Agenda packet — Glendora City Council, September 24, 2024 (part 8 of 11)

Appendix I
Preliminary Low Impact Development (LID) Plan
C&V Consulting, Inc.

September 2023 (revised December 2023)
Item #6. Page 1378
Meeting Date: 9/24/2024 / Packet Page #: 1514
Prepared Date: September 2023
Revised Date: December 2023
Preliminary Low Impact Development (LID) Plan
Property:

VTTM No. 84292
APN: 8646-029-009, 8646-029-014
723-745 E. Route 66
Glendora, CA 91740
Prepared for:

Brandywine Homes
16580 Aston
Irvine, CA 92606
Contact: Chris Courtney
Prepared by:

C&V Consulting, Inc.
9830 Irvine Center Drive
Irvine, CA 92618
(949) 916-3800
Contact: Dane P. McDougall, P.E.

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Receipt of WDID

REPLACE THIS SHEET
To be provided prior to final approval
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Preliminary Low Impact Development Plan
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Notice of Intent

REPLACE THIS SHEET
To be provided prior to final approval
Item #6. Page 1381
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Preliminary Low Impact Development Plan
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Table of Contents

SECTION PAGE
SECTION 100
COVER ............................................................................................................................................................ I RECEIPT OF WDID .......................................................................................................................................... II NOTICE OF INTENT...........................................................................................................................................III TABLE OF CONTENTS...................................................................................................................................... IV LIST OF FIGURES............................................................................................................................................ IV LIST OF APPENDICES ...................................................................................................................................... IV PROJECT OWNER’S CERTIFICATION.................................................................................................................. V ENGINEER CERTIFICATION .............................................................................................................................. VI SECTION 200 ...............................................................................................................................................1 A.Contact Information/List of Responsible Parties .......................................................................................1 SECTION 300 ...............................................................................................................................................2 A.References ................................................................................................................................................2 SECTION 400 – BODY OF LID....................................................................................................................3 A.Objectives /Methodology ...........................................................................................................................3 B.Project Site Background and Description ..................................................................................................3 C.Existing Site Drainage Condition...............................................................................................................3 D.Proposed Site Drainage Conditions ..........................................................................................................4 E.LID Project Types, Characteristics, & Activities.........................................................................................5 F.Pollutant Source Identification ...................................................................................................................5 G.Non-Structural BMPs.................................................................................................................................6 H.Structural BMPs.........................................................................................................................................9 I.LID and Treatment BMPs..........................................................................................................................11 J.BMP Maintenance, Inspection, and Repair..............................................................................................13 K.Inspection, Maintenance, and Responsibility for BMPs ..........................................................................13 L.Operation/Maintenance Funding after Project Completion......................................................................16 List of Figures
Figure 1: BMP Exhibit
Figure 2: Impaired Waters
List of Appendices
Appendix A: Volume and Flowrate Calculations & Hydrologic Report Appendix B: Site BMPs
Appendix C: Infiltration System Storage Analysis/ Treatment BMPs Details Appendix D: EPA Catch Basing Cleaning/ Stencil Examples Appendix E: General Education Materials
Appendix F: Operation and Maintenance Plan
Appendix G: Geotechnical Investigation
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September 2023 v
Project Owner’s Certification
of the
Preliminary Low Impact Development (LID) Plan
Project Name: VTTM NO. 84292
Project Number: APN 8646-029-009, 8646-029-014
Project Address: 723-745 E. Route 66
Glendora, CA 90740
This Preliminary Low Impact Development (LID) Plan for the VTTM NO. 84292 project has been prepared for Brandywine Homes by C&V Consulting, Inc. It is intended to comply with the requirements of the City of Glendora’s Conditions of Approval.

The undersigned is authorized to approve implementation of provisions of this plan as appropriate and will strive to have the plan carried out by successors consistent with the County of Los Angeles LID Manual and the intent of the NPDES storm water requirements.
"I certify under penalty of law that this document and all attachments were prepared under my jurisdiction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathered the information, to the best of my knowledge and belief, the information submitted is true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.”
Owner’s Name: Chris Courtney
Owner’s Title:

Company: Brandywine Homes
Address: 16580 Aston, Irvine, CA 92606
Email:

Telephone No.:

Signature: Date:

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September 2023 vi
Engineer Certification
Engineer’s Name: Dane P. McDougall
Engineer’s Title: President
Company: C&V Consulting, Inc.

Address: 9830 Irvine Center Drive, Irvine, CA 92618
Email: [email protected]
Telephone No. (949) 916-3800
I hereby certify that this Low Impact Development Plan is in compliance with, and meets the requirements set forth in, Order No. R4-2021-0105, of the Los Angeles Regional Water Quality Control Board.

Engineer’s Signature Date
Place Stamp Here
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Section 200
A. Contact Information/List of Responsible Parties
The property contact information is:

Chris Courtney
Brandywine Homes
16580 Aston
Irvine, CA 92606
The property owner shall have primary responsibility and significant authority for the implementation, maintenance, and inspection of the property BMPs. Duties of the Owner include but are not limited to:
• Implementing all elements of the LID, including but not limited to:
o Implementation of prompt and effective erosion and sediment control measures
o Implementing all non-storm water management, and materials and waste management activities, such as: monitoring, discharges, general site clean-up; vehicle and equipment cleaning, spill control; good construction housekeeping to ensure that no materials other than storm water are discharged which may have an adverse effect on receiving waters or storm drain systems, etc.
• Inspections and Maintenance.
• Routine inspections as described in the Low Impact Development Plan. • Ensuring elimination of all unauthorized discharges
• The Owner shall be assigned authority to mobilize crews in order to make immediate repairs to the control measures.
• Coordinate all of the necessary corrections/repairs are made immediately, and that the project complies with the LID at all times.
• Managing and report any Illicit Connections or Illegal Discharges.

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Section 300
A. References
The following documents are made a part of this LID by reference:
• Project plans and specifications for the City of Glendora to support the project, prepared by C&V Consulting, Inc., 9830 Irvine Center Drive, Irvine, California 92618.
• Los Angeles Resources Water Quality Control Board (LARWQCB) Order R4- 2021-0105 effective September 10, 2021
• State Water Resources Control Board (SWRCB) National Pollutant Discharge Elimination System (NPDES) No. CAS000002, Waste Discharge Requirements (WDRs) for Discharges of Storm Water Runoff Associated with Construction Activity, adopted on September 8, 2022.
• California Stormwater BMP Handbook – Construction, November 2009. • California Stormwater BMP Handbook – New Development and Redevelopment, January 2003.
• County of Los Angeles Department of Public Works L.I.D. Standards Manual, February 2014
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Section 400 – Body of LID
A. Objectives /Methodology
This Low Impact Development (LID) Plan has the following main objectives:
1) Identify all pollutant sources, including sources of sediment that may affect the quality of storm water discharges associated with daily use / activity (storm water discharges) from the property site.
2) Identify, construct, implement and maintain Best Management Practices (BMPs) to reduce or eliminate pollutants in storm water discharges and authorized non-storm water discharges from the property site.
3) Develop a maintenance schedule for BMPs designed to reduce or eliminate pollutants.

The method of quantifying stormwater design capture volume was to utilize the Los Angeles County Public Works’ HydroCalc program for the project site. Since the 85 th
percentile rainfall depth was determined to be greater than the 0.75-in rainfall depth, the 85 th percentile rainfall depth was applied to the analysis to obtain the 24-hr clear runoff volume.

B. Project Site Background and Description
The proposed project site comprises two parcels with a total land area of 1.845 acres. It is located at 723-745 East Route 66, City of Glendora, County of Los Angeles. (APN:8646-029-009, 8646-029-014). The site is bounded by E. Route 66 to the south, A.T. & S.F. Railroad to the north, commercial buildings to the east and west.

The site is currently a vacant auto center building structure with a paved covered lot area. The perimeter of the site is bounded by block walls and chain linked fencing.

Vegetation within the site is minimal per geographic observation matching its commercial land use.

The project proposes the construction of six (6) residential buildings consisting of thirtynine (39) dwelling units with private garages, private drive aisles, sidewalks, and common landscaped areas. The project site will be accessible with an entrance/ exit along E. Route 66. Drive aisles and parking areas will be composed of asphalt concrete pavement. Proposed development imperviousness is assumed to be 86% per Los Angeles County Hydrology Manual recommended value based on development type.

Refer to Figure 1 for the project location shown in the Vicinity Map within the LID Exhibit.

C. Existing Site Drainage Condition
The existing drainage condition of the site generally surface sheet flows south-westerly towards E. Route 66 with elevations ranging between approximately 785.5 and 777.6 Item #6. Page 1387
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feet above mean sea level. There is no offsite stormwater run-on due to perimeter control with existing walls along the boundary of the site. Adjacent properties’ drainage slopes away from the proposed site. The outflow of the proposed site continues westerly downstream along E. Route 66 eventually enters existing Los Angeles County Flood Control District’s (LACFCD) catch basin inlets at S. Pasadena Avenue. The runoff continues through LACFCD’s 54-inch reinforced concrete pipe to Big Dalton Wash. All flow ultimately discharges to the San Gabriel River which drains to the Pacific Ocean at San Pedro Bay. Water bodies downstream of the project site are listed on the most current 303(d) list as follows:
• San Gabriel River Reach 3 (Whittier Narrows to Ramona) o Indicator Bacteria
• San Gabriel River Reach 2 (Firestone to Whittier Narrows) o Coliform Bacteria
o Cyanide
o Lead
• San Gabriel River Reach 1 (Estuary to Firestone)
o Coliform Bacteria
• San Gabriel River Estuary
o Copper
o Dioxin
o Nickel
o Oxygen, Dissolved
• San Pedro Bay
o Chlordane
o DDT (tissue & sediment)
o PCBs (Polychlorinated biphenyls)
o Sediment Toxicity
The MS4 facilities downstream of the project site are engineered, therefore the project is exempt from Hydromodification Control requirements per LACPW LID Manual as stated below:
“Projects that discharge directly or through a storm drain into concrete or otherwise engineered channel (i.e., channelized or armored with rip-rap, shotcrete), which, in turn, discharge into receiving water that is not susceptible to hydromodification impacts.” Refer to Figure 2, Drainage Map for additional drainage information.

D. Proposed Site Drainage Conditions
The onsite residential development drainage management area is analyzed as a single subarea as design stormwater mitigation intends to be routed to a single outlet at the south-west corner of the site. There are three (3) onsite inlets that collect and direct runoffs into the proposed interconnected underground infiltration / detention system for water quality treatment sized for the 85th percentile rain event in conformance with water quality treatment standards.

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Brandywine Homes Section 400
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During the design storm event when the infiltration/ detention system reaches full capacity, excess runoff is routed to the parkway drain connection to the public right of way. In cases of a larger storm event beyond the design storm, runoff will pond at the localized inlets and the grading design ensures runoff overflow towards E. Route 66 following historical drainage pattern.

Per Geotechnical Investigation, prepared by Alta California Geotechnical, Inc. dated June 22, 2023, the historic high groundwater is approximately 100-feet below the ground surface (CDMG, 1998). Infiltration Testing was undertaken using two ten (10) foot-deep borings. The testing was performed in general conformance with the County of Los Angeles Technical Guidance Document Standards. The data was then adjusted to provide a tested infiltration rates of 13.4 and 10.8 inches per hour utilizing the Porchet Method. The results do not include the factor of safety; therefore, a safety factor of 3 was applied to obtain the design infiltration rate within the infiltration system analysis.

Refer to Appendix G, Geotechnical Report for additional infiltration information.

E. LID Project Types, Characteristics, & Activities
Per the California Regional Water Quality Control Board Los Angeles Region MS4 Order R2021-0105 Part VIII.F, the proposed project is classified as a “Priority Development Project”.

Par VIII.F.1.i.(a) of the 2021 LARWQCB MS4 NPDES Permit defines “Priority Development Projects”, requiring Low Impact Development (LID) planning, to include “Projects equal to 1 acre or greater of disturbed area and adding more than 10,000 square feet or more of impervious surface area (collectively over the entire project site).

F. Pollutant Source Identification
The following is a list of materials to be used in the daily construction activities at the project site, which will potentially contribute to pollutants, other than sediment, to storm water runoff. Control Practices for each activity are identified below:
• Vehicle fluids, including oil, grease, petroleum, and coolants from personal vehicles.
• Landscaping materials and wastes (topsoil, plant materials, herbicides, fertilizers, mulch, pesticides)
• General trash debris and litter
• Pet waste (bacteria/ fecal coliforms)
Project proponents shall implement Site Design concepts that achieve each of the following:
• Minimize Urban Runoff
• Minimize Impervious Footprint
• Conserve Natural Areas
• Minimize Directly Connected Impervious Areas (DCIAs)
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Brandywine Homes Section 400
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The Best Management Practices (BMPs) that have been selected for implementation on this project are detailed in the following sections.

G. Non-Structural BMPs
Non-structural BMPs are generally managerial, educational, inspection and/ or maintenance oriented. These items consist of educating employees and occupants, developing, and implementing HOA guidelines, implementing BMPs and enforcing Code requirements.

Table-1: Non-Structural Source Control BMPs

BMP TECHNIQUE
INCLUDED?

YES NO NOTES
N1
Education for Property Owners,
Tenants and Occupants
X HOA to comply
N2 Activity Restrictions X HOA to comply
N3
Common Area Landscape
Management
X HOA to comply
N4 BMP Maintenance X HOA to maintain
N5
Title 22 CCR Compliance (How
development will comply)
X HOA to comply
N6
Local Industrial Permit
Compliance
X Not Applicable
N7 Spill Contingency Plan X Not Applicable
N8
Underground Storage Tank
Compliance
X Not Applicable
N9
Hazardous Materials
Disclosure Compliance
X Not Applicable
N10 Uniform Fire Code
Implementation
X Not Applicable
N11 Common Area Litter Control X HOA to comply
N12 Employee Training X HOA to comply
N13
Housekeeping of Loading
Docks
X Not Applicable
N14
Common Area Catch Basin
Inspection
X HOA to comply
N15
Street Sweeping Private
Streets and Parking Lots
X HOA to comply
N16 Retail Gasoline Outlets X Not Applicable
Education for Employees and Occupants
Practical informational materials will be provided to homeowners, HOA and employees on general good housekeeping practices that contribute to protection of storm water Item #6. Page 1390
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quality. Among other things, these materials will describe the use of chemicals (including household type) that should be limited to the property, with no discharge of specified wastes via hosing or other direct discharge to gutters, catch basins and storm drains. Initially, the Owner will provide these materials. Thereafter, such materials will be available through the HOA education program.

This program must be maintained, enforced, and updated periodically by the HOA.

Educational materials including, but not limited to, the materials included in the Appendix E of this plan will be made available to the employees and contractors of the HOA.

Activity Restrictions
Activities on this site will be limited to activities related to residential living. The project’s Conditions, Covenants, and Restrictions (CC&Rs) will outline the activities that are restricted on the property. Such activities related to the LID include car washing, car maintenance and disposal of used motor fluids, pet waste cleanup, and trash container areas.

