geotechnical Consultant, owner, and governing agencies to dispose of
vegetation and other deleterious materials in designated areas onsite.
B. Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be
removed as necessary to the satisfaction of the Geotechnical Consultant.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
C. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells,
pipelines, other utilities, or other structures located within the limits of grading shall be removed and/or
abandoned in accordance with the requirements of the governing agency and to the satisfaction of the
Geotechnical Consultant.
D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be
scarified to a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform
moisture content that is at or near optimum moisture content. The scarified materials shall then be
compacted to the project requirements and tested as specified.
E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the
placement of fill. A licensed surveyor shall provide survey control for determining elevations of
processed areas and keyways.
III. Placement of Fill
A. Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided
that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials
shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion
potential, and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in
a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved
prior to being imported.
B. Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of
materials and prevent abrupt changes in material type. Fill materials derived from benching should be
dispersed throughout the fill area instead of placing the materials within only an equipment-width from
the cut/fill contact.
C. Oversize Materials: Rocks greater than 8 inches in largest dimension shall be disposed of offsite or be
placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are
designated as suitable for oversize rock placement. Rocks that are smaller than 8 inches in largest
dimension may be utilized in the fill provided that they are not nested and are their quantity and
distribution are acceptable to the Geotechnical Consultant.
D. The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed
6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain near uniform moisture
content and uniform blend of materials.
E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as
recommended by the geotechnical report. Where the moisture content of the engineered fill is less than
recommended, water shall be added, and the fill materials shall be blended so that near uniform moisture
content is achieved. If the moisture content is above the limits specified by the Geotechnical Consultant,
the fill materials shall be aerated by discing, blading, or other methods until the moisture content is
acceptable.
F. Each layer of fill shall be compacted to the project standards in accordance to the project specifications
and recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical
Consultant, the fill shall be compacted to a minimum of 90 percent of the maximum dry density as
determined by ASTM Test Method: D1557-09.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
G. Benching: Where placing fill on a slope exceeding a ratio of 5 to 1 (horizontal to vertical), the ground
should be keyed or benched. The keyways and benches shall extend through all unsuitable materials into
suitable materials such as firm materials or sound bedrock or as recommended by the Geotechnical
Consultant. The minimum keyway width shall be 15 feet and extend into suitable materials, or as
recommended by the geotechnical report and approved by the Geotechnical Consultant. The minimum
keyway width for fill over cut slopes is also 15 feet, or as recommended by the geotechnical report and
approved by the Geotechnical Consultant. As a general rule, unless otherwise recommended by the
Geotechnical Consultant, the minimum width of the keyway shall be equal to 1/2 the height of the fill
slope.
H. Slope Face: The specified minimum relative compaction shall be maintained out to the finish face of
fill and stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting
back to the compacted core. The actual amount of overbuilding may vary as field conditions dictate.
Alternately, this may be achieved by back rolling the slope face with suitable equipment or other methods
that produce the designated result. Loose soil should not be allowed to build up on the slope face. If
present, loose soils shall be trimmed to expose the compacted slope face.
I. Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and governing agencies,
permanent fill slopes shall be designed and constructed no steeper than 2 to 1 (horizontal to vertical).
J. Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated
by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or
overexcavation is needed.
K. Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When
grading is interrupted by rain, filing operations shall not resume until the Geotechnical Consultant
approves the moisture and density of the previously placed compacted fill.
IV. Cut Slopes
A. The Geotechnical Consultant shall inspect all cut slopes, including fill over cut slopes, and shall be
notified by the contractor when cut slopes are started.
B. If adverse or potentially adverse conditions are encountered during grading; the Geotechnical
Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions.
C. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper
than the requirements of the local governing agencies. Short-term stability of the cut slopes and other
excavations is the contractor's responsibility.
V. Drainage
A. Back drains and Subdrains: Back drains and subdrains shall be provided in fill as recommended by the
Geotechnical Consultant and shall be constructed in accordance with the governing agency and/or
recommendations of the Geotechnical Consultant. The location of subdrains, especially outlets, shall be
surveyed and recorded by the Civil Engineer.
B. Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage
shall not be permitted to flow over the tops of slopes.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
C. Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in
accordance with the recommendations of the Geotechnical Consultant.
D. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as
the prevailing drainage.
VI. Erosion Control
A. All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the
project specifications and/or landscape architect's recommendations. Such measures to protect the slope
face shall be undertaken as soon as practical after completion of grading.
B. During construction, the contractor shall maintain proper drainage and prevent the ponding of water.
The contractor shall take remedial measures to prevent the erosion of graded areas until permanent
drainage and erosion control measures have been installed.
VII. Trench Excavation and Backfill
A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavations. Knowing
and following these requirements is the contractor's responsibility. All trench excavations or open cuts in
excess of 5 feet in depth shall be shored or laid back. Trench excavations and open cuts exposing adverse
geologic conditions may require further evaluation by the Geotechnical Consultant. If a contractor fails to
provide safe access for compaction testing, backfill not tested due to safety concerns may be subject to
removal.
B. Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30.
Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting.
C. Backfill: Jetting of backfill materials is generally not acceptable. Where permitted by the Geotechnical
Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular,
free-draining and have a Sand Equivalent greater than 30.
VIII. Geotechnical Observation and Testing During Grading
A. Compaction Testing: Fill shall be tested by the Geotechnical Consultant for evaluation of general
compliance with the recommended compaction and moisture conditions. The tests shall be taken in the
compacted soils beneath the surface if the surficial materials are disturbed. The contractor shall assist the
Geotechnical Consultant by excavating suitable test pits for testing of compacted fill.
B. Where tests indicate that the density of a layer of fill is less than required, or the moisture content not
within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory
conditions of the fill. The portions of the fill that are not within specifications shall be reworked until the
required density and/or moisture content has been attained. No additional fill shall be placed until the last
lift of fill is tested and found to meet the project specifications and approved by the Geotechnical
Consultant.
C. If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather,
excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of
fill placement, results in a quality of work that is unacceptable, the consultant shall notify the contractor,
and the contractor shall rectify the conditions, and if necessary, stop work until conditions are
satisfactory.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
D. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical
Consultant's discretion. Generally, compaction tests shall be taken at intervals not exceeding two feet in
fill height and 1,000 cubic yards of fill materials placed.
E. Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation
and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the
surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can
determine the test locations. Alternately, the test locations can be surveyed and the results provided to the
Geotechnical Consultant.
F. Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be
removed and recompacted at the contractor's expense. The depth and extent of removals will be
determined by the Geotechnical Consultant.
G. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for
the Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with
the approved geotechnical report and project specifications.
H. Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall
submit reports documenting their observations during construction and test results. These reports may be
subject to review by the local governing agencies.
DETAIL 1CANYON SUBDRAIN
VER 1.0 NTS
ADVANCED GEOTECHNICAL SOLUTIONS
2 ft
3 ft3 ft
1 ft
DIRECT SOLID OUTLET PIPE TO
APPROVED DRAINAGE AREA PER
PROJECT CIVIL ENGINEER
CONSTRUCT DRAIN OUTLET
A MINIMUM 1-FOOT
ABOVE GRADE
CUTOFF WALL CONSISTING OF
GROUT, CONCRETE, BENTONITE
OR OTHER MATERIAL
APPROVED BY
GEOTECHNICAL CONSULTANT
20 FOOT MINIMUM 5 FT.
MIN.
