HomeMy WebLinkAboutCT 2017-0005; GRAND WEST; STORM WATER QUALITY MANAGEMENT PLAN; 2018-03-01..
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CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
GRAND WEST
SWQMP No. CT 2017-0005/PUD 2017-0005
ENGINEER OF WORK:
Lawrence S. Eisenhart, C068233, 09/30/2019
PREPARED FOR:
Eric DeJong
807 E Mission Rd.
San Marcos, CA 92069
858-7 55-0216
PREPARED BY:
Masson & Associates, Inc.
200 E. Washington Ave. Suite 200
Escondido, California 92025
760-7 41-3570
DATE:
March 1, 2018
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MAR O 2 2018
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TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1 a: DMA Exhibit
Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment 1 e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
Geotech Report
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Project Name: Grand West
Project ID: CT 2017-0005
CERTIFICATION PAGE
I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs
for this project, and that I have exercised responsible charge over the design of the project as
defined in Section 6703 of the Business and Professions Code, and that the design is consistent
with the requirements of the BMP Design Manual, which is based on the requirements of
SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order .
I have read and understand that the City Engineer has adopted minimum requirements for
managing urban runoff, including storm water, from land development activities, as described in
the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability
and accurately reflects the project being proposed and the applicable source control and site
design BMPs proposed to minimize the potentially negative impacts of this project's land
development activities on water quality. I understand and acknowledge that the plan check
review of this SWQMP by the City Engineer is confined to a review and does not relieve me, as
the Engineer in Responsible Charge of design of storm water BMPs for this project, of my
responsibilities for project design.
Engineer of Work's Signature, PE Number & Expiration Date
Lawrence S. Eisenhart, P.E.
Print Name
Masson & Associates, Inc .
Company
March 1, 2018
Date
PROJECT VICINITY MAP
C cityof
Carlsbad
STORM WATER STANDARDS
QUESTIONNAIRE
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
E-34
I INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY
DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City
staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and signed questionnaire must be submitted with each development project application. Only one completed
and signed questionnaire is required when multiple development applications for the same project are submitted
concurrently.
PROJECT INFORMATION
PROJECT NAME: Grand West PROJECT ID: CT 2017-0005
ADDRESS: (street number not assigned) 972, 988 Grand Ave, Carlsbad CA APN: 203-130-25-00, 203-130-26-00
The project is (check one): D New Development 0g Redevelopment
The total proposed disturbed area is: 18 550 ft2 ( 0.43 ) acres
The total proposed newly created and/or replaced impervious area is: 13 243 ft2 ( 0.30 ) acres
If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project: No
Project ID NIA SWQMP#:
Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
E-34 Page 1 of 4 REV 02/16
STEP 1
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building D • 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 auestion, the oroiect is a 'develooment oroiect', ao to Steo 2.
STEP2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1. Constructing newor 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; D • 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 D • accordance with the US EPA Green Streets guidance?
3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? D •
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ... " and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USE PA Green Street guidance):
If you answered "no" to the above questions, your project is not exemot from PDP, ao to Steo 3.
STEP3 , .,.:\if;, TO BE COMPLET£D FOR ALL NEW OR REDEVELOPMENT PROJECTS . ·• .. · ..
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )):
YES NO
1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, D • and public develooment oroiects on oublic 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 • D more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on oublic or orivate 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 D • a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside D • development project includes develooment on anv natural slope that is twenty-five percent orareater.
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 • D a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a street, road, highway
freeway or driveway? A street, road, highway, freeway or driveway is any paved impervious surface D •
used for the transoortation of automobiles, trucks, motorcvcles, 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
D • 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 oroiect to the ESA (i.e. not comminqled with flows from adiacent 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 D • shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.
9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes
RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily D •
Traffic (ADT) of 100 or more vehicles per day.
10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land D • and are expected to generate pollutants post construction?
11 . Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC D • 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 "Mv project is a 'STANDARD PROJECT' ... " and complete annlicantinformation.
E-34 REV02/16
STEP4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS(PDP)
ONLY
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of Impervious surface in an amount
..of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
Existing impervious area (A)= 7,020 sq. ft. 0 • Total proposed newly created or replaced impervious area (B) = __ _,J .... 3,.,2 ..... 4.,_3 _______ sq. ft.
?ercent Impervious area created or replaced (B/A)*100 =___.J..,,8..,,.8 ___ %
f 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
pplicant Information.
f you answered "no," the structural BMP's required for PDP apply to the entire development. Go to step 5, check the
check the first box statin "M ro ect Is a PDP .. : and com lete a !leant information.
STEPS
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
'$( My project Is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
My project Is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT'
stormwatet requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project
Requirement Checklist Form E-3{;' and incorporate low impact development strategies throughout myproject.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed Impervious area calculations
nd exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply.
My Project is NOT a 'deve!_opment project' and Is not subject to the requirements of the BMP Manual.
ppllcant Information and Signature Box
are not limited to au Clean Water Act Section 303( impaired water bodies; areas
niticance by the State Water Resources Control Board (Water Quality Control Plan
for the San Diego Basin (1994) and ame ments); water bodies designated with the RARE benellclal use by the Sta'te Water
Resources Control Board (Water Quality ntrol Plan for the San Diego Basin (1994) and amendments); areas designated as
preseives or their equivalent under the M ti Species Conservation Program within the Cities and County of San Diego; Habitat
Management Plan; end any other equivalent environmentally sensitive areas 'Artlich have been Identified by the City.
This Box for City
U 01 se n,y
YES
City Concurrence: D
By:
Date:
Project ID:
NO
D
SITE INFORMATION CHECKLIST
Project Summarv Information
Project Name Grand West
Proiect ID CT 2017-0005
Project Address 972 & 988 Grand Avenue
Assessor's Parcel Number(s) (APN(s)) 203-130-25-00, 203-130-26-00
Project Watershed (Hydrologic Unit) Carlsbad 904.21
Parcel Area 0.43 Acres ( 18,550 Sauare Feet)
Existing Impervious Area
(subset of Parcel Area) 7,020 Acres ( 0.16 Square Feet)
Area to be disturbed by the project
(Project Area) 0.43 Acres ( 18,550 Square Feet)
Project Proposed Impervious Area
(subset of Proiect Area) 13,243 Acres ( 0.30 Square Feet)
Project Proposed Pervious Area
(subset of Proiect Area) 5,153 Acres ( 0.13 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
E-34 REV 02/16
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
,/Existing development
Previously graded but not built out
Agricultural or other non-impervious use
Vacant, undeveloped/natural
Description/ Additional Information:
Existing Land Cover Includes (select all that apply):
/Vegetative Cover
Non-Vegetated Pervious Areas
,/Impervious Areas
Description/ Additional Information:
The site is an existing residential site with impervious area like footprint, driveway and patio.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
NRCS Type A
I NRCS Type B
NRCS Type C
NRCS Type D
Approximate Depth to Groundwater (GW):
GW Depth < 5 feet
5 feet < GW Depth < 10 feet
,11 0 feet < GW Depth < 20 feet
GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
I None
Description / Additional Information:
Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from
the site? At a minimum, this description should answer (1) whether existing drainage
conveyance is natural or urban; (2) describe existing constructed storm water conveyance
systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]:
E-34
The project site is located at 972 and 988 Grand Avenue in Carlsbad. The site bounded by
Grand Avenue to the southeast and residences on all other sides. The project is zoned RD-M
with a General Plan Land Use designation of R15, which allows for 11.5 du/acre per Staff.
The project site is generally flat at an approximate elevation of 68 feet msl and consists of
residential buildings, driveways and landscapes. The site is located approximately 0.46 miles
south of the Buena Vista Lagoon. The surface runoff from the site currently drains into
Grand Avenue and which ultimately reaches Buena Vista Lagoon and Pacific Ocean via curb,
gutter and storm drain system.
Stormwater discharges from the site are not considered direct discharges, as defined by the
State Water Board. Existing site topography, drainage patterns, and stormwater conveyance
systems are shown on the Grading Plans. The site accepts no off site runoff from the
adjacent roadways or adjoining properties.
REV 02/16
Descriotion of Prooosed Site Development and Drainaae Patterns
Project Description / Proposed Land Use and/or Activities:
The proposed site is planned to be developed into Two (2) Triplex Townhome Condominiums,
for a total number of 6 units. The proposed projects land use is consistent with the surrounding
development and will not adversely impact the adjoining lands or the character of the
neighborhood.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
As with any residential development, the project will include impervious surfaces. Im pervious
surfaces will include; roofs, driveways, parking areas, streets, patios and hard landscaping. The
increase in runoff as a function of the new impervious surfaces will be mitigated by a retention
basin.
List/describe proposed pervious features of the project (e.g., landscape areas):
The project will include several types of pervious surfaces within the design. The pervious
surfaces include; landscaping, grass areas and bio-filtration Basins, and planting areas.
Does the project include grading and changes to site topography?
./Yes
No
Description/ Additional Information:
Considering the site has previously been developed, the site will require minor re-contouring to
make the site developable for the new propose plan. Although, every effort has been made to
reduce the earthwork, the site will require approximately 2,980 cubic yards of fill be
implemented for the proposed design presented.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
./ Yes
No
Description/ Additional Information:
As shown on the plan, few new drainage systems have been included in the designs which play
an important role in controlling surface runoff. The facilities include; area yard drains, storm
drainage pipe, perforated underdrain pipes, rip rap energy dissipaters and three bio-filtration
basins. All of these systems work in conjunction to control and discharge flows in a manner
most similar to the existing condition.
Identify whether any of the following features, activities, and/or pollutant source
areas will be present (select all that apply):
./ On-site storm drain inlets
Interior floor drains and elevator shaft sump pumps
./ Interior parking garages
./ Need for future indoor & structural pest control
./ Landscape/Outdoor Pesticide Use
Pools, spas, ponds, decorative fountains, and other water features
Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
./ Fire Sprinkler Test Water
./ Miscellaneous Drain or Wash Water
./ Plazas, sidewalks, and parking lots
E-34 REV 02/16
Identification of Receivina Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable):
Surface runoff draining from the site is discharged in a controlled fashion into a storm drain on
Monroe Street approximately 1 mile upstream of the Buena Vista Lagoon . Runoff then travels an
additional 1.5 miles within the Lagoon before reaching the Pacific Ocean.
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Bodv Pollutant(s)/Stressor(s) TMDLs
Buena Vista Creek/ 904.21 Toxicity, Selenium, Bifenthrin, Needed Benthic Community Effects
Buena Vista Lagoon/ 904.21 Indicator Bacteria, Nutrients, Needed Sedimentation/Siltation, Toxicity
Pacific Ocean Shoreline, Buena Indicator Bacteria Needed Vista Creek HA/ 904.21
Identification of Proiect Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
BMP Desiqn Manual Appendix 8.6):
Also a Receiving
Not Applicable to Anticipated from the Water Pollutant of
Pollutant the Project Site Proiect Site Concern
Sediment X NA
Nutrients X NA
Heavv Metals X NA
Orqanic Comoounds X NA
Trash & Debris X NA
Oxygen Demanding P(l) NA Substances
Oil & Grease P(2) NA
Bacteria & Viruses
p
Pesticides X NA
P = Potential
(1) = A potential pollutant if landscaping exists onsite.
(2) = A potential pollutant if the project uncovered parking areas.
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
Yes, hydromodification management flow control structural BMPs required.
No, the project will discharge runoff directly to existing underground storm drains
discharging directly to water storage reservoirs, lakes, enclosed embayment's, or the
Pacific Ocean.
No, the project will discharge runoff directly to conveyance channels whose bed and bank
are concrete-lined all the way from the point of discharge to water storage reservoirs,
lakes, enclosed embayment's, or the Pacific Ocean .
./ No, the project will discharge runoff directly to an area identified as appropriate
for an exemption by the WMAA for the watershed in which the project resides.
Description/ Additional Information (to be provided if a 'No' answer has been selected above):
Since the project is exempt from hydromodification, the critical coarse sediment is not an
issue for this project site.
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
Yes
No, No critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design
Manual been performed?
6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
6.2.2 Downstream Systems Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
No optional analyses performed, the project will avoid critical coarse sediment yield
areas identified based on WMAA maps
If optional analyses were performed, what is the final result?
No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
Critical coarse sediment yield areas exist but additional analysis has determined
that protection is not required. Documentation attached in Attachment 8 of the
SWQMP.
Critical coarse sediment yield areas exist and require protection. The project will
implement management measures described in Sections 6.2.4 and 6.2.5 as applicable,
and the areas are identified on the SWQMP Exhibit.
Discussion/ Additional Information:
E-34 REV 02/16
Flow Control for Post-Project Runoff*
*This Section onlv reauired if hvdromodification manaaement reauirements apply
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see Section 6.3.1 ). For each POC, provide a POC identification name or number
correlating to the project's HMP Exhibit and a receiving channel identification name or number
correlating to the project's HMP Exhibit.
N/A, the project will discharge runoff directly to an area identified as appropriate
for an exemption by the WMAA for the watershed in which the project resides.
Therefore the HMP is not required.
Has a geomorphic assessment been performed for the receiving channel(s)?
No, the low flow threshold is 0.1Q2 (default low flow threshold)
Yes, the result is the low flow threshold is 0.1Q2
Yes, the result is the low flow threshold is 0.3Q2
Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion/ Additional Information: (optional)
N/A, the project will discharge runoff directly to an area identified as appropriate
for an exemption by the WMAA for the watershed in which the project resides.
Other Site Reauirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or City
codes governing minimum street width, sidewalk construction, allowable pavement types, and
drainage requirements.
N/A
City of Ca rlsbad ....... Zoning Ordinance
City of Carlsbad ....... Design Guidelines
City of Carlsbad ....... Grading and Drainage Ordinance
City of Carlsbad ....... Engineering Standards
Optional Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
N/A
E-34 REV 02/16
C cicyof
Carlsbad
Project Name: Grand West
Project ID: CT 2017-0005
DWG No. or Building Permit No.:
STANDARD PROJECT
REQUIREMENT CHECKLIST
E-36
Project Information
Source Control BMPa
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to
implement source control BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
"No" means the BMP is applicable to the project but it Is not feasible to Implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "NIA" means the BMP Is not applicable at the project site because the project does not Include the feature that Is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion~ustification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 1..,.XYes 1 No N/A
DiscussioNJustification if SC-1 not implemented: -
-
SC-2 Storm Drain Stenciling or Slgnage (xves) No N/A
Discussion~ustification if SC-2 notimplemented: -
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind ~ ""
Yes No j XN/A ) Dispersal ...._ ~
Discussion/justification if SC-3 not Implemented:
No post development storage of material Is proposed.
E-36 Page 1 of 4 Revised 09/16
Source Control Requirement (continued) Applied?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Yes No Cl XN~ Wind Dispersal
Discussion/justification if SC-4 not implemented:
No post development outdoor work areas are proposed.
SC-5 Protect Trash Storage Areas from Rainfall , Run-On, Runoff, and Wind Dispersal lf""xYe~ No N/A
Discussion/justification if SC-5 not implemented: -
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance).
D On-site storm drain inlets lX Yes~'
D Interior floor drains and elevator shaft sump pumps :_x yes_)
D Interior parking garages ~X yes~,
D Need for future indoor & structural pest control --... l.._X Yes__.
D Landscape/Outdoor Pesticide Use :xYes ,
D Pools, spas, ponds, decorative fountains, and other water features 1...-XNo-....
D Food service -i...-XNo-....
D Refuse areas ,-..._XYes ,
D Industrial processes ( XNo_)
D Outdoor storage of equipment or materials i...-xNo-....
DVehicle and Equipment Cleaning C XNo_::
D Vehicle/Equipment Repair and Maintenance I X No_::
D Fuel Dispensing Areas I XNo-....
DLoading Docks (' X No--:
D Fire Sprinkler Test Water ...-X Yes __,,t
D Miscellaneous Drain or Wash Water ...-XYes ,
D Plazas, sidewalks, and parkinq lots r-:,i. Yes~.
For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" cu,~ -~ ~-
This is a residential project with no common interior parking structure.
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information
to implement site design BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of the
Model BMP Design Manual. Discussion / justification is not required.
"No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
orovided .
Source Control Requirement I -Annlied?
SD-1 Maintain Natural DrainaQe Pathways and HydroloQic Features I XYes l No I NIA
Discussion/justification if SD-1 not implemented: .... ,I -
-
SD-2 Conserve Natural Areas, Soils, and Vegetation I Yes ii' X No ) IN/A
Discussion/justification if SD-2 not implemented: "------
Considering the existing and proposed plan the entire site will be minor regraded to accommodate the development
plan. No significant trees or vegetation was observed on site.
-
SD-3 Minimize Impervious Area 7 XYes l No IN/A
Discussion/justification if SD-3 not implemented: ~ ,I -
SD-4 Minimize Soil Compaction I Yes I X No ) NIA
Discussion/justification if SD-4 not implemented: "------
As the site will be completely regraded, soil compaction of import soils will be required. Unfortunately, no native areas
will remain undisturbed.
-
SD-5 Impervious Area Dispersion I Yes/! X No "\ I NIA
Discussion/justification if SD-5 not implemented: '--j -
The project is a redevelopment project that will implement the same approximate impervious footprint and drainage
patterns, that will not lend itself the ability to implement dispersion areas on site.
E-36 Revised 03/16
Source Control Requirement (continued) I -Applied?
SD-6 Runoff Collection {I Yes )i No IX N/A
Discussion/justification if SD-6 not implemented: -
-
SD-7 Landscaping with Native or Drought Tolerant Species (XYes ) No I NIA
Discussion/justification if SD-7 not implemented: -
-
SD-8 Harvesting and Using Precipitation I Yes l(X No i)NIA
Discussion/justification if SD-8 not implemented: -
See Form 1-7 for calculation.
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of
the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control
must be based on the selection process described in Chapter 5. PDPs subject to
hydromodification management requirements must also implement structural BMPs for flow
control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both
storm water pollutant control and flow control for hydromodification management can be
achieved within the same structural BMP(s).