Community Car Wash Racks
No community car wash rack or area will be provided, therefore, vehicle washing by residents on the property will not be allowed per the CC&Rs.

Self-Contained Washing
Self-contained washing of vehicles by residents or owners on the property will not be allowed per the CC&Rs.

Outdoor Material Storage Areas
Outdoor material storage areas refer to storage areas or storage facilities solely for the storage of materials. Improper storage of materials outdoors may provide an opportunity for toxic compounds, oil and grease, heavy metals, nutrients, suspended solids, and other pollutants to enter the storm water conveyance system. Outdoor Storage by residents or owners on the property will not be allowed per the CC&Rs.

Common Area Landscaped Management
Identify on-going landscape maintenance requirements that are consistent with those in the County Water Conservation Resolution (or city equivalent) that include fertilizer and/or pesticide usage consistent with Management Guidelines for Use of Fertilizers Runoff-Minimizing Landscape Design
As part of the design of all common area landscape areas, similar planting material with similar water requirements will be used in order to reduce excess irrigation runoff and promote surface filtration. Such common areas will be maintained by the HOA.

Item #6. Page 1391
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Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Brandywine Homes Section 400
September 2023 8
BMP Maintenance
The HOA will implement maintenance of each non-structural BMP and scheduled cleaning and/or maintenance of all structural BMP facilities.

Common Area Litter Control
The HOA must implement trash management and litter control procedures in common areas aimed at reducing pollution of drainage water. The HOA may contract a landscape maintenance company to provide this service during regularly scheduled maintenance which will consist of litter patrol and noting trash disposal violations and reporting the violations to the HOA for investigation.

Employee Training
A training program will be established as it would apply to future employees, contractors, and homeowners of the HOA to inform and train in maintenance activities regarding the impact of dumping oil, paints, solvents, or other potentially harmful chemicals into storm drains; the proper use of fertilizers and pesticides in landscaping maintenance practices; and the impacts of littering and improper water disposal.

The HOA (or a hired firm) will conduct the training program which will include targeted training sessions with specific construction disciplines (landscaping, concrete finishers, painters, etc.). See Appendix E for examples of educational materials that will be provided to the Employees.

The project’s CC&Rs will include provisions for future employee training programs conducted on a yearly basis prior to the rainy season.

Drainage Facility Inspection & Maintenance
The HOA will be responsible for implementing each of the BMPs detailed in this plan.

The HOA will also be responsible for cleaning and maintaining the BMPs on a regular basis. Refer to Appendix G for the Operation and Maintenance Plan. Refer to Appendix C for site specific drainage BMP information.

Catch Basin Inspection
The HOA will maintain the drainage systems, including catch basins and culverts. The HOA is required to have catch basins inspected and, if necessary, cleaned prior to the storm season, no later than October 15th each year or prior to the first 24-hour storm event, whichever occurs first. These duties may be contracted out to the landscape maintenance firm hired by the HOA.

Refer to Appendix D for additional inspection Information.

Street Sweeping in Private Streets and Parking Lots
The HOA shall have all streets and parking lots swept on a weekly basis. This procedure will be intensified around October 15
th of each year prior to and throughout
rain storm period.

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Brandywine Homes Section 400
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H. Structural BMPs
Table-2 and Table-3 identifies the structural source control BMPs for Design and how each is implemented to achieve each Site Design concept. BMP fact sheets are provided by the LACDPW Low Impact Development Standards Manual and the California Stormwater Quality Association.

Table-2: LACDPW Source Control BMPs

BMP TECHNIQUE
INCLUDED?

YES NO NOTES
S-1
Storm Drain Message and
Signage X
Catch basins will be
appropriately marked
S-2 Outdoor Material Storage Area X Not Applicable
S-3
Outdoor Trash Storage and
Waste Handling Area X Not Applicable
S-4
Outdoor Loading/Unloading
Dock Area X No Loading Dock Areas
S-5
Outdoor Repair/Maintenance
Area
X No Maintenance Bays
S-6
Outdoor
Vehicle/Equipment’s/Accessory
Washing Area
X No Wash Areas
S-7 Fueling Area X No Fueling Areas
S-8 Landscape Irrigation Practices X HOA CC&Rs
S-9 Building Materials Selection X HOA CC&Rs
S-10 Animal Care and Handling
Facilities X No Animal Care Facility
S-11 Outdoor Horticulture Areas X Not Applicable
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Brandywine Homes Section 400
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Table-3: CASQA Source Control BMPs for Design

BMP TECHNIQUE
INCLUDED?

YES NO NOTES
SE-7
Street Sweeping and
Vacuuming
X Pet waste collection stations, HOA
SD-10 Site Design &
Landscape Planning
X
Common Landscape Area Design,
HOA
SD-11 Roof Runoff Controls X
Roof drains will be disconnected from
the MS4
SD-12 Efficient Irrigation X
Landscape design will implement
efficient irrigation
SD-13 Storm Drain Signage X
Catch basins will be appropriately
marked
SD-20 Pervious Pavements X
Site design does not allow for this
BMP.

SD-21 Alternative Building
Materials X Not Applicable
SD-30 Fueling Areas X Not Applicable
SD-31 Maintenance Bays &
Docks
X Not Applicable
SD-32 Trash Storage Areas X Not Applicable
SD-33 Vehicle Washing
Areas X Not Applicable
SD-34 Outdoor Material
Storage Areas X Not Applicable
SD-35 Outdoor Work Areas X Not Applicable
SD-36 Outdoor Processing
Areas X Not Applicable
Storm Drain Stenciling/ Signage
Phrase "No Dumping – Drains to Ocean" or equally effective phrase to be stenciled on catch basins to alert the public to the destination of pollutants discharged into storm water. This stenciling will be inspected and re-stenciled on a periodic basis by the HOA.

Refer to Appendix D for stenciling example.

Landscape & Irrigation System Design
As part of the design of all common area landscape irrigation shall employ water conservation principles, including, but not limited to, such provisions as water sensors, programmable irrigation times (for short cycles), etc. will be used. Such common areas will be maintained by the HOA.

Efficient Landscape System & Landscape Maintenance
Management programs will be designed and established by the HOA, who will maintain the common areas within the project site. These programs will include how to mitigate Item #6. Page 1394
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the potential dangers of fertilizer and pesticide usage (refer to the Maintenance and Frequency Table). Ongoing maintenance will be consistent with the State of California Model- Water Efficient Landscape Ordinance. Fertilizer and pesticide usage shall be consistent with County Management Guidelines for use of Fertilizers and Pesticides.

Building Materials Selection
Material selection will minimize the use of copper, galvanized metals and other materials that could add significant amounts of harmful pollutants to stormwater runoff.

Street Sweeping and Vacuuming
The HOA shall have all streets and parking lots swept on a weekly basis. This procedure will be intensified around October 15
th of each year prior to and throughout
rain storm period.

I. LID and Treatment BMPs
Treatment BMPs shall be installed by the developer, through the construction and development of the project, for instance; landscaping and irrigation systems shall be designed by licensed landscape architects and installed by qualified contractors to specifications and standards of the City of Glendora. The structural BMPs used for this project are summarized below:

Expected pollutants associated with this development include vehicle discharge fluids, landscaping materials and waste, litter, and pet waste. To mitigate these pollutants, the structural best management practices are summarized below.

Table-4: Treatment BMPs

BMP NAME
INCLUDED?

IF NOT APPLICABLE, STATE BRIEF

YES NO REASON
RET-1 Bioretention X Alternative BMP selected
RET-2 Infiltration Basin X Alternative BMP selected
RET-3 Infiltration Trench X
Proposed Infiltration BMP will be utilized
in the proposed development and
provide full treatment of the SWQDV.

RET-4 Dry Well X Alternative BMP selected
RET-5
Permeable
Pavement without
an Underdrain
X Alternative BMP selected
RET-6 Rain Barrel/Cistern X Alternative BMP selected
BIO-1 Biofiltration X Alternative BMP selected
VEG-1 Green Roof X Space not available for BMP
VEG-2 Stormwater Planter X Space not available for BMP
VEG-3 Tree-Well Filter X Space not available for BMP
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BMP NAME
INCLUDED?

IF NOT APPLICABLE, STATE BRIEF

YES NO REASON
VEG-4 Vegetated Swale X Space not available for BMP
VEG-5
Vegetated Filter
Strip
X Alternative BMP selected
T-1 Sand Filter X Alternative BMP selected
T-2
Constructed
Wetland
X Alternative BMP selected
T-3
Extended Detention
Basin
X Alternative BMP selected
T-4 Wet Pond X Alternative BMP selected
T-5
Permeable
Pavement with an
Underdrain
X Alternative BMP selected
T-6
Proprietary
Treatment Control
Measures
X Alternative BMP selected
PRE-2 Drain Inserts X
Drain inserts will be utilized in the
proposed development as pre-treatment
for the infiltration system.

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Infiltration Trench System
Catch basin inlets with drain inserts are proposed to intercept site generated runoff and be routed to the infiltration trench system. The inlets are designed to intercept the majority of the first flows during a rain event and drain inserts are to reduce the impact of sediment and debris into the infiltration system. The infiltration system will also be utilized as the detention system which overflow will be mitigated to the proposed parkway at the low point of the site for flows greater than the 85th percentile storm event runoff volume following historical drainage pattern.

The proposed system will treat the required volume within target drawdown duration of 48 hours. The treatment capacity of the system is determined by the drawdown duration and the design infiltration rate. The calculation is copies below for reference:

Drainage
Management
Area (DMA)
Size (ac) SWQDV
(cf)*
Detention
Capacity (cf)
48-hr
Treatment
Capacity (cf)
A-1 1.845 5,248.1 5,255.4 26,652.3
*Los Angeles County Department of Public Works (LACDPW) HydroCalc Software was utilized to calculate stormwater quality design volume (SWQDV). The governing flowrate per the 85
th Percentile storm event was utilized for design. Refer to Appendix A for HydroCalc outputs.

The Infiltration systems will address the pollutants of concern associated with the development type. Refer to Appendix C for more information on Infiltration Trench System sizing. Treatment Volumes are to be verified with proposed perviousness per final site plan during Final Engineering.

J. BMP Maintenance, Inspection, and Repair
Inspections will be conducted as follows:
• Annually and prior to the start of the rainy season
• Every (1) month during rainy season
• At any other time(s) or intervals of time specified in the contract documents Repairs and/ or maintenance procedures shall be carried out at the soonest possible time.

K. Inspection, Maintenance, and Responsibility for BMPs Table-5 and Table-6 show the lists of the post-construction BMPs (routine non-structural and structural), the required ongoing maintenance, the inspection and maintenance frequency, the inspection criteria, and the entity or party responsible for implementation, maintenance, and/or inspection.

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Table-5: Non-Structural BMP Maintenance Responsibility/Frequency Matrix

BMP RESPONSIBILITY FREQUENCY
Homeowner/
Business owner
Education,
Activity
Restrictions
HOA will provide
educational materials.

Those materials and
responsibilities must be
passed onto subsequent
property owners.

Continuous. CC&Rs to be provided to
homeowners at the time they purchase the
property and updates provided by the HOA as
they occur.

Common Area
Landscape
Management
HOA will appoint a
landscape maintenance
contractor
Monthly during regular maintenance and use
with management guidelines for use of
fertilizers and pesticides.

Parking Areas
and Drive Aisle
Management
HOA
The Drives Aisles are to be swept on a routine
scheduled basis to facilitate the pickup of trash
and debris (plant or otherwise) and to remove
excessive oil, grease and build-up. During
sweeping, debris is to be removed from the
parking areas and drives and then scrubbed
and rinsed. This sweeping schedule will be at a
minimum occurrence of once a week and as
necessary to rid / reduce active pollutants from
the pavement areas. This maintenance
requirement will be listed in the Convent,
Conditions and Restrictions (CC&Rs) of this
project. These CC&Rs will be recorded to the
property at the County Recorder’s Office and
be included on the final Title report of these
properties.

Litter Control by
Sweeping
HOA
Weekly inspection of trash receptacles to
ensure that lids are closed and pick up any
excess trash on the ground, noting trash
disposal violations to the HOA for remediation.

Employee
Training HOA
Monthly for maintenance personnel and
employees to include the educational materials
contained in the approved LID.

Refer to Appendix E.

Common Area
Catch Basin
Inspection &
Cleaning
HOA will appoint a
landscape maintenance
contractor for common
areas and storm drain
facilities.

Inspect basins once a month. Clean debris and
silt in bottom of catch basins as needed.

Intensified on or about October 15th each year
or prior to the first 24-hour storm event,
whichever occurs first.

Item #6. Page 1398
Meeting Date: 9/24/2024 / Packet Page #: 1534
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Brandywine Homes Section 400
September 2023 15
Table-6: Structural BMP Maintenance Responsibility/ Frequency Matrix

BMP RESPONSIBILITY FREQUENCY
Common Area
Efficient Irrigation
HOA will appoint a
landscape
contractor after
construction
Once a week, in conjunction with maintenance
activities. Verify that runoff minimizing landscape
design continues to function by checking that
water sensors are functioning properly, that
irrigation heads are adjusted properly to eliminate
overspray to hardscape areas, and to verify that
irrigation timing and cycle lengths are adjusted in
accordance with water demands, given time of
year, weather and day or night time temperatures.

Common Area
Runoff Efficient
Landscape
Design
HOA will appoint a
landscaping
contractor
Once a week in conjunction with maintenance
activities and prior to finalizing any replanting
schemes. Verify that plants continue to be
grouped according to similar water requirements
in order to reduce excess irrigation runoff.

Infiltration Trench HOA
Infiltration Trench maintenance will conform to
pipe manufacturer’s specifications. Additional
information to be provided during final engineering
in Appendix C.

Drain Inserts HOA
Drain inserts maintenance will conform to
manufacturer’s specifications. Additional
information to be provided during final engineering
in Appendix C.

Item #6. Page 1399
Meeting Date: 9/24/2024 / Packet Page #: 1535
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Brandywine Homes Section 400
September 2023 16
L. Operation/Maintenance Funding after Project Completion The post-construction BMPs as described above will be funded and maintained by:

Chris Courtney
Brandywine Homes
16580 Aston
Irvine, CA 92606
Maintenance and requirements of the maintenance for the properties will be listed in the Convent, Conditions and Restrictions (CC&Rs) of this project and will be the responsibility of the property owner at all times. These CC&Rs will be recorded to the property at the County Recorder’s Office and be included on the Title report of these properties.