SOLID PIPE PERFORATED PIPE
CUTOFF WALL
DIMENSIONS
NOTE: LOCATION OF CANYON SUBDRAINS AND OUTLETS
SHOULD BE DOCUMENTED BY PROJECT CIVIL ENGINEER.
OUTLETS MUST BE KEPT UNOBSTRUCTED AT ALL TIMES.
CANYON SUBDRAIN TERMINUS
DESIG
N
G
R
A
D
E
2% MIN.
EXISTING GRADE
UNSUITABLE
BEARING MATERIAL
(REMOVE)REQUIRED BENCHING
SUITABLE
BEARING MATERIAL
SUBDRAIN OPTION 1 OR 2
(SEE DETAIL 2)
ENGINEERED FILL
PLACE SUBDRAIN AT LOWEST
GRADE WITHIN CANYON REMOVAL
CANYON SUBDRAIN PROFILE
DESIGN GRADE
DETAIL 2DRAIN SPECIFICATIONS
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
4-INCH SOLID
OUTLET PIPE
2-INCH MIN.
BELOW PIPE
2-FT. MIN.
3-FT.
MIN.
OPTION 2
DRAIN
MATERIAL
WITH
FILTER FABRIC
OPTION 1
4-INCH SOLID
OUTLET PIPE
2-INCH MIN
BELOW PIPE
2-FT. MIN
2-FT.
MIN
DRAIN
MATERIAL
WITH
FILTER FABRIC
BUTTRESS/STABILIZATION DRAIN
GRAVEL TRENCH TO BE FILLED WITH 3/4-INCH MAX ROCK OR APPROVED EQUIVALENT
SUBSTITUTE
MIRAFI 140 FILTER FABRIC WITH A MINIMUM 6-INCH OVERLAP
4-INCH ABS OR PVC PIPE OR APPROVED EQUIVALENT SUBSTITUTE WITH A MINIMUM
OF 8 PERFORATIONS (1/4-INCH DIAMETER) PER LINEAL FOOT IN
BOTTOM HALF OF PIPE
(ASTM D2751, SDR-35 OR ASTM D3034, SDR-35
ASTM D1527, SCHD. 40 OR ASTM D1785, SCHD. 40)
DRAIN MATERIAL:
FILTER FABRIC:
PIPE:
OR EQUIVALENT SUBSTITUTE
OPTION 2
12-INCH MINIMUM
ABOVE PIPE
APPROVED
DRAIN
MATERIAL
APPROVED
FILTER
FABRIC, WITH
6-INCH
OVERLAP
6-INCHES MINIMUM,
ADJACENT TO AND
BELOW PIPE
DRAIN MATERIAL:
FILTER FABRIC:
MINIMUM VOLUME OF 9 CUBIC FEET
PER LINEAL FOOT OF 3/4-INCH MAX
ROCK OR APPROVED EQUIVALENT
SUBSTITUTE
MIRAFI 140 FILTER FABRIC OR
APPROVED EQUIVALENT SUBSTITUTE
6-INCHES MINIMUM,
ADJACENT TO AND
BELOW PIPE
12-INCH MINIMUM
ABOVE PIPE
APPROVED
FILTER
MATERIAL
CANYON SUBDRAIN
OPTION 1
6 OR 8-INCH ABS OR PVC PIPE OR APPROVED SUBSTITUTE WITH A MINIMUM
OF 8 PERFORATIONS (1/4-INCH DIAMETER) PER LINEAL FOOT IN
BOTTOM HALF OF PIPE
(ASTM D2751, SDR-35 OR ASTM D3034, SDR-35
ASTM D1527, SCHD. 40 OR ASTM D1785, SCHD. 40)
CONTINUOUS RUN IN EXCESS OF 5OO FEET REQUIRES 8-INCH DIAMETER PIPE
(ASTM D3034, SDR-35, OR ASTM D1785, SCHD. 40)
PIPE:
NOTE:
FILTER MATERIAL: MINIMUM VOLUME OF
9 CUBIC FEET PER LINEAL
FOOT OF CALTRANS
CLASS 2 PERMEABLE MATERIAL
DETAIL 3STABILIZATION/BUTTRESS FILL
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
4 FOOT MIN.
BENCH HEIGHT
BENCH WIDTH
VARIES
SEE DETAIL 2 FOR DRAIN SPECIFICATIONS
DESI
G
N
G
R
A
D
E
CODE COMPLIANT
SETBACK, 15 FOOT MIN.
2%
2%
BLANKET FILL - AS REQUIRED BY
GEOTECHNICAL CONSULTANT
AND/OR CODE COMPLIANCE
(3 FOOT MIN.)
CONSTRUCT DRAIN OUTLET
A MINIMUM 1-FOOT
ABOVE GRADE
HEEL
WIDTH
CODE COMPLIANT KEYWAY
WITH MINIMUM DIMENSIONS:
TOE 2 FOOT MIN.
HEEL 3 FOOT MIN.
WIDTH 15 FOOT MIN.
CODE COMPLIANT
SETBACK, 15 FOOT MIN.
NOTES:
1. DRAIN OUTLETS TO BE PROVIDED EVERY 100 FEET
CONNECT TO PERFORATED DRAIN PIPE BY “L” OR “T”
AT A MINIMUM 2% GRADIENT.
2. THE NECESSITY AND LOCATION OF ADDITIONAL
DRAINS SHALL BE DETERMINED IN THE FIELD
BY THE GEOTECHNICAL CONSULTANT. UPPER STAGE
OUTLETS SHOULD BE EMPTIED ONTO CONCRETE
TERRACE DRAINS.
3. DRAIN PIPE TO EXTEND FULL LENGTH OF
STABILIZATION/BUTTRESS WITH A MINIMUM GRADIENT
OF 2% TO SOLID OUTLET PIPES.
4. LOCATION OF DRAINS AND OUTLETS
SHOULD BE DOCUMENTED BY PROJECT
CIVIL ENGINEER. OUTLETS MUST BE KEPT
UNOBSTRUCTED AT ALL TIMES.
TOE
2%
M
I
N
.
DETAIL 4FILL OVER CUT SLOPE
SUITABLE BEARING MATERIAL
CODE COMPLIANT KEYWAY
WITH MINIMUM DIMENSIONS:
TOE: 2 FOOT MIN.
HEEL: 3 FOOT MIN.
WIDTH: 15 FOOT MIN.