PDP structural BMPs must be verified by the City at the completion of construction. This may
include requiring the project owner or project owner's representative to certify construction of
the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must
be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the
BMP Design Manual).
Use this form to provide narrative description of the general strategy for structural BMP
implementation at the project site in the box below. Then complete the PDP structural BMP
summary information sheet for each structural BMP within the project (copy the BMP summary
information page as many times as needed to provide summary information for each individual
structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information
must describe how the steps for selecting and designing storm water pollutant control BMPs
presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of
BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether
pollutant control and flow control BMPs are integrated together or separate.
The pollution control measures and structural BMP's have been implemented on site. The
proposed Bio-filtration Basins will treat onsite runoff, prior to discharge.
Hydromodification is exempt for this project therefore flow Control BMP is not required.
The bio-filtration basin has a high rating for removal of all likely pollutants from storm water.
E-36 Revised 03/16
[Continued from previous page -This page is reserved for continuation of description of general
strategy for structural BMP implementation at the site.]
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMPl
Structural BMP ID No.
DWG 481-1A Sheet No. 4
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
./ Partial retention by biofiltration with partial retention (PR-1)
Biofiltration (BF-1)
Flow-thru treatment control included as pre-treatment/forebay for an onsite
retention or biofiltration BMP (provide BMP type/description and indicate which
onsite retention or biofiltration BMP it serves in discussion section below)
Detention pond or vault for hydromodification management
Other (describe in discussion section below)
Purpose:
./ Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control
Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Discussion (as needed):
IMP#1
IMP#2
IMP#3
E-36 Revised 03/16
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment Contents Checklist
Seauence
Attachment 1 a OMA Exhibit (Required)
Attachment 1 b
Attachment 1 c
Attachment 1 d
See OMA Exhibit Checklist on the
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Tabular Summary of DMAs Showing
OMA ID matching OMA Exhibit, OMA
Area, and OMA Type (Required)*
*Provide table in this Attachment OR
on OMA Exhibit in Attachment 1 a
Form 1-7, Harvest and Use Feasibility
Screening Checklist (Required unless
the entire project will use infiltration
BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)
Refer to Appendices C and D of the
BMP Design Manual to complete
Form 1-8.
I Included
I Included on OMA Exhibit in
Attachment 1 a
Included as Attachment 1 b,
separate from OMA Exhibit
I Included
Not included because the entire
project will use infiltration BMPs
I Included
Not included because the entire
project will use harvest and use
BMPs
Attachment 1 e Pollutant Control BMP Design I Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
&tii5
'
+
DMA AREA IMPERVIOUS AREA OVERFLOW # OF RISER SIZE IN TOTAL POND
IMP # (SF) (SF) PIPE RISERS FEET (X,Y) DEPTH
(IN) (FT)
1 2,164 * 1 * 3.0
2 2,414 * 1 * 3.0
3 8,630 * 1 * 3.0
j
i
SIDEWALK UNDERDRAIN /
~ ~~x :,~ /
6FZe2 ~ / ~/
X o..~~ ' // • / ~\
~' / G /
/ / ,# / \ l, ~J ~5 / / ~
X ;, ~/ X \ • . ABOVE GROUND PLANTER , &ti,8
/,
"" DISCHARGE POINT
BIO-FILTRATION CHART
1 85th percentile 24-hr storm depth
2 Area tributary to BMP (s)
3 Area Weighted runoff factor
4 Rain Barrels volume reduction
5 Street trees volume reduction
6 Calculator DCV =
(3630 x C x d x A) -TCV -RCV
!Area Weighted runoff factor =
=
1 85th percentile 24-hr storm depth
2 Area tributary to BMP (s)
3 Area Weighted runoff factor
4 Rain Barrels volume reduction
5 Street trees volume reduction
6 Calculator DCV =
(3630 x C x d x A) -TCV -RCV
=
1 85th percentile 24-hrstorm depth
2 Area tributary to BMP {s)
3 Area Weighted runoff factor
4 Rain Barrels volume reduction
5 Street trees volume reduction
6 Calculator DCV =
(3630x Cx d x A) -TCV-RCV
!Area Weighted runoff factor -
d= 0.590 inches
A= 0.09 acres
C= 0.55 unitless
TCV= 0 cubic-feet
RCV= 0 cubic-feet
DCV= 103.6 cubic-feet
( (0.9*(2164)+0.1 *( 1697) )/(3861))
0.55
d= 0.590 inches
A= 0.11 acres
C= . 0.51 unitless
TCV= 0 cubic-feet
RCV= 0 cubic-feet
DCV= 117.8 cubic-feet
{(0.9*(2414)+0.1 *(2337))/(4751))
0.51
d= 0.590 inches
A= 0.23 acres
C= 0.79 unitless
TCV= 0 cubic-feet
RCV= 0 cubic-feet
DCV= 386.2 cubic-feet
( (0.9*(8630)+0.1 *(1308) )/(9938))
0.79
MULCH AMENDED GRAVEL GRAVEL DEPTH BOTTOM BASIN DISTANCE FROM TOP OF PERFORATED SLOPE REQUIRED BMP PROVIDED BMP BASIN VOLUME
DEPTH SOIL DEPTH DEPTH BELOW UNDERDRAIN ELEVATION BOTTOM OF POND GRATE PIPE Z: 1 AREA AREA REQUIRED
"A" (IN) "B" (IN) "c" (IN) (IN) (FT) TO TOP OF RISER ELEVATION (FT) (IN) (SF) (SF) (CF)
3" 18" 11" 12" 64.9 8" 65.6 * N/A 64 64 192
3" 18" 11 n 12" 64.7 8" 65.3 * N/A 71 71 213
3" 18" 13.5" 12" 65.3 8" 65.8 * N/A 236 236 708
* TO BE DETERMINED DURING FINAL ENGINEERING PHASE
1·
~-~------\Z._ ______ _
12'
RISER FOR ., •
EMERGENCY
OVERFLOW
----------~,~-~
3" OUTFALL PIPE
GRAVITY DISCHARGE
TO STREET
OBOVE GROUND PLANTER
N.T.S.
I
WATER QUALITY FLOW
FROM BASIN 1 . . ' ,, .
I BIO-FILTRATION BASIN 2
ABOVE GROUND PLANTER I
' ' ' ~
V . A ,, < . ' ' , . .
WATER QUALITY
I
FLOW
~ . ~
V
SUMP VAULT I-
I-w
W/PUMP w w
~ c::: ~ I-
I-V U)
ti) 0
==o I-
QI-w ..Jw C)
LI. C) c::: c::: c::: <(
~<( ::c o::c, u, u !a >-rn
OCHEMA TIC DRAINAGE SYSTEM
N.T.S.
LEGEND
SYMBOL DESCRIPTION
OMA BOUNDARY --------
SOIL TYPE
GROUNDWATER TABLE
PROPOSED BASIN
GROUND WALL
• ID •
• '-' •
R/W
I
SHRUBS
BIO-FILTRATION
AREA
____ :57_
,, B,,
GRATER THAN 11'
UNDERDRAIN
OUTLFOW PIPE
TO VAULT
810-FIL TRA TION BASIN DETAIL
N.T.S.
,_,
"'
BASIN VOLUME
PROVIDED
(CF)
192
213
708
WATER QUALITY FLO w
,, FROM BASIN3
< ' -
@
.N
0 20 10 ;.....__ 20
SCALE IN FEET
GRAPHIC SCALE
1"=20'
------------
40 60
LAGUNA DR. LAGUNA DR.
CALIF. COORD. INDEX 362-1665
VICINITY MAP:
NOT TO SCALE
Planning ..t. Engineering ..t. Surveying
Solved.
200 E. Washington Ave., Suite 200
Escondido, CA 92025
0. 760.741.3570
& ASSOCIATES. INC.
F. 760.741.1786
www.masson-assoc.com
OMA MAP
RBCORD COPY I !!&WI Nd. I
111M. IM'IE I Z&lliiii I
Appendix I: Forms and Checklists
Use this checklist to ensure the required information has been included on the OMA Exhibit:
The OMA Exhibit must identify:
./ Underlying hydrologic soil group
./ Approximate depth to groundwater
./ Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
./ Critical coarse sediment yield areas to be protected (if present). "See Course Sediment Exhibit."
./ Existing topography and impervious areas
./ Existing and proposed site drainage network and connections to drainage offsite
./ Proposed grading
./ Proposed impervious features
./ Proposed design features and surface treatments used to minimize imperviousness
./ Drainage management area (OMA) boundaries, OMA ID numbers, and OMA areas (square footage or
acreage), and OMA type (i.e., drains to BMP, self-retaining, or self-mitigating)
./ Structural BMPs (identify location and type of BMP)
l-2
Appendix I: Forms and Checklists
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
Toilet and urinal flushing
Landscape irrigation
v' Other: None Provider
2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance
for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section
B.3.2.
[Provide a summary of calculations here]
Toilet Use (36 Hours use)= 22 Cubic-feet
Landscape Use (Over 36 Hours)= 6 Cubic-feet
Total anticipated Use (Over 36 Hour)= 29 Cubic-feet
25%*607.6=152 > 29 Cubic-feet
3. Calculate the DCV using worksheet B.2-1 .
DCV = 607.6 ( cubic feet)
3a. Is the 36 hour demand greater
than or equal to the DCV?
Yes
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?
y~ I
Hal vest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to detem1ine
feasibility. Harvest and use may only be
able to be used for a portion of the site,
or (optionally) the storage may need to be
upsized to meet long term capture targets
while draining in longer than 36 hours.
Is hatvest and use feasible based on further evaluation?
D Yes, refer to A ndix E to select and size harvest and use BMPs.
v"No, select alternate BMPs.
I-
3c. Is the 36 hour demand
less than 0.25DCV?
Harvest and use Is
considered to be
Infeasible because of
the site design
constrain
February 26,
C . . f I fil . F "b"li C d" . Form 1-8 atcgorizauon o n 1 tratton east t ty on 1t10n
Part 1 -Full Infiltration Feasibility Screening Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria Screening Question
Is the estimated reliable infiltration rate below proposed facility
locations greater than 0.5 inches per hour? The response to this
Screening Question must be based on a comprehensive evaluation of
the factors presented in Appendix C.2 and Appendix D.
Provide basis:
Yes No
X
Three (3) separate percolation tests were completed within 50 feet of each proposed water quality basin
locations. The calculated infiltration rates at each location (with an applied factor of safety of 2) are 0.12,
0.12, & 0.15 inches per hour.
For reference refer to Geotechnical Investigation by Construction Testing & Engineering, Inc.
(CTE), dated May 31, 2017.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of g eotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot be
mitigated to an acceptable level? T he response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.2.
Provide basis:
X
Basins can be constructed within the areas with favorable permeability (Figure 2) and with adequately set
back from proposed structural improvements; risk of geotechnical hazards will not be significantly
increased.
Sum marize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
Criteria
3
Appendix I: Forms and Checklists
Form I-8 Page 2 of 4
Screening Question
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of groundwater contamination (shallow
water table, storm water pollutants or other factors) that cannot
be mitigated to an acceptable level? The response to this Screening
Question must be based on a comprehensive evaluation o f the factors
presented in Appendix C.3.
Yes No
X
Provide basis:
~ccording to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 feet away from the
site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicabili ty.
4
Can infiltration g reater than 0.5 inches per hour be allowed
without causing potential water balance issues such as change of
seasonality of ephemeral streams or increased discharge of
contaminated groundwater to surface waters? The response to this
Screening Question must be based on a comprehensive evaluation of
the factors presented in Appendix C.3.
X
Provide basis:
rThe nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet from the
!Site. Due to the significant distance to the lagoon it is unlikely to be impacted by infiltrating site water.
Summarize findings of studies; provide reference to studies, calcuJations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
Part 1
Result
*
If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The
feasibility screening category is Full Infiltration
If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generalJy be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
No Full
Infiltration,
!Proceed to Part ~
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/ or studies may be required by Agency/Jurisdictions to substantiate findings
,_ February 26,
Form 1-8 Page 3 of 4
Part 2 Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria
5
Screening Question
Do soil and geologic conditions allow for infiltration in any
appreciable rate or volume? The response to this Screening
Question must be based on a comprehensive evaluation of the factors
presented in Appendix C.2 and Appendix D.
Provide basis:
Yes
X
No
[Three (3) separate percolation tests were completed within 50 feet of each proposed water quality basin
locations, and the calculated infiltration rates at each location (with an applied factor of safety of 2) are
0.12, 0.12, & 0.15 inches per hour, which exceeds the 0.05 inches per hour.
For reference refer to Geotechnical Investigation by Construction Testing & Engineering, Inc.
(CTE), dated May 31, 2017.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
kliscussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed without
increasing risk of geotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot
be mitigated to an acceptable level? The response to this Screening
Q uestion must be based on a comprehensive evaluation of the factors
presented in Appendix C.2.
Provide basis:
X
Basins can be constructed within the areas with favorable permeability (Figure 2) and with adequately set
back from proposed structural improvements; risk of geotechnical hazards will not be significantly
increased.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
Criteria
7
------------~--------
Form 1-8 Page 4 of 4
Screening Question
Can Infiltration in any appreciable quantity be allowed without
posing significant risk for groundwater related concerns
(shallow water table, storm water pollutants or other factors)?
The response to this Screening Q uestion must be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
Yes No
X
Provide basis:
~ccording to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 feet away from the
Site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
8
Can infiltration be allowed without violating downstream water
rights? The response to this Screening Question must be based on a
comprehensive evaluation of the factors presented in Append.ix C.3.
Provide basis:
X
The nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet from the site. Due to
he significant distance to the lagoon it is unlikely to be impacted by infiltrating site water.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
Part 2
Result*
If all answers from row 1-4 are yes then partial infiltration design is potentially feasible.
The feasibility screening category is Partial Infiltration.
If any answer from row 5-8 is no, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
Partial
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 Agency/Jurisdictions to substantiate findings.
I-February 26,
1 85th percentile 24-hr storm depth d= 0.590 inches
2 Area tributary to BMP (s) A= 0.09 acres
3 Area Weighted runoff factor C= 0.55 unitless
4 Rain Barrels volume reduction TCV= 0 cubic-feet
5 Street trees volume reduction RCV= 0 cubic-feet
6 Calculator DCV =
3630 x C x d x A -TCV -RCV
DCV= 103.6 cubic-feet
I Area Weighted runoff factor = ( (0.9*(2164)+0.1 *(1697) )/(3861))
= 0.55
1 85th percentile 24-hr storm depth d= 0.590 inches
2 Area tributary to BMP (s) A= 0.11 acres
3 Area Weighted runoff factor C= 0.51 unitless
4 Rain Barrels volume reduction TCV= 0 cubic-feet
5 Street trees volume reduction RCV= 0 cubic-feet
6 Calculator DCV = DCV= 117.8 cubic-feet
3630 x C x d x A -TCV -RCV
I Area Weighted runoff factor = ((0.9*(2414)+0.1 *(2337))/(4751))
= 0.51
1 85th percentile 24-hr storm depth d= 0.590 inches
2 Area tributary to BMP (s) A= 0.23 acres
3 Area Weighted runoff factor C= 0.79 unitless
4 Rain Barrels volume reduction TCV= 0 cubic-feet
5 Street trees volume reduction RCV= 0 cubic-feet
6 Calculator DCV =
3630 x C x d x A -TCV -RCV DCV= 386.2 cubic-feet
I Area Weighted runoff factor = ((0.9*(8630)+0.1 *( 1308) )/(9938))
= 0.79
~........ .•.. .. --~ ........ ,.
Remaining DCV after implementing retention BMPs
,,,.,,_ .. ,, .... ~
103.6 cubic-feet
P artial Retention
2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible
3 Allowable drawdown tim e for aggregate storage below the underdrain
4 D epth of runoff that can be infiltrated [Line 2 x Line 3)
5 Aggregate p ore space
6 Required d epth of gravel below the underdrain [Line 4/ Line 5)
7 Assumed surface area of the biofiltration BMP
8 M edia retained pore space
9 Volume retained by BMP [!Line 4 + (Line 12 x Line 8))/12) x Line 7
10 D CV that requires biofiltration [Line 1 -Line 9)
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximum]
12 Media Thickness [1 8 inches minimum]
13
Aggregate Storage above underdrain invert (12 inches typical) -use O inches for sizing if
the aggregate is not over the entire bottom surface area
14 M edia available pore space
15 Media filtration rate to be used for sizing
B ase line Calculations
16 Allowable Routing Time for sizing
17 D epth filtered during storm [ Line 15 x Line 16)
18 Depth of D etention Storage
[Line 11 + (Line 12 x Line 14) + (Line13 x Line 5)]
19 Total Depth Treated [Line 17 + Line 18)
Option 1-Biofilter 1.5 times the DCV
20 Required bio filtered volume [1 .5 x Line 1 OJ
21 Required Footprint lLine 20 / Line 19] x 12
Option 2 -Store 0.75 ofre maining DCV in pores and ponding
22 Required Storage (surface + pores) Volume [0.75 x Line 10)
23 Required Footprint lLine 22/ Line 18] x 12
Footprint of th e BMP
24 Area draining to the BMP
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03)
27 Footprint of the BMP = Maximum(M:inimum(Lioe 21, Line 23), Line 26)
Note: Line 7 is used to estim ate the amount of volume retained b y the BMP. U pdate assum ed surfaa: area in Line 7
until its equivalent to the required biofiltration footp1int (eith er Line 21 0 1· Line 23)
0.12
36
4.32
0.4
10.8
65
0.1
33.15
70.45
6
18
12
0.2
5
6
30
14.4
44.4
106
29
53
44
3861
0.55
64
64
I-February 26,
in/hr.
hours
inches
in/in
inches
sq-ft
in/in
cubic-feet
cubic-feet
inches
inches
inches
in/in
in/hr.
hours
inches
inches
inches
cubic-feet
sq-ft
cubic-feet
sq-ft
sq-ft
sq-ft
sq-ft
~--···· ............ .....,,...,n,.~, ...
maining DCV after implementing retention BMPs
, ... ,.,_., .... ~
117.8 cubic-feet
P artial Retention
2 Infiltration rate from Worksheet D.5-1 if partial in£tlcration is feasible
3 Allowable drawdown time for aggregate storage below the underdrain
4 D epth of runoff that can be infiltrated [Line 2 x Line 3)
5 Aggregate p ore space
6 Required depth of gravel below the underdrain [Line 4/ Line 5)
7 Assum ed surface area of the biofiltration BMP
8 Media retained pore space
9 Volum.e retained by BMP [[Line 4 + (Line 12 x Line 8))/12) x Line 7
10 DCV that requires biofiltration lLine 1 -Line 9)
BMP P aram e ters
11 Surface Ponding [6 inch minimum, 12 inch m aximum]
12 Media Thickness [18 inches minin1Um]
13 Aggregate Storage above undcrdrain invert (12 inches typical) -use 0 inches for sizing if
the aggregate is no t over the entire bottom surface area
14 M ed ia available pore space
15 M edia filtration rate to be used for sizing
Baseline Calculations
16 Allowable Routing Time for sizing
17 Depth filtered during storm [ Line 15 x Line 16)
18 Depth of Detention Storage
lL ine 11 + (Line 12 x Line 14) + (Line13 x Line 5))
19 T otal Depth Treated [Line 17 + Line 18)
Option 1 -Biofilter 1.5 times the DCV
20 Required bio ftltered volume [1.5 x Line 10)
21 Requited Footprint [Line 20/ Line 19) x 12
Option 2 -Store 0 .75 of remaining DCV in pores and ponding
22 Required Storage (surface + pores) Volwne [0.75 x Line 10)
23 Required Footprint [Line 22/ Line 18] x 12
Footprint of the BMP
24 Area draining to the BMP
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03)
27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26)
Note : Line 7 is used to estimate the amount of volume retained by the BMP. U pdate assumed surface area in Line 7
until its equ ivalent to the required bio filu-ation footprint (either Line 21 or Line 23)
0.12 in/hr.