Item #6. Page 1400
Meeting Date: 9/24/2024 / Packet Page #: 1536
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Figure 1:

BMP Exhibit
Item #6. Page 1401
Meeting Date: 9/24/2024 / Packet Page #: 1537
0 P
Item #6. Page 1402
Meeting Date: 9/24/2024 / Packet Page #: 1538
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Figure 2:

Impaired Waters
Item #6. Page 1403
Meeting Date: 9/24/2024 / Packet Page #: 1539

PROJECT SITE

LOCATION
ENTERS

EXISTING

CATCH BASIN

LOS ANGELES COUNTY
INLETS

FLOOD DISTRICT
54-INCH REINFORCED

CONCRETE PIPE
SOURCE:

SURFACE FLOW
Item #6. Page 1404
Meeting Date: 9/24/2024 / Packet Page #: 1540
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REF: \\pwgisd02\mpmgis$\MPMGIS\projects\mpm\gismaps\wk_2627\SanGabrielRiver_wtrshed.mxd DATE: 08/21/07 Data contained in this map is produced in whole
or part from the Los Angeles County Department
of Public Works' digital database.
0 0.875 1.75 3.5
I
MILES
Mapping & Property Management Division, Mapping & GIS Services Section LEGEND

SAN GABRIEL RIVER WATERSHED

UNINCORPORATED AREA

DAM / LAKE / RESERVOIR

MAJOR RIVER

MAJOR CHANNEL

COUNTY OF LOS ANGELES

SAN GABRIEL RIVER WATERSHED
Proposed
Project Site
Item #6. Page 1405
Meeting Date: 9/24/2024 / Packet Page #: 1541
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix A:

Volume and Flowrate Calculations & Hydrologic Report
The proposed development was analyzed for the 85th Percentile storm event using the LACDPW HydroCalc software. The governing design storm event is determined to be 85 th
percentile as it is greater than the 0.75 in storm event in accordance with the LA County BMP Design Manual. Below is a summary of the HydroCalc outputs:
85th Percentile Storm Event

1.00 in
DMA
85 th Percentile Storm ✓
Volume (cf) Flowrate (cfs)
A-1 0.4335 5,248.1122
Refer to LACDPW HydroCalc Output Data within this Appendix for Volume and Flowrate Calculations.

Item #6. Page 1406
Meeting Date: 9/24/2024 / Packet Page #: 1542
Peak Flow Hydrologic Analysis
File location: P:/B/BWHX-047/Admin/Reports/Hydrology/Preliminary/Appendix B - Hydrology/BWHX-047 Report.pdf Version: HydroCalc 1.0.3
Input Parameters
Project Name BWHX-047_LID
Subarea ID A-1
Area (ac) 1.85
Flow Path Length (ft) 478.0
Flow Path Slope (vft/hft) 0.0192

0.75-inch Rainfall Depth (in) 0.75
Percent Impervious 0.86
Soil Type 7
Design Storm Frequency 0.75 inch storm
Fire Factor 0
LID True
Output Results
Modeled (0.75 inch storm) Rainfall Depth (in) 0.75
Peak Intensity (in/hr) 0.2026
Undeveloped Runoff Coefficient (Cu) 0.1
Developed Runoff Coefficient (Cd) 0.788
Time of Concentration (min) 27.0
Clear Peak Flow Rate (cfs) 0.2953
Burned Peak Flow Rate (cfs) 0.2953
24-Hr Clear Runoff Volume (ac-ft) 0.0904
24-Hr Clear Runoff Volume (cu-ft) 3936.0965
Item #6. Page 1407
Meeting Date: 9/24/2024 / Packet Page #: 1543
Peak Flow Hydrologic Analysis
File location: P:/B/BWHX-047/Admin/Reports/Hydrology/Preliminary/Appendix B - Hydrology/BWHX-047 Report.pdf Version: HydroCalc 1.0.3
Input Parameters
Project Name BWHX-047_LID
Subarea ID A-1
Area (ac) 1.85
Flow Path Length (ft) 478.0
Flow Path Slope (vft/hft) 0.0192
85th Percentile Rainfall Depth (in) 1.0
Percent Impervious 0.86
Soil Type 7
Design Storm Frequency 85th percentile storm
Fire Factor 0
LID True
Output Results
Modeled (85th percentile storm) Rainfall Depth (in) 1.0 Peak Intensity (in/hr) 0.2974
Undeveloped Runoff Coefficient (Cu) 0.1
Developed Runoff Coefficient (Cd) 0.788
Time of Concentration (min) 22.0
Clear Peak Flow Rate (cfs) 0.4335
Burned Peak Flow Rate (cfs) 0.4335
24-Hr Clear Runoff Volume (ac-ft) 0.1205
24-Hr Clear Runoff Volume (cu-ft) 5248.1122
Item #6. Page 1408
Meeting Date: 9/24/2024 / Packet Page #: 1544
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix B:

Site BMPs
Item #6. Page 1409
Meeting Date: 9/24/2024 / Packet Page #: 1545
County of Los Angeles D-1 February 2014
S-1: Storm Drain Message and Signage
Purpose
Waste material dumped into storm drain inlets can adversely impact surface and ground waters. In fact, any material discharged into the storm drain system has the potential to significantly impact downstream receiving waters. Storm drain messages have become a popular method of alerting and reminding the public about the effects of and the prohibitions against waste disposal into the storm drain system. The signs are typically stenciled or affixed near the storm drain inlet or catch basin. The message simply informs the public that dumping of wastes into storm drain inlets is prohibited and/or that the drain ultimately discharges into receiving waters.

General Guidance
 The signs must be placed so they are easily visible to the public.  Be aware that signs placed on sidewalk will be worn by foot traffic.

Design Specifications
 Signs with language and/or graphical icons that prohibit illegal dumping, must be posted at designated public access points along channels and streams within the project area. Consult with Los Angeles County Department of Public Works (LACDPW) staff to determine specific signage requirements for channels and streams.
 Storm drain message markers, placards, concrete stamps, or stenciled language/icons (e.g., “No Dumping – Drains to the Ocean”) are required at all storm drain inlets and catch basins within the project area to discourage illegal or inadvertent dumping. Signs should be placed in clear sight facing anyone approaching the storm drain inlet or catch basin from either side (see Figure D-1 and Figure D-2). LACDPW staff should be contacted to determine specific requirements for types of signs and methods of application. A stencil can be purchased for a nominal fee from LACDPW Building and Safety Office by calling (626) 458-3171. All storm drain inlet and catch basin locations must be identified on the project site map.

Maintenance Requirements
Legibility and visibility of markers and signs should be maintained (e.g., signs should be repainted or replaced as necessary). If required by LACDPW, the owner/operator or homeowner’s association shall enter into a maintenance agreement with the agency or record a deed restriction upon the property title to maintain the legibility of placards and signs.

Item #6. Page 1410
Meeting Date: 9/24/2024 / Packet Page #: 1546
S-1: Storm Drain Message and Signage
County of Los Angeles D-2 February 2014
Figure D-1. Storm Drain Message Location – Curb Type Inlet Figure D-2. Storm Drain Message Location – Catch Basin/Area Type Inlet

CONCRETE

PERIMETER
Item #6. Page 1411
Meeting Date: 9/24/2024 / Packet Page #: 1547
County of Los Angeles D-19 February 2014
S-8: Landscape Irrigation Practices
Purpose
Irrigation runoff provides a pathway for pollutants (i.e., nutrients, bacteria, organics, sediment) to enter the storm drain system. By effectively irrigating, less runoff is produced resulting in less potential for pollutants to enter the storm drain system.

General Guidance
 Do not allow irrigation runoff from the landscaped area to drain directly to storm drain system.
 Minimize use of fertilizer, pesticides, and herbicides on landscaped areas.  Plan sites with sufficient landscaped area and dispersal capacity (e.g., ability to receive irrigation water without generating runoff).
 Consult a landscape professional regarding appropriate plants, fertilizer, mulching applications, and irrigation requirements (if any) to ensure healthy vegetation growth.

Design Specifications
 Choose plants that minimize the need for fertilizer and pesticides.  Group plants with similar water requirements and water accordingly.  Use mulch to minimize evaporation and erosion.
 Include a vegetative boundary around project site to act as a filter.  Design the irrigation system to only water areas that need it.  Install an approved subsurface drip, pop-up, or other irrigation system.1The irrigation system should employ effective energy dissipation and uniform flow spreading methods to prevent erosion and facilitate efficient dispersion.  Install rain sensors to shut off the irrigation system during and after storm events.  Include pressure sensors to shut off flow-through system in case of sudden pressure drop. A sudden pressure drop may indicate a broken irrigation head or water line.
 If the hydraulic conductivity in the soil is not sufficient for the necessary water application rate, implement soil amendments to avoid potential geotechnical hazards (i.e., liquefaction, landslide, collapsible soils, and expansive soils). 1 If alternative distribution systems (e.g., spray irrigation) are approved, the County will establish guidelines to implement these new systems.

Item #6. Page 1412
Meeting Date: 9/24/2024 / Packet Page #: 1548
S-8: Landscape Irrigation Practices
County of Los Angeles D-20 February 2014
 For sites located on or within 50 feet of a steep slope (15% or greater), do not irrigate landscape within three days of a storm event to avoid potential geotechnical instability.2
 Implement Integrated Pest Management practices.

For additional guidelines and requirements, refer to the Los Angeles County Department of Health Services.

Maintenance Requirements
Maintain irrigation areas to remove trash and debris and loose vegetation. Rehabilitate areas of bare soil. If a rain or pressure sensor is installed, it should be checked periodically to ensure proper function. Inspect and maintain irrigation equipment and components to ensure proper functionality. Clean equipment as necessary to prevent algae growth and vector breeding. Maintenance agreements between LACDPW and the owner/operator may be required. Failure to properly maintain building and property may subject the property owner to citation.
2 As determined by the City of Los Angeles, Building and Safety Division Item #6. Page 1413
Meeting Date: 9/24/2024 / Packet Page #: 1549
County of Los Angeles D-21 February 2014
S-9: Building Materials Selection
Purpose
Building materials can potentially contribute pollutants of concern to stormwater runoff through leaching. For example, metal buildings, roofing, and fencing materials may be significant sources of metals in stormwater runoff, especially due to acidic precipitation.

The use of alternative building materials can reduce pollutant sources in stormwater runoff by eliminating compounds that can leach into stormwater runoff. Alternative building materials may also reduce the need to perform maintenance activities (i.e., painting) that involve pollutants of concern, and may reduce the volume of stormwater runoff. Alternative materials are available to replace lumber and paving.

Design Specifications
Lumber
Decks and other house components constructed using pressure-treated wood that is typically treated using arsenate, copper, and chromium compounds are hazardous to the environment. Pressure-treated wood may be replaced with cement-fiber or vinyl.

Roofs, Fencing, and Metals
Minimizing the use of copper and galvanized (zinc-coated) metals on buildings and fencing can reduce leaching of these pollutants into stormwater runoff. The following building materials are conventionally made of galvanized metals:
 Metal roofs;
 Chain-link fencing and siding; and
 Metal downspouts, vents, flashing, and trim on roofs.

Architectural use of copper for roofs and gutters should be avoided. As an alternative to copper and galvanized materials, coated metal products are available for both roofing and gutter application. Vinyl-coated fencing is an alternative to traditional galvanized chain-link fences. These products eliminate contact of bare metal with precipitation or stormwater runoff, and reduce the potential for stormwater runoff contamination.

Roofing materials are also made of recycled rubber and plastic.

Green roofs may be an option. Green roofs use vegetation such as grasses and other plants as an exterior surface. The plants reduce the velocity of stormwater runoff and absorb water to reduce the volume of stormwater runoff. One potential problem with using green roofs in the Los Angeles County area is the long, hot and dry summers, which may kill the plants if they are not watered. See the Green Roof Fact Sheet (RET7) in Appendix E.

Item #6. Page 1414
Meeting Date: 9/24/2024 / Packet Page #: 1550
S-9: Building Materials Selection
County of Los Angeles D-22 February 2014
Pesticides
The use of pesticides around foundations can be reduced through the use of alternative barriers. Sand barriers can be applied around foundations to deter termites, as they cannot tunnel through sand. Metal shields also block termites from tunneling.

Additionally, diatomaceous earth can be used to repel or kill a wide variety of other pests.

Maintenance Requirements
The integrity of structural elements that are subject to damage (e.g., signs) must be maintained by the owner/operator as required by local codes and ordinances.

Maintenance agreements between LACDPW and the owner/operator may be required.

Failure to properly maintain building and property may subject the property owner to citation.

Item #6. Page 1415
Meeting Date: 9/24/2024 / Packet Page #: 1551
Street Sweeping and Vacuuming SE-7
Categories
EC Erosion Control
SE Sediment Control :

TC Tracking Control ;
WE Wind Erosion Control
NS Non-Stormwater
Management Control
WM Waste Management and
Materials Pollution Control
Legend:
; Primary Objective
: Secondary Objective
Targeted Constituents
Sediment ;
Nutrients
Trash ;
Metals
Bacteria
Oil and Grease ;
Organics
Potential Alternatives
None
Description and Purpose
Street sweeping and vacuuming includes use of self-propelled and walk-behind equipment to remove sediment from streets and roadways, and to clean paved surfaces in preparation for final paving. Sweeping and vacuuming prevents sediment from the project site from entering storm drains or receiving waters.

Suitable Applications
Sweeping and vacuuming are suitable anywhere sediment is tracked from the project site onto public or private paved streets and roads, typically at points of egress. Sweeping and vacuuming are also applicable during preparation of paved surfaces for final paving.

Limitations
Sweeping and vacuuming may not be effective when sediment is wet or when tracked soil is caked (caked soil may need to be scraped loose).

Implementation
Controlling the number of points where vehicles can leave the site will allow sweeping and vacuuming efforts to be focused, and perhaps save money.
Inspect potential sediment tracking locations daily.
Visible sediment tracking should be swept or vacuumed on a daily basis.
Do not use kick brooms or sweeper attachments. These
tend to spread the dirt rather than remove it.

November 2009 California Stormwater BMP Handbook 1 of 2 Construction
www.casqa.org
Item #6. Page 1416
Meeting Date: 9/24/2024 / Packet Page #: 1552
Street Sweeping and Vacuuming SE-7
November 2009 California Stormwater BMP Handbook 2 of 2 Construction
www.casqa.org
If not mixed with debris or trash, consider incorporating the removed sediment back into the project
Costs
Rental rates for self-propelled sweepers vary depending on hopper size and duration of rental.

Expect rental rates from $58/hour (3 yd3 hopper) to $88/hour (9 yd3 hopper), plus operator costs. Hourly production rates vary with the amount of area to be swept and amount of sediment. Match the hopper size to the area and expect sediment load to minimize time spent dumping.

Inspection and Maintenance
Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. When actively in use, points of ingress and egress must be inspected daily. When tracked or spilled sediment is observed outside the construction limits, it must be removed at least daily. More frequent removal, even continuous removal, may be required in some jurisdictions.
Be careful not to sweep up any unknown substance or any object that may be potentially hazardous.
Adjust brooms frequently; maximize efficiency of sweeping operations. After sweeping is finished, properly dispose of sweeper wastes at an approved dumpsite.

References
Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000.

Labor Surcharge and Equipment Rental Rates, State of California Department of Transportation (Caltrans), April 1, 2002 – March 31, 2003.

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County of Los Angeles E-23 February 2014
RET-3: Infiltration Trench
Description
An infiltration trench is a narrow trench
constructed in naturally pervious soils
designed for retaining and infiltrating
stormwater runoff into the underlying native
soils and groundwater table. Infiltration
trenches are typically filled with gravel and
sand, although use of manufactured
percolation tank modules may be
considered in place of gravel fill. Infiltration
trenches provide stormwater runoff
treatment through a variety of natural
mechanisms (i.e., filtration, adsorption,
biological degradation) as water flows through the soil profile.