ENGINEERED FILL
*THE “CUT” PORTION OF THE SLOPE SHALL
BE EXCAVATED AND EVALUATED BY THE
GEOTECHNICAL CONSULTANT PRIOR TO
CONSTRUCTING THE “FILL” PORTION
SUITABLE
BEARING MATERIAL
NOTES:
1. THE NECESSITY AND LOCATION OF DRAINS
SHALL BE DETERMINED IN THE FIELD
BY THE GEOTECHNICAL CONSULTANT
2. SEE DETAIL 2 FOR DRAIN SPECIFICATIONS
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
“CUT
”
S
L
O
P
E *“FILL”
S
L
O
P
E
DESI
G
N
G
R
A
D
E
EXISTIN
G
G
R
A
D
E
UNSUI
T
A
B
L
E
B
E
A
R
I
N
G
M
A
T
E
R
I
A
L
(
R
E
M
O
V
E
)
WIDTH
4 FOOT MIN.
BENCH HEIGHT
BENCH WIDTH
VARIES
HEEL
TOE
2%
M
I
N
.
DETAIL 5FILL OVER NATURAL SLOPE
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
WIDTH
4 FOOT MIN.
BENCH HEIGHT
BENCH WIDTH
VARIES
EXISTING
G
R
A
D
E
NOTES:
1. WHEN THE NATURAL SLOPE APPROACHES OR
EXCEEDS THE DESIGN GRADE SLOPE RATIO,
SPECIAL RECOMMENDATIONS ARE NECESSARY
BY THE GEOTECHNICAL CONSULTANT
2. THE GEOTECHNICAL CONSULTANT WILL
DETERMINE THE REQUIREMENT FOR AND
LOCATION OF SUBSURFACE DRAINAGE SYSTEMS.
3. MAINTAIN MINIMUM 15 FOOT HORIZONTAL WIDTH
FROM FACE OF SLOPE TO BENCH/BACKCUT
SUITABLE BEARING MATERIAL
UNSUIT
A
B
L
E
B
E
A
R
I
N
G
M
A
T
E
R
I
A
L
(
R
E
M
O
V
E
)
DESI
G
N
G
R
A
D
E
ENGINEERED FILL
HEEL
TOE
CODE COMPLIANT KEYWAY
WITH MINIMUM DIMENSIONS:
TOE: 2 FOOT MIN.
HEEL: 3 FOOT MIN.
WIDTH: 15 FOOT MIN.
A 1:1 MINIMUM
PROJECTION FROM DESIGN
SLOPE TOE TO TOE OF KEYWAY
RE-GRADE NATURAL SLOPE
WITH ENGINEERED FILL
VARIABLE
BACKCUT
2%
M
I
N
.
DETAIL 6SKIN FILL CONDITION
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
NOTES:
1. MAINTAIN MINIMUM 15 FOOT HORIZONTAL WIDTH
FROM FACE OF SLOPE TO BENCH/BACKCUT
2. SEE DETAIL 2 FOR DRAIN SPECIFICATIONS
WIDTH
4 FOOT MIN.
BENCH HEIGHT
BENCH WIDTH
VARIES
HEEL
TOE
CODE COMPLIANT KEYWAY
WITH MINIMUM DIMENSIONS:
TOE: 2 FOOT MIN.
HEEL: 3 FOOT MIN.
WIDTH: 15 FOOT MIN.
SUITABLE BEARING MATERIAL
EXISTING GRADE
UNSUI
T
A
B
L
E
B
E
A
RI
N
G
M
A
T
E
RI
A
L
(
R
E
M
O
V
E
)
DESI
G
N
G
R
A
D
E
L
2%
M
I
N
.
DETAIL 7
PARTIAL CUT SLOPE
STABILIZATION
VER 1.0 NTS
ADVANCED GEOTECHNICAL SOLUTIONS
11
2W
H H1 EXIST
I
N
G
G
R
A
D
E
4 FOOT MIN.
BENCH HEIGHT
BENCH WIDTH
VARIES
SUITABLE BEARING MATERIAL
DESIG
N
G
R
A
D
E
ENGINEERED FILL
UNSUITABLE
BEARING MATERIAL
(REMOVE)
2
W
1 FOOT TILT BACK (MIN.)
15 FOOT MIN.
NOTES:
1. IF RECOMMENDED BY THE GEOTECHNICAL CONSULTANT,
THE REMAINING CUT PORTION OF THE SLOPE MAY REQUIRE
REMOVALAND REPLACEMENT WITH AN ENGINEERED FILL
2. “W” SHALL BE EQUIPMENT WIDTH (15 FEET) FOR SLOPE HEIGHT
LESS THAN 25 FEET. FOR SLOPES GREATER THAN 25 FEET, “W” SHALL
BE DETERMINED BY THE GEOTECHNICAL CONSULTANT. AT NO
TIME SHALL “W” BE LESS THAN H/2
3. DRAINS WILL BE REQUIRED (SEE DETAIL 2)
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTS
DETAIL 8
CUT & CUT-FILL LOT
OVEREXCAVATION
DESIGN GRADE
REMOVE AND REPLACE
WITH ENGINEERED FILL
SUITABLE BEARING MATERIAL
DEPTH *
5 FEET
MIN.1:1UNSU
I
T
A
B
L
E
B
E
A
R
I
N
G
M
A
T
E
RI
A
L
(REM
O
V
E
)
ENGINEERED FILL
REQUIRED BENCH
DESIGN GRADE
REMOVE AND REPLACE
WITH ENGINEERED FILL
SUITABLE BEARING MATERIAL
DEPTH *
5 FEET
MIN.