36 hours
4.32 inches
0.4 in/in
10.8 inches
85 sq-ft
0.1 in/in
43.35 cubic-feet
74.45 cubic-feet
6 inches
18 inches
12 inches
0.2 in/in
5 in/hr.
6 hours
30 inches
14.4 inches
44.4 inches
112 cubic-feet
30 sq-ft
56 cubic-feet
47 sq-ft
4751 sq-ft
0.5
71 sq-ft
71 sq-ft
~--'"· .... "... ... ·----, .. _, .......... ~
maining DCV after implementing retention BMPs 386.2 cubic-feet
Partial Retention
2 Infiltration rate from \'<lorksheet D.5-1 if partial infiltration is feasible
3 Allowable drawdown ti.me for aggregate storage below the underdrain
4 Depth of runoff that can be infiltrated [Line 2 x Line 3]
5 Aggregate p ore space
6 Required depth of gravel below the underdrain [Line 4/ Line 5)
7 Assumed surface area of the biofiltration BMP
8 Media retained pore space
9 Volume retained by BMP [lLine 4 + (Line 12 x Line 8)]/12J x L ine 7
10 DCV that requires biofiltration [Line 1 -Line 9]
BMP Parameters
11 Surface Ponding [6 inch minimum, 12 inch maximum] **
12 Media Thickness [18 inches minimum]
13 Aggregate Storage above underdrain invert (12 inches typical) -use O inches for sizing if
the aggregate is not over the entire bottom surface area
14 Media available pore space
15 Media filtration rate to b e used for sizing
Baseline Calculations
16 AJlowable Ro uting Time for sizing
17 Depth filtered during storm [ Line 15 x Line 16)
18 D epth of Detention Storage
[Line 11 + (Line 12 x Line 14) + (Line13 x Line 5)]
19 Total Depth Treated [Line 17 + Line 18)
Option 1-Biofilter 1.5 times the DCV
20 Required bio filtered volume [1.5 x Line 10J
21 Required Footprint LLine 20/ Line 19] x 12
Option 2 -Store 0 .75 of remaining DCV in pores and ponding
22 Required Storage (surface+ pores) Volume l0.75 x Line 10)
23 Required Footprint [Line 22/ Line 18) x 12
Footprint of the BMP
24 Area draining to the BMP
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2)
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.03]
27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26)
Note: Line 7 is used to estimate the am ount of volume retained by the BMP. Update assumed surfaa: area in Line 7
until its equivalent to the required biofiltration footprint (either line 21 or Line 23)
0.15
36
5.4
0.4
13.5
400
0.1
240
146.2
6
18
12
0.2
5
6
30
14.4
44.4
219
59
110
91
9938
0.79
236
236
I-February 26,
in/hr.
hours
inches
in/in
inches
sq-ft
in/in
cubic-feet
cubic-feet
inches
inches
inches
in/in
in/hr.
hours
inches
inches
inches
cubic-feet
sq-ft
cubic-feet
sq-ft
sq-ft
sq-ft
sq-ft
ArcGIS ... 85th percentile precipitation -San Diego County
[ [TI Details ] I 88 Basemap
o o m
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Nole9end
E,.ri.com H•lp T•rm.1 ol Un Privacy C.onta:t
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Modify Map .:. Sign In
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
Attachment
Sequence
Attachment 2a
Attachment 2b
Attachment 2c
Attachment 2d
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
None required since this site will be exempt from
Hydromodification requirements.
Contents Checklist
Hydromodification Management Included
Exhibit (Required)
See Hydromodification Management
Exhibit Checklist on the back of this
!Attachment cover sheet.
Management of Critical Coarse Exhibit showing project drainage
Sediment Yield Areas (WMAA Exhibit ooundaries marked on WMAA
is required, additional analyses are Critical Coarse Sediment Yield
optional) !Area Map (Required)
See Section 6.2 of the BMP Design Optional analyses for Critical Coarse
Manual. Sediment Yield Area Determination
6.2.1 Verification of
Geomorphic Landscape Units
Onsite
6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
Geomorphic Assessment of Receiving Not performed
Channels (Optional) Included
See Section 6.3.4 of the BMP Design
Manual.
Flow Control Facility Design and Included
Structural BMP Drawdown
Calculations (Required)
See Chapter 6 and Appendix G of the
BMP Desiqn Manual
I-February 26,
Use this checklist to ensure the required information has been included on the
Hydromodification Management Exhibit:
Not required since this site will be exempt from
Hydromodification requirements.
The Hydromodification Management Exhibit must identify:
Underlying hydrologic soil group
Approximate depth to groundwater
Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)
Critical coarse sediment yield areas to be protected (if present)
Existing topography
Existing and proposed site drainage network and connections to drainage offsite
Proposed grading
Proposed impervious features
Proposed design features and surface treatments used to minimize imperviousness
Point(s) of Compliance (POC) for Hydromodification Management
Existing and proposed drainage boundary and drainage area to each POC (when necessary,
create separate exhibits for pre-development and post-project conditions)
Structural BMPs for hydromodification management (identify location, type of BMP, and
size/detail)
Appendix I: Form s and Checklists
ATTACHMENT 3
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural BMP Maintenance
Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
} Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
~ Specific maintenance indicators and actions for proposed structural BMP(s). This shall be based on Section 7.7 of the BMP
Design Manual and enhanced to reflect actual proposed components of the structural BMP(s).
o The indicators of required maintenance include the failure of any of the BMP's. Failure of the BMP could include clogging of an
inlet as indicated by failure to drain or slow draining of the bio Basin. The Basin should drain in a 72 hour period and be free
debris.
~ How to access the structural BMP(s) to inspect and perform maintenance.
o Maintenance of the BMP can easily be accessed from the projects common open space. Permeable pavers have been provided
on the access pathway for equipment should it be necessary to maintain the bio-filtration BMP. Access to clean out the pipe
can be done via removable catch basin grate inlet.
~ Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow
the inspector to view necessary components of the structural BMP and compare to maintenance thresholds)
o The access corridor to the Structural BMP's has been overlain with concrete pavers, insuring permanent access to the Bio
Retention Basin, headwall and spillway.
» Manufacturer and part number for proprietary parts of structural BMP(s) when applicable.
o No specific proprietary parts or part numbers
» Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level posts or other markings shall be included
in all BMP components that will trap and store sediment, trash, and/or debris, so that the inspector may determine how full
the BMP is, and the maintenance personnel may determine where the bottom of the BMP is . If required, posts or other
markings shall be indicated and described on structural BMP plans.)
o Please see inspection and fact sheets on the following pages.
» Recommended equipment to perform maintenance.
o Routine maintenance can be accomplished with hand tools. Should major maintenance (such as replacement of amended soil
or gravel) be required, it is anticipated that a small backhoe will be needed.
» When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as
confined space entry or hazardous waste management.
o No special training or certification is required.
Appendix I: Forms and Checklists
TABLE 7-3. Maintenance Indicators and Actions for Vegetated BMPs
Typical Maintenance Indicator(s) Maintenance Actions for Vegetated BMPs
Accumulation of sediment, litter, or Remove and properly dispose of accumulated materials, without
debris damage to the vegetation.
Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans.
Overgrown vegetation Mow or trim as appropriate, but not less than the design height of
the vegetation per original plans when applicable (e.g. a vegetated
swale may require a minimum vegetation height).
Erosion due to concentrated irrigation Repair/re-seed/re-plant eroded areas and adjust the irrigation system.
flow
Erosion due to concentrated storm Repair/re-seed/ re-plant eroded areas, and make appropriate
water runoff flow corrective measures such as adding erosion control blankets, adding
stone at flow entry points, or minor re-grading to restore proper
drainage according to the ori!,>inal plan. If the issue is not corrected
by restoring the BMP to the original plan and grade, The County
must be contacted prior to any additional repairs or reconstruction.
Standing water in vegetated swales Make appropriate corrective measures such as adjusting irrigation
system, removing obstructions of debris or invasive vegetation,
loosening or replacing top soil to allow for better infiltration, or
minor re-grading for proper drainage. If the issue is not corrected by
restoring the BMP to the original plan and grade, County staff in the
Watershed Protection Program must be contacted prior to any
additional repairs or reconstruction.
Standing water ill bioretention, Make appropriate corrective measures such as adjusting irrigation
biofiltration with partial retention, or system, removing obstructions of debris or invasive vegetation,
biofiltration areas, or flow-through clearing underdrains (where applicable), or repairing/ replacing
planter boxes for longer than 96 hours clogged or compacted soils.
following a storm event*
Obstructed inlet or outlet structure Clear obstructions.
Damage to structural components such as Repair or replace as applicable.
weirs, inlet or outlet structures
*These BMPs typically include a surface ponding layer as part of their function which may take 96 hours to drain
following a storm event.
I-February 26,
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City's standard Single Sheet BMP Plan.]
~8
13#1;8
X
-",_,
S' is) 13#1; 5
~0 X
' 0~
/£;!k 7
X
+ ~
PROPOSED
GROUND
BASIN
WALL
R/W
I
SHRUBS
&fs5
X
BIO-FILTRATION
AREA
____ 57_
EXISTING
GROUND
+
;"'
I
·-
UNDERDRAIN
BIO-FILTRATION BASIN DETAIL
fr;)' 7
X
&6;6
X
f1
66.56
BASIN
WALL
PROPOSED
GROUND
OVERFLOW PIPE
TO STREET
OVERFLOW
STRUCTURE
OUTLFOW PIPE
TO VAULT
-+-
!fil5
X
I
\
N.T.S.
LEGEND
SYMBOL
PROJECT BOUNDARY
BIOFIL TRA TION BASIN
20 10 0
..N
20 40 -----
SCALE IN FEET
GRAPHIC SCALE
1"=20'
---------------------------------------~---------------
DESCRIPTION
--
' ' ' ' • • ' ' • ' • • •
' -• • ' • • ' • • • • • • ' ' • • • ' ' • • • ' ' •
60
--'Ill[' iiiiii ci'iiil
SWMP NO. ____ _
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME DEJONG ARIE E II / DEJONG SILVA
ADDRESS 807 E MISSION RD. CONTACT
SAN MARCOS, CA 92069 ------
PHONE NO. _______ _
PLAN PREPARED BY:
NAME BRUCE TAIT C032247
COMPANY MASSON & ASSOCIATES. INC .
ADDRESS 200 E. WASHINGTON A VE, /1200
ESCONDIDO. CA 92025
SlGNATIJRE
PHONE NO. _..c7,.,60-"--'-7"-41,_-..,,3,,.57'->0'----
BMP NOTES: CERTIFICATION QSD/QSP 21715
1. THESE BMPSARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S
RECOMMENDATIONS OR THESE PLANS.
2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR
APPROVAL FROM THE CITY ENGINEER.
3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES
WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER.
4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF
HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION
AND INSTALLATION.
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
6. SEE PROJECT SWMP FOR ADDITIONAL INFORMATION.
BMPID# BMPTYPE SYMBOL CASQA NO.
TREATMENT CONTROL
€) BIOFILTRATION TC-32
HYDROMODIFICATION & TREATMENT CONTROL
N/A
HYDROMODIFICATION
NIA
LOW IMPACT DESIGN (L.I.D.)
SMART N/A SD-12 IRRIGATION
SOURCE CONTROL --
@ NEED FOR FUTURE
INDOOR/STRUCTURAL SC-41 .
PEST CONTROL
@ LANDSCAPE/OUTDOOR
PESTICIDE USE: SC-41
PROVIDE IMP
ROOFTOP DRAIN TO
® PERVIOUS LANDSCAPE SC-10 . AREA, AVOID USE OF
UNPROTECTED
METALS
PLAZAS, SIDEWALKS,
~ AND PARKING LOTS: SE-7
SWEEP REGULARLY, SC-43
COLLECT DEBRIS,
COLLECT
WASTEWATER AND
DISCHARGE TO
SANITARY SEWER
* CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS
IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS:
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
BMP
QUANTITY
371 S.F.
NIA
TABLE
DRAWING NO.
-
-
SHEET NO.(S) INSPECTION * MAINTENANCE *
FREQUENCY FREQUENCY
-MONTHLY MONTHLY
. MONTHLY AS-NEEDED
Planning .._ Engineering • Surveying
Solved.
200 E. Washington Ave., Suite 200
& ASSOCIATES. INC.
Escondido, CA 92025
0. 760.741.3570
F. 760.741.1786
www.masson-assoc.com
1• -, 11 cl'rt oF cmtSBlD II~
~DFPMIIENT •• .. _.,...
GRAND AVENUE
RECORD COPY I PRC-:illi • NO. I
I lifXWiti I -IIUL MW: IIUL
~ DESCRIPTION .. DAE _,., .... C11Y•1•111.
4 TIMES PER YEAR
----... ------
-----.. --...
--------
-------
Construction Testing & Engineering, Inc.
Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying
GEOTECHNICAL INVESTIGATION
PROPOSED TWO TRIPLEX TOWNHOME CONDOMINIUMS
972 AND 988 GRAND AVENUE
CARLSBAD, CALIFORNIA
Prepared for:
MR. ERIC DEJONG
C/O: CONSULTANTS COLLABORATIVE
MS. TERRY MATHEW
160 INDUSTRIAL STREET
SAN MARCOS, CALIFORNIA 92078
Prepared by:
CONSTRUCTION TESTING & ENGINEERING, INC.
1441 MONTIEL ROAD, SUITE 115
ESCONDIDO, CALIFORNIA 92026
CTE JOB NO.: 10-136430
n.-
L\,: .:. -~ -!~.,~~
. ·--~~
AUG O 8 2017
crry er.----., , . _ PL -I l.,; i"\LSBAD
ANNING DIVISION
May 31, 2017
1441 Montiel Road, Suite 115 Escondido, CA 92026 Ph (760) 746-4955 Fax (760) 746--9806 I www.cte-inc.net
TABLE OF CONTENTS
1.0 INTRODUCTION AND SCOPE OF SERVICES ................................................................... I
1.1 Introduction ................................................................................................................... I
1.2 Scope of Services .......................................................................................................... I
2.0 SITE DESCRIPTION ............................................................................................................... 2
3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2
3. I Field Investigation ........................................................................................................ 2
3.2 Laboratory Testing ........................................................................................................ 2
3 .3 Percolation Testing ....................................................................................................... 3
3 .3 .1 Calculated Infiltration Rates .......................................................................... 4
3 .3 .2 Calculated Infiltration Rates .......................................................................... 6
4.0 GEOLOGY ............................................................................................................................... 7
4. I General Setting ............................................................................................................. 7
4.2 Geologic Conditions ..................................................................................................... 7
4.2.1 Residual Soil .................................................................................................. 7
4.2.2 Quaternary Old Paralic Deposits (Qop) ......................................................... 8
4.3 Groundwater Conditions ............................................................................................... 8
4.4 Geologic Hazards .......................................................................................................... 8
4.4.1 Surface Fault Rupture .................................................................................... 9
4.4.2 Local and Regional Faulting .......................................................................... 9
4.4.3 Liquefaction and Seismic Settlement Evaluation ........................................ I 0
4.4.4 Tsunamis and Seiche Evaluation ................................................................. I 0
4.4.5 Landsliding .................................................................................................. 11
4.4.6 Compressible and Expansive Soils .............................................................. 11
4.4.7 Corrosive Soils ............................................................................................. 12
5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................. 13
5.1 General ........................................................................................................................ 13
5.2 Site Preparation ........................................................................................................... 13
5 .3 Site Excavation ........................................................................................................... 14
5.4 Fill Placement and Compaction .................................................................................. 14
5.5 Fill Materials ............................................................................................................... 15
5.6 Temporary Construction Slopes ................................................................................. 16
5.7 Foundations and Slab Recommendations ................................................................... 17
5.7.1 Foundations .................................................................................................. 17
5. 7 .2 Foundation Settlement ................................................................................. 18
5.7.3 Foundation Setback ...................................................................................... 18
5.7.4 Interior Concrete Slabs ................................................................................ 19
5 .8 Seismic Design Criteria .............................................................................................. 20
5. 9 Lateral Resistance and Earth Pressures ...................................................................... 21
5.10 Exterior Flatwork ...................................................................................................... 23
5. I I Pavements ................................................................................................................. 23
5 .12 Drainage .................................................................................................................... 24
5.13 Slopes ........................................................................................................................ 25
5 .14 Plan Review .............................................................................................................. 26
5 .15 Construction Observation ......................................................................................... 26
6.0 LI MITA TIO NS OF INVESTIGATION ................................................................................. 27
FIGURES
FIGURE I
FIGURE 2
FIGURE 3
FIGURE 4
APPENDICES
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
TABLE OF CONTENTS
SITE LOCATION MAP
GEOLOGIC/ EXPLORA T!ON LOCATION MAP
REGIONAL FAULT AND SEISMICITY MAP
CONCEPTUAL RETAINING WALL DRAINAGE
REFERENCES
FIELD EXPLORATION METHODS LOGS
LABORATORY METHODS AND RES UL TS
STANDARD GRADING SPECIFICATIONS
C.4-1 WORKSHEET
Geotechnical Investigation
Proposed Two Triplex Townhomes
Page 1
972 and 988 Grand Avenue, Carlsbad, California
May 31, 2017 CTE Job No.: 10-136430
1.0 INTRODUCTION AND SCOPE OF SERVICES
1.1 Introduction
This report presents the results of the geotechnical investigation, performed by Construction Testing
and Engineering, Inc. (CTE), and provides preliminary conclusions and recommendations for the
proposed improvements at the subject site located in Carlsbad, California. This investigation was
performed in general accordance with the terms ofCTE proposal G-4029A, dated March 27, 2017.