Infiltration trenches differ from infiltration basins in that the former are used for small drainage areas and stores stormwater runoff out of sight underground within the void spaces of rocks or stones or percolation tank modules. Infiltration basins are used for larger drainage areas and stormwater is stored within a visible ponded surface.

Infiltration vaults and infiltration leach fields are subsurface variations of the infiltration trench concept in which stormwater runoff is distributed to the upper zone of the subsurface gravel bed by means of perforated pipes.

A schematic of a typical infiltration trench is presented in Figure E-3.

LID Ordinance Requirements
Infiltration trenches can be used to meet the on-site retention requirements of the LID Ordinance. Infiltration trenches will prevent pollutants in the SWQDv from being discharged off-site.

Advantages
· Reduces or eliminates stormwater runoff discharge to receiving water for most storm events
· Reduces peak stormwater runoff, which provides erosion control · Provides groundwater recharge
· Provides effective treatment through settling and filtering while requiring relatively small space.
· Fits in narrow areas and unused areas of a development site. · Is suitable for use when water is not available for irrigation or base flow.

Source: Washington County
Item #6. Page 1429
Meeting Date: 9/24/2024 / Packet Page #: 1565
RET-3: Infiltration Trench
County of Los Angeles E-24 February 2014
Figure E-3. Infiltration Trench Schematic
Item #6. Page 1430
Meeting Date: 9/24/2024 / Packet Page #: 1566
RET-3: Infiltration Trench
County of Los Angeles E-25 February 2014
Disadvantages
· Is not appropriate for areas with too low or too high permeability soils · May not be appropriate for industrial sites or locations with contaminated soils or where spills may occur because of the potential threat to groundwater contamination
· Must be protected from high sediment loads
· May result in standing water, which may allow vector breeding · Is not appropriate on fill or sites with steep slopes General Constraints and Implementation Considerations
· Infiltration trenches can be integrated into open space buffers and other landscape areas.
· The potential for groundwater contamination must be carefully considered,.

Infiltration trenches are not suitable for sites that:
o Use or store chemicals or hazardous materials, unless they are prevented from entering the trench; or
o Un-remediated “brownfield sites” where there is known groundwater or soil contamination.
· Infiltration trenches should be sited away from tree drip lines and kept free of vegetation.
· If the corrected in-situ infiltration rate exceed 2.4 in/hr, then stormwater runoff may need to be fully-treated with an upstream stormwater quality control measure prior to infiltration to protect groundwater quality. · Infiltration trenches cannot be located on sites with a slope greater than 15 percent.
· Pretreatment to remove sediment is required to protect infiltration trench from high sediment loads.
· If possible, the entire tributary area of the infiltration trench should be stabilized before construction begins. If this is not possible, all flows should be diverted around the infiltration trench to protect it from sediment loads during construction or the top two inches of soil from the infiltration trench floor should be removed after the site has been stabilized. Excavated material should be stored such that it cannot be washed back into the infiltration trench if a storm occurs during construction.
· The equipment used to construct the infiltration trench should have extra wide low-pressure tires. Construction traffic should not enter the infiltration trench because it can compact soil, which reduces infiltration capacity. If heavy equipment is used on the base of the infiltration trench, the infiltrative capacity may be restored by tilling or aerating prior to placing the infiltrative bed.

Item #6. Page 1431
Meeting Date: 9/24/2024 / Packet Page #: 1567
RET-3: Infiltration Trench
County of Los Angeles E-26 February 2014
· Clean, washed gravel should be placed in the excavated trench in lifts and lightly compacted with a plate compactor. Use of unwashed gravel can result in clogging.
· A geomembrane liner should be installed generously with overlapping seams on sides, bottom, and one foot below the surface of the infiltration trench. · After construction is completed, the entire tributary area of the infiltration trench should be stabilized before allowing stormwater runoff to enter it. · An observation well must be installed to check water levels, detention time, and evidence of clogging. An access road along the entire length of the infiltration trench is required unless it is located along an existing road or parking lot that can be safely used for maintenance access.

Design Specifications
The following sections provide design specifications for infiltration trenches.

Geotechnical
Due to the potential to contaminate groundwater, cause slope instability, impact surrounding structures, and potential for insufficient infiltration capacity, an extensive geotechnical site investigation must be conducted during the site planning process to verify site suitability for an infiltration trench. All geotechnical investigations must be performed according to the most recent GMED Policy GS 200.1. Soil infiltration rates and the groundwater table depth must be evaluated to ensure that conditions are satisfactory for proper operation of an infiltration trench. The project applicant must demonstrate through infiltration testing, soil logs, and the written opinion of a licensed civil engineer that sufficiently permeable soils exist on-site to allow the construction of a properly functioning infiltration trench.

Infiltration trenches are appropriate for soils with a minimum corrected in-situ infiltration rate of 0.3 in/hr. The geotechnical report must determine if the proposed project site is suitable for an infiltration trench and must recommend a design infiltration rate (see “Design Infiltration Rate” under the “Sizing” section). The geotechnical investigation should be such that a good understanding is gained as to how the stormwater runoff will move through the soil (horizontally or vertically) and if there are any geological conditions that could inhibit the movement of water.

Pretreatment
Pretreatment is important for all structural stormwater quality control measures, but it is particularly important for retention facilities. Pretreatment refers to design features that provide settling of large particles before stormwater runoff enters a stormwater quality control measure in order to reduce the long-term maintenance burden. Pretreatment should be provided to reduce the sediment load entering an infiltration trench in order to maintain the infiltration rate of the infiltration trench. To ensure that infiltration trenches are effective, the project applicant must incorporate pretreatment devices that provide Item #6. Page 1432
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RET-3: Infiltration Trench
County of Los Angeles E-27 February 2014
sediment reduction (e.g., vegetated swales, vegetated filter strips, sedimentation manholes, and proprietary devices).

Setbacks
Infiltration trenches must be sited following the setbacks from the most recent GMED Policy GS 200.1.

Geometry
· Infiltration trenches must be designed and constructed to be at least 24 inches wide and 3 to 5 feet deep.
· The longitudinal slope of the trench should not exceed three percent. · The filter bed media layers must have the following composition and thickness:
o Top layer: 2 inches of pea gravel
o Middle layer: 3 to 5 feet of washed 2- to 6-inch gravel; void spaces should be approximately 30 to 40 percent
o Bottom layer: 6 inches of sand or geomembrane liner equivalent.

Sizing
Infiltration trenches are sized a simple sizing method where the SWQDv must be completely infiltrated within 96 hours. Infiltration trenches provide stormwater runoff storage in the voids of the rock fill or percolation tank modules.

Step 1: Determine the SWQDv
Infiltration trenches must be designed to capture and retain the SWQDv (see Section 6 for SWQDv calculation procedures).

Step 2: Determine the design infiltration rate
Determine the corrected in-situ infiltration rate (fdesign) of the native soil using the procedures described in the most recent GMED Policy GS 200.1.

Step 3: Calculate the surface area
Determine the size of the required infiltration surface by assuming the SWQDv will fill the available void spaces of the gravel storage layer. The maximum depth of stormwater runoff that can be infiltrated within the maximum retention time (96 hrs) is calculated using the following equation:
=

12 ×

Item #6. Page 1433
Meeting Date: 9/24/2024 / Packet Page #: 1569
RET-3: Infiltration Trench
County of Los Angeles E-28 February 2014
Where:
dmax = Maximum depth of water that can be infiltrated within the maximum retention time [ft];
fdesign = Design infiltration rate [in/hr]; and
t = Maximum retention time (max 96 hrs) [hr].

Select the infiltration trench depth (dt) such that:
≤

Where:
dt = Depth of infiltration trench [ft];
dmax = Maximum depth of water that can be infiltrated within the maximum retention time [ft]; and
nt = Infiltration trench fill porosity.

Calculate the infiltrating surface area (bottom of the infiltration trench) required:
=

×
Where:

A = Surface area of the bottom of the infiltration trench [ft2 ];
SWQDv = Stormwater quality design volume [ft3
];
dt = Depth of infiltration trench fill [ft]; and
nt = Infiltration trench porosity.

Flow Entrance and Energy Dissipation
Energy dissipation controls, constructed of sound materials such as stones, concrete, or proprietary devices that are rated to withstand the energy of the influent flow, must be installed at the inlet to the infiltration trench. Flow velocity at the inlet must be 4 ft/s or less. Consult with LACDPW for the type and design of energy dissipation structure.

Drainage
The specifications for designing drainage systems for infiltration trenches are presented below:
· The bottom of infiltration trench must be native soil that is over-excavated at least one foot in depth with the soil replaced uniformly without compaction. Amending the excavated soil with two to four inches (~15 to 30 percent) of coarse sand is recommended.

Item #6. Page 1434
Meeting Date: 9/24/2024 / Packet Page #: 1570
RET-3: Infiltration Trench
County of Los Angeles E-29 February 2014
· The use of vertical piping, either for distribution or infiltration enhancement, is prohibited. This application may be classified as a Class V Injection Well per 40 CFR Part 146.5(e)(4).
· The infiltration capacity of the subsurface layers should be sufficient to ensure a maximum detention time of 96 hours. An observation well must be installed to allow observation of detention time.

Hydraulic Restriction Layer
The entire infiltrative area, including the side slopes must lined with a geomembrane liner to prevent soil from migrating into the top layer and reducing the infiltration capacity. The specifications of the geomembrane liner are presented in Table E-5. The entire trench area, including the sides, must be lined with a geomembrane liner prior to placing the media bed. Provide generous overlap at the seams.

Table E-5. Geomembrane Liner Specifications for Infiltration Trenches Parameter Test Method Specifications
Material Nonwoven geomembrane liner
Unit weight 8 oz/yd3 (minimum)
Filtration rate 0.08 in/sec (minimum)
Puncture strength ASTM D-751 (Modified) 125 lbs (minimum) Mullen burst strength ASTM D-751 400 lb/in2 (minimum)
Tensile strength AST D-1682 300 lbs (minimum)
Equiv. opening size US Standard Sieve No. 80 (minimum)
Observation Well
The observation well is a vertical section of perforated PVC pipe, four- to six-inch diameter, installed flush with the top of the infiltration trench on a footplate and with a locking, removable cap. The observation well is needed to monitor the infiltration rate in infiltration trench and is useful for marking the location of the infiltration trench.

Vegetation
· Infiltration trenches must be kept free of vegetation. · Trees and other large vegetation should be planted away from infiltration trenches such that drip lines do not overhang the infiltration area.

Restricted Construction Materials
Use of pressure-treated wood or galvanized metal at or around an infiltration trench is prohibited.

Item #6. Page 1435
Meeting Date: 9/24/2024 / Packet Page #: 1571
RET-3: Infiltration Trench
County of Los Angeles E-30 February 2014
Overflow Device
An overflow device must be provided in the event that stormwater runoff overtops the infiltration trench or if the infiltration trench becomes clogged. The overflow device must be able to convey stormwater runoff to a downstream conveyance system or other acceptable discharge point.

Maintenance Access
The infiltration trench must be safely accessible during wet and dry weather conditions if it is publicly-maintained. An access road along the entire length of the infiltration trench is required unless the trench is located along an existing road or parking lot that can be safely used for maintenance access. If the infiltration trench becomes plugged and fails, access is needed to excavate the infiltration trench and replace the filter bed media. All dimensions of the infiltration trench should also be increased by two inches to provide a fresh surface for infiltration. To prevent damage and compaction, access must able to accommodate a backhoe working at “arm’s length” from the infiltration trench.

Maintenance Requirements
Maintenance and regular inspections are important for proper function of infiltration trenches. The following are general maintenance requirements:
· Conduct regular inspection and routine maintenance for pretreatment devices. · Inspect infiltration trench and its observation well frequently to ensure that water infiltrates into the subsurface completely within the maximum detention time of 96 hours. If water is present in the observation well more than 96 hours after a major storm, the infiltration trench may be clogged. Maintenance activities triggered by a potentially clogged facility include:
o Check for debris/sediment accumulation, rake surface and remove sediment (if any), and evaluate potential sources of sediment and vegetative or other debris (i.e., embankment erosion, channel scour, overhanging trees). If suspected upstream sources are outside of the County's jurisdiction, additional pretreatment (i.e., trash racks, vegetated swales) may be necessary.
o Assess the condition of the top aggregate layer for sediment buildup and crusting. Remove the top layer of pea gravel and replace. If slow draining conditions persist, the entire infiltration trench may need to be excavated and replaced.
· Eliminate standing water to prevent vector breeding.
· Inspect infiltration trenches annually. Remove and dispose of trash and debris as needed, but at least prior to the beginning of the wet season. · Inspect overflow devices for obstructions or debris, which should be removed immediately. Repair or replace damaged pipes upon discovery.

Item #6. Page 1436
Meeting Date: 9/24/2024 / Packet Page #: 1572
RET-3: Infiltration Trench
County of Los Angeles E-31 February 2014
A summary of potential problems that may need to be addressed by maintenance activities is presented in Table E-6.

The County requires execution of a maintenance agreement to be recorded by the property owner for the on-going maintenance of any privately-maintained stormwater quality control measures. The property owner is responsible for compliance with the maintenance agreement. A sample maintenance agreement is presented in Appendix H.

Table E-6. Infiltration Trench Troubleshooting Summary
Problem Conditions When Maintenance Is
Needed Maintenance Required
Trash and Debris Trash and debris > 5 ft3/1,000 ft2 Remove and dispose of trash and debris.

Contaminants and Pollution Any evidence of oil, gasoline, contaminants, or other pollutants
Remove any evidence of visual
contamination.

Erosion/Sediment
Accumulation
Undercut or eroded areas at inlet
structures
Repair eroded areas and regrade if necessary.

Accumulation of sediment, debris,
and oil/grease in pretreatment
devices
Remove sediment, debris, and/or
oil/grease.

Accumulation of sediment, debris,
and oil/grease on surface, inlet or
overflow structures
Remove sediment, debris, and/or
oil/grease.

Water Drainage Rate Standing water, or by inspection of observation wells
Remove the top layer of the
infiltration trench bottom and
replace if necessary.

Item #6. Page 1437
Meeting Date: 9/24/2024 / Packet Page #: 1573

TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-78 December 20, 2013
PRE-2: Catch Basin Insert Fact Sheet
Catch basin inserts are manufactured filters or fabric placed in a drop inlet to remove sediment and debris and may include sorbent media (oil absorbent pouches) to remove floating oils and grease. Catch basin inserts are selected specifically based upon the orientation of the inlet and the expected sediment and debris loading.

Opportunity Criteria
x Catch basin inserts come in such a wide range of
configurations that it is practically impossible to generalize the expected performance. Inserts should mainly be used for catching coarse sediments and floatable trash and are
effective as pretreatment in combination with other types of structures that are recognized as water quality treatment BMPs. Trash and large objects can greatly reduce the effectiveness of catch basin inserts with respect to sediment and hydrocarbon capture.
x Catch basin inserts are applicable for drainage area that include parking lots, vehicle maintenance areas, and roadways with catch basins that discharge directly to a receiving water.