5 FEET
MIN.1:11:1EXISTING GRADE
CUT LOT OVEREXCAVATION
CUT-FILL LOT OVEREXCAVATION
EXISTI
N
G
G
R
A
D
E
** SUBSURFACE
DRAINAGE
** SUBSURFACE
DRAINAGE
NOTES:
* SEE REPORT FOR RECOMMENDED DEPTHS, DEEPER OVEREXCAVATION MAY BE REQUIRED BY
THE GEOTECHNICAL CONSULTANT BASED ON EXPOSED FIELD CONDITIONS
** CONSTRUCT EXCAVATION TO PROVIDE FOR POSITIVE DRAINAGE TOWARDS STREETS,
DEEPER FILLAREAS OR APPROVED DRAINAGE DEVICES BASED ON FIELD CONDITIONS
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTSNTSNTS
REMOVAL ADJACENT TO
EXISTING FILL DETAIL 91:11:
1
ADDITIONAL
ENGINEERED FILL
(TO DESIGN GRADE)
DESIGN GRADE
EXISTING GRADE
TEMPORARY
ENGINEERED FILL
(TO BE REMOVED)
ENGINEERED FILL
(EXISTING)
UNSUITABLE
BEARING MATERIAL
(REMOVE)
SUITABLE BEARING MATERIAL
*
*REMOVE BEFORE PLACING ADDITIONAL ENGINEERED FILL
TYPICAL UP-CANYON PROFILE
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTSNTSNTS
OVERSIZED MATERIAL
DISPOSAL CRITERIA
DETAIL 10
WINDROW PROFILE
GRANULAR MATERIALAPPROVED BY
THE GEOTECHNICAL CONSULTANT AND
CONSOLIDATED IN-PLACE BY FLOODING
GRANULAR MATERIALAPPROVED BY
THE GEOTECHNICAL CONSULTANT AND
CONSOLIDATED IN-PLACE BY FLOODING
GRANULAR MATERIALAPPROVED BY
THE GEOTECHNICAL CONSULTANT AND
CONSOLIDATED IN-PLACE BY FLOODING
ENGINEERED FILL
HORIZONTALLY PLACED ENGINEERED FILL, FREE OF OVERSIZED MATERIALS AND
COMPACTED TO MINIMUM PROJECT STANDARDS
COMPACT ENGINEERED FILLABOVE OVERSIZED MATERIALS TO FACILITATE
“TRENCH” CONDITION PRIOR TO FLOODING GRANULAR MATERIALS
WINDROW CROSS-SECTION
15 FOOT MINIMUM WIDTH
ENGINEERED FILL BETWEEN
WINDROWS
OVERSIZED MATERIAL DISPOSAL PROFILE
TYPICAL WINDROWS,
PLACED PARALLEL TO
SLOPE FACE
10 FEET
15 FEET
CLEAR ZONE DIMENSIONS FOR REFERENCE ONLY, ACTUAL DEPTH, WIDTH,
WINDROW LENGTH, ETC. TO BE BASED ON ELEVATIONS OF FOUNDATIONS,
UTILITIES OR OTHER STRUCTURES PER THE GEOTECHNICAL CONSULTANT OR
GOVERNING AGENCY APPROVAL
CLEAR ZONE
CLEAR ZONE
DESIGN GRADE
4 FEET
15 FEET
ENGINEERED FILL
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTSNTSNTS
SETTLEMENT PLATE DETAIL 11
PROTECT IN-PLACE AT DESIGN GRADE
3-INCH SCHEDULE 40 PVC PIPE
5-FOOT SECTIONS ATTACHED
WITH GLUED COUPLING JOINTS
EXTENSION ROD CONSISTING OF
5-FOOT SECTIONS OF 3/4-INCH
GALVANIZED PIPE, TOP AND
BOTTOM THREADED
3/4-INCH PIPE COUPLING
DESIGN GRADE
3/4-INCH PIPE NIPPLE WELDED
TO SETTLEMENT PLATE
FOUND PLATE ON ONE-FOOT
COMPACTED SAND BEDDING
SETTLEMENT PLATE,
2’ x 2’ x 1/4” STEEL
SUITABLE BEARING MATERIAL
NOTES:
1. SETTLEMENT PLATE LOCATIONS SHALL BE SUFFICIENTLY IDENTIFIED BY THE
CONTRACTOR AND BE READILY VISIBLE TO EQUIPMENT OPERATORS.
2. CONTRACTOR SHALL MAINTAIN ADEQUATE HORIZONTAL CLEARANCE FOR EQUIPMENT
OPERATION AND SHALL BE RESPONSIBLE FOR REPAIRING ANY DAMAGE TO
SETTLEMENT PLATE DURING SITE CONSTRUCTION.
3. A MINIMUM 5-FOOT ZONE ADJACENT TO SETTLEMENT PLATE/EXTENSION RODS SHALL BE
ESTABLISHED FOR HAND-HELD MECHANICAL COMPACTION OF ENGINEERED FILL.
ENGINEERED FILL SHALL BE COMPACTED TO MINIMUM PROJECT STANDARD.
4. ELEVATIONS OF SETTLEMENT PLATE AND ALL EXTENSION ROD PLACEMENT SHALL BE
DOCUMENTED BY PROJECT CIVIL ENGINEER OR SURVEYOR.
2 FEET
VER 1.0
ADVANCED GEOTECHNICAL SOLUTIONS
NTSNTSNTS
SETTLEMENT MONUMENT DETAIL 12
PVC PIPE
3 FEET
MINIMUM
CONCRETE OR
SLURRY BACKFILL
REBAR OR
MIN. 6-INCH FLAT HEADED BOLT
WITH 2-INCH CLEARANCE AND
SURROUNDED WITH PVC PIPE
SPRINKLER VAULT,
PLACED ABOVE GRADE
TO REDUCE SEDIMENT INFILL
DESIGN GRADE
ENGINEERED FILL
PVC CAP
NOTES:
1. SETTLEMENT MONUMENT LOCATIONS SHALL BE SUFFICIENTLY IDENTIFIED
AND BE READILY VISIBLE TO EQUIPMENT OPERATORS.
2. ELEVATIONS OF SURFACE MONUMENTS SHALL BE DOCUMENTED BY
PROJECT CIVIL ENGINEER OR SURVEYOR.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX C
HOMEOWNER MAINTENANCE RECOMMENDATIONS
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
HOMEOWNER MAINTENANCE AND IMPROVEMENT CONSIDERATIONS
Homeowners are accustomed to maintaining their homes. They expect to paint their houses periodically,
replace wiring, clean out clogged plumbing, and repair roofs. Maintenance of the home site, particularly
on hillsides, should be considered on the same basis or even on a more serious basis because neglect can
result in serious consequences. In most cases, lot and site maintenance can be taken care of along with
landscaping, and can be carried out more economically than repair after neglect.
Most slope and hillside lot problems are associated with water. Uncontrolled water from a broken pipe,
cesspool, or wet weather causes most damage. Wet weather is the largest cause of slope problems,
particularly in California where rain is intermittent, but may be torrential. Therefore, drainage and erosion
control are the most important aspects of home site stability; these provisions must not be altered without
competent professional advice. Further, maintenance must be carried out to assure their continued
operation.
As geotechnical engineers concerned with the problems of building sites in hillside developments, we
offer the following list of recommended home protection measures as a guide to homeowners.
Expansive Soils
Some of the earth materials on site have been identified as being expansive in nature. As such, these
materials are susceptible to volume changes with variations in their moisture content. These soils will
swell upon the introduction of water and shrink upon drying. The forces associated with these volume
changes can have significant negative impacts (in the form of differential movement) on foundations,
walkways, patios, and other lot improvements. In recognition of this, the project developer has
constructed homes on these lots on post-tensioned or mat slabs with pier and grade beam foundation
systems, intended to help reduce the potential adverse effects of these expansive materials on the
residential structures within the project. Such foundation systems are not intended to offset the forces
(and associated movement) related to expansive soil, but are intended to help soften their effects on the
structures constructed thereon.
Homeowners purchasing property and living in an area containing expansive soils must assume a certain
degree of responsibility for homeowner improvements as well as for maintaining conditions around their
home. Provisions should be incorporated into the design and construction of homeowner improvements
to account for the expansive nature of the onsite soils material. Lot maintenance and landscaping should
also be conducted in consideration of the expansive soil characteristics. Of primary importance is
minimizing the moisture variation below all lot improvements. Such design, construction and
homeowner maintenance provisions should include:
Employing contractors for homeowner improvements who design and build in recognition of local building code and site specific soils conditions.
Establishing and maintaining positive drainage away from all foundations, walkways, driveways,
patios, and other hardscape improvements.
Avoiding the construction of planters adjacent to structural improvements. Alternatively, planter sides/bottoms can be sealed with an impermeable membrane and drained away from the
improvements via subdrains into approved disposal areas.
Sealing and maintaining construction/control joints within concrete slabs and walkways to reduce the potential for moisture infiltration into the subgrade soils.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Utilizing landscaping schemes with vegetation that requires minimal watering. Alternatively, watering should be done in a uniform manner as equally as possible on all sides of the foundation,
keeping the soil "moist" but not allowing the soil to become saturated.