CTE understands that the proposed site improvements are to consist of two structures of two-to
three-story construction, paved parking and flatwork, retention basins, associated utilities,
landscaping, and ancillary improvements. Preliminary recommendations for excavations, fill
placement, and foundation design for the proposed improvements are presented in this report.
Reviewed references are provided in Appendix A.
1.2 Scope of Services
The scope of services provided included:
• Review of readily available geologic and geotechnical reports.
• Excavation of exploratory borings utilizing limited-access manually operated drilling equipment.
• Percolation testing in accordance with County of San Diego Department of Environmental
Health (DEH) procedures.
• Laboratory testing of selected soil samples.
• Description of site geology and evaluation of potential geologic hazards.
• Engineering and geologic analysis.
• Preparation of this geotechnical investigation report.
\\Esc __ ,crvcr\projects\ l O-l 3643Ci\Rpt __ Gcotcchnical.doc
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand Avenue, Carlsbad, California
May 31, 2017
Page 2
CTE Job No.: 10-136430
2.0 SITE DESCRIPTION
The project site is located at 972 and 988 Grand Avenue in Carlsbad, California (Figure 1 ). The site
is bounded by Grand A venue to the southeast and residences on all other sides. The project area is
generally flat at an approximate elevation of 68 feet msl ( above mean sea level).
3.0 FIELD INVESTIGATION AND LABORATORY TESTING
3 .1 Field Investigation
CTE performed the field investigation on May 9, 2017. The field work consisted of a site
reconnaissance and excavation of four exploratory borings and four percolation test holes. The
borings were excavated with a manually operated three-inch diameter auger. Bulk samples were
collected from the cuttings.
The soils were logged in the field by a CTE Engineering Geologist. and were classified in general
accordance with the Unified Soil Classification System via visual and tactile methods. The field
descriptions have been modified, where appropriate, to reflect laboratory test results. Boring logs.
including descriptions of the soils encountered, are included in Appendix B. The approximate
locations of the borings are presented on Figure 2.
3.2 Laboratory Testing
Laboratory tests were conducted on selected soil samples for classification purposes, and to evaluate
physical properties and engineering characteristics. Laboratory tests included: Gradation, Expansion
Index (El), and Chemical Characteristics. Test descriptions and laboratory test results for the
selected soils are included in Appendix C.
\\E,c_scrver\projccts\ IO-I 3643G\Rpt_ GeotechmcaLdoc
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand Avenue, Carlsbad, California
May 31, 2017
3.3 Percolation Testing
Page 3
CTE Job No.: 10-136430
The percolation testing was performed in accordance with SD DEH Case III method, which is
performed when presoak water infiltrates through the hole overnight. The presoak duration for all
tests ranged from approximately 23 to 24 hours, which is within the SD DEH 15 to 30 hour presoak
range. Percolation test results and rates are presented below in Table 3.3. The C.4-1 infiltration
feasibility worksheet is also included in Appendix E.
TABl,R $.),., . cc >.' .. \. .,.
·; ·;(--:·.; ;,
';.'. PE~COLATl~~tµ'ft!S ·.
·,;,1'
Boring/Depth Time Time Initial Water Final Water Water Level Percolation Rate
{inches) Change Level Level Change
(minutes) (inches) (inches) (inches) Inches/ Inches
P-1/51.0 Hour I
Minut
Soil: e
Qop 0930 Initial 43.0 NIA NIA
1000 30 43.0 44.1875 1.19
Case Ill 1030 60 43.0 43.875 0.88
1100 90 43.875 44.75 0.88
1130 120 43.0 44.25 1.25
1200 150 43.0 43.75 0.75
1230 180 43.75 44.375 0.63
1300 210 43.0 43.75 0.75
1330 240 43.0 43.75 0.75 1.5 0.025
Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate
(inches) Change (inches) Level Change
(minutes) (inches) (inches) Inches/ Inches
P-2149.0 Hour I
Minut
Soil: e
Qop 0932 Initial 41.0 NIA NIA
1002 30 41.0 42.5 1.50
Case III 1032 60 41.0 42.4 1.40
1102 90 41.0 42.4375 1.44
1132 120 41.0 42.1875 1.19
1202 150 41.0 41.75 0.75
1232 180 41.75 42.31 0.56
1302 210 41.0 41.60 0.60
\\Esc __ scrvcr\projedsl I 0-13643G\Rpt_ Gcotedmical.doc
Geotechnical Investigation
Proposed Two Triplex Townhomes
Page 4
972 and 988 Grand A venue, Carlsbad, California
May 31, 2017 CTE Job No.: 10-136430
1332 240 41.60 42.2875 0.69 1.38 0.023
Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate
(inches) Change (inches) Level Change
(minutes) (inches) (inches) Inches/ Inches
P-3/51.0 Hour I
Minut
Soil: e
Qop 0934 Initial 39.0 NIA NIA
1004 30 39.0 40.9375 1.94
Case Ill 1034 60 39.0 40.625 1.63
1104 90 39.0 40.5 1.50
1134 120 39.0 40.5 l.50
1204 150 39.0 40.375 1.38
1234 180 39.0 40.375 1.38
1304 210 39.0 40.1875 1.19
1334 240 39.0 40.25 1.25 2.5 0.042
Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate
(inches)
P-4/50.0
Soil:
Qop
Case III
NOTES
Change (inches) Level Change
(minutes) (inches) (inches)
0936 Initial 42.0 NIA NIA
1006 30 42.0 42.25 0.25
1036 60 42.25 42.50 0.25
1106 90 42.50 42.75 0.25
1136 120 42.75 43.00 0.25
1206 150 42.0 42.0625 0.0625
1236 180 42.625 42.125 0.0625
1306 210 42.125 42. 1875 0.0625
1336 240 42.1875 42.25 0.0625
Qop = Quaternary Old Paralic Deposits.
Water level was measured from a fixed point at the top of the hole.
The test holes had a diameter six inches.
Weather was overcast and mild during the percolation testing.
3.3.1 Calculated Infiltration Rates
Inches/ Inches
Hour I
Minut
e
0.125 0.0021
As per the County of San Diego BMP design documents (February 2016) infiltration rates
arc to be evaluated through the Porchet Method. CTE utilized the Porchet Method through
\\l'sc _ servcrlprnjcctsl 10-13643( i\Rpt_ (ieotech111cal .doc
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand Avenue, Carlsbad, California
May 31, 2017
Page 5
CTE Job No.: 10-136430
guidance of the County of Riverside (2011 ). The intent of the infiltration rate is to take into
account bias inherent in percolation test bore hole sidewall infiltration, which would not
occur at a constructed basin bottom where such sidewalls are not present.
The infiltration rate (It) is derived by the equation:
It= {(change H 60 r) / [change t(r+2Hav)]}
Where:
Change t=time interval
Df=final depth to water
r=test hole radius
change t=60 minutes
Do=initial depth to water
Dt=total depth of test hole
Ho=Dt -Do is initial height of water at selected time interval
Hf=Dt-Df-is the final height of water at the selected time interval
Change H=is the change in height over the time interval
Hav=(Ho+Hf) / 2 is the average head height over the time interval
Given the measurement values of Table 1.0, the calculated infiltration rates without a Factor of
Safety applied are as follows.
P-1
( units in inches)
Df=43.75
Do=43.0
Dt=5 l.O
r=3
change t=JO minutes
Calculated Infiltration Rate=0.2466 inches/hour
P-2
(units in inches)
Df=42.2875
D0=41.60
Dt=49.0
r=J
change t=30 minutes
Calculated Infiltration Rate=0.2411 inches/hour
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P-3
(units in inches)
Df=40.25
Do=39.0
Dt=S 1.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.2913 inches/hour
P-4
(units in inches)
Df=42.2875
D0=41.60
Dt=49.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.020 inches/hour
3 .3 .2 Calculated Infiltration Rates
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Infiltration rates have been calculated utilizing the factor of safety (FOS) of 2 in the following Table
1.1. The project stormwater or basin designer may modify the factor of safety based on their
independent evaluation. The infiltration feasibility information is also presented on the attached
C .4-1 Worksheet.
TABLE3.3.2
RESULTS OF PERCOLATION TESTING WITH FACTOR OF SAFETY APPLIED
Test Location Percolation Rate Infiltration Rate Infiltration Rate with FOS of
(inches/minute) (inches per hour) 2 Applied (inches per hour)
P-1 0.025 0.25 0.12
P-2 0.023 0.24 0.12
P-3 0.042 0.29 0.15
P-4 0.0021 0.020 0.010
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Based on the calculated rates and other site factors, portions of the site meet minimum
County requirements for partial infiltration. An area that could be considered for partial
Infiltration design options is presented on Figure 2.
4.0 GEOLOGY
4.1 General Setting
Carlsbad is located within the Peninsular Ranges physiographic province that is characterized by
northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending
regional faults. The greater San Diego Region can be further subdivided into the coastal plain area,
a central mountain-valley area and the eastern mountain valley area. The project site is located
within the coastal plain area that is characterized by Cretaceous, Tertiary, and Quaternary
sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous
crystalline rocks.
4.2 Geologic Conditions
Based on the regional geologic map prepared by Kennedy and Tan (2007), the near surface geologic
unit underlying the site consists of Quaternary Old Paralic Deposits. Unit 6-7. However, based on
the site explorations, Residual Soil was observed overlying the Quaternary Old Paralic Deposits.
Descriptions of the geologic and soil units encountered are presented below.
4.2.1 Residual Soil
Where observed, the Residual Soil generally consists ofloose to medium dense, dark reddish
brown, silty to clayey fine grained sand. This unit is relatively thin and blankets the
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underlying Old Paralic Deposits, and is not considered suitable for support of proposed
structural improvements or compacted fill without first processing as indicated herein.
4.2.2 Quaternary Old Paralic Deposits (Qop)
Quaternary Old Paralic Deposits were found to be the underlying geologic unit at the site.
Where observed, these materials generally consist of medium dense to dense, reddish brown
silty to clayey fine grained sandstone. These materials are considered suitable for support of
proposed improvements and compacted fill as indicated herein.
4.3 Groundwater Conditions
During the recent investigation, likely perched subsurface water was encountered at a depth of
approximately 11 feet below existing grades. Based on site conditions and recent findings, the
potential for relatively shallow subsurface water exists at the site, which could seasonally impact
deeper site excavations and earthwork during project construction. This groundwater may also
impact the retention basin feasibility. However, a permanent shallow static groundwater table is not
generally anticipated to be present at the subject site. Proper site drainage is to be designed,
installed, and maintained as per the recommendations of the project civil engineer of record.
4.4 Geologic Hazards
Geologic hazards that were considered to have potential impacts to site development were evaluated
based on field observations. literature review, and laboratory test results. It appears that the geologic
hazards at the site are primarily limited to those caused by shaking from earthquake-generated
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ground motions. The following paragraphs discuss the geologic hazards considered and their
potential risk to the site.
4.4. 1 Surface Fault Rupture
Based on the site reconnaissance and review of referenced literature, the site is not within a
State of California-designated Alquist-Priolo Earthquake Fault Studies Zone or Local
Special Studies Zone and no known active fault traces underlie, or project toward, the site.
According to the California Division of Mines and Geology, a fault is active if it displays
evidence of activity in the last 11,000 years (Hart and Bryant, revised 2007). Therefore, the
potential for surface rupture from displacement or fault movement beneath the proposed
improvements is considered to be low.
4.4.2 Local and Regional Faulting
The California Geological Survey (CGS) and the United States Geological Survey (USGS)
broadly group faults as "Class A" or "Class B" (Cao, 2003; Frankel et aL 2002). Class A
faults are generally identified based upon relatively well-defined paleoseismic activity, and a
fault-slip rate of more than 5 millimeters per year (mm/yr). In contrast, Class B faults have
comparatively less defined paleoseismic activity and are considered to have a fault-slip rate
less than 5 mm/yr. The nearest known Class B fault is the Newport-Inglewood Fault, which
is approximately 8.5 kilometers west of the site (Blake, T.F., 2000). The nearest known
Class A fault is the Temecula segment of the Elsinore Fault, which is located approximately
38.6 kilometers east of the site.
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The site could be subjected to significant shaking in the event of a major earthquake on any
of the faults noted above or other faults in the southern California or northern Baja California
area.
4.4.3 Liquefaction and Seismic Settlement Evaluation
Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths
during earthquake-induced shaking and behave like a liquid. This is due to loss of
point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction
potential varies with water level, soil type, material gradation, relative density, and probable
intensity and duration of ground shaking. Seismic settlement can occur with or without
liquefaction; it results from densification of loose soils.
The site is underlain at shallow depths by medium dense to dense Quaternary Old Paralic
Deposits. In addition, loose surficial soils within proposed improvement areas arc to be
overexcavated and compacted as engineered fill as recommended herein. Therefore, the
potential for liquefaction or significant seismic settlement at the site is considered to be low.
4.4.4 Tsunamis and Seiche Evaluation
According to State of California Emergency Management Agency mapping, the site is not
located within a tsunami inundation zone based on distance from the coastline and elevation
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above sea level. Damage resulting from oscillatory waves (seiches) is considered unlikely
due to the absence of nearby confined bodies of water.
4.4.5 Landsliding
According to mapping by Tan ( 1995), the site is considered only "Marginally Susceptible" to
landsliding and no landslides are mapped in the site area. Furthermore, landslides or similar
associated features were not observed during the recent field exploration. Therefore,
landsliding is not considered to be a significant geologic hazard at the site.
4.4.6 Compressible and Expansive Soils
The Residual Soil across the surface of the site is considered to be potentially compressible.
Therefore, these soils should be overexcavated, processed, and placed as a properly
compacted fill as recommended herein. Based on the field data, site observations, and
laboratory results, the underlying Old Paralic Deposits are not considered to be subject to
significant compressibility under the anticipated loads.
Based on observation and laboratory test results, soils at the site arc generally anticipated to
exhibit Very Low expansion potential (Expansion Index of20 or less). Therefore, expansive
soils are not anticipated to present significant adverse impacts to site development.
Additional evaluation of near-surface soils can and should be performed based on field
observations during grading activities.
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4.4. 7 Corrosive Soils
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Chemical testing was performed to evaluate the potential effects that site soils may have on
concrete foundations and various types of buried metallic utilities. Soil environments
detrimental to concrete generally have elevated levels of soluble sulfates and/or pH levels
less than 5.5. According to American Concrete Institute (ACI) Table 318 4.3.1, specific
guidelines have been provided for concrete where concentrations of soluble sulfate (SO4) in
soil exceed 0.1 percent by weight. These guidelines include low water: cement ratios,
increased compressive strength, and specific cement type requirements.
Based on the results of the Sulfate and pH testing performed, onsite soils are anticipated to
generally have a negligible corrosion potential to Portland cement concrete improvements.
A minimum resistivity value less than approximately 5,000 ohm-cm, and/or soluble chloride
levels in excess of 200 ppm generally indicate a corrosive environment to buried metallic
utilities and untreated conduits. Based on the obtained resistivity value of 15,700 ohm-cm
and soluble chloride level of 13.4 ppm, onsite soils are anticipated to have a low corrosion
potential for buried uncoated/unprotected metallic conduits. Nevertheless, at a minimum,
the use of buried plastic piping or conduits could be beneficial, where feasible.
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The results of the chemical tests performed are presented in the attached Appendix C.
However, CTE does not practice corrosion engineering. Therefore, a corrosion engineer or
other qualified consultant could be contacted if site specific corrosivity issues are of concern.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 General
CTE concludes that the proposed improvements at the site are feasible from a geotechnical
standpoint, provided the recommendations in this report are incorporated into the design and
construction of the project. Recommendations for the proposed earthwork and improvements are
included in the following sections and Appendix D. However, recommendations in the text of this
report supersede those presented in Appendix D should variations exist. These recommendations
should either be confirmed as appropriate and/or updated during or following rough grading at the
site.
5.2 Site Preparation
Prior to grading, the site should be cleared of any existing building materials or improvements that
are not to remain. Objectionable materials, such as construction debris and vegetation, not suitable
for structural backfill should be properly disposed of offsite. In the area of the proposed structures
(and a minimum five feet laterally beyond, where feasible), existing soils should be uniformly
excavated to a minimum depth of 18 inches below the bottom of the deepest proposed foundations,
or to the depth of suitable material, whichever depth is greatest. Localized areas of loose and
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potentially compressible material could require overexcavation to deeper elevations, based on
conditions encountered during grading. Overexcavations should extend at least five feet laterally
beyond the limits of the proposed building, where feasible.