OC-Specific Design Criteria and Considerations
□ Frequent maintenance and the use of screens and grates to keep trash out may decrease the likelihood of clogging and prevent obstruction and bypass of incoming flows. □ Consult proprietors for specific criteria concerning the design of catch basin inserts. □ Catch basin inserts can be installed with specific media for pollutants of concern.

Proprietary Manufacturer / Supplier Websites
x Table XIV.2 is a list of manufacturers that provide catch basin inserts. The inclusion of these manufacturers does not represent an endorse of their products. Other devices and manufacturers may be acceptable for pretreatment.

Table XIV.2: Proprietary Catch Basin Insert Manufacturer Websites Device Manufacturer Website
AbTech Industries UltraUrban Filter™ AbTech Industries www.abtechindustries.com Aquashield AquaGuardian™ Catch Basin
Insert
Aquashield™ Inc. www.aquashieldinc.com
Bowhead StreamGuard™ Bowhead Environmental & Safety,
Inc. http://www.shopbowhead.com/
Contech® Triton Catch
Basin Filter™
Contech® Construction Products
Inc. www.contech-cpi.com
Contech® Triton Curb Inlet
Filter™
Contech® Construction Products
Inc. www.contech-cpi.com
Also known as:
¾ Drop Inlet Filters
¾ Catch Basin Filters
Catch Basin Insert (DrainPac™)
Item #6. Page 1438
Meeting Date: 9/24/2024 / Packet Page #: 1574

TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-79 December 20, 2013
Table XIV.2: Proprietary Catch Basin Insert Manufacturer Websites Device Manufacturer Website
Contech® Triton Basin
StormFilter™
Contech® Construction Products
Inc. www.contech-cpi.com
Contech® Curb Inlet
StormFilter™
Contech® Construction Products
Inc. www.contech-cpi.com
Curb Inlet Basket SunTree Technologies Inc. www.suntreetech.com Curb Inlet Grates EcoSense International™ http://www.ecosenseint.com/ DrainPacTM United Storm Water, Inc. http://www.unitedstormwater.com Grate Inlet Skimmer Box SunTree Technologies Inc. www.suntreetech.com KriStar FloGard+PLUS® KriStar Enterprises Inc. www.kristar.com KriStar FloGard® KriStar Enterprises Inc. www.kristar.com KriStar FloGard LoPro
Matrix Filter® KriStar Enterprises Inc. www.kristar.com Nyloplast Storm-PURE
Catch Basin Insert
Nyloplast Engineered Surface
Drainage Products www.nyloplast-us.com
StormBasin® FabCo® Industries Inc. www.fabco-industries.com Stormdrain Solutions
Interceptor FabCo®
Industries Inc. www.fabco-industries.com
Stormdrain Solutions
Inceptor® Stormdrain Solutions www.stormdrains.com
StormPod® FabCo® Industries Inc. www.fabco-industries.com Stormwater Filtration
Systems EcoSense International™ http://www.ecosenseint.com/ Ultra-CurbGuard® UltraTech International Inc. www.spillcontainment.com Ultra-DrainGuard® UltraTech International Inc. www.spillcontainment.com Ultra-GrateGuard® UltraTech International Inc. www.spillcontainment.com Ultra-GutterGuard® UltraTech International Inc. www.spillcontainment.com Ultra-InletGuard® UltraTech International Inc. www.spillcontainment.com Item #6. Page 1439
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Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix C:

Infiltration System Storage Analysis/ Treatment BMPs Details (Project specific details and treatment system detail to be provided prior to final approval.) Item #6. Page 1440
Meeting Date: 9/24/2024 / Packet Page #: 1576

INFILTRATION TRENCH VOLUME CALCULATIONS
Infiltration and Storage System Parameters:

VBMP = 5,248.1 cubic feet (cf)
KMEASURED = 13.4 and 10.8 inches per hour (in/hr), per Geotechnical Report prepared by ALTA California Geotechnical, Inc. dated June 22, 2023)
KDESIGN (design infiltration rate) = 4.03 in/hr (safety factor of 3 applied) nT (porosity of trench fill) = 0.40 (unitless)
dT (depth and width of trench fill) = 7 ft
dP (ponding trench fill depth below perforated pipe) = 1 ft SACF (Surface Area Correction Factor- 1.0 does not account for sides for conservativeness) = 1 Static Volume Calculation:
234 linear feet (lf) of 60-inch perforated pipes (trench length = 236 ft) 𝑉𝑝𝑖𝑝𝑒 = 𝜋 × (2.5 𝑓𝑡)
2 × (234𝑓𝑡) = 4,594.6 𝑐𝑓
𝑉𝑔𝑟𝑎𝑣𝑒𝑙 = (234 𝑓𝑡 + 2 𝑓𝑡) × (7 𝑓𝑡) × (1 𝑓𝑡) × 0.40 = 660.8 𝑐𝑓 ∑𝑉 = 4,594.6 𝑐𝑓 + 660.8 𝑐𝑓 = 5,255.4 𝑐𝑓;
Drawdown Calculation:

𝑆𝑢𝑟𝑓𝑎𝑐𝑒 𝐴𝑟𝑒𝑎 = (234 𝑓𝑡 + 2 𝑓𝑡) × (7 𝑓𝑡) = 1,652.0 𝑠𝑓
𝑉48−ℎ𝑟 = (
1 12) (4.03
𝑖𝑛
ℎ𝑟
) (1,652.0 𝑠𝑓)(48 ℎ𝑟𝑠) = 𝟐𝟔, 𝟔𝟓𝟐. 𝟑 𝒄𝒇 > 𝟓, 𝟐𝟒𝟖. 𝟏 𝒄𝒇✓
𝐷𝑟𝑎𝑤𝑑𝑜𝑤𝑛 𝑇𝑖𝑚𝑒 𝑜𝑓 𝐷𝐶𝑉 = (
1 12) (4.03
𝑖𝑛
ℎ𝑟
) (1,652.0 𝑠𝑓)(𝑥 ℎ𝑟𝑠) = 5,248.1 𝑐𝑓

𝟗. 𝟓 𝒉𝒓𝒔 < 𝟒𝟖 𝒉𝒓𝒔✓
Summary Table
(DMA) Required DCV (cf)
Underground Trench
with Perforated Pipe
Length (lf)
Provided Volume
in Pipe and
Trench Only
Required
DCV (cf)
Whole
Site 5,248.1 234 lf of 60-inch pipe 5,255.4 cft 7,923
The proposed underground infiltration trench can statically store 5,255.4 cubic feet of stormwater which ensures the required design capture volume of 5,248.1 cubic feet are fully infiltrated prior to any storm runoff exiting the project site. Per drawdown calculation above, the infiltration trench can infiltrate a total of 26,652.3 cubic feet within a 48-hour time period, hence, the required design capture volume will be infiltrated within the 48-hour period.

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Item #6. Page 1442
Meeting Date: 9/24/2024 / Packet Page #: 1578
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix D:

EPA Catch Basing Cleaning/ Stencil Examples
Item #6. Page 1443
Meeting Date: 9/24/2024 / Packet Page #: 1579
Item #6. Page 1444
Meeting Date: 9/24/2024 / Packet Page #: 1580
Item #6. Page 1445
Meeting Date: 9/24/2024 / Packet Page #: 1581
Item #6. Page 1446
Meeting Date: 9/24/2024 / Packet Page #: 1582
Sample Stencil 1
Item #6. Page 1447
Meeting Date: 9/24/2024 / Packet Page #: 1583
Sample Stencil 2
Item #6. Page 1448
Meeting Date: 9/24/2024 / Packet Page #: 1584
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix E:

General Education Materials
Item #6. Page 1449
Meeting Date: 9/24/2024 / Packet Page #: 1585
Swimming
Pool Tips
•Make sure all
chemicals are
dissipated before
draining a pool or
spa
•Do not drain pools
within 5 days of
adding chemicals
•Never backwash a
filter into the street
or stormdrain
•Cleanup chemical
spills with
absorbent, don’t
wash it down the
drain
•Dispose of leftover
chemicals and paints
through a licensed
hazardous waste
disposal provider
Follow these simple steps to
prevent stormwater pollution…
Stormdrains
take runoff
directly to creeks
and the ocean without treatment.

Pool chemicals can harm our
natural creeks and waterways.

Anything going into our
stormdrains that isn’t
rainwater contributes to
stormwater pollution, which
contaminates our creeks and
ocean, kills marine life and
causes beach closures.
...not pool chemicals
Storm Drains are
for Rain...

Item #6. Page 1450
Item #6. Page 1451
Meeting Date: 9/24/2024 / Packet Page #: 1587
A Yard is a Terrible
Thing to Waste!
Storm drains are for rain…not yard waste.

Residential yard waste represents about 13 percent
of the total waste generated in L.A. County.

Pesticides, fertilizer and yard waste such as leaves and mowed grass wash from the ground and streets into storm drains and flow straight to the ocean — untreated.

Remember to use pesticides and fertilizer
wisely and pick-up yard waste.

Item #6. Page 1452
Meeting Date: 9/24/2024 / Packet Page #: 1588
L.A. County residents can help solve the stormwater
pollution problem by taking these easy steps…
• Do not over-fertilize and do not use fertilizer or pesticides near ditches, gutters or storm drains.
• Do not use fertilizer or pesticides before a rain.
• Follow the directions on the label carefully.
• Use pesticides sparingly — more is not better.
“Spot” apply, rather than “blanket” apply.
• When watering your lawn, use the least amount of
water possible so it doesn’t run into the street carrying pesticides and other chemicals with it.
• Use non-toxic products for your garden and lawn
whenever possible.
• If you must store pesticides or fertilizer, make sure they are in a sealed, water-proof container in a
covered area to prevent runoff.
• Do not blow, sweep, hose or rake leaves or other
yard trimmings into the street, gutter or storm drain.

A message from the County of Los Angeles Department of Public Works.

Printed on recycled paper.

Item #6. Page 1453
Meeting Date: 9/24/2024 / Packet Page #: 1589
Item #6. Page 1454
Meeting Date: 9/24/2024 / Packet Page #: 1590
Don’t Paint the Town Red!
Storm drains are for rain…
they’re not for paint disposal.

More than 197,000 times each month, L.A. County residents wash their dirty paint brushes under an outdoor faucet.

This dirty rinse water flows into the street, down the
storm drain and straight to the ocean — untreated.

Remember to clean water-based paint brushes in the
sink, rinse oil-based paint brushes with paint thinner, and take old paint and paint-related products to a Household Hazardous Waste/E-Waste collection event.

Item #6. Page 1455
Meeting Date: 9/24/2024 / Packet Page #: 1591
L.A. County residents can help solve the stormwater
pollution problem by taking these easy steps when
working with paint and paint-related products…
• Never dispose of paint or paint-related products in the gutters or storm drains. This is called illegal dumping.

Take them to a Household Hazardous Waste/E-Waste
collection event. Call 1 (888) CLEAN LA or visit
www.888CleanLA.com to locate an event near you.
• Buy only what you need. Reuse leftover paint for
touch-ups or donate it to a local graffiti abatement
program. Recycle or use excess paint.
• Clean water-based paint brushes in the sink.
• Oil-based paints should be cleaned with paint thinner.

Filter and reuse paint thinner. Set the used thinner
aside in a closed jar to settle-out paint particles.
• Store paints and paint-related products in rigid,
durable and watertight containers with
tight-fitting covers.

A message from the County of Los Angeles Department of Public Works.

Printed on recycled paper.

Item #6. Page 1456
Meeting Date: 9/24/2024 / Packet Page #: 1592
Item #6. Page 1457
Meeting Date: 9/24/2024 / Packet Page #: 1593
Storm drains are for rain…
they’re not pooper scoopers.

L.A. County residents walk a dog without picking up
the droppings more than 62,000 times per month.

Disease-causing dog waste washes from the
ground and streets into storm drains and
flows straight to the ocean — untreated.

Remember to bring a bag and
clean up after your dog.

P ick Up After Your Pooch!
Item #6. Page 1458
Meeting Date: 9/24/2024 / Packet Page #: 1594
Dog owners can help solve the stormwater pollution
problem by taking these easy steps…
• Clean up after your dog every single time.
• Take advantage of the complimentary waste bags
offered in dispensers at local parks.
• Ensure you always have extra bags in your car so
you are prepared when you travel with your dog.
• Carry extra bags when walking your dog and make
them available to other pet owners who are without.
• Teach children how to properly clean up after a pet.

Encourage them to throw the used bags in the
nearest trash receptacle if they are away from home.
• Put a friendly message on the bulletin board at
the local dog park to remind pet owners to clean
up after their dogs.
• Tell friends and neighbors about the ill effects of
animal waste on the environment. Encourage
them to clean up after their pets as well.

Item #6. Page 1459
Meeting Date: 9/24/2024 / Packet Page #: 1595
Are You a Litter Bug
and Don’t Know It?
Take our quiz!
Have you ever...
• Dropped a cigarette butt or trash on the ground?
• Failed to pick up after your dog while out on a walk? • Overwatered your lawn after applying
fertilizers/pesticides?
• Disposed of used motor oil in the street,
gutter or garbage?
If you answered yes to any of these actions, then
YOU ARE A LITTER BUG!
Each of these behaviors contribute to stormwater
pollution, which contaminates our ocean and
waterways, kills marine life and causes beach closures.

You can become part of the solution!
To find out how, flip this card over.

For more information, call or visit:

Item #6. Page 1460
Meeting Date: 9/24/2024 / Packet Page #: 1596
• Put your garbage where it belongs — in the trash can. • Pick up after your dog when out on a walk.
• Reduce pesticide and fertilizer use; don’t overwater
after application or apply if rain is forecast.
• Dispose of used motor oil at an oil recycling center
or at a free Household Hazardous Waste/E-Waste
collection event.

A message from the County of Los Angeles Department of Public Works.

Printed on recycled paper.

Follow these simple steps to
prevent stormwater pollution:

Item #6. Page 1461
Meeting Date: 9/24/2024 / Packet Page #: 1597
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix F:

Operation and Maintenance Plan
(Operation and Maintenance Plan to be provided during Final Engineering) Item #6. Page 1462
Meeting Date: 9/24/2024 / Packet Page #: 1598
Preliminary Low Impact Development Plan
723-745 E. Route 66, City of Glendora
Appendix G:

Geotechnical Investigation
Item #6. Page 1463
Meeting Date: 9/24/2024 / Packet Page #: 1599
Corona Office
Phone: 951.509.7090
BRANDYWINE HOMESS June 22, 2023
16580 Aston Street Project No. 1‐0486
Irvine, CA 92606
Attention: Mr. Stephen Edwards
Subject: PRELIMINARY GEOTECHNICAL INVESTIGATION
APN: 8646‐029‐009 and ‐014
723‐731 East Route 66, City of Glendora
County of Los Angeles, California
References: See Appendix A
Dear Mr. Edwards:

Alta California Geotechnical, Inc. (Alta) is pleased to present this Preliminary Geotechnical Investigation for APN: 8646‐029‐009 and ‐014, located at 723‐731 East Route 66 in the City of Glendora, Los Angeles County, California. This report is based on Alta’s recent subsurface investigation, laboratory testing, engineering analyses, and a review of the referenced reports.