Maintaining positive drainage away from structures and providing roof gutters on all structures with downspouts installed to carry roof runoff directly into area drains or discharged well away from the structures.
Avoiding the placement of trees closer to the proposed structures than a distance of one-half the mature height of the tree.
Observation of the soil conditions around the perimeter of the structure during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to
maintain relatively constant moisture conditions.
Sulfates
Homeowners should be cautioned against the import and use of certain fertilizers, soil amendments,
and/or other soils from offsite sources in the absence of specific information relating to their chemical
composition. Some fertilizers have been known to leach sulfate compounds into soils otherwise
containing "negligible" sulfate concentrations and increase the sulfate concentrations in near-surface soils
to "moderate" or "severe" levels. In some cases, concrete improvements constructed in soils containing
high levels of soluble sulfates may be affected by deterioration and loss of strength.
Water - Natural and Man Induced
Water in concert with the reaction of various natural and man-made elements, can cause detrimental
effects to your structure and surrounding property. Rain water and flowing water erodes and saturates the
ground and changes the engineering characteristics of the underlying earth materials upon saturation.
Excessive irrigation in concert with a rainy period is commonly associated with shallow slope failures and
deep seated landslides, saturation of near structure soils, local ponding of water, and transportation of
water soluble substances that are deleterious to building materials including concrete, steel, wood, and
stucco.
Water interacting with the near surface and subsurface soils can initiate several other potentially
detrimental phenomena other then slope stability issues. These may include expansion/contraction cycles,
liquefaction potential increase, hydro-collapse of soils, ground surface settlement, earth material
consolidation, and introduction of deleterious substances.
The homeowners should be made aware of the potential problems which may develop when drainage is
altered through construction of retaining walls, swimming pools, paved walkways and patios. Ponded
water, drainage over the slope face, leaking irrigation systems, over-watering or other conditions which
could lead to ground saturation must be avoided.
Before the rainy season arrives, check and clear roof drains, gutters and down spouts of all accumulated debris. Roof gutters are an important element in your arsenal against rain damage. If you do not have roof gutters and down spouts, you may elect to install them. Roofs, with their, wide, flat area can shed tremendous quantities of water. Without gutters or other adequate drainage, water falling from the eaves collects against foundation and basement walls.
Make sure to clear surface and terrace drainage ditches, and check them frequently during the rainy season. This task is a community responsibility.
Test all drainage ditches for functioning outlet drains. This should be tested with a hose and done
before the rainy season. All blockages should be removed.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Check all drains at top of slopes to be sure they are clear and that water will not overflow the slope itself, causing erosion.
Keep subsurface drain openings (weep-holes) clear of debris and other material which could block them in a storm.
Check for loose fill above and below your property if you live on a slope or terrace.
Monitor hoses and sprinklers. During the rainy season, little, if any, irrigation is required. Oversaturation of the ground is unnecessary, increases watering costs, and can cause subsurface drainage.
Watch for water backup of drains inside the house and toilets during the rainy season, as this may indicate drain or sewer blockage.
Never block terrace drains and brow ditches on slopes or at the tops of cut or fill slopes. These are designed to carry away runoff to a place where it can be safely distributed.
Maintain the ground surface upslope of lined ditches to ensure that surface water is collected in
the ditch and is not permitted to be trapped behind or under the lining.
Do not permit water to collect or pond on your home site. Water gathering here will tend to either seep into the ground (loosening or expanding fill or natural ground), or will overflow into the
slope and begin erosion. Once erosion is started, it is difficult to control and severe damage may result rather quickly.
Never connect roof drains, gutters, or down spouts to subsurface drains. Rather, arrange them so
that water either flows off your property in a specially designed pipe or flows out into a paved driveway or street. The water then may be dissipated over a wide surface or, preferably, may be carried away in a paved gutter or storm drain. Subdrains are constructed to take care of ordinary subsurface water and cannot handle the overload from roofs during a heavy rain.
Never permit water to spill over slopes, even where this may seem to be a good way to prevent ponding. This tends to cause erosion and, in the case of fill slopes, can eat away carefully designed and constructed sites.
Do not cast loose soil or debris over slopes. Loose soil soaks up water more readily than
compacted fill. It is not compacted to the same strength as the slope itself and will tend to slide when laden with water; this may even affect the soil beneath the loose soil. The sliding may clog terrace drains below or may cause additional damage in weakening the slope. If you live below a
slope, try to be sure that loose fill is not dumped above your property.
Never discharge water into subsurface blanket drains close to slopes. Trench drains are sometimes used to get rid of excess water when other means of disposing of water are not readily
available. Overloading these drains saturates the ground and, if located close to slopes, may cause slope failure in their vicinity.
Do not discharge surface water into septic tanks or leaching fields. Not only are septic tanks
constructed for a different purpose, but they will tend, because of their construction, to naturally accumulate additional water from the ground during a heavy rain. Overloading them artificially during the rainy season is bad for the same reason as subsurface subdrains, and is doubly
dangerous since their overflow can pose a serious health hazard. In many areas, the use of septic tanks should be discontinued as soon as sewers are made available.
Practice responsible irrigation practices and do not over-irrigate slopes. Naturally, ground cover of ice plant and other vegetation will require some moisture during the hot summer months, but during the wet season, irrigation can cause ice plant and other heavy ground cover to pull loose. This not only destroys the cover, but also starts serious erosion. In some areas, ice plant and other heavy cover can cause surface sloughing when saturated due to the increase in weight and weakening of the near-surface soil. Planted slopes should be planned where possible to acquire sufficient moisture when it rains.
Do not let water gather against foundations, retaining walls, and basement walls. These walls are built to withstand the ordinary moisture in the ground and are, where necessary, accompanied by
subdrains to carry off the excess. If water is permitted to pond against them, it may seep through
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
the wall, causing dampness and leakage inside the basement. Further, it may cause the foundation to swell up, or the water pressure could cause structural damage to walls.
Do not try to compact soil behind walls or in trenches by flooding with water. Not only is flooding the least efficient way of compacting fine-grained soil, but it could damage the wall foundation or saturate the subsoil.
Never leave a hose and sprinkler running on or near a slope, particularly during the rainy season. This will enhance ground saturation which may cause damage.
Never block ditches which have been graded around your house or the lot pad. These shallow ditches have been put there for the purpose of quickly removing water toward the driveway, street or other positive outlet. By all means, do not let water become ponded above slopes by blocked
ditches.
Seeding and planting of the slopes should be planned to achieve, as rapidly as possible, a well-established and deep-rooted vegetal cover requiring minimal watering.
It should be the responsibility of the landscape architect to provide such plants initially and of the residents to maintain such planting. Alteration of such a planting scheme is at the resident's risk.
The resident is responsible for proper irrigation and for maintenance and repair of properly
installed irrigation systems. Leaks should be fixed immediately. Residents must undertake a program to eliminate burrowing animals. This must be an ongoing program in order to promote slope stability. The burrowing animal control program should be conducted by a licensed
exterminator and/or landscape professional with expertise in hill side maintenance.