Excavations in proposed pavement, flatwork, or other minor improvement areas should be conducted
to a minimum depth of two feet below proposed or existing grades, or to suitable underlying
materials, whichever depth is shallowest.
A CTE geotechnical representative should observe the exposed ground surface at the overexcavation
bottoms to evaluate the exposed conditions. The exposed subgrades to receive fill should be proof-
rolled or scarified a minimum of nine inches, moisture conditioned to a minimum of two percent
above optimum, and properly compacted prior to additional fill placement.
5.3 Site Excavation
Generally, excavation of site materials may be accomplished with heavy-duty construction
equipment under normal conditions. However, the Old Paralic Deposits may become increasingly
difficult to excavate with depth. Materials also appear to be, at least locally, very granular and could
be very sensitive to caving and/or erosion.
5.4 Fill Placement and Compaction
Granular fill and backfill should be compacted to a minimum relative compaction of90 percent at a
moisture content of at least two percent above optimum, as evaluated by ASTM D 1557. The
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optimum lift thickness for fill soil will depend on the type of compaction equipment used.
Generally, backfill should be placed in uniform, horizontal lifts not exceeding eight inches in loose
thickness. Fill placement and compaction should be conducted in conformance with local
ordinances.
5.5 Fill Materials
Properly moisture-conditioned very low expans10n potential soils derived from the on-site
excavations are considered suitable for reuse on the site as compacted fill. If used, these materials
should be screened of organics and materials generally greater than three inches in maximum
dimension. Irreducible materials greater than three inches in maximum dimension should generally
not be used in shallow fills (within three feet of proposed grades). In utility trenches, adequate
bedding should surround pipes.
Imported fill beneath structures, flatwork, and pavements should have an Expansion Index of 30 or
less (ASTM D 4829). Imported fill soils for use in structural or slope areas should be evaluated by
the geotechnical engineer before being imported to the site.
Minor retaining wall backfill ( if necessary) located within a 45-degree wedge extending up from the
heel of the wall should consist of soil having an Expansion Index of20 or less (ASTM D 4829) with
less than 30 percent passing the No. 200 sieve. The upper 12 to 18 inches of wall backfill could
consist of lower permeability soils, in order to reduce surface water infiltration behind walls. The
project structural engineer and/or architect should detail proper wall backdrains, including gravel
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drain zones, fills, filter fabric, and perforated drain pipes. However, a conceptual wall backdrain
detail, which may be suitable for use at the site, is provided as Figure 4.
5.6 Temporary Construction Slopes
The following recommended slopes should be relatively stable against deep-seated failure, but may
experience localized sloughing. On-site soils are considered Type B and Type C soils with
recommended slope ratios as set forth in Table 5.6. However, due to the at least locally granular and
erodible nature of the onsite soils, maximum 1.5: 1 temporary slopes are anticipated to be more
reliable, and vertical excavations may not remain standing, even at shallow or minor heights.
TABLE 5.6
RECOMMENDED TEMPORARY SLOPE RA nos
SOIL TYPE SLOPE RATIO MAXIMUM HEIGHT (Horizontal: vertical)
B (Old Paralic Deposits) 1: 1 (OR FLATTER) 10 Feet
C (Residual Soil) 1.5: 1 (OR FLATTER) 10 Feet
Actual field conditions and soil type designations must be verified by a "competent person" while
excavations exist, according to Cal-OSHA regulations. In addition, the above sloping
recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic,
equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all
unshared slopes.
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5.7 Foundations and Slab Recommendations
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The following recommendations are for preliminary design purposes only. These recommendations
should be reviewed after completion of earthwork to document that conditions exposed are as
anticipated, and that the recommended structure design parameters are appropriate.
5.7.1 Foundations
Following the preparatory grading recommended herein, continuous and isolated spread
footings are anticipated to be suitable for use at this site. It is anticipated that building
footings will be founded entirely in properly compacted fill with very low expansion
potential.
Foundation dimensions and reinforcement should be based on an allowable bearing value of
2,500 pounds per square foot for footings founded entirely upon properly placed compacted
fill materials embedded a minimum of 18 inches below the lowest adjacent subgrade
elevation. If utilized, continuous footings should be at least 18 inches wide; isolated footings
should be at least 24 inches in least dimension. The above bearing values may also be
increased by one third for short duration loading which includes the effects of wind or
seismic forces.
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An uncorrected 150-pci subgrade modulus is considered suitable for elastic design of
foundations as embedded and/or detailed herein.
Minimum reinforcement for continuous footings should consist of four No. 4 reinforcing
bars; two placed near the top and two placed near the bottom or as per the project structural
engineer. The structural engineer should design isolated footing reinforcement. Footing
excavations should generally be maintained above optimum moisture content until concrete
placement.
5.7.2 Foundation Settlement
The maximum total settlement is expected to be on the order of one inch and the maximum
differential settlement is expected to be on the order of I /2 inch over a distance of
approximately 40 feet. Due to the absence of a shallow static or sustained groundwater table
and the generally dense nature of underlying materials, dynamic settlement is not expected to
adversely affect the proposed improvements.
5. 7. 3 Foundation Setback
Footings for structures should be designed such that the horizontal distance from the face of
adjacent slopes to the outer edge of the footing is at least 10 feet. In addition, footings
should bear beneath a I: I plane extended up from the nearest bottom edge of adjacent
trenches and/or excavations. Deepening of affected footings may be a suitable means of
attaining the prescribed setbacks.
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5.7.4 Interior Concrete Slabs
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Lightly loaded concrete slabs should be a minimum of 4.5 inches in thickness. Minimum
slab reinforcement should consist of #3 reinforcing bars placed on maximum 16-inch
centers, each way, at above mid-slab height, but with proper concrete cover. Subgrade
materials should generally be maintained at above optimum moisture content until slab
underlayment and concrete are placed.
Slabs subjected to heavier loads may reqmre thicker slab sections and/or increased
reinforcement. A 140-pci subgrade modulus is considered suitable for elastic design of
minimally embedded improvements such as slabs-on-grade.
In moisture-sensitive floor areas, a suitable vapor retarder of at least 15-mil thickness ( with
all laps or penetrations sealed or taped) overlying a four-inch layer of consolidated crushed
aggregate or gravel (with SE of30 or more) should be installed, as per the 2013 CBC/Green
Building Code. An optional maximum two-inch layer of similar material may be placed
above the vapor retarder to help protect the membrane during steel and concrete placement.
This recommended protection is generally considered typical in the industry. If proposed
floor areas or coverings are considered especially sensitive to moisture emissions, additional
recommendations from a specialty consultant could be obtained. CTE is not an expert at
preventing moisture penetration through slabs. A qualified architect or other experienced
professional should be contacted if moisture penetration is a more significant concern.
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5.8 Seismic Design Criteria
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The seismic ground motion values listed in the table below were derived in accordance with the
ASCE 7-10 Standard and 2016 CBC. This was accomplished by establishing the Site Class based on
the soil properties at the site, and then calculating the site coefficients and parameters using the
United States Geological Survey Seismic Design Maps application using the site coordinates of
33.1639 degrees latitude and -117.3448 degrees longitude. These values are intended for the design
of structures to resist the effects of earthquake ground motions.
TABLE5.8
SEISMIC GROUND MOTION VALUES
PARAMETER VALUE CBC REFERENCE (2013)
Site Class D ASCE 7, Chapter 20
Mapped Spectral Response 1.145 Figure 1613.3.1 (I) Acceleration Parameter, Ss
Mapped Spectral Response 0.439 Figure 1613.3.1 (2) Acceleration Parameter, S1
Seismic Coefficient, F., 1.042 Table 1613.3.3 (I)
Seismic Coefficient, F, 1.561 Table 1613.3.3(2)
MCE Spectral Response l.193 Section 1613.3.3 Acceleration Parameter, SMs
MCE Spectral Response 0.685 Section 1613.3.3 Acceleration Parameter, SM1
Design Spectral Response 0.795 Section 1613.3.4 Acceleration, Parameter Sos
Design Spectral Response 0.457 Section 1613.3.4 Acceleration, Parameter S01
Peak Ground Acceleration PGAM 0.474 ASCE 7, Section 11.8.3
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5. 9 Lateral Resistance and Earth Pressures
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Lateral loads acting against retaining walls may be resisted by friction between the footings and the
supporting compacted fill soil and/or Old Paralic Deposits or passive pressure acting against
structures. If frictional resistance is used, an allowable coefficient of friction of 0.30 (total frictional
resistance equals the coefficient of friction multiplied by the dead load) is recommended for concrete
cast directly against competent soils. A design passive resistance value of 250 pounds per square
foot per foot of depth (with a maximum value of2,000 pounds per square foot) may be used. The
allowable lateral resistance can be taken as the sum of the frictional resistance and the passive
resistance, provided the passive resistance does not exceed two-thirds of the total allowable
resistance.
If proposed, retaining walls up to approximately eight feet high and backfilled using granular soils
may be designed using the equivalent fluid weights given below.
TABLE 5.10
EQUIVALENT FLUID UNIT WEIGHTS
(pounds per cubic foot)
SLOPE BACKFILL
WALL TYPE LEVEL BACKFILL 2: I (HORIZONTAL:
VERTICAL)
CANTILEVER WALL 30 48 (YIELDING)
RESTRAINED WALL 60 75
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Lateral pressures on cantilever retaining walls (yielding walls) due to earthquake motions may be
calculated based on work by Seed and Whitman ( 1970). The total lateral thrust against a properly
drained and backfilled cantilever retaining wall above the groundwater level can be expressed as:
For non-yielding (or "restrained") walls, the total lateral thrust may be similarly calculated
based on work by Wood (1973):
Where PA = Static Active Thrust ( determined using Table 5. 9)
PK= Static Restrained Wall Thrust (determined using Table 5.9)
~p AI-: = Dynamic Active Thrust Increment= (3/8) kh yH2
~PKE = Dynamic Restrained Thrust Increment = kh yH2
k1i = 2/3 Peak Ground Acceleration = 2/3 (PGAM)
H = Total Height of the Wall
y = Total Unit Weight of Soil;::::; 135 pounds per cubic foot
The increment of dynamic thrust in both cases should be distributed triangularly with a line of action
located at H/3 above the bottom of the wall (SEAOC, 2013).
These values assume non-expansive backfill and free-draining conditions. Measures should be taken
to prevent moisture buildup behind all retaining walls. Drainage measures should include free-
draining backfill materials and sloped, perforated drains. These drains should discharge to an
appropriate off-site location. A general or conceptual detail for Retaining Wall Drainage, which
may be appropriate for the subject site based on the review of the project structural engineer and/or
architect, is attached as Figure 4. Waterproofing should be as specified by the project architect or
the waterproofing specialty consultant.
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5.10 Exterior Flatwork
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To reduce the potential for cracking in exterior non-traffic flatwork areas caused by mmor
movement of subgrade soils and typical concrete shrinkage, it is recommended that such flatwork
measure a minimum 4.5 inches thick and be installed with crack-control joints at appropriate spacing
as designed by the project architect. Additionally, it is recommended that flatwork be installed with
at least No. 3 reinforcing bars on maximum 18-inch centers, each way, at above mid-height of slab
but with proper concrete cover, or other reinforcement per the project consultants. Doweling of
flatwork joints at critical pathways or similar could also be beneficial in resisting minor sub grade
movements.
Subgrades should be prepared according to the earthwork recommendations previously given, before
placing concrete. Positive drainage should be established and maintained next to all flatwork.
Sub grade materials shall be maintained at, or be elevated to, above optimum moisture content prior
to concrete placement.
5.11 Pavements
Pavement sections provided are based on estimated Resistance "R"-Value results, traffic indices, and
the assumption that the upper foot of compacted fill subgrade and overlying aggregate base materials
are properly compacted to a minimum 95% relative compaction at a minimum of two percent above
optimum moisture content (as per ASTM D 1557). Beneath proposed pavement areas, loose, clayey,
or otherwise unsuitable soils are to be removed to the depth of competent underlying material as
recommended in Section 5.2. R-Value of subgrade material should be verified during grading and
pavement sections may be modified as necessary.
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TABLE 5.12
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RECOMMENDED AC OR PCC PAVEMENT SECTION TIIICKNESSES
Traffic Area Assumed Preliminary Asphalt Pavements Portland Cement
Traffic Index Subgrade AC CalTrans Class II or Concrete
"R"-Value Thickness Crushed Miscellaneous Pavements On
(INCHES) Aggregate Base Subgrade
Thickness (INCHES)
(INCHES)
Light Auto 4.5 30 3.0 5.0 6.0
Parking & Drive
Areas
Heavy Quantity 5.5 30 3.0 9.0 7.0
Drive or Impact
Areas
Asphalt paved areas should be designed, constructed, and maintained in accordance with, for
example, the recommendations of the Asphalt Institute, or other widely recognized authority.
Concrete paved areas should be designed and constructed in accordance with the recommendations
of the American Concrete Institute or other widely recognized authority, particularly with regard to
thickened edges, joints, and drainage. The Standard Specifications for Public Works construction
("Greenbook") or Caltrans Standard Specifications may be referenced for pavement materials
specifications.
5.12 Drainage
Surface runoff should be collected and directed away from improvements by means of appropriate
erosion-reducing devices, and positive drainage should be established around proposed
improvements. Positive drainage should be directed away from improvements and slope areas at a
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CTE Job No.: 10-13643G
minimum gradient of two percent for a distance of at least five feet. However, the project civil
engineer should evaluate the on-site drainage and make necessary provisions to keep surface water
from affecting the site.
Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes
and improvements. However, it is understood that some agencies are encouraging the use of storm-
water cleansing devices. Therefore, if storm water cleansing devices must be used, it is generally
recommended that they be underlain by an impervious barrier and that the infiltrate be collected via
subsurface piping and discharged off site. If infiltration must occur, water should infiltrate as far
away from structural improvements as feasible. Additionally, any reconstructed slopes descending
from infiltration basins should be equipped with subdrains to collect and discharge accumulated
subsurface water ( Appendix D contains general or typical details for internal fill slope drainage).
Infiltration/percolation design and associated information elsewhere in this report should also be
reviewed in its entirely.
5.13 Slopes
Based on observed conditions and anticipated soil strength characteristics, cut and fill slopes, if
proposed at the site, should be constructed at ratios of2: 1 (horizontal: vertical) or flatter. These fill
slope inclinations should exhibit factors of safety greater than 1.5.
Although properly constructed slopes on this site should be grossly stable, the soils will be
somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of
I \Esc _ serve r\pro_iects \ l 0-I 3 643 Cr\R pt_ Geolcch n ica I.doc
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand A venue, Carlsbad, California
May 31, 2017
Page 26
CTE Job No.: 10-136430
slopes unless that water is confined to properly designed and constructed drainage facilities.
Erosion-resistant vegetation should be maintained on the face of all slopes. Typically, soils along
the top portion of a fill slope face will creep laterally. CTE recommends against building distress-
sensitive hardscape improvements within five feet of slope crests.
5 .14 Plan Review
CTE should be authorized to review the project grading and foundation plans pnor to
commencement of earthwork to identity potential conflicts with the intent of the geotechnical
recommendations.
5.15 Construction Observation
The recommendations provided in this report are based on preliminary design information for the
proposed construction and the subsurface conditions observed in the explorations performed. The
interpolated subsurface conditions should be checked in the field during construction to verify that
conditions are as anticipated. Foundation recommendations may be revised upon completion of
grading and as-built laboratory test results.
Recommendations provided in this report are based on the understanding and assumption that CTE
will provide the observation and testing services for the project. All earthwork should be observed
and tested to verify that grading activities have been performed according to the recommendations
contained within this report. CTE should evaluate all footing trenches before reinforcing steel
placement.
\\Esc_ scrvcr\pro_jccts\ IO-I 3643G\Rpt_ Gcotcchnical.do,
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand A venue, Carlsbad, California
May 31, 2017
6.0 LIMITATIONS OF INVESTIGATION
Page 27
CTE Job No.: 10-13643G
The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been
conducted according to current engineering practice and the standard of care exercised by reputable
geotechnical consultants performing similar tasks in this area. No other warranty, expressed or
implied, is made regarding the conclusions, recommendations and opinions expressed in this report.
Variations may exist and conditions not observed or described in this report may be encountered
during construction.
The recommendations presented herein have been developed in order to help reduce the potential
adverse effects of soils movement. However, even with the design and construction precautions
provided, some post-construction movement and associated distress should be anticipated.
The findings of this report are valid as of the present date. However, changes in the conditions of a
property can occur with the passage of time, whether they are due to natural processes or the works
of man on this or adjacent properties. In addition, changes in applicable or appropriate standards
may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the
findings of this report may be invalidated wholly or partially by changes outside our control.
Therefore, this report is subject to review and should not be relied upon after a period of three years.
CTE's conclusions and recommendations are based on an analysis of the observed conditions. If
conditions different from those described in this report arc encountered, this office should be notified
and additional recommendations, if required, will be provided.