Alta’s review of the geotechnical data indicates that the proposed development is feasible, from a geotechnical perspective, provided that the recommendations presented in this report are incorporated into the grading and improvement plans and implemented during site development.

Included in this report are:
 Discussion of the site geotechnical conditions.
 Recommendations for remedial and site grading, including unsuitable soil removals.  Geotechnical site construction recommendations.
 Preliminary foundation design parameters.

Item #6. Page 1464
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Project Number 1‐0486 Page ii
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

If you have any questions or should you require any additional information, please contact the undersigned at (951) 509‐7090. Alta appreciates the opportunity to provide geotechnical consulting services for your project.

Sincerely,
Alta California Geotechnical, Inc. Reviewed By:
___________________________________
LOGAN A. MARQUETTE
Civil Engineering Associate
Project Manager
___________________________________
SCOTT A. GRAY/RGE 2857
Reg. Exp.: 12‐31‐24
Registered Geotechnical Engineer
President
________________________________
THOMAS J. MCCARTHY/CEG 2080
Reg. Exp.: 9‐30‐24
Certified Engineering Geologist
Vice President
Distribution: (1) Addressee
JBC:SAG 1‐0486, June 22, 2023 (Preliminary Geotechnical Investigation, Glendora)

Item #6. Page 1465
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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

TABLE OF CONTENTS

1.0 INTRODUCTION................................................................................................................. 1

1.1 Purpose ................................................................................................................. 1

1.2 Scope of Work ....................................................................................................... 1

1.3 Report Limitations................................................................................................. 2

2.0 PROJECT DESCRIPTION...................................................................................................... 2

2.1 Site Location and Existing Conditions.................................................................... 2

2.2 Proposed Development......................................................................................... 2

3.0 SITE INVESTIGATION.......................................................................................................... 3

3.1 Subsurface Investigation and Laboratory Testing.................................................. 3

3.2 Infiltration Testing ................................................................................................. 3

4.0 GEOLOGIC CONDITIONS .................................................................................................... 4

4.1 Geologic and Geomorphic Setting ......................................................................... 4

4.2 Stratigraphy........................................................................................................... 4

4.2.1 Undocumented Artificial Fill (Map symbol afu) ......................................... 4

4.2.2 Young Alluvial Fan Deposits (Map symbol Qyf).......................................... 5

4.3 Geologic Structure................................................................................................. 5

4.3.1 Tectonic Framework .................................................................................. 5

4.3.2 Regionally Mapped Active Faults............................................................... 6

4.3.3 Geologic Structure ..................................................................................... 6

4.4 Groundwater......................................................................................................... 6

4.5 Earthquake Hazards............................................................................................... 6

4.5.1 Local and Regional Faulting ....................................................................... 6

4.5.2 Seismicity................................................................................................... 7

4.5.3 Surface Rupture......................................................................................... 7

4.5.4 Liquefaction............................................................................................... 7

4.5.5 Dry Sand Settlement.................................................................................. 8

5.0 ENGINEERING PROPERTIES AND ANALYSIS ....................................................................... 8

5.1 Materials Properties.............................................................................................. 8

5.1.1 Excavation Characteristics......................................................................... 8

5.1.2 Compressibility .......................................................................................... 9

5.1.3 Moisture .................................................................................................... 9

5.1.4 Hydro‐Consolidation.................................................................................. 9

5.1.5 Expansion Potential ................................................................................. 10

5.1.6 Earthwork Adjustments........................................................................... 10

5.1.7 Chemical Analyses ................................................................................... 10

5.2 Engineering Analysis............................................................................................ 11

5.2.1 Bearing Capacity and Lateral Earth Pressures.......................................... 11 Item #6. Page 1466
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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

6.0 CONCLUSIONS AND RECOMMENDATIONS...................................................................... 11

6.1 General Earthwork Recommendations................................................................ 11

6.1.1 Site Preparation....................................................................................... 11

6.1.2 Unsuitable Soil Removals......................................................................... 12

6.1.3 Over‐excavation of Building Pads ............................................................ 13

6.2 General Earthwork Recommendations................................................................ 14

6.2.1 Compaction Standards............................................................................. 14

6.2.2 Groundwater/Seepage ............................................................................ 14

6.2.3 Documentation of Removals ................................................................... 14

6.2.4 Treatment of Removal Bottoms .............................................................. 14

6.2.5 Fill Placement .......................................................................................... 15

6.2.6 Moisture Content .................................................................................... 15

6.2.7 Mixing...................................................................................................... 15

6.2.8 Import Soils.............................................................................................. 15

6.2.9 Utility Trenches........................................................................................ 16

6.2.9.1 Excavation.......................................................................................................... 16

6.2.9.2 Backfill ............................................................................................................... 16

6.2.10 Backcut Stability ...................................................................................... 17

6.3 Storm Water Infiltration Systems........................................................................ 17

6.4 Boundary Conditions........................................................................................... 18

7.0 DESIGN CONSIDERATIONS............................................................................................... 18

7.1 Structural Design ................................................................................................. 18

7.1.1 Foundations............................................................................................. 19

7.1.2 Conventional Slab/Foundation Systems .................................................. 19

7.1.3 Post‐Tensioned Slabs/Foundation Design Recommendations................. 20

7.2 Moisture Barrier.................................................................................................. 21

7.3 Seismic Design..................................................................................................... 22

7.4 Block Walls .......................................................................................................... 23

7.5 Footing Excavations............................................................................................. 23

7.6 Retaining Walls.................................................................................................... 23

7.7 Exterior Slabs and Walkways............................................................................... 25

7.7.1 Subgrade Compaction.............................................................................. 25

7.7.2 Subgrade Moisture .................................................................................. 25

7.7.3 Concrete Slab Thickness .......................................................................... 25

7.7.4 Concrete Slab Reinforcement.................................................................. 25

7.7.5 Control Joints........................................................................................... 25

7.8 Concrete Design .................................................................................................. 26

7.9 Corrosion............................................................................................................. 26

7.10 Site Drainage ....................................................................................................... 26 Item #6. Page 1467
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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

7.11 Pavement Design................................................................................................. 27

8.0 LOT MAINTENANCE......................................................................................................... 28

8.1 Lot Drainage ........................................................................................................ 28

8.2 Burrowing Animals.............................................................................................. 28

9.0 FUTURE PLAN REVIEWS................................................................................................... 28

10.0 CLOSURE.......................................................................................................................... 29

10.1 Geotechnical Review ........................................................................................... 29

10.2 Limitations........................................................................................................... 29 APPENDIX A: REFERENCES
APPENDIX B: SUBSURFACE INVESTIGATION
APPENDIX C: LABORATORY TESTING
APPENDIX D: MAINTENANCE CONSIDERATIONS
APPENDIX E: EARTHWORK SPECIFICATIONS
APPENDIX F: GRADING DETAILS
Item #6. Page 1468
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Project Number 1‐0486 Page 1
June 23, 2023
Corona Office
Phone: 951.509.7090

1.0 INTRODUCTION
This report presents Alta’s findings, conclusions, and geotechnical recommendations for the proposed residential development of APN: 8646‐029‐009 and ‐014 located at 723‐ 731 East Route 66, in the City of Glendora, Los Angeles County, California.

1.1 Purpose
The purpose of this report is to examine the existing onsite geotechnical conditions and assess their impact on the proposed development. The property is depicted on the enclosed Plate 1. This report is suitable for use in developing grading plans and preliminary construction cost estimates.

1.2 Scope of Work
Alta’s Scope of Work for this geotechnical investigation included the following:
 Reviewing the referenced reports and air photos (Appendix A).  Site geologic mapping.
 Excavating, logging, and sampling four (4) hollow‐stem auger borings to a maximum depth of 26‐feet below the existing ground surface (Appendix B).
 Conducting laboratory testing on samples obtained during our investigation (Appendix C).
 Performing an infiltration study and providing a preliminary assessment of the infiltration characteristics of the onsite soils and their impact on storm water disposal.
 Evaluating engineering geologic and geotechnical engineering data, including laboratory data, to develop recommendations for site remedial grading including specialized grading techniques for unsuitable soil removals along the property boundary, import soil, foundations, and utilities.
 Preparing this report and accompanying exhibits.

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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

1.3 Report Limitations
The conclusions and recommendations presented in this report are based on the field and laboratory information generated during this investigation, and a review of the referenced reports. The information contained in this report is intended to be used for development of grading plans and preliminary construction cost estimates.

2.0 PROJECT DESCRIPTION

2.1 Site Location and Existing Conditions
The rectangular shaped approximately ±1.8‐acre, site is relatively flat and consists of a paved parking lot, a dirt field, and a single commercial structure with associated concrete flatwork. The dirt field has remnants of previously placed asphaltic concrete, however, much has been eroded away. The site is bounded to the north by a railroad easement, to the east and west by commercial properties, and to the south by Route 66.

Historic aerial images are available as far back as 1948 and indicate that the site was originally utilized for agricultural purposes. By 1964, the site was cleared and three structures were constructed, one in the southwest corner of the property and two in the southeast corner of the property. The southwestern structure was expanded to its current configuration and the two southeastern structures were demolished by 1974. The dirt field was paved with asphaltic concrete by 1980 and the site has remained largely unchanged since. (Historic Aerials, 2023).

2.2 Proposed Development
It is our understanding that the site is to be developed to support multifamily residential structures and associated improvements. It is Alta’s understanding that conventional cut‐and‐fill grading techniques will be used to develop the site for the support of wood‐frame and stucco construction with shallow foundations and reinforced concrete slabs‐on‐grade, and associated improvements.

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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

3.0 SITE INVESTIGATION

3.1 Subsurface Investigation and Laboratory Testing
Alta conducted a subsurface investigation on May 24th, 2023, consisting of the excavation, logging, and select sampling of four (4) hollow‐stem auger borings to a maximum depth of 26‐feet below the existing ground surface. The locations of the borings are shown on Plate 1 and the boring logs are presented in Appendix B.

Laboratory testing was performed on bulk and ring samples obtained during the field investigation. A brief description of the laboratory test procedures and the test results are presented in Appendix C.

3.2 Infiltration Testing
It is Alta’s understanding that the site may utilize infiltration systems for storm water disposal. Details of the systems are not known at this time.

Infiltration testing was undertaken using two ten (10) foot‐deep borings (P‐1 and P‐2) as shown on Plate 1. The testing was performed on May 25, 2023 in general conformance with the County of Los Angeles Technical Guidance Document Standards. The test wells were presoaked for 24 hours, and then water level readings were recorded every 10 minutes until the readings stabilized.

The data was then adjusted to provide an infiltration rate utilizing the Porchet Method. The resulting infiltration rate is presented in Table 3‐1. The results do not include a Factor of Safety. Recommendations for infiltration BMP design are presented in Section 6.3.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

Table 3‐1‐Summary of Infiltration Testing
(No Factor of Safety)
Test Designation P‐1 P‐2
Approximate Depth of Test 10 ft 10 ft
Time Interval 10 minutes 10 minutes
Radius of Test Hole 4 inches 4 inches
Tested Infiltration Rate 13.4 (in/hr) 10.8 (in/hr)

4.0 GEOLOGIC CONDITIONS

4.1 Geologic and Geomorphic Setting
Regionally, the subject site is located in the Peninsular Ranges geomorphic province, which characterizes the southwest portion of southern California where major right lateral active fault zones predominately trend northwest‐southeast.

The Peninsular Ranges province is composed of plutonic and metamorphic rock, with lesser amounts of Tertiary volcanic and sedimentary rock, Quaternary drainage in‐fills and sedimentary veneers.

4.2 Stratigraphy
Based on our literature review and subsurface investigation the site is underlain by undocumented artificial fill and young alluvial fan deposits. These geologic units are briefly described below.

4.2.1 Undocumented Artificial Fill (Map symbol afu)
The undocumented artificial fill encountered at the site consists primarily of tannish brown and brown silty sand and gravelly sand in a slightly moist and medium dense condition. The unit was logged to depths ranging from two and a half (2.5) to five (5) feet below the ground surface.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

4.2.2 Young Alluvial Fan Deposits (Map symbol Qyf)
The artificial fill is underlain by young alluvial fan deposits consisting of brown and dark brown to reddish brown and orange brown gravelly sand and silty sand/clayey sand in a dry to slightly moist, medium dense to very dense condition. Gravel/cobble lenses are common. The unit was logged to a depth of 26.0 feet below the ground surface.

4.3 Geologic Structure

4.3.1 Tectonic Framework
Jennings (1985) defined eight structural provinces within California that have been classified by predominant regional fault trends and similar fold structure. These provinces are in turn divided into blocks and sub‐blocks that are defined by “major Quaternary faults.” These blocks and sub‐ blocks exhibit similar structural features. Within this framework, the site is located within Structural Province I, which is controlled by the dominant northwest trend of the San Andreas Fault and is divided into two blocks, the Coast Range Block, and the Peninsular Range Block. The Peninsular Range Block, on which this site is located, is characterized by a series of parallel, northwest trending faults that exhibit right lateral dip‐ slip movement. These faults are terminated by the Transverse Range block to the north and extend southward to the Baja Peninsula. These northwest trending faults divide the Peninsular Range block into eight sub‐blocks. The site is located on the extreme northern portion of the Riverside Sub‐block, one of the eight sub‐blocks, which is bound on the west by the Elsinore fault zone and on the east by the San Jacinto fault zone.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

4.3.2 Regionally Mapped Active Faults
Several large, active fault systems including the Sierra Madre, Elsinore‐ Whittier, San Jacinto, and the San Andreas occur in the region surrounding the site. These fault systems have been studied extensively and in a large part control the geologic structure of southern California.

4.3.3 Geologic Structure
Based upon our site investigation and literature review, the onsite alluvial sediments are of Holocene age, and are not folded or faulted.

4.4 Groundwater
Our subsurface investigation did not encounter groundwater to the depth of twenty (26) feet below the ground surface. The historic high groundwater depth approximately 100‐feet below the ground surface (CDMG, 1998).

4.5 Earthquake Hazards
The subject site is located in southern California, which is a tectonically active area. The type and magnitude of seismic hazards affecting a site are dependent on the distance to the causative fault and the intensity and magnitude of the seismic event. The seismic hazard may be primary, such as surface rupture and/or ground shaking, or secondary, such as liquefaction and/or ground lurching.

4.5.1 Local and Regional Faulting
The nearest known active faults (movement occurring ≤ 11,700 years ago) are the: Sierra Madre fault, San Jose fault, Clamshell‐Sawpit fault, Cucamonga fault, Raymond fault, Chino fault, and Elsinore fault located

1.4, 4.8, 6.6, 7.1, 8.2, 9.1, and 13.0 miles from the site (USGS, 2008).

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June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

4.5.2 Seismicity
Ground shaking hazards caused by earthquakes along other active regional faults exist. The 2022 California Building Code requires use‐ modified spectral accelerations and velocities for most structural designs.