Geotechnical Review
Due to the fact that soil types may vary with depth, it is recommended that plans for the construction of
rear yard improvements (swimming pools, spas, barbecue pits, patios, etc.), be reviewed by a geotechnical
engineer who is familiar with local conditions and the current standard of practice in the vicinity of your
home.
In conclusion, your neighbor’s slope, above or below your property, is as important to you as the slope
that is within your property lines. For this reason, it is desirable to develop a cooperative attitude
regarding hillside maintenance, and we recommend developing a “good neighbor” policy. Should
conditions develop off your property, which are undesirable from indications given above, necessary
action should be taken by you to insure that prompt remedial measures are taken. Landscaping of your
property is important to enhance slope and foundation stability and to prevent erosion of the near surface
soils. In addition, landscape improvements should provide for efficient drainage to a controlled discharge
location downhill of residential improvements and soil slopes.
Additionally, recommendations contained in the Geotechnical Engineering Study report apply to all
future residential site improvements, and we advise that you include consultation with a qualified
professional in planning, design, and construction of any improvements. Such improvements include
patios, swimming pools, decks, etc., as well as building structures and all changes in the site configuration
requiring earth cut or fill construction.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX D
PRELIMINARY STORM WATER INFILTRATION FEASIBILITY ANALYSIS
APPENDIX D
INFILTRATION TESTING
1.0 TESTING METHODS AND PROCEDURES
To evaluate feasibility for infiltration onsite and to provide preliminary design infiltration rates, three (3)
borehole percolation tests were performed in general conformance with Appendix D, Section D.3.3.2 of
the recently adopted BMP Design Manual.
To provide representative continuous soil/geologic logs for the percolation test holes, two of the
percolation test borings were located adjacent to exploratory soil borings that were logged and sampled as
part of our investigation (TB-1 and TB-2). A third boring (HS-3), utilizing the hollowstem auger rig, was
drilled and logged to a depth of approximately 6 feet from existing design grade in the approximate
location of the single family units (Parcel B). Based upon the lithology observed in the other borings HS-
1 thru HS-4, TB-1 & TB-2 the lithology was found to be relatively uniform with a minor increase in
depth of the geologic contact with the Santiago formation along north to northwestern portion of the
Home Avenue portion of the project. Locations of the percolation test holes and the exploratory soil
borings are shown on Plate 1, included herewith.
The percolation boreholes (P-1 and P-2) were excavated with a limited access tripod drill rig utilizing a 6-
inch diameter flight auger, and extended to depths of approximately ”48” below ground surface.
Borehole HS-3 was excavated with a CME 75 truck-mounted hollowstem auger drill rig and extended
through topsoil or undocumented artificial fill, into Old Paralic Deposits. The Old Paralic Deposits can
generally be described as a fine-grained, light brown to light gray sand that is slightly moist to moist and
medium dense to dense. A third percolation hole utilized the geotechnical boring HS-3 in the northwest
corner of Parcel B. This percolation test is identified as HSP-3 and extended to a total depth of 72 inches
form exiting grade.
The resulting test holes were cleaned of loose debris, then filled with several gallons of clean, potable
water and allowed to pre-soak overnight. The following day the test holes were cleaned of sediment and
the bottom was lined with approximately 2-inches of washed gravel prior to percolation testing. A series
of falling head percolation tests were then performed. Test holes P-1 through P-3 were filled with clean,
potable water to a minimum of 20 inches above the bottom of the test hole and allowed to infiltrate. The
water levels was allowed to drop for a 30-minute period, the water level was then measured and the drop
rate calculated in inches per hour. Infiltration test borings P-1 and P-2 were dry after the 30 minute
period. Therefore, the sandy soil criteria was met and the time interval for those two test borings was
decreased to 10 minute intervals. The test holes were then refilled with water as necessary and the test
procedure was repeated over the course of approximately 6 hours for test borings HS-3 and until a
stabilized percolation rate was recorded for test borings P-1 and P-2.
The stabilized percolation rate was then converted to an infiltration rate based on the “Porchet Method”
utilizing the following equation:
Logs of the field testing and graphical representations of the test data presented as infiltration versus time
interval are attached herewith as supporting documents for Worksheet C.4-1.
2.0 TEST RESULTS AND PRELIMINARY DESIGN VALUES
The results of our testing are summarized in Table 1 below.
TABLE 1
SUMMARY OF INFILTRATION/PERCOLATION TEST RESULTS
Test
Hole No. Location Depth of Test
Hole
Approximate
Test Elevation
ft. above msl
Geologic Unit Description
Tested
Infiltration Rate
(inches/hour)
P-1 800 Grand 48” (4’) 62 msl Qop Medium to Fine-
grained Sand 2.00
P-2 800 Grand 48” (4’) 61 msl Qop Medium to Fine-
grained Sand 2.83
HSP -3 Home Ave 72” (6’) 57 msl Qop Medium to Fine-
grained Sand 0.77
In accordance with Appendix D, Section D.5 of the BMP Design Manual, a ‘Factor of Safety’ should be
applied to the tested infiltration rates to determine the design infiltration rates. The factor of safety is
determined by Worksheet D.5-1 and possesses a numerical value between 2 and 9. For the proposed
project site, the factor of safety worksheet yielded a Combined Factor of Safety (Stotal) of 3. However, for
the purposes of feasibility screening, it is recommended by San Diego County that a Factor of Safety of
2.0 be utilized. Table 2 below summarizes the design infiltration rates for the subject test holes utilizing a
factor of safety of 2.0.
TABLE 2
SUMMARY OF DESIGN INFILTRATION RATES
Test Hole No. Location Tested Infiltration
Rate (in /hr.) Factor of Safety Design Infiltration
Rate (in./hr.)
P-1 800 Grand 2.0 2.0 1.0
P-2 800 Grand 2.83 2.0 1.42
HSP-3 Home Ave 0.77 2.0 0.39
AVERAGE RATE 0.93
3.0 DESIGN CONSIDERATIONS
3.1. Groundwater
The soil borings extended ten feet or greater below the bottom of the percolation test borings and
encountered groundwater/saturated soil as summarized in table 3.
TABLE 3
SUMMARY OF DEPTH TO GROUNDWATER
Test Hole No. Location Depth To Groundwater
P-1 800 Grand 14*
P-2 800 Grand 15*
HSP-3 Home Ave 16.5*
*-Extrapolated from adjacent boring
Based on our observations and experience with similar projects in the vicinity, the seasonal high
groundwater is anticipated to be approximately 14 feet below existing grade (approximate
elevation 48 msl).
3.2. Geotechnical Hazards
Slopes greater than 25% are not present onsite. Retaining walls and/or basement structures are
proposed on the partially subterranean 800 Grand portion of the site. Dependent on final design,
utility trenches (Parcel A & B) and basement walls (Parcel A) in proximity to BMP basins could
be subject to water intrusion. It is recommended that if infiltration is to be used it should only be
used on the Home Avenue portion and should be located a minimum of 25 to 30 feet away from
the southerly edge of the Grand Avenue structure.