1\Esc _ server\prnJccts \ I 0-1 3 64 3 Cr\R pt_ Gcotcch n ica I doc
Geotechnical Investigation
Proposed Two Triplex Townhomes
972 and 988 Grand Avenue, Carlsbad, California
May 31, 2017
Page 28
CTE Job No.: 10-136430
The opportunity to be of service on this project is appreciated. If you have any questions regarding
this report, please do not hesitate to contact the undersigned.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
~/
Dan T. Math, GE #2665
Principal Engineer
-~
I
Aaron J. Beeby, CEG #2603
Project Geologist
AJB/JFL/DTM:nri
.Jay F. Lynch, CEG #1890
Principal Engineering Geologist
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~c_ 1441 Monllel Rd Ste 115, Escondido. CA 92028 Ph (760) 746-4955
SITE INDEX MAP
PROPOSED TWO TRIPLEX TOJNBOME CONDOMINIUIIS 972 AND 988 GRAND AVENUE CARLSBAD, CALIFORNIA
SCALE: DATE:
AS SHOWN 5/17
CTE JOB NO.: FIGURE:
10-136t3G 1
0, ~ " N
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LEGEND
Approximate Boring Location
Approximate Percolation Test Location
Quaternary Old Paralic Deposits
Partial Infiltration Area Indicated for
BMP Design Options
----~
30'
I--.._
0
--I -15'
:
30'
I
C ~ Construction Testing & Engineering, Inc. '!!!!§,c 1441 Montlel Rd St& 116, Escondido, CA 92026 Ph (760) 746-4965
GIOLOGIC/DPLORATION LOCATION lfAP SCA~~~30' OAr:/17
PROPOSED TWO TRIPLEX TOWNBOME CONDOMINIUMS
972 AND 988 GRAND AVENUE CTE JOB NO.: FIGURE:
CARISBAD, CALIFORNIA 1O-13643G 2
NOTES: FAULT ACTIVITY MAP OF CAIJFORNIA, 2010, CAIJFORNIA GEOLOGIC DATA MAP SERIES MAP NO. 6;
EPICENTERS OF AND AREAS DAMAGED BY M25 CAIJFORNIA EARTHQUAKES, 1800-1999 ADAPTED AFl'ER TOPPOZADA, BRANUM, PETERSEN, HALISI'ORM, CRAMER, AND REICHLE, 2000,
CDMG MAP SHEET 49
REFERENCE FOR ADDITIONAL EXPLANATION; MODlFJED mu CISN AND USGS SEISMIC MAPS
--·······+·
12 0 6 12
LEGEND ~e~-~-s---~---'-~I 1inch = 12mi.
HISTORIC FAULT DISPLACEMENT (LAST 200 YEARS)
HOLOCENE FAULT DISPLACEMENT (DURING PAST 11 ,700 YEARS)
LATE QUATERNARY FAULT DISPLACMENT (DURING PAST 700,000 YEARS)
QUATERNARY FAULT DISPLACEMENT (AGE UNDIFFERENTIATED)
PREQUATERNARY FAULT DISPLACEMENT (OLDER THAN 1.6 MILLION YEARS)
1800-
1868
.:'.. 7.0 0
6.5-6.9 0
5.5-5.9 0
5.0-5.4 0
1869-
1931
• •
1932-
2010
• •
~ LAST TWO DIGITS OF M :::._ 6.5
~ EARTHQUAKE YEAR
'•
'' . ·, .
.......... ~ ..
···········~c
·· . .. ..
---------------~
··.~ •.
M E I ...--. C
Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido. CA 92026 Ph (760) 748-4955
REGIONAL FAULT AND SEISMICITY MAP t-.-------1
PROPOSED TWO TRIPLEX TOWNHOME CONDOMINIUMS 972 AND 988 GRAND A VENUE CARLSBAD CALIFORNIA
RETAINING WALL
FINISH GRADE
<l
WALL FOOTING
12" TO 18" OF LOW R
PERMEABILITY NATIVE
MATERIAL COMPACTED TO 90%
RELATIVE COMPACTION
,-0 V -·,:-·,.-. ',.,. •;"fY ;_._ •,:.;:. ·,."--•.,_._.,._./,':-•.,',"t. •, •• _ ;,:-•,..t.·,:-·.,.:~ ·,:-·,:--.,:-•,:-;:•,::,..•. ·,:~ ·,.;:-,_..
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.·:.-.·,:·-·: •. ·;.-.·:.-.·!l"t4,-:.'&,-v,:.,1i,,1t,w/$_u~O. · . · ED
\)o ~ 0 .::.::~: .. ::f·.-:,.:·/j'.~{lii,iiftf·~iru°lf\jf. FI
t. 0 .: ~~:/::·i·.):\:,rJ \~.'··$.:{ :6t·iili:'t:it'v.:· ,::,_-f .....
• .., .......... ,.-.-. .-.-. .-.-.:.,W!"'-?,.t;v.~:ro FINO TO BE p, Q • • .. ·.·:.·r.•: .. .-... :.-r.-.·.,cr/-.·J.:'-Yl.'»·.~ ....
o o -:·.::-:·.-::-:::-:·:~·~·.-::~·:::·;&:~j,t.re:E)··· Y ARCHITECT : Q: :))!}\~:{})}:;:{)}}:/
0 ~ C) :{/:f}}:/:::f~{:}:)\ff IA. PERFORATED PVC
~ " -,:-,:-,1·.-:-,:-,:-,:-,:-, -,:-,TI PE (SCHEDULE 40 OR ........ , ,\ .......... , ...... \ ..... 1l7
: o v :·:: ... :·-~:.:,;: ... : .. ;.-.:·:'.<-·::,.:--;·\{·:,:~:.-/ QUIV AL ENT) MINIMUM
A.\ .. ~-.::-.::.\{}):)~/{·):/ 1 % GRADfENT.TO SUIT ABLE
I> C d CJ A.~ • ··;·:•,::/ OUTLET
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CT~L Construction Testing & Engineering, Inc. ~c 1441 Montlel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
CTEJOB NO 10-1 36430
RETAINING WALL DRAlNAGE DETAIL SC•IINO SCALE
DATE Fl URF
5/17 4
----
. " -·-APPENDIX A ...
REFERENCES ,.. ..
--..., ----------..
-----------.. --
-----------
---------------
-------..
--
REFERENCES
I. American Society for Civil Engineers, 2010, "Minimum Design Loads for Buildings and
Other Structures," ASCE/SEI 7-10.
2. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using
Modified Effort," Volume 04.08
3. Blake, T.F., 2000, "EQFAULT," Version 3.00b, Thomas F. Blake Computer Services and
Software.
4. California Building Code, 2013, "California Code of Regulations, Title 24, Part 2, Volume 2
of2," California Building Standards Commission, published by ICBO, June.
5. California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps
of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by
Martin and Ross.
6. California Emergency Management Agency/California Geological Survey, "Tsunami
Inundation Maps for Emergency Planning.
7. Frankel, A.D., Petersen, M.D., Mueller, C.S., Haller, K.M., Wheeler, R.L., Leyendecker,
E.V., Wesson, R. L., Harmsen, S.C., Cramer, C.H., Perkins, D.M., Rukstales,K.S.,2002,
Documentation for the 2002 update of the National Seismic Hazard Maps: U.S. Geological
Survey Open-File Report 2002-420, 39p
8. Hart, Earl W., Revised 2007, "Fault-Rupture Hazard Zones in California, Alquist Priolo,
Special Studies Zones Act of 1972," California Division of Mines and Geology, Special
Publication 42.
9. Jennings, Charles W., 1994, "Fault Activity Map of California and Adjacent Areas" with
Locations and Ages of Recent Volcanic Eruptions.
10. Kennedy, M.P. and Tan, S.S., 2007, "Geologic Map of the Oceanside 30' x 60' Quadrangle,
California", California Geological Survey, Map No. 2, Plate I of 2.
11. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake
swarm [abs.]: EOS, v. 66, no. 46, p.952.
12. SEAOC, Blue Book-Seismic Design Recommendations, "Seismically Induced Lateral Earth
Pressures on Retaining Structures and Basement Walls," Article 09.10.010, October 2013.
13. Seed, H.B., and R.V. Whitman, 1970, "Design of Earth Retaining Structures for Dynamic
Loads," in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and
Design of Earth-Retaining Structures, pp. 103-147, Ithaca, New York: Cornell University.
---
-------..
--... -
------------------.. --
14. Simons, R.S., 1979, Instrumental Seismicity of the San Diego area, 1934-1978, in Abbott,
P.L. and Elliott, W.J., eds., Earthquakes and other perils, San Diego region: San Diego
Association of Geologists, prepared for Geological Society of America field trip, November
1979, p.101-105.
15. Tan, S. S., and Giffen, D. G., 1995, "Landslide Hazards in the Northern Part of the San
Diego Metropolitan Area, San Diego County, California: Oceanside and San Luis Rey
Quadrangles, Landslide Hazard Identification Map No. 35", California Department of
Conservation, Division of Mines and Geology, Open-File Report 95-04, State of California,
Division of Mines and Geology, Sacramento, California.
16. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05 .
Pasadena: California Institute of Technology.
-----,,.
--------
---... ---------------
, . ... .. -
APPENDIXB
EXPLORATION LOGS
Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
DEFINITION OF TERMS
PRIMARY DfV1S1ONS
GRAVELS
MORE THAN
HALF OF
COARSE
FRACTION IS
LARGER THAN
NO. 4 SIEVE
SANDS
MORE THAN
HALF OF
COARSE
FRACTION IS
SMALLER THAN
NO. 4 SIEVE
CLEAN
GRAVELS
< 5% FINES
GRAVELS
WITH FINES
CLEAN
SANDS
< 5% FINES
SILTS AND CLAYS
LIQUID LIMIT IS
LESS THAN 50
SILTS AND CLAYS
LIQUID LIMIT IS
GREATER THAN 50
HIGHLY ORGANIC SOILS
SYMBOLS SECONDARY DIVISIONS
WELL GRADED GRAVELS, GRAVEL-SAND MlXTURES
LITTLE OR NO FINES
POORLY GRADED GRAVELS OR GRAVEL SAND MIXTURES,
LITTLE OF NO FINES
SIL TY GRAVELS, GRAVEL-SAND-SILT MIXTURES,
NON-PLASTIC FINES
CLAYEY GRAVELS, GRAVEL-SAND-CLAY MlXTURES,
PLASTIC FINES
WELL GRADED SANDS, GRA YELL Y SANDS, LITTLE OR NO
FINES
POORLY GRADED SANDS, GRA YELL Y SANDS, LITTLE OR
NO FINES
SILTY SANDS, SAND-SILT MlXTURES, NON-PLASTIC FINES
INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY
OR CLAYEY FINE SANDS. SLIGHTLY PLASTIC CLAYEY SIL TS
INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY,
GRA YELL Y SANDY SIL TS OR LEAN CLAYS
ORGANIC SILTS AND ORGANIC CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE
SANDY OR SILTY SOILS ELASTIC SILTS
INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS
ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SILTY CLAYS
PEAT AND OTHER HIGHLY ORGANIC SOILS
GRAIN SIZES
BOULDERS COBBLES GRAVEL SAND SILTS AND CLAYS COARSE FfNE COARSE MEDIUM FINE
12" 3" 3/4" 4 10 40 200
CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SIZE
ADDITIONAL TESTS
(OTHER THAN TEST PIT AND BORING LOG COLUMN HEADINGS)
MAX-Maximum Dry Density
GS-Grain Size Di stribution
SE-Sand Equivalent
EI-Expansion Index
CHM-Sulfate and Chloride
Content , pH, Res istivity
COR -Corrosivity
SD-Sample Disturbed
PM-Permeability
SG-Specific Gravity
HA-Hydrometer Analysis
AL-Atterberg Limits
RV -R-Value
CN-Consolidation
CP-Collapse Potential
HC-Hydrocollapse
REM-Remolded
PP-Pocket Penetrometer
WA-Wash Analysis
OS-Direct Shear
UC-Unconfined Compression
MD-Moisture/Density
M-Moisture
SC-Swell Compression
01-Organic lmpurities
FIGURE: BLI
--c@ Construction Testing & Engineering, Inc.
--·-··-·· ·--· -··--·----·
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
-PROJECT: DRILLER: SHEET: of -CTEJOBNO: DRILL METHOD: DRILLING DATE:
LOGGED BY: SAMPLE METHOD: ELEVATION: ----
u C: 0 i u 5-.0
~ 8. ,E' l e Oil BORING LEGEND ~ 0 >, 0 Laboratory Tests u on 0 "' on ..J 1,1., ~ i:: ~ <Ii u '-' u ~ .s i:: "' Ci u :E -"I u ~ la' C. > ~ ·.s <Ii '3 i§ 0 ., Ee ::E ::i ... Ci a:l Ci c.,
DESCRIPTION -...
• ... -~ Block or Chunk Sample ,_ ----... -~ -Bulk Sample
... --... -
-... --... -.. ... --Standard Penetration Test -... -..
--
... -7 -Modified Split-Barrel Drive Sampler (Cal Sampler) ... --... --.. ... -I -Thin Walled Armv Corp. of Engineers Sample
... --... --... -~ Groundwater Table -... -------~ --------------------------------------------------·------------·---~------... --Soil Tvpe or Classification Change
... --,....._ ?--?--?--?--?--?--?----\_ Formation Change r(Approximate boundaries queried (?)l --------Quotes are placed around classifications where the soils ''SM" ---exist in situ as bedrock -... --FIGURE: I BL2 -
II 1111 II II II 11 11 11 It I I I\ 11 11 1 t I I I I I J I I
PROJECT:
CTEJOBNO:
LOGGED BY:
SM
"SM"
-----"SC"
(;j ~ Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026-Ph (760) 746-4955
PROPOSED TRIPLEX CONDOMINIUMS
l0-13643G
EXCAVATOR: AJB
EXCAVATION METHOD HAND AUGER EXCAVATION DA TE: 5/9/2017
AJB
OJ) 0 ....J
tJ i-0
---
" "E. " ~ ~ ~ 8 er, E-
~ -,-
-5 ...,. ~ g-= ri:
SAMPLING METHOD: BULK ELEVATION: -68 FEET
BORING LOG B-1 Laboratory Tests
o cco _______________________________________ ...,_ ______ __
0
--
--
--
--
-5-
--
---
--
--
-H}-
--
----
--
-IS-
--
--
DESCRIPTION
RESIDUAL SOIL:
Loose, moist, dark reddish brown silty fine Qrained SAND.
QUATERNARY VERY OLD PARALIC DEPOSITS:
Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive.
Abundant manganese nodules
Medium dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive, moderately
cemented.
Groundwater seepage encountered at approximately 11.9 feet
Total Depth: 12.5' (Refusal on gravel)
Groundwater seepage encountered at approximately 11.9 feet
EI
K-1
11 I I 11 11 II t I 11 11 1111II1111 Ii l I II I I I I I I
PROJECT:
CTEJOBNO:
LOGGED BY:
SM
"SC"
----"SM"
----
"SC"
Cl~ Constr~ction Testing & Engine~ring, Inc ... _ ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
PROPOSED TRIPLEX CONDOMINIUMS
10-13643G
EXCAVATOR: AJB
EXCAVATION METHOD HAND AUGER EXCAVATION DATE: 5/9/2017
AJB
----
---
..,
"ii " ti ~ ~ ., <n 1--
~ ~ r--..c C
SAMPLING METHOD: BULK ELEVATION: ----68 FEET
BORING LOG B-2 Laboratory Tests
a ..::.:: ~
0 ~8------------------------------------------,i----------
0
--
... -
... -
... ----
--5-
---... -
,... -
... -
,... -
Ho-
... -
DESCRIPTION
RESIDUAL SOIL:
Loose, sliQhtly moist, dark brown, silty fine grained SAND.
QUATERNARY VERY OLD PARALIC DEPOSITS:
Medium dense to dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive,
manganeze nodules.
Medium dense, moist, light reddish brown, silty fine grained SANDSTONE, oxidized, massive, moderately ____ cemeawct. _______________________________________________________________________________ _
Medium dense to dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive.
Gravel
Groundwater seepage encountered at approximately 11.6 feet.
GS
--------Medium .dense,..wet,..g.r,av., .poorly. gradedmediurn.gwiii:ied.SANDSJ".ONE with. gi:ave~ Id able.------------I----+--+---+---+-........... , ,----------------------------------------+---------t --Total Deoth: 12.5' (Refusal on gravel)
... -Groundwater seepage encountered at aooroximatelv 11.6 feet
... -
--
l"ILTI l~F-1 8-]
11 111111 I l II II 11 11 11 11 11 11 11 11 11 Ii 11 11
PROJECT:
CTEJOBNO:
LOGGED BY:
C u 5-
SM
"SM"
Cl~ Construction Testing & Engineering,_ Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
PROPOSED TRIPLEX CONDOMINIUMS
10-136430
EXCAVATOR: AJB
EXCAVATION METHOD: HAND AUGER EXCAVATION DATE: 5/9/2017
AJB
...
C. " 0 § Q. ::l vi ~ ~ -r-
..i:: C a -.!:ii: ~
0 ~ 8
0 .. -.. -
I--
--
-J
--
--.. -
--
;o--
--
--
--
--
-15-
--
--
SAMPLING METHOD: BULK ELEVATION: -68 FEET
BORING LOG B-3 Laboratory Tests
1----------------------------------------+---------1 DESCRIPTION
RESIDUAL SOIL:
Loose, moist, dark brown, siltv fine grained SAND.
QUATERNARY VERY OLD PARALIC DEPOSITS:
Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive, manganese
nodules.
Gravel
Becomes dense with abundant manganese
Total Depth: 5' (Refusal on gravel)
No groundwater encountered
GS,CHM
l<HilJRF·I H-3
ti 11 11 ti If ti It lt 11 It 11 It II 1111 1111 •• II
c@ Construction Testing & Engineering, Inc.
-----·
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
PROJECT PROPOSED TRIPLEX CONDOMINIUMS EXCAVATOR: AJB
CTEJOBNO: 10-136430 EXCAVATION METHOD: HAND AUGER EXCAVATION DA TE: 5/9/2017
LOGGED BY: AJB SAMPLING METHOD: BULK ELEVATION: -68 FEET
C 0 .., "' ~ ~ 'l5. ., ~ E ;,-, t OJ) -§ Q, BORING LOG B-4 ;,-, 0 ;:, Laboratory Tests -~ VJ VJ ,::, .,, ..J " i:::: !:! VJ u [::, -~ .., ~ u :.a i:::: Cl t -"' !;' c 0 c,i g. ._ ,, ~ 8 Ci ~ ::i 0 Cl
DESCRIPTION
SM 0 RESIDUAL SOIL:
._ -Loose, moist, dark reddish brown, silty fine grained SAND with trace gravel, roots .
"SM" ... -QUATERNARY VERY OLD PARALIC DEPOSITS:
Medium dense, moist, reddish brown, silty fine grained SANDSTONE with gravel, oxidized, massive .