Seismic design parameters using soil profile types identified in the 2022 California Building Code are presented in Section 7.3.

4.5.3 Surface Rupture
Active faults are not known to exist within the project and a review of Special Publication 42 indicates the site is not within a California State designated earthquake Fault Rupture Hazard Zone (CGS, 2018).

Accordingly, the potential for fault surface rupture on the subject site is very low.

4.5.4 Liquefaction
Seismic agitation of relatively loose saturated sands, silty sands, and some silts can result in a buildup of pore pressure. If the pore pressure exceeds the overburden stresses, a temporary quick condition known as liquefaction can occur. Liquefaction effects can manifest in several ways including: 1) loss of bearing; 2) lateral spread; 3) dynamic settlement; and 4) flow failure. Lateral spreading has typically been the most damaging mode of failure.

In general, the more recent that a sediment has been deposited, the more likely it will be susceptible to liquefaction. Other factors that must be considered are: groundwater, confining stresses, relative density, and the intensity and duration of seismically‐induced ground shaking.

The site is not within a State‐identified zone of required investigation for liquefaction (CGS, 1999). Groundwater was not encountered during the Item #6. Page 1475
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ALTA CALIFORNIA GEOTECHNICAL, INC.
subsurface investigation which extended to a depth of 26 feet. The nearest groundwater well indicates that groundwater is 519‐ft. below the ground surface.

Based on the depth of groundwater, it is our opinion that the potential for liquefaction is minimal at the site.

4.5.5 Dry Sand Settlement
Dry sand settlement is the process of non‐uniform settlement of the ground surface during a seismic event. Based on our subsurface investigation and our removal/recompaction recommendations, the potential for dry sand settlement is anticipated to be low and within foundation design tolerances.

5.0 ENGINEERING PROPERTIES AND ANALYSIS

5.1 Materials Properties
Presented herein is a general discussion of the engineering properties of the onsite materials that will be encountered during construction of the proposed project. Descriptions of the soil (Unified Soil Classification System) are presented on the boring logs in Appendix B.

5.1.1 Excavation Characteristics
Based on the data provided from the subsurface investigation, it is our opinion that the onsite materials possess favorable excavation characteristics such that conventional earth moving equipment can be utilized. Gravel and cobbles will be encountered during the excavations in the young alluvial fan deposits.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

5.1.2 Compressibility
The undocumented artificial fill and upper portions of young alluvial fan deposits onsite are considered compressible and unsuitable to support the proposed improvements. Recommended removal depths are presented in Section 6.1.2.

5.1.3 Moisture
The moisture content of the undocumented artificial fill and young alluvial fan deposits that will require removal and recompaction as discussed in Section 6.1.2 are typically under‐optimum and will require moisture conditioning for compaction.

5.1.4 Hydro‐Consolidation
Hydro‐consolidation is the effect of introducing water into soil that is prone to collapse. Upon loading and initial wetting, the soil structure and apparent strength are altered resulting in almost immediate settlement.

That settlement can have adverse impacts on engineered structures, particularly in areas where it is manifested differentially. Differential settlements are typically associated with differential wetting, irregularities in the subsurface soil conditions, or irregular loading patterns.

Based on soil type and gravel content of the soils encountered, the potential for hydro‐collapse in the underlying young alluvial fan deposits is minimal and should be within foundation tolerances upon the completion of the recommended unsuitable soil removals.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

5.1.5 Expansion Potential
Expansion index testing was performed on samples taken during our subsurface investigation. Based on the results, it is anticipated that the majority of materials onsite are “very low” to “low” in expansion potential (0≤EI≤50, Appendix C) when tested per ASTM D: 4829.

5.1.6 Earthwork Adjustments
The values presented in Table 5‐1 are deemed appropriate for estimating purposes and may be used in an effort to balance earthwork quantities.

As is the case with every project, contingencies should be made to adjust the earthwork balance when grading is in‐progress and actual conditions are better defined.

TABLE 5‐1
Earthwork Adjustment Factors
Geologic Unit Adjustment Factor Range Average
Undocumented Artificial Fill/
Young Alluvial Fan Deposits Shrink 6% to 10% 8%

5.1.7 Chemical Analyses
Chemical testing was performed on samples of material underlying the proposed site. Soluble sulfate test results indicate that the soluble sulfate concentrations of the soils tested are classified as negligible (Class S0) per ACI 318‐14.

Negligible chloride levels were detected in the onsite soils. Resistivity testing conducted as part of this investigation, indicates that the soils are “slightly corrosive” to buried metals (per Romanoff, 1989). Additional discussions on corrosion are presented in Section 7.10. Corrosion tests results are presented in Appendix C.

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ALTA CALIFORNIA GEOTECHNICAL, INC.

5.2 Engineering Analysis
Presented below is a general discussion of the engineering analysis methods that were utilized to develop the conclusions and recommendations presented in this report.

5.2.1 Bearing Capacity and Lateral Earth Pressures
Ultimate bearing capacity values were obtained using the graphs and formula presented in NAVFAC DM‐7.1. Allowable bearing was determined by applying a factor of safety of at least 3 to the ultimate bearing capacity. Static lateral earth pressures were calculated using Rankine methods for active and passive cases. If it is desired to use Coulomb forces, a separate analysis specific to the application can be conducted.

6.0 CONCLUSIONS AND RECOMMENDATIONS
Based on Alta’s findings during our subsurface investigation, the laboratory test results, and our staff’s previous experience in the area, it is Alta’s opinion that the development of the site is feasible from a geotechnical perspective. Presented below are Alta’s recommendations that should be incorporated into site development and construction plans.

6.1 General Earthwork Recommendations
All grading shall be accomplished under the observation and testing of the project geotechnical consultant in accordance with the recommendations contained herein and the City of Glendora criteria.

6.1.1 Site Preparation
Vegetation, construction debris, and other deleterious materials are unsuitable as structural fill material and should be disposed of offsite prior to commencing grading/construction. Any septic tanks, seepage pits Item #6. Page 1479
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ALTA CALIFORNIA GEOTECHNICAL, INC.
or wells should be abandoned as per the County of Los Angeles Department of Health Services.

Existing concrete should be removed prior to the placement of engineered fill. The demolished concrete may be incorporated into compacted, engineered fills after it is crushed to a maximum size of six (6) inches. Prior to placement as engineered fill any protruding steel rebar should be cut from the concrete pieces and disposed of offsite.

Existing asphaltic concrete should be removed prior to the placement of engineered fill. From a geotechnical perspective, this material may be incorporated into compacted, engineered fills after it is crushed to a maximum size of six (6) inches. The crushed asphalt should not be placed under residential structures, but rather, it can be placed in approved non‐ residential areas, such as streets, parking areas or open space. These recommendations should be verified by the environmental consultant.

6.1.2 Unsuitable Soil Removals
The artificial fill and the upper portions of the young alluvial fan deposits near the surface are compressible and as such, are not suitable to support the proposed structures. Accordingly, it is recommended to completely remove the undocumented artificial fills and highly weathered portions of the underlying young alluvial fan deposits across the site and as close to the property boundaries as possible.

As such, it is anticipated that, on average, the upper three (3) to five (5) feet of existing soils will require removal and recompaction, extending at a minimum 1:1 projection horizontally outside the structures. This recommended removal combined with the foundation recommendations Item #6. Page 1480
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presented in Section 7.1 should provide suitable support for the proposed structures.

The Project Geotechnical Consultant should observe the removal bottom prior to placing fill. If unsuitable soils such as undocumented artificial fill are exposed upon the completion of the removals recommended above, additional removals will be required.

For streets, in general, a minimum removal and recompaction of the upper two (2) feet of soil is recommended, although deeper removals may be required if undocumented fill is exposed at that depth. Removal bottoms in parking lot areas should be tested to determine that the exposed soils have a minimum relative compaction of 85% of the laboratory maximum density (per ASTM test method D‐1557).

Material removed as part of the unsuitable soil removals can be used as artificial fill, provided it is free of deleterious materials.

6.1.3 Over‐excavation of Building Pads
Footings for structures should be underlain by a minimum of two (2) feet of compacted fill. As such, for building pads where unsuitable soil removals do not provide the minimum depth of compacted fill, or where design grades and/or remedial grading activities create cut/fill transitions, the cut and shallow fill portions of the building pads should be over‐excavated to provide the required depth of fill below the footings.

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6.2 General Earthwork Recommendations

6.2.1 Compaction Standards
All fill and processed natural ground shall be compacted to a minimum relative compaction of 90 percent, as determined by ASTM Test Method:

D‐1557. Fill material should be moisture conditioned to optimum moisture or above, and as generally discussed in Alta’s Earthwork Specification Section presented in Appendix E. Compaction shall be achieved with the use of sheepsfoot rollers or similar kneading type equipment.

6.2.2 Groundwater/Seepage
It is anticipated that groundwater will not be encountered during construction. It is possible that perched water conditions could be encountered depending on the time of year construction occurs.

6.2.3 Documentation of Removals
All removal/over‐excavation bottoms should be observed and approved by the project Geotechnical Consultant prior to fill placement.

Consideration should be given to surveying the removal bottoms and undercuts after approval by the geotechnical consultant and prior to the placement of fill. Staking should be provided in order to verify undercut locations and depths.

6.2.4 Treatment of Removal Bottoms
At the completion of removals/over‐excavation, the exposed removal bottom should be ripped to a minimum depth of eight (8) inches, moisture‐conditioned to above optimum moisture content and compacted in‐place to the project standards.

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6.2.5 Fill Placement
After removals, scarification, and compaction of in‐place materials are completed, additional fill may be placed. Fill should be placed in eight‐ inch bulk maximum lifts, moisture conditioned to optimum moisture content or above, compacted and tested as grading/construction progresses until final grades are attained.

6.2.6 Moisture Content
The moisture content of the upper in‐situ soils is primarily below optimum, as shown on the boring logs in Appendix B. These soils will require moisture conditioning prior to placement as engineered fill.

6.2.7 Mixing
Mixing of materials may be necessary to prevent layering of different soil types and/or different moisture contents. Mixing should be accomplished prior to and as part of the compaction of each fill lift.

6.2.8 Import Soils
Import soils, if necessary, should consist of clean, low expansive, structural quality, compactable materials similar to the on‐site soils and should be free of trash, debris, or other objectionable materials. The project Geotechnical Consultant should be notified not less than 72 hours in advance of the locations of any soils proposed for import. Import sources should be sampled, tested, and approved by the project Geotechnical Consultant at the source prior to the importation of the soils to the site. The project Civil Engineer should include these requirements on plans and specifications for the project.

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6.2.9 Utility Trenches

6.2.9.1 Excavation
Utility trenches should be supported, either by laying back excavations or shoring, in accordance with applicable OSHA standards. In general, existing site soils are classified as Soil Types "B" and “C” per OSHA standards. Upon completion of the recommended removals and re‐compaction, the artificial fill will be classified as Soil Type "B". The Project Geotechnical Consulting should be consulted if geologic conditions vary from what is presented in this report.

6.2.9.2 Backfill
Trench backfill should be compacted to at least 90 percent of maximum dry density as determined by ASTM D‐1557. Onsite soils will not be suitable for use as bedding material but will be suitable for use in backfill provided oversized materials are removed. No surcharge loads should be imposed above
excavations. This includes spoil piles, lumber, concrete trucks, or other construction materials and equipment. Drainage above excavations should be directed away from the banks.

Care should be taken to avoid saturation of the soils.

Compaction should be accomplished by mechanical means.

Jetting of native soils will not be acceptable.

Under‐slab trenches should also be compacted to project specifications. If select granular backfill (SE > 30) is used, compaction by flooding will be acceptable.

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6.2.10 Backcut Stability
Temporary backcuts, if required during unsuitable soil removals, should be made no steeper than 1:1 without review and approval of the geotechnical consultant. Flatter backcuts may be necessary where geologic conditions dictate and where minimum width dimensions are to be maintained.

Care should be taken during remedial grading operations in order to minimize the risk of failure. Should failure occur, complete removal of the disturbed material will be required.

In consideration of the inherent instability created by temporary construction backcuts for removals, it is imperative that grading schedules are coordinated to minimize the unsupported exposure time of these excavations. Once started, these excavations and subsequent fill operations should be maintained to completion without intervening delays imposed by avoidable circumstances. In cases where five‐day workweeks comprise a normal schedule, grading should be planned to avoid exposing at‐grade or near‐grade excavations through a non‐work weekend. Where improvements may be affected by temporary instability, either on or offsite, further restrictions such as slot cutting, extending workdays, implementing weekend schedules, and/or other requirements considered critical to serving specific circumstances may be imposed.

6.3 Storm Water Infiltration Systems
From a geotechnical perspective, allowing storm water to infiltrate the onsite soil in concentrated areas increases the potential for settlement, liquefaction, and water‐related damage to structures/improvements, such as wet slabs or pumping subgrade, and should be avoided where possible. If infiltration systems are Item #6. Page 1485
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required on this site, care should be taken in designing systems that control the storm water as much as possible.

Preliminary infiltration testing was conducted at the site as part of this investigation, and the methodology is discussed in 3.2. The resulting infiltration rates for P‐1 and P‐2 was calculated to be 13.4 and 10.8‐inches per hour, respectively. The results do not include a factor of safety.

Groundwater was not encountered during our investigation to a maximum depth of 26.0 feet below the ground surface. The historic high groundwater depth approximately 100‐feet below the ground surface (CDMG, 1998).

The Project Geotechnical Consultant should review the final WQMP design prior to construction.

6.4 Boundary Conditions
The site is bounded to the north by a railroad easement, to the east and west by commercial properties, and to the south by Route 66. Construction of retaining/screen walls along these boundaries will require additional geotechnical recommendations concerning unsuitable soil removals and foundation design parameters. Boundary conditions for the project should be reviewed by the Project Geotechnical Consultant as the design progresses.

7.0 DESIGN CONSIDERATIONS

7.1 Structural Design
It is anticipated that multi‐story, wood‐frame residential structures with slab on‐ grade and shallow foundations will be constructed. Upon the completion of rough grading, finish grade samples should be collected and tested in order to provide specific recommendations as they relate to the individual building pads. These test results and corresponding design recommendations should be presented in a final rough grading report. Final slab and foundation design recommendations Item #6. Page 1486
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should be made based upon specific structure sitings, loading conditions, and as‐ graded soil conditions.

It is anticipated that the majority of onsite soils will possess “very low” to “low” expansion potential when tested in general accordance with ASTM Test Method D: 4829. For budgeting purposes, the following foundation design requirements for a range of potential expansion characteristics are presented.

7.1.1 Foundations
Foundations may be preliminary designed based on the values presented in Table 7‐1 below.

Table 7‐1
Foundation Design Parameters*
Allowable Bearing 2000 lbs/ft2 assuming a minimum footing width and embedment of 12 inches.

Lateral Bearing 250 lbs/ft2 at a depth of 12 inches plus 250 lbs/ft2 for each additional 12 inches of embedment to a maximum of 2000
lbs/ft2
Sliding Coefficient 0.35
Differential Settlement Dynamic:

Differential = 0.5‐inches in 40 feet
Static:

Differential = 0.5‐inch in 40 feet
*These values may be increased as allowed by Code to resist transient loads such as wind or seismic. Building code and structural design considerations may govern depth and reinforcement requirements and should be evaluated.