3.3. Soil and Groundwater Contamination
During our recent site investigation, no soil contamination was observed, nor is any
contamination known to exist onsite. Groundwater was not encountered during out subsurface
investigations, and is not anticipated to be contaminated. Based on the State of California
Regional Water Quality Control Board (RWQCB) GeoTracker website, the closest site that had
environmental issues is located at 880 Carlsbad Village Drive, approximately 0.1 mile
southeasterly of the subject site. That site is listed as a leaking underground storage tank (LUST)
site that has a clean-up status as “completed”, and the RWQCB case for that site is now closed.
3.4. Pretreatment prior to infiltration
At this time, it is not anticipated that stormwater will undergo pretreatment such as sedimentation
or filtration prior to infiltration.
3.5. Soil Characteristics
The infiltration surfaces are in Old Paralic Deposits. As encountered, these materials can
generally be described as medium to fine-grained sand with some silt, in a medium dense to
dense condition. This unit exhibited favorable characteristics for infiltration and appeared to be
relatively uniform, but somewhat denser with depth.
3.6. Proximity to water supply wells
No water supply wells are known to exist within 100 feet of the proposed basin.
4.0 CONCLUSIONS AND RECOMMENDATIONS
Based on the results of our preliminary infiltration testing, the onsite soils possess observed infiltration
rates ranging between 0.77 and 2.83 inches/hour. When utilizing a factor of safety of 2, preliminary
design infiltration rates range between 0.39 and 1.42 inches/hour, with an recommended average design
infiltration rate of 0.94 inches/hour. Based on the results of our site specific testing, infiltration rates for
the project site are above 0.50 inches/hour. For the Home Avenue, single family residential portion of the
site it is our opinion that partial or full infiltration is feasible. For the southern portion of the project (800
Grand) which will consist of the partially subterranean condominium structure it is our opinion that
infiltration is not feasible due to the potential for water intrusion and for additional hydrostatic pressure
on the proposed subterranean garage. Accordingly infiltration on the 800 Grand portion of the site project
should not be considered.
ATTACHMENTS
STORM WATER STANDARDS BMP DESIGN MANUAL – WORKSHEET FORM C.4-1
SUPPORT DOCUMENTS AND FIELD DATA
Categorization of Infiltration Feasibility Condition-800 Grand
Worksheet C.4-1
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 Yes No
1
Is the estimated reliable infiltration rate below proposed facility locations
greater than 0.5 inches per hour? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.2 and Appendix D.
Provide basis:
Two (2) borehole percolation tests were performed in proposed/possible BMP locations. Testing was performed
in general conformance with Appendix D, Section D.3.3.2 of the recently adopted BMP Design Manual. The
stabilized percolation rates were then converted to infiltration rates using the “Porchet Method”. The observed
infiltration rates were calculated to be: 2.0 inches/hour in test hole P-1and 2.83 inches/hour in test hole P-2. Using
a factor of safety of 2 for feasibility screening purposes yielded design infiltration rates of 1.00 in/hr and 1.42
in/hr. Inclusive of the additional infiltration test on the Home Ave (0.38in/hr) yields an average infiltration rate of
0.93 in/hr.
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:
The average infiltration rates at this portion of the project site are greater than 0.5 inches/hour. However,
infiltration is not recommended due to the adverse affects the infiltration water may have on the subterranean
parking garage (increase in hydrostatic pressure, water proofing issues with the structure, and buoyancy issues
which could result in differential settlement).
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
Worksheet C.4-1 Page 2 of 4- 800 Grand
Criteria Screening Question Yes No
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water
pollutants or other factors) that cannot be mitigated to an acceptable level?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
No known contamination exists at the site and the closest know site with contamination issues is located
approximately 0.1 miles southeast of the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface
waters? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
Provide basis:
The design infiltration rates at the project site are greater than 0.5 inches/hour. Infiltration at a rate greater than
0.5 inches/hour is not feasible for this project due to the subterranean component of the structure. As such, this
screening question does not control the feasibility of infiltration at the project site. Per Section C.4.4 of the BMP
Design Manual, final determination should be made by the project design engineer.
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
*To be completed using gathered site information and best professional judgment considering the definition of MEP
in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate findings
Worksheet C.4-1 Page 3 of 4- 800 Grand
Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
5
Do soil and geologic conditions allow for infiltration in any appreciable rate
or volume? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.2 and
Appendix D.
Provide basis:
As discussed in our response to Criteria No. 1, site specific infiltration testing yielded infiltration rates of greater
than 0.5 inches/hour. The sandy nature of the subsurface materials beneath the site, allow for infiltration in an
appreciable rate or volume. It is anticipated that over the lifetime of the development the infiltration rates will
further diminish. The BMP Design Manual utilizes the subjective terminology of ‘appreciable’ and fails to define
a lower bound infiltration rate. It is our current understanding that an ‘appreciable’ infiltration rate is interpreted
to be any perceptible amount of infiltration. Therefore, in consideration of the current interpretation, the soil and
geologic conditions at the project site allow for infiltration in an ‘appreciable’ rate or volume.
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:
For the “Grand Avenue” Condominium structure supported by the proposed partially subterranean garage,
infiltration may create unwanted mounding and hydrostatic pressures on the buried portions of the structure.
Accordingly , it is our opinion that the condominium portion is not suitable for infiltration.
Worksheet C.4-1 Page 4 of 4
Criteria Screening Question Yes No
7
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
The proposed basin location has adequate separation (10 feet) to seasonal high groundwater. There are no known
water supply wells within 100 feet of the project site. According to the State Water Board’s Geotracker website,
the closest site with contamination issues is located 0.1 miles from the site. That site is reported as a LUST
cleanup, and the case has been closed. Land use in the project vicinity is predominantly multi-family residential
with locally interspersed commercial/retail. There are no known contamination risks from current land use
activities. As such, we do not anticipate that construction of the proposed BMP basin will adversely impact
receiving channels in the project vicinity.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
The project site is graded and is located in a developed neighborhood with impermeable surfaces where surface
waters are controlled and directed to storm drain inlets. There is no apparent evidence that construction of BMP
basins would divert or otherwise preclude flow to downstream water bodies. Per Section C.4.4 of the BMP
Design Manual, final determination should be made by the project design engineer.
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.
If any answer from row 5-8 is “No”, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
*To be completed using gathered site information and best professional judgment considering the definition of
MEP in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate
findings
Categorization of Infiltration Feasibility Condition- Home Ave
Worksheet C.4-1
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 Yes No
1
Is the estimated reliable infiltration rate below proposed facility locations
greater than 0.5 inches per hour? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.2 and Appendix D.
Provide basis:
One (1) borehole percolation tests was performed in proposed/possible BMP location. One was conducted for
Home Ave single family detached (HS-3); and two were conducted for the 800 Grand condominium portion P1
and P2 . Testing was performed in general conformance with Appendix D, Section D.3.3.2 of the recently adopted
BMP Design Manual. The stabilized percolation rates were then converted to infiltration rates using the “Porchet
Method”. The observed infiltration rates were calculated to be 0.77 inches/hour in test hole HSP-3 (Home Ave)
and 2.0 inches/hour in test hole P-1and 2.83 inches/hour in test hole P-2 on the Grand Ave. portion. Using a factor
of safety of 2 for feasibility screening purposes yielded design infiltration rates of 0.39(Home Ave). Using a
factor of safety of 2 for feasibility screening purposes yielded design infiltration rates of 1.00 in/hr and 1.42 in/hr.
and 0.38in/hr. It is our opinion that an average infiltration rate of 0.93 in/hr should be used for both sites given the
similar soils and geology.