........
,--Total Depth: 3' (Refusal on gravel)
.... 5-No groundwater encountered
._ -
--
--
--
-rn-
--
--
--
--
-1.s-
--
--
FIC.IIUl--:-1 R-4
--------------------------------------
APPENDIXC
LABORATORY METHODS AND RESULTS
------------------
------------------
APPENDIXC
LABORATORY METHODS AND RESULTS
Laboratory Testing Program
Laboratory tests were performed on representative soil samples to detect their relative engineering
properties. Tests were performed following test methods of the American Society for Testing
Materials or other accepted standards. The following presents a brief description of the various test
methods used.
Classification
Soils were classified visually according to the Unified Soil Classification System. Visual
classifications were supplemented by laboratory testing of selected samples according to ASTM
D2487. The soil classifications are shown on the Exploration Logs in Appendix B.
Particle-Size Analysis
Particle-size analyses were performed on selected representative samples according to ASTM D 422.
Expansion Index
Expansion testing was performed on selected samples of the matrix of the on-site soils according to
ASTMD4829.
Chemical Analysis
Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride
content, pH, Corrosivity, and Resistivity.
--c .. ~,~
---LOCATION -B-1 ---LOCATION -B-3
--LOCATION -B-3 ---LOCATION -B-3 ---LOCATION -B-3 --------------LA BORA TORY SUMMARY
Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido. CA 92026 Ph (760) 746--4955
EXPANSION INDEX TEST
ASTM D4829
DEPTH EXPANSION INDEX EXPANSION
POTENTIAL (feet)
0-10
SULFATE
DEPTH
feet
0-5
CHLORIDE
DEPTH
feet
0-5
p.H.
DEPTH
feet
0-5
RESISTIVITY
CALIFORNIA TEST 424
DEPTH
(feet)
0-5
7
RESULTS
m
28.4
RESULTS
m
13.4
RESULTS
8.07
RESULTS
ohms-cm
15,700
VERY LOW
CTE JOB NO. 10-13643G
U. S. STANDARD SIEVE SIZE
ro ~ ~ co 0 0
N ;;:; CX)~ <D O 0 0 0 0 0 ~ ~ ~ "I" ~N t"'l "I" lO ~ N
100 . -------.. i""'r-,. r-,. t i-,... ~ :::::: ::-....... 90 ~ 1'-r-,. r--r-,. " .... ~.
80 ' 70 \
' l 60 \
(!) \ z in ~ !/)
c( 50 a. \ I-z w (.J a: 40 w ' a.
30 \
\ 20 ' ....... ... r--:
10
0
100 10 1 0.1 0.01 0.001
PARTICLE SIZE (mm)
PARTICLE SIZE ANALYSIS
CTE~
Sample Designation Sample Depth (feel) Symbol Liquid Limit (¾) Plasticity lndex Classification
Construction Testing & Engineering, Inc. B-2 0-1 • --SM
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 8-3 0-5 • --SM
CTE JOB NUMBER: 10-136430 FIGURE: C-1
-------APPENDIXD -STANDARD SPECIFICATIONS FOR GRADING -, ...
-------..
----
-------------
-
-
-----
---·-----·---------------------
Appendix D Page D-1
Standard Specifications for Grading
Section 1 -General
Construction Testing & Engineering, Inc. presents the following standard recommendations for
grading and other associated operations on construction projects. These guidelines should be
considered a portion of the project specifications. Recommendations contained in the body of
the previously presented soils report shall supersede the recommendations and or requirements as
specified herein. The project geotechnical consultant shall interpret disputes arising out of
interpretation of the recommendations contained in the soils report or specifications contained
herein.
Section 2 -Responsibilities of Project Personnel
The geotechnical consultant should provide observation and testing services sufficient to general
conformance with project specifications and standard grading practices. The geotechnical
consultant should report any deviations to the client or his authorized representative.
The Client should be chiefly responsible for all aspects of the project. He or his authorized
representative has the responsibility of reviewing the findings and recommendations of the
geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or
other consultants to perform work and/or provide services. During grading the Client or his
authorized representative should remain on-site or should remain reasonably accessible to all
concerned parties in order to make decisions necessary to maintain the flow of the project.
The Contractor is responsible for the safety of the project and satisfactory completion of all
grading and other associated operations on construction projects, including, but not limited to,
earth work in accordance with the project plans, specifications and controlling agency
requirements.
Section 3 -Preconstruction Meeting
A preconstruction site meeting should be arranged by the owner and/or client and should include
the grading contractor, design engineer, geotechnical consultant, owner's representative and
representatives of the appropriate governing authorities.
Section 4 -Site Preparation
The client or contractor should obtain the required approvals from the controlling authorities for
the project prior, during and/or after demolition, site preparation and removals, etc. The
appropriate approvals should be obtained prior to proceeding with grading operations.
STANDARD SPECIFICATIONS OF GRADING
Page 1 of 26
--------------------------------------
Appendix D
Standard Specifications for Grading
Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods,
stumps, trees, root of trees and otherwise deleterious natural materials from the areas to be
graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill
areas.
Demolition should include removal of buildings, structures, foundations, reservoirs, utilities
(including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts,
tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be
graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the
project perimeter and cutoff and capping of wells in accordance with the requirements of the
governing authorities and the recommendations of the geotechnical consultant at the time of
demolition.
Trees, plants or man-made improvements not planned to be removed or demolished should be
protected by the contractor from damage or injury.
Debris generated during clearing, grubbing and/or demolition operations should be wasted from
areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be
performed under the observation of the geotechnical consultant.
Section 5 -Site Protection
Protection of the site during the period of grading should be the responsibility of the contractor.
Unless other provisions are made in writing and agreed upon among the concerned parties,
completion of a portion of the project should not be considered to preclude that portion or
adjacent areas from the requirements for site protection until such time as the entire project is
complete as identified by the geotechnical consultant, the client and the regulating agencies.
Precautions should be taken during the performance of site clearing, excavations and grading to
protect the work site from flooding, ponding or inundation by poor or improper surface drainage.
Temporary provisions should be made during the rainy season to adequately direct surface
drainage away from and off the work site. Where low areas cannot be avoided, pumps should be
kept on hand to continually remove water during periods of rainfall.
Rain related damage should be considered to include, but may not be limited to, erosion, silting,
saturation, swelling, structural distress and other adverse conditions as determined by the
geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and
should be subject to overexcavation and replacement with compacted fill or other remedial
grading as recommended by the geotechnical consultant.
ST AND ARD SPECIFICATIONS OF GRADING
Page 2 of 26
-
111111
------------------------------------
Appendix D Page D-3
Standard Specifications for Grading
The contractor should be responsible for the stability of all temporary excavations.
Recommendations by the geotechnical consultant pertaining to temporary excavations (e.g.,
backcuts) are made in consideration of stability of the completed project and, therefore, should
not be considered to preclude the responsibilities of the contractor. Recommendations by the
geotechnical consultant should not be considered to preclude requirements that are more
restrictive by the regulating agencies. The contractor should provide during periods of extensive
rainfall plastic sheeting to prevent unprotected slopes from becoming saturated and unstable.
When deemed appropriate by the geotechnical consultant or governing agencies the contractor
shall install checkdams, desilting basins, sand bags or other drainage control measures.
In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies exist to
depths of greater than 1.0 foot; they should be overexcavated and replaced as compacted fill in
accordance with the applicable specifications. Where affected materials exist to depths of 1.0
foot or less below proposed finished grade, remedial grading by moisture conditioning in-place,
followed by thorough recompaction in accordance with the applicable grading guidelines herein
may be attempted. If the desired results are not achieved, all affected materials should be
overexcavated and replaced as compacted fill in accordance with the slope repair
recommendations herein. If field conditions dictate, the geotechnical consultant may
recommend other slope repair procedures.
Section 6 -Excavations
6.1 Unsuitable Materials
Materials that are unsuitable should be excavated under observation and
recommendations of the geotechnical consultant. Unsuitable materials include, but may
not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured,
weathered, soft bedrock and nonengineered or otherwise deleterious fill materials.
Material identified by the geotechnical consultant as unsatisfactory due to its moisture
conditions should be overexcavated; moisture conditioned as needed, to a uniform at or
above optimum moisture condition before placement as compacted fill.
If during the course of grading adverse geotechnical conditions are exposed which were
not anticipated in the preliminary soil report as determined by the geotechnical consultant
additional exploration, analysis, and treatment of these problems may be recommended.
STANDARD SPECIFICATIONS OF GRADING
Page 3 of 26
----------------------------·----------
AppendixD Page D-4
Standard Specifications for Grading
6.2 Cut Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent cut slopes should not be steeper than 2: 1 (horizontal:
vertical).
The geotechnical consultant should observe cut slope excavation and if these excavations
expose loose cohesionless, significantly fractured or otherwise unsuitable material, the
materials should be overexcavated and replaced with a compacted stabilization fill. If
encountered specific cross section details should be obtained from the Geotechnical
Consultant.
When extensive cut slopes are excavated or these cut slopes are made in the direction of
the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided
at the top of the slope.
6.3 Pad Areas
All lot pad areas, including side yard terrace containing both cut and fill materials,
transitions, located less than 3 feet deep should be overexcavated to a depth of 3 feet and
replaced with a uniform compacted fill blanket of 3 feet. Actual depth of overexcavation
may vary and should be delineated by the geotechnical consultant during grading,
especially where deep or drastic transitions are present.
For pad areas created above cut or natural slopes, positive drainage should be established
away from the top-of-slope. This may be accomplished utilizing a berm drainage swale
and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes
of 2 percent or greater is recommended.
Section 7 -Compacted Fill
All fill materials should have fill quality, placement, conditioning and compaction as specified
below or as approved by the geotechnical consultant.
7 .1 Fill Material Quality
Excavated on-site or import materials which are acceptable to the geotechnical consultant
may be utilized as compacted fill, provided trash, vegetation and other deleterious
materials are removed prior to placement. All import materials anticipated for use on-site
should be sampled tested and approved prior to and placement is in conformance with the
requirements outlined.
STANDARD SPECIFICATIONS OF GRADING
Page4 of 26
----------
----
--
-
-
--
-----·-----
AppendixD Page D-5
Standard Specifications for Grading
Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided
sufficient fill material is placed and thoroughly compacted over and around all rock to
effectively fill rock voids. The amount of rock should not exceed 40 percent by dry
weight passing the 3/4-inch sieve. The geotechnical consultant may vary those
requirements as field conditions dictate.
Where rocks greater than 12 inches but less than four feet of maximum dimension are
generated during grading, or otherwise desired to be placed within an engineered fill,
special handling in accordance with the recommendations below. Rocks greater than
four feet should be broken down or disposed off-site.
7.2 Placement of Fill
Prior to placement of fill material, the geotechnical consultant should observe and
approve the area to receive fill. After observation and approval, the exposed ground
surface should be scarified to a depth of 6 to 8 inches. The scarified material should be
conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture
content at or slightly above optimum moisture conditions and compacted to a minimum
of 90 percent of the maximum density or as otherwise recommended in the soils report or
by appropriate government agencies.
Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in
loose thickness prior to compaction. Each lift should be moisture conditioned as needed,
thoroughly blended to achieve a consistent moisture content at or slightly above optimum
and thoroughly compacted by mechanical methods to a minimum of 90 percent of
laboratory maximum dry density. Each lift should be treated in a like manner until the
desired finished grades are achieved.
The contractor should have suitable and sufficient mechanical compaction equipment and
watering apparatus on the job site to handle the amount of fill being placed in
consideration of moisture retention properties of the materials and weather conditions.
When placing fill in horizontal lifts adjacent to areas sloping steeper than 5: 1 (horizontal:
vertical), horizontal keys and vertical benches should be excavated into the adjacent slope
area. Keying and benching should be sufficient to provide at least six-foot wide benches
and a minimum of four feet of vertical bench height within the firm natural ground, firm
bedrock or engineered compacted fill. No compacted fill should be placed in an area
after keying and benching until the geotechnical consultant has reviewed the area.
Material generated by the benching operation should be moved sufficiently away from
STANDARD SPECIFICATIONS OF GRADING
Page 5 of 26
--·--
-----------·---·----------
·--·------
AppendixD Page D-6
Standard Specifications for Grading
the bench area to allow for the recommended review of the horizontal bench prior to
placement of fill.
Within a single fill area where grading procedures dictate two or more separate fills,
temporary slopes (false slopes) may be created. When placing fill adjacent to a false
slope, benching should be conducted in the same manner as above described. At least a
3-foot vertical bench should be established within the firm core of adjacent approved
compacted fill prior to placement of additional fill. Benching should proceed in at least
3-foot vertical increments until the desired finished grades are achieved.
Prior to placement of additional compacted fill following an overnight or other grading
delay, the exposed surface or previously compacted fill should be processed by
scarification, moisture conditioning as needed to at or slightly above optimum moisture
content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory
maximum dry density. Where unsuitable materials exist to depths of greater than one
foot, the unsuitable materials should be over-excavated.
Following a period of flooding, rainfall or overwatering by other means, no additional fill
should be placed until damage assessments have been made and remedial grading
performed as described herein.
Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill
provided the fill is placed and thoroughly compacted over and around all rock. No
oversize material should be used within 3 feet of finished pad grade and within 1 foot of
other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should
be placed below the upper IO feet of any fill and should not be closer than 15 feet to any
slope face. These recommendations could vary as locations of improvements dictate.
Where practical, oversized material should not be placed below areas where structures or
deep utilities are proposed. Oversized material should be placed in windrows on a clean,
overexcavated or unyielding compacted fill or firm natural ground surface. Select native
or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded
over and around all windrowed rock, such that voids are filled. Windrows of oversized
material should be staggered so those successive strata of oversized material are not in
the same vertical plane.
It may be possible to dispose of individual larger rock as field conditions dictate and as
recommended by the geotechnical consultant at the time of placement.
STANDARD SPECIFICATIONS OF GRADING
Page 6 of 26
---------------------------
----------
Appendix D Page D-7
Standard Specifications for Grading
The contractor should assist the geotechnical consultant and/or his representative by
digging test pits for removal determinations and/or for testing compacted fill. The
contractor should provide this work at no additional cost to the owner or contractor's
client.
Fill should be tested by the geotechnical consultant for compliance with the
recommended relative compaction and moisture conditions. Field density testing should
conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at
a minimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic
yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found
not to be in conformance with the grading recommendations should be removed or
otherwise handled as recommended by the geotechnical consultant.
7.3 Fill Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent fill slopes should not be steeper than 2: 1 (horizontal:
vertical).
Except as specifically recommended in these grading guidelines compacted fill slopes
should be over-built two to five feet and cut back to grade, exposing the firm, compacted
fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If
the desired results are not achieved, the existing slopes should be overexcavated and
reconstructed under the guidelines of the geotechnical consultant. The degree of
overbuilding shall be increased until the desired compacted slope surface condition is
achieved. Care should be taken by the contractor to provide thorough mechanical
compaction to the outer edge of the overbuilt slope surface.
At the discretion of the geotechnical consultant, slope face compaction may be attempted
by conventional construction procedures including backrolling. The procedure must
create a firmly compacted material throughout the entire depth of the slope face to the
surface of the previously compacted firm fill intercore.
During grading operations, care should be taken to extend compactive effort to the outer
edge of the slope. Each lift should extend horizontally to the desired finished slope
surface or more as needed to ultimately established desired grades. Grade during
construction should not be allowed to roll off at the edge of the slope. It may be helpful
to elevate slightly the outer edge of the slope. Slough resulting from the placement of
individual lifts should not be allowed to drift down over previous lifts. At intervals not
STANDARD SPECIFICATIONS OF GRADING
Page 7 of 26
--------------------------------------
Appendix D Page D-8
Standard Specifications for Grading
exceeding four feet in vertical slope height or the capability of available equipment,
whichever is less, fill slopes should be thoroughly dozer trackrolled.
For pad areas above fill slopes, positive drainage should be established away from the
top-of-slope. This may be accomplished using a berm and pad gradient of at least two
percent.
Section 8 -Trench Backfill
Utility and/or other excavation of trench backfill should, unless otherwise recommended, be
compacted by mechanical means. Unless otherwise recommended, the degree of compaction
should be a minimum of 90 percent of the laboratory maximum density.
Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two
feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical
means. If on-site materials are utilized, they should be wheel-rolled, tamped or otherwise
compacted to a firm condition. For minor interior trenches, density testing may be deleted or
spot testing may be elected if deemed necessary, based on review of backfill operations during
construction.
If utility contractors indicate that it is undesirable to use compaction equipment in close
proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical
compaction equipment and/or shading of the conduit with clean, granular material, which should
be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction
procedures. Other methods of utility trench compaction may also be appropriate, upon review of
the geotechnical consultant at the time of construction.
In cases where clean granular materials are proposed for use in lieu of native materials or where
flooding or jetting is proposed, the procedures should be considered subject to review by the
geotechnical consultant. Clean granular backfill and/or bedding are not recommended in slope
areas.
Section 9 -Drainage
Where deemed appropriate by the geotechnical consultant, canyon subdrain systems should be
installed in accordance with CTE's recommendations during grading.
Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be
installed in accordance with the specifications.
STANDARD SPECIFICATIONS OF GRADING
Page 8 of 26
--------
Appendix D Page D-9
Standard Specifications for Grading
Roof, pad and slope drainage should be directed away from slopes and areas of structures to
suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swales).
For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum
• of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2
• percent should be maintained over the remainder of the site. ----------------------------
Drainage patterns established at the time of fine grading should be maintained throughout the life
of the project. Property owners should be made aware that altering drainage patterns could be
detrimental to slope stability and foundation performance.
Section l 0 -Slope Maintenance
I 0.1 -Landscape Plants
To enhance surficial slope stability, slope planting should be accomplished at the
completion of grading. Slope planting should consist of deep-rooting vegetation
requiring little watering. Plants native to the southern California area and plants relative
to native plants are generally desirable. Plants native to other semi-arid and arid areas
may also be appropriate. A Landscape Architect should be the best party to consult
regarding actual types of plants and planting configuration.
10.2 -Irrigation
Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into
slope faces.
Slope irrigation should be minimized. If automatic timing devices are utilized on
irrigation systems, provisions should be made for interrupting normal irrigation during
periods of rainfall.
10.3 -Repair
As a precautionary measure, plastic sheeting should be readily available, or kept on hand,
to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This
measure is strongly recommended, beginning with the period prior to landscape planting.
If slope failures occur, the geotechnical consultant should be contacted for a field review
of site conditions and development of recommendations for evaluation and repair.
If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas
and currently unaffected areas should be covered with plastic sheeting to protect against
additional saturation.
STANDARD SPECIFICATIONS OF GRADING
Page 9 of 26
-------------------------
------------
AppendixD Page D-10
Standard Specifications for Grading
In the accompanying Standard Details, appropriate repair procedures are illustrated for
superficial slope failures (i.e., occurring typically within the outer one foot to three feet of
a slope face).
STANDARD SPECIFICATIONS OF GRADING
Page 10 of 26
--------
-------------., ------------... , -
FINISH CUT
SLOPE
----------
BENCHING FILL OVER NATURAL
FILL SLOPE
10'
TYPICAL
SURFACE OF FIRM
EARTH MATERIAL
15' MIN. (INCLINED 2% MIN. INTO SLOPE)
BENCHING FILL OVER CUT
FINISH FILL SLOPE
SURFACE OF FIRM
EARTH MATERIAL
15' MIN OR STABILITY EQUIVALENT PER SOIL
ENGINEERING (INCLINED 2% MIN. INTO SLOPE)
NOTTO SCALE
BENCHING FOR COMPACTED FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 11 of 26
--
---
------------------------... ----------.. --
MINIMUM
DOWNSLOPE
KEY DEPTH
TOE OF SLOPE SHOWN
ON GRADING PLAN
FILL .--.-.-------------.----_.....,. ___ _ .,,,,,. ~ .,,,,,.
-.,,,. .,,,,,. ...._""€.~\~ ..... .,,,. ..... .,,,,,. ~~ .,,,...... ~
.,,,........... ~€,P,..~ ..........
-.-~ p,..~\J .,,,,,. .,,,. .,,,,,. -~su'i. '-....,_.-_________ .....,.
---\S .,,,. ..,.. .-..,.. 1 O' TYPICAL BENCH
/ .-_,,.. .-WIDTH VARIES
A1 .,,,,,...-/'r .......... / 1 .,,,,,.. .-COMPETENT EARTH
/ ..,.. _,,.. MATERIAL --
2% MIN ---
15' MINIMUM BASE KEY WIDTH
TYPICAL BENCH
HEIGHT
PROVIDE BACKDRAIN AS REQUIRED
PER RECOMMENDATIONS OF SOILS
ENGINEER DURING GRADING
WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS,
BENCHING IS NOT NECESSARY. FILL IS NOT TO BE
PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL.
NOT TO SCALE
FILL SLOPE ABOVE NATURAL GROUND DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 12 of 26
I I I I I I t I I I ( I I I I I I i' I I I I I I I I I I I I I I I f I I I I
en -I )> z
Cl )>
lJ
0 en
""C ""Cm
~9
CD :I!
...I, C1
w~
0 -..... 0
NZ c, en
"Tl 0
JJ
Ci)
lJ )> g
z Ci)
REMOVE ALL TOPSOIL, COLLUVIUM,
AND CREEP MATERIAL FROM
TRANSITION
CUT/FILL CONTACT SHOWN
ON GRADING PLAN
CUT/FILL CONTACT SHOWN
ON nAS-BUIL T"
NATURAL
TOPOGRA~PY ___ _ ---------_ ---CUT SLOPE*
FILL _ ..... -..... --.......... f.l/lo\J'i:.
..... -'.E.'E-?-~ --
..... -~oC~ -----ullip,.i -
_.,. ----_ .....
--\..\}\J\ ----~:--------t ...--:So\\.., cO\;; ..... -..... 4' TYPICAL
,O-r ..... -
15' MINIMUM
NOT TO SCALE
10'TYPICAL
BEDROCK OR APPROVED
FOUNDATION MATERIAL
*NOTE: CUT SLOPE PORTION SHOULD BE
MADE PRIOR TO PLACEMENT OF FILL
FILL SLOPE ABOVE CUT SLOPE DETAIL
------
-----
------------------------
SURFACE OF
COMPETENT
MATERIAL _,__, ______________ _
TYPICAL BENCHING
SEE DETAIL BELOW
MINIMUM 9 FP PER LINEAR FOOT
OF APPROVED FILTER MATERIAL
CALTRANS CLASS 2 PERMEABLE MATERIAL
FILTER MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
COMPACTED FILL
DETAIL
REMOVE UNSUITABLE
MATERIAL
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
MINIMUM 4" DIAMETER APPROVED
PERFORATED PIPE (PERFORATIONS
DOWN)
6" FILTER MATERIAL BEDDING
14"
MINIMUM
SIEVE SIZE PERCENTAGE PASSING
APPROVED PIPE TO BE SCHEDULE 40
POLY-VINYL-CHLORIDE (P.V.C.) OR
APPROVED EQUAL. MINIMUM CRUSH
STRENGTH 1000 psi
1"
¾"
¾"
NO.4
NO. B
NO. 30
NO.SO
NO. 200
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
LENGTH OF RUN
INITIAL 500'
500' TO 1500'
> 1500'
NOTTO SCALE
PIPE DIAMETER
4"
TYPICAL CANYON SUBDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 14 of 26
------------------.. ---------.... -----
---
CANYON SUBDRAIN DETAILS
-----------------__ ......
............ ' '' ''
COMPACTED FILL
'
SURFACE OF
COMPETENT
MATERIAL
TYPICAL BENCHING \ ' '' ,_.,,
SEE DETAILS BELOW
'
TRENCH DETAILS
6" MINIMUM OVERLAP
REMOVE UNSUITABLE
MATERIAL
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
OPTIONAL V-DITCH DETAIL MINIMUM 9 FP PER LINEAR FOOT
OF APPROVED DRAIN MATERIAL
0
24"
MINIMUM
MINIMUM 9 FP PER LINEAR FOOT
OF APPROVED DRAIN MATERIAL
60° To go·
MIRAFI 140N FABRIC
OR APPROVED EQUAL
APPROVED PIPE TO BE
SCHEDULE 40 POLY-
VINYLCHLORIDE (P.V.C.)
OR APPROVED EQUAL.
MINIMUM CRUSH STRENGTH
1000 PSI.
DRAIN MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
SIEVE SIZE
1 ½·
1"
¾"
¾"
NO. 200
PERCENTAGE PASSING
88-100
5-40
0-17
0-7
0-3
LENGTH OF RUN
INITIAL 500'
500' TO 1500'
> 1500'
NOTTO SCALE
GEOFABRIC SUBDRAIN
STANDARD SPECIFICATIONS FOR GRADING
Page 15 of 26
PIPE DIAMETER
4"
6"
8"
----
----------
------
• -------·-------
FRONT VIEW
CONCRETE
CUT-OFF WALL
SUBDRAIN PIPE
SIDE VIEW
CONCRETE
6"Min.
24"Min. ~
6"Min.
CUT-OFF WALL----• 6"Min.
SOILD SUBDRAIN PIPE
t-.-~ ;...,
.. 'i, .. . PERFORATED SUBDRAIN PIPE .~.: .. ·.: ...... .
-------um.--1· .. · ·· · .. ·,,---7\illfflllm.-----............. . ·-... ~ ... -~.
NOT TO SCALE
RECOMMENDED SUBDRAIN CUT-OFF WALL
STANDARD SPECIFICATIONS FOR GRADING
Page 16 of 26
----... --------------------------------
-----
FRONT VIEW
SUBDRAIN OUTLET
PIPE (MINIMUM 4" DIAMETER)
SIDE VIEW
ALL BACKFILL SHOULD BE COMPACTED
IN CONFORMANCE WITH PROJECT
SPECIFICATIONS. COMPACTION EFFORT
SHOULD NOT DAMAGE STRUCTURE
• .... t • '
.II'' -•• I • _,. -'t ,
,"i..• ,· ... ,·.-;_,
J., ,•. , •• ' ._,._,._, .,· .... ,· .. ' ,· ...
A . ... .Ji.. I ...... I 'Ir,, -·· -··-..
i---24"Min.
i----24.Min.
NOTE: HEADWALL SHOULD OUTLET AT TOE OF SLOPE
OR INTO CONTROLLED SURFACE DRAINAGE DEVICE
ALL DISCHARGE SHOULD BE CONTROLLED
THIS DETAIL IS A MINIMUM DESIGN AND MAY BE
MODIFIED DEPENDING UPON ENCOUNTERED
CONDITIONS AND LOCAL REQUIREMENTS
NOTTO SCALE
24"Min.
12"
TYPICAL SUBDRAIN OUTLET HEADWALL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 17 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
SLOPE PER PLAN
FILTER MATERIAL
I I
BENCHING
H/2
AN ADDITIONAL BACKDRAIN
AT MID-SLOPE WILL BE REQUIRED FOR
SLOPE IN EXCESS OF 40 FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
(GENERALLY 1/2 SLOPE HEIGHT, 15' MINIMUM)
DIMENSIONS ARE MINIMUM RECOMMENDED
NOT TO SCALE
TYPICAL SLOPE STABILIZATION FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 18 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
SLOPE PER PLAN
FILTER MATERIAL
2%M
H/2
ADDITIONAL BACKDRAIN AT
MID-SLOPE WILL BE REQUIRED
FOR SLOPE IN EXCESS OF 40
FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
DIMENSIONS ARE MINIMUM RECOMMENDED
NOT TO SCALE
TYPICAL BUTTRESS FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 19 of 26
FINAL LIMIT OF
EXCAVATION
OVEREXCAVATE
OVERBURDEN
(CREEP-PRONE)
DAYLIGHT
LINE
OVEREXCAVATE 3'
AND REPLACE WITH
COMPACTED FILL
COMPETENT BEDROCK
TYPICAL BENCHING
LOCATION OF BACKDRAIN AND
OUTLETS PER SOILS ENGINEER
AND/OR ENGINEERING GEOLOGIST
DURING GRADING. MINIMUM 2%
FLOW GRADIENT TO DISCHARGE
LOCATION.
EQUIPMENT WIDTH (MINIMUM 15')
NOT TO SCALE
DAYLIGHT SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 20 of 26
PROPOSED GRADING
BASE WIDTH "W" DETERMINED
BY SOILS ENGINEER
NATURAL GROUND
COMPACTED FILL
NOT TO SCALE
PROVIDE BACKDRAIN, PER
BACKDRAIN DETAIL. AN
ADDITIONAL BACKDRAIN
AT MID-SLOPE WILL BE
REQUIRED FOR BACK
SLOPES IN EXCESS OF
40 FEET HIGH. LOCATIONS
OF BACKDRAINS AND OUTLETS
PER SOILS ENGINEER AND/OR
ENGINEERING GEOLOGIST
DURING GRADING. MINIMUM 2%
FLOW GRADIENT TO DISCHARGE
LOCATION.
TYPICAL SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 21 of 26
FINISH SURFACE SLOPE
3 FP MINIMUM PER LINEAR FOOT
APPROVED FILTER ROCK*
CONCRETE COLLAR
PLACED NEAT
A
2.0% MINIMUM GRADIENT
A
4" MINIMUM DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
COMPACTED FILL
4" MINIMUM APPROVED
PERFORATED PIPE**
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
DURING GRADING TYPICAL BENCH INCLINED
TOWARD DRAIN
**APPROVED PIPE TYPE:
MINIMUM
12" COVER
SCHEDULE 40 POLYVINYL CHLORIDE
(P.V.C.) OR APPROVED EQUAL.
MINIMUM CRUSH STRENGTH 1000 PSI
BENCHING
DETAIL A-A
TEMPORARY FILL LEVEL
MINIMUM 4" DIAMETER APPROVED
SOLID OUTLET PIPE
*FILTER ROCK TO MEET FOLLOWING
SPECIFICATIONS OR APPROVED EQUAL:
SIEVE SIZE
1"
¾"
¾" N0.4
NO. 30
NO. 50
NO. 200
PERCENTAGE PASSING
100
90-1 00
40-100
25-40
5-15
0-7
0-3
NOT TO SCALE
TYPICAL BACKDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 22 of 26
FINISH SURFACE SLOPE
MINIMUM 3 FT3 PER LINEAR FOOT
OPEN GRADED AGGREGATE*
TAPE AND SEAL AT COVER
CONCRETE COLLAR
PLACED NEAT COMPACTED FILL
A
2.0% MINIMUM GRADIENT
A
MINIMUM 4" DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
MINIMUM
12" COVER
*NOTE: AGGREGATE TO MEET FOLLOWING
SPECIFICATIONS OR APPROVED EQUAL:
SIEVE SIZE PERCENTAGE PASSING
1 ½" 100
1" 5-40
¾" 0-17
¾" 0-7
NO. 200 0-3
TYPICAL
BENCHING
DETAIL A-A
NOT TO SCALE
MIRAFI 140N FABRIC OR
APPROVED EQUAL
4" MINIMUM APPROVED
PERFORATED PIPE
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
BENCH INCLINED
TOWARD DRAIN
TEMPORARY FILL LEVEL
MINIMUM 4" DIAMETER APPROVED
SOLID OUTLET PIPE
BACKDRAIN DETAIL (GEOFRABIC)
STANDARD SPECIFICATIONS FOR GRADING
Page 23 of 26
SOIL SHALL BE PUSHED OVER
ROCKS AND FLOODED INTO
VOIDS. COMPACT AROUND
AND OVER EACH WINDROW.
FILL SLOPE
l FILL SLOPE l
CLEAR ZONE __/
STACK BOULDERS END TO END.
DO NOT PILE UPON EACH OTHER.
~/L_-----------------
COMPETENT MATERIAL
NOT TO SCALE
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 24 of 26
STAGGER
ROWS
STREET
10'
5' MINIMUM OR BELOW
DEPTH OF DEEPEST
UTILITY TRENCH
(WHICHEVER GREATER)
FINISHED GRADE BUILDING
0
NO OVERSIZE, AREA FOR
FOUNDATION, UTILITIEs~l
AND SWIMMING POOL:__i_
0 0
'L--d 4·L-.
WINDROW~
0
TYPICAL WINDROW DETAIL (EDGE VIEW)
GRANULAR SOIL FLOODED
TO FILL VOIDS
HORIZONTALLY PLACED
COMPACTION FILL
PROFILE VIEW
NOT TO SCALE
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 25 of 26
-.. -------------------------------·--...
--
GENERAL GRADING RECOMMENDATIONS
CUT LOT
----------
3'MIN -------_,.. -UNWEATHERED BEDROCK
OVEREXCAVATE
AND REGRADE
COMPACTED FILL
CUT/FILL LOT (TRANSITION)
UNWEATHERED BEDROCK
NOT TO SCALE
TRANSITION LOT DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 26 of 26
__..,-ORIGINAL
..,,.,---_,GROUND .,,,,,.,,
.,,,,,..,,,,,.
'MIN
OVEREXCAVATE
AND REGRADE
--------------------------------------
APPENDIXE
C.4-1 WORKSHEET
Worksheet C.4-1: Categorization oflnfiltration Feasibility Condition
Categorization of Infiltration Feasibility Condition 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.
X
Provide basis: The NRCS soils across the site are all Type B soils with medium surface runoff. The site soils are
generally consistent with the NRCS mapped soil types based on site explorations and percolation
testing. Quaternary Old Paralic Deposits underlie the entire site and are anticipated at the base of
the proposed basins.
Four percolation tests were completed within the Old Paralic Deposits. The calculated infiltration
rates (with an applied factor of safety of two) ranged from 0.0 l to 0.15 inch per hour.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of 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.
X
Provide basis: Provided the basins are constructed in the areas with favorable permeability (Figure 2) and
adequately set back from proposed structural improvements, risk of geotechnical hazards will not
be significantly increased.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
C-11
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4~1 Page 4 of 4
Criteria Screening Question
7
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Yes No
X
Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 feet away
from the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
X
Provide basis: The nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet
from the site. Due to the significant distance to the lagoon it is unlikely to be impacted by
infiltrating site water.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/data source applicability and why it was not feasible to mitigate low
infiltration rates.
If all answers from row 1-4 are yes then partial infiltration design is potentially feasible.
Part 2 The feasibility screening category is Partial Infiltration.
Result* If any answer from row 5-8 is no, then infiltration of any volume is considered to be
infeasible within the drainage area. Tbe feasibility screening category is No Infiltration.
Partial
*To be completed using gathered site information and best professional judgment considering the definition of MEP m
the MS4 Permit. Additional testing and/or studies may be required by City Engineer to substantiate findings
C-14
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4-1 Page 2 of 4
Criteria Screening Question
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water pollutants
or other factors) that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.3.
Yes No
X
Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 feet away
from the site.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface waters?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
X
Provide basis: The nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet
from the site. Due to the significant distance to the lagoon it is unlikely to be impacted by
infiltrating site water.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
Part 1
If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The
feasibility screening category is Full Infiltration
Result* If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
No Full
*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 City Engineer to substantiate findings.
C-12
Appendix C: Geotechnical and Groundwater Investigation Requirements
Worksheet C.4-1 Page 3 of 4
Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question
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.
Yes
X
No
Provide basis: Based on the working draft version of Appendix C, it is CTE's understanding that the lower limit
of partial infiltration is 0.05 inches/hour. The majority of the site exceeds this rate, therefore
partial infiltration is possible.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed without increasing risk
of geotechnical hazards (slope stability, groundwater mounding, utilities, or
other factors) that cannot be mitigated to an acceptable level? The response to
this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.2.
X
Provide basis: Provided the basins are constructed in the areas with favorable permeability (Figure 2) and
adequately set back from proposed structural improvements, risk of geotechnical hazards will not
be significantly increased.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
C-13