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:
Yes an infiltration rate of 0.93in/hr can be used for the design of possible infiltration on the Home Avenue
portion of the project. This opinion is based upon: the similarity of the soils exposed in the 3 percolation
test borings; the lower rate found in HS-1 is likely related to the near surface compaction as a result of the
original parking lot and drive isle construction activities. The types of soils and the blow counts within the
upper soils are relatively uniform. Accordingly, once the proposed infiltration section is cut to the design
grade (18 to 24 inches) it is conservatively estimated that the average rate presented herein can be utilized for
design.
Based upon the proposed location in the drive aisles/parking areas it is not anticipated that this will
adversely affect the proposed improvements provided the building slabs are adequately waterproofed with a
suitable moisture barrier and the buried utility lines are located outside of the pervious pavement or
adequately backfilled with a sand cement slurry where they intercept the permeable pavement.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
Worksheet C.4-1 Page 2 of 4-Home Ave.
Criteria Screening Question Yes No
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water
pollutants or other factors) that cannot be mitigated to an acceptable level?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
No known contamination exists at the site and the closest know site with contamination issues is located
approximately 0.1 miles southeast of the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface
waters? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
Provide basis:
The design infiltration rates at the Home Ave portion of the project are suitable provided they do not infiltrate
into the buried utilities and that they are a minimum of 25 to 30 feet horizontally away from the Grand Ave
podium structure and drain in a south to north direction. Per Section C.4.4 of the BMP Design Manual, final
determination should be made by the project design engineer.
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
*To be completed using gathered site information and best professional judgment considering the definition of MEP
in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate findings
Worksheet C.4-1 Page 3 of 4-Home Ave
Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
5
Do soil and geologic conditions allow for infiltration in any appreciable rate
or volume? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.2 and
Appendix D.
Provide basis:
Site specific infiltration testing yielded infiltration rates of greater than 0.5 inches/hour. The sandy nature of the
subsurface materials beneath the site, allow for infiltration in an appreciable rate or volume. It is anticipated that
over the lifetime of the development the infiltration rates will further diminish. The BMP Design Manual utilizes
the subjective terminology of ‘appreciable’ and fails to define a lower bound infiltration rate. It is our current
understanding that an ‘appreciable’ infiltration rate is interpreted to be any perceptible amount of infiltration.
Therefore, in consideration of the current interpretation, the soil and geologic conditions at the project site allow
for infiltration in an ‘appreciable’ rate or volume.
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:
Partial Infiltration can be allowed in the proposed BMP basin/Permeable pavement locations without
significantly increasing the risk of geotechnical hazards provided appropriate mitigation/remedial grading
measures are performed during site development/basin construction. The infiltration surface for the proposed
BMPs have not been finalized at this time, however, it is expected that they will be within the native material at
the site (Old Paralic Deposits) As encountered, the Old Paralic Deposits beneath the site, consist predominantly
of sand and silty sand, in a dense to very dense condition. Some gravely sand was observed at the bottom of the
Old Paralic Deposits. Below the Old Paralic Deposits, a less permeable silty claystone was encountered and
assigned to the Santiago Formation. More detailed recommendations should be provided when final design
plans become available. For the “Home” Avenue portion of the development it is our opinion that infiltration
within the proposed driveways and parking lots is suitable.
Worksheet C.4-1 Page 4 of 4 Home Ave
Criteria Screening Question Yes No
7
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
The proposed basin location has adequate separation (>10 feet) to seasonal high groundwater. There are no
known water supply wells within 100 feet of the project site. According to the State Water Board’s Geotracker
website, the closest site with contamination issues is located 0.1 miles from the site. That site is reported as a
LUST cleanup, and the case has been closed. Land use in the project vicinity is predominantly multi-family
residential with locally interspersed commercial/retail. There are no known contamination risks from current land
use activities. As such, we do not anticipate that construction of the proposed BMP basin will adversely impact
receiving channels in the project vicinity.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
The project site is graded and is located in a developed neighborhood with impermeable surfaces where surface
waters are controlled and directed to storm drain inlets. There is no apparent evidence that construction of BMP
basins would divert or otherwise preclude flow to downstream water bodies. Per Section C.4.4 of the BMP
Design Manual, final determination should be made by the project design engineer.
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.
If any answer from row 5-8 is “No”, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
*To be completed using gathered site information and best professional judgment considering the definition of
MEP in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate
findings
HS-3&HSP-3
0-0.5' afu
0.5-6' Qop
TD=6'
HS-1
0-0.5' afu
0.5-19' Qop
19-20' Tsa
@ 16.5' Saturated
TD=20'
HS-4
0-0.5' afu
0.5-18' Qop
18-20' Tsa
@ 15' Saturated
TD=20'
HS-2
0-0.4' afu
0.4-20' Qop
20-21.5' Tsa
@ 18' Saturated
TD=21.5'
TB-2
0-0.5' afu
0.5-11' Qop
TD=11'
TB-1
0-1' afu
1-16' Qop
@ 14' Saturated
TD=16'
P-3
P-2
P-1
afu
(Qop)
((Tsa))
afu
(Qop)
((Tsa))A'A
B'
B
Parcel "B"
Parcel "A"
TB-2
Undocumented Fill
Old Paralic Deposits
Santiago Formation
Hollowstem Auger Boring
Tri Pod Auger Boring
Percolation Boring
Cross Section Location
LEGEND:
P-1
PLATE 1
HS-1
Tsa
Qop
afu
GEOLOGIC MAP
A A'
A
700
680 -.,_
LL.. -:z
0 660 .,_
<( > w _J w HS-3 Qop
640 -----1--? ------?--
Tsa
620
B
700 -
-.,_
LL.. 680 --
:z
0 .,_
<( > w 660 _J -
w
C
640
UTB-=._2 Qo~ ~-----
Qop
Proposed 3-Story Structure
afu
O.SftL----------~---------------.
ropose
Basement
Qop
---
A'
700
680
660
TB-2
-.,_
LL.. -:z
0 .,_
<( > w _J w
----------?----------. ----? 640
afu
0.5ft
I
~
-?----
Tsa
Tsa HS-4
I I
I Ramp Down I
-----------?---
CROSS SECTIONS A-A', AND B-B'
SCALE H&V 1 "=20'
-
Tsa
Proposed 3 Story Structure
Proposed
Basement
Qop -? ------
Tsa
620
B'
-700
-.,_
f--680 LL.. -:z
0 .,_
<( > 660 w
_J w
Fl_
TB-1 -----640
LEGEND:
Existing Gra de
""" --Assu med ( +6") Finish Grade
PLATE2
~~GS ADVANCED GEOTECHNICAL SOLUTIONS, INC
485 Corporate Drive, Suite B
Escondido, California 92029
Telephone: (7 l4) 786-5661 Fax: (714) 409-3287
Project# Report# Date:
P /W 1607-03 1607-03 October 2016