7.1.2 Conventional Slab/Foundation Systems
Based on the onsite soils conditions and information supplied by the 2022 CBC, conventional slab/foundation systems may be designed in accordance with Tables 7‐1 and 7‐2.

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TABLE 7‐2

CONVENTIONAL FOUNDATION DESIGN PARAMETERS
Expansion Potential Very Low to Low
Soil Category I
Design Plasticity Index 10
Minimum Footing
Embedment
12 inches*
*The minimum footing embedments presented herein are based on expansion indexes. The structural engineer should determine minimum embedments based on the number of floors supported by the footings, the structural loading, and the requirements of the latest California Building Code.

Minimum Footing Width 12‐inches‐The structural engineer should determine the minimum footing width based on loading and the latest California Building Code.

Footing Reinforcement No. 4 rebar, one (1) on top, one (1) on bottom Slab Thickness 4 inches (actual)
Slab Reinforcement* No. 3 rebar spaced 18 inches on center, each way Under‐Slab Requirement See Section 7.2
Slab Subgrade Moisture Minimum of 110 percent of optimum moisture to a depth of 12 inches prior to placing concrete.

Footing Embedment
Adjacent to Swales and
Slopes
If exterior footings adjacent to drainage swales are to exist within five (5) feet horizontally of the swale, the footing should be embedded sufficiently to assure embedment below the swale bottom is maintained. Footings adjacent to slopes should be embedded such that at least five‐ (5) feet is provided horizontally from edge of the footing to the face of the slope.

7.1.3 Post‐Tensioned Slabs/Foundation Design Recommendations Post‐tensioned slabs for the project may be preliminarily designed utilizing the parameters presented in Tables 7‐1 and 7‐3. The parameters presented herein are based on methodology provided in the Design of Post‐Tensioned Slabs‐On‐Ground, Third Edition, by the Post‐Tensioning Institute, in accordance with the 2022 CBC.

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TABLE 7‐3
POST‐TENSION SLAB DESIGN PARAMETERS
Category Expansion Potential Minimum
Embedment
Edge Lift Center Lift
Em (ft) Ym
(inch) Em (ft) Ym (inch)
I Very Low to Low 12 inches* 5.4 0.61 9.0 0.26
Slab Subgrade Moisture
Category I Minimum 110% of optimum moisture to a depth of 12 inches prior to pouring concrete
Embedment*
The minimum outer footing embedment presented herein are based on expansion indexes. The structural engineer should verify the minimum embedment based on the number of floors supported by the footings, the structural loading, and the requirements of the latest California Building Code. If mat slabs are utilized, alternate embedment depths can be provided.

Moisture Barrier
A moisture barrier should be provided in accordance with the recommendations presented in Section 7.2 The parameters presented herein are based on procedures presented in the Design of Post‐Tensioned Slabs‐On‐ Ground, Third Edition. No corrections for vertical barriers at the edge of the slab, or for adjacent vegetation have been assumed. The design parameters are based on a Constant Suction Value of 3.9 pF.

7.2 Moisture Barrier
A moisture and vapor retarding system should be placed below the slabs‐on‐ grade in portions of the structure considered to be moisture sensitive and should be capable of effectively preventing the migration of water and reducing the transmission of water vapor to acceptable levels. Historically, a 10‐mil plastic membrane, such as Visqueen, placed between one to four inches of clean sand, has been used for this purpose. The use of this system or other systems can be considered, at the discretion of the designer, provided the system reduces the vapor transmission rates to acceptable levels.

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7.3 Seismic Design
The site classes were determined based on the referenced reports and published geologic maps in the area in general conformance with Chapter 20 of ASCE 7‐16.

Based on the density of the underlying soils, a Site Class of D (shear wave velocity of 259 m/s) was selected. The seismic design parameters were calculated using a program based on the USGS website and ASCE 7‐16 procedures. It is our understanding that based on the proposed structures, code allows or the use of an alternate method to calculate SD1, assuming the structure has a fundamental period that does not exceed 0.5s. The resulting values are presented in Table 7‐4.

If the structures have fundamental periods exceeding 0.5s, then a site‐specific strong motion analysis shall be performed.

TABLE 7‐4 Seismic Ground Motion Values
2022 CBC and ASCE 7‐16
Parameter Value
Site Class D
Site Latitude 34.1294
Site Longitude ‐117.8538
Spectral Response Acceleration Parameter, SS 1.667
Spectral Response Acceleration Parameter, S1 0.631
Site Coefficient, Fa 1.0
Site Coefficient, Fv 1.7
MCE Spectral Response Acceleration Parameter, SMS 1.667 MCE Spectral Response Acceleration Parameter, SM1 1.073 Design Spectral Response Acceleration Parameter, SDS 1.111 Design Spectral Response Acceleration Parameter, SD1 0.715 Peak Ground Acceleration, PGAM 0.78
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7.4 Block Walls
Block walls, if used, should be embedded a minimum of 2 feet below the lowest adjacent grade. Construction joints (not more than 20 feet apart) should be included in the block wall construction. Side yard walls should be structurally separated from the rear yard wall.

7.5 Footing Excavations
Soils from the footing excavations should not be placed in slab‐on‐grade areas unless properly compacted and tested. The excavations should be cleaned of all loose/sloughed materials and be neatly trimmed at the time of concrete placement. The Project Geotechnical Consultant should observe the footing excavations prior to the placement of concrete to determine that the excavations are founded in suitably compacted material.

7.6 Retaining Walls
Retaining walls should be founded on engineered fill and should be backfilled with granular soils that allow for drainage behind the wall. Foundations may be designed in accordance with the recommendations presented in Table 7‐1, above. Unrestrained walls, free to horizontally move 0.0005H (for dense cohesionless backfill), may be designed to resist lateral pressures imposed by a fluid with a unit weight determined in accordance with the Table 7‐5 below. The table also presents design parameters for restrained (at‐rest) retaining walls.

These parameters may be used to design retaining walls that may be considered as restrained due to the method of construction or location (corner sections of unrestrained retaining walls).

TABLE 7‐5
Equivalent Fluid Pressures for 90% Compacted Fill (Select Material) Backfill Active Pressure (psf/ft) At‐Rest Pressure (psf/ft) Level 35 55
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Per the requirements of the 2022 CBC, the seismic force acting on the retaining walls with backfill exceeding 6‐feet in height may be resolved utilizing the formula

15.5H2 lb/lineal ft (H=height of the wall). This force acts at approximately 0.6H above the base of the wall (inverted triangle). The seismic value can be converted as required by the retaining wall engineer. Retaining walls should be designed in general accordance with Section 1807A.2 of the 2022 CBC.  Restrained retaining walls should be designed for “at‐rest” conditions.  The design loads presented in the above table are to be applied on the retaining wall in a horizontal fashion and as such friction between wall and retained soils should not be allowed in the retaining wall analyses.  Additional allowances should be made in the retaining wall design to account for the influence of construction loads, temporary loads, and possible nearby structural footing loads.
 Select backfill should be granular, structural quality backfill with a Sand Equivalent of 20 or better and an ASCE Expansion Index of 20 or less. The backfill must encompass the full active wedge area. The upper one foot of backfill should be comprised of native on‐site soils (see Plate A).  The wall design should include waterproofing (where appropriate) and backdrains or weep holes for relieving possible hydrostatic pressures. The backdrain should be comprised of a 4‐inch perforated PVC pipe in a 1 ft. by 1 ft., ¾‐inch gravel matrix, wrapped with a geofabric. The backdrain should be installed with a minimum gradient of 2 percent and should be outletted to an appropriate location. For subterranean walls this may include drainage by sump pumps.
 No backfill should be placed against concrete until minimum design strengths are achieved.

It should be noted that the allowable bearing and lateral bearing values presented in Table 7‐1 are based on level conditions at the toe. Modified design parameters can be presented for retaining walls with sloping condition at the toe.

Other conditions should be evaluated on a case‐by‐case basis.

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RETAINING WALL BACKFILL DETAIL
NATIVE

BACKFILL
12 tN. MtN.
*OR AS MODIFIED

BY A SPECIFIC REPORT
DRAIN I.ATERALLY,

OR PROVIDE WEEP

HOLES AS REQUIRED

TO DMIN
PIPE: 4-INCH PERFORATED PVC, SCHEDULE 40, SDR35 OR APPROVED ALTERNATE MINIMUM 8 PERFORATIONS (1/4-IN. DIA.) PER LINEAL FT. IN BOTTOM HALF OF PIPE
ROCK: MINIMUM VOLUME OF 1 CU. FT. OF 3/4_IN. MAX. ROCK PER. LINEAL FOOT

OF PIPE, OR APPROVED ALTERNATE
FILTER FABRIC: MIRAFI 140 FILTER FABRIC OR APPROVED EQUIVALENT "64
ALTA cALTFoRNTA eEorEcl{NrcAL, tNc,
'vER, tTto PI-ATE A
PATH: S\Drofllns\ALTA GEoTECHNICAI\GRAoING DETAIIS\PLATE A.dws Item #6. Page 1493
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7.7 Exterior Slabs and Walkways
Exterior concrete slabs and walkways should be designed and constructed in consideration of the following recommendations.

7.7.1 Subgrade Compaction
The subgrade below exterior concrete slabs should be compacted to a minimum of 90 percent relative compaction as determined by ASTM Test Method: D 1557.

7.7.2 Subgrade Moisture
The subgrade below concrete slabs should be moisture conditioned to a minimum of 110 percent of optimum moisture (low expansion) prior to concrete placement.

7.7.3 Concrete Slab Thickness
Concrete flatwork and driveways should be designed utilizing four‐inch minimum thickness.

7.7.4 Concrete Slab Reinforcement
Utilization of reinforcement for flatwork and driveways is subject to a cost/benefit analysis. Reinforcement will decrease the amount of cracking that may occur in flatwork, however, planning for occasional repairs may be more cost effective. Utilizing closely spaced control joints is likely more cost‐effective than utilizing reinforcement. The majority of the soils onsite are classified as very low in expansion potential.

Consideration should be given to reinforcing flatwork with irregular (non‐ square/rectangular) shapes.

7.7.5 Control Joints
Weakened plane joints should be installed on walkways at intervals of approximately eight feet (maximum) or less. Exterior slabs should be designed to withstand shrinkage of the concrete.

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7.8 Concrete Design
As stated in Section 5.1.7, negligible concentrations of sulfates were detected in the onsite soils. Therefore, the use of sulfate resistant concrete is not required per ACI 318‐14 at this time. Post‐grading conditions should be evaluated, and final recommendations made at that time.

7.9 Corrosion
Based on preliminary testing, the onsite soils are mildly corrosive to buried metal objects. Consideration should be given to protecting buried metals from corrosion. Typical measures may include using non‐corrosive backfill, protective coatings, wrapping, plastic pipes, or a combination of these methods. A corrosion engineer should be consulted if specific design recommendations are required by the improvement designer.

Per ACI 318‐14, an exposure class of C1 would be applicable to metals encased in concrete (rebar in footings) due to being exposed to moisture from surrounding soils. Per Table 19.3.2.1 of ACI 318‐14, the requirements for concrete with an exposure class of C1 are a minimum compressive strength of 2500 psi and a maximum water‐soluble chloride ion content in concrete of 0.30 (percent by weight of cement).

7.10 Site Drainage
Positive drainage away from the proposed structures should be provided and maintained. Roof, pad, and lot drainage should be collected and directed away from the structures toward approved disposal areas through drainage terraces, gutters, down drains, and other devices. Design fine grade elevations should be maintained through the life of the structure or if design fine grade elevations are altered, adequate area drains should be installed in order to provide rapid discharge of water, away from structures. Residents or Homeowner Associations should be made aware that they are responsible for maintenance and cleaning of Item #6. Page 1495
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all drainage terraces, down drains, and other devices that have been installed to promote site and structure drainage.

7.11 Pavement Design
Pavement sections for the proposed streets shall be designed based on laboratory testing conducted on samples taken from the soil subgrade.

Preliminarily, based on an assumed R‐Value of 30, the pavement may be designed utilizing the sections presented in Table 7‐6. These sections should be verified upon the completion of grading, based on R‐Value testing.

Table 7‐6
Preliminary Pavement Sections
Traffic
Index
Pavement Section Options
OR

5.0 3‐inch AC on 5.5‐inch AB 4‐inch AC on 4‐inch AB

5.5 3‐inch AC on 7‐inch AB 4‐inch AC on 5‐inch AB

6.0 3.5‐inch AC on 7.5‐inch AB 4‐inch AC on 6.5‐inch AB AC‐Asphalt Concrete
AB‐Caltrans Class II Base
The underlying subgrade soil should be suitably moisture conditioned, processed and compacted to a minimum of 90 percent of the laboratory maximum density (ASTM: D 1557) to at least twelve (12) inches below subgrade. After subgrade compaction, the exposed grade should then be "proof"‐rolled with heavy equipment to ensure the grade does not "pump" and is verified as non‐yielding.

Aggregate base should consist of Class 2 (Caltrans) aggregate base and should be compacted to at least 95 percent of the maximum laboratory dry density as determined in accordance with ASTM Test Method: D 1557.

Preparation for compaction operations and pavement construction operations should be accomplished in accordance with the current requirements of the City of Glendora and under the observation and testing of the project geotechnical consultant.

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8.0 LOT MAINTENANCE
Ongoing maintenance of the improvements is essential to the long‐term performance of structures. As such, the owners must implement certain maintenance procedures. The attached " Maintenance and Improvement Considerations" presented in the Appendix E may be included as part of the sales packet to educate the owners in issues related to drainage, maintenance, backyard improvements, etc. The following recommendations should also be implemented.

8.1 Lot Drainage
Roof, pad, and lot drainage should be collected and directed away from structures and slopes and toward approved disposal areas. Design fine grade elevations should be maintained through the life of the structure or if design fine grade elevations are altered, adequate area drains should be installed in order to provide rapid discharge of water, away from structures and slopes. Residents should be made aware that they are responsible for maintenance and cleaning of all drainage terraces, down drains, and other devices that have been installed to promote structure and slope stability.

8.2 Burrowing Animals
Residents or owners should undertake a program for the elimination of burrowing animals.

9.0 FUTURE PLAN REVIEWS
This report represents a geotechnical review of the site. As the project design for the project progresses, site specific geologic and geotechnical issues should be considered in the design and construction of the project. Consequently, future plan reviews may be necessary. These reviews may include reviews of:
 Grading Plans
 Foundation Plans
 Utility Plans
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These plans should be forwarded to the project Geotechnical Consultant for review.

10.0 CLOSURE

10.1 Geotechnical Review
For the purposes of this report, multiple working hypotheses were established for the project, utilizing the available data and the most probable model is used for the analysis. Future information collected during the proposed grading operations is intended to evaluate the hypothesis and as such, some of the assumptions summarized in this report may need to be changed. Some modifications of the grading recommendations may become necessary, should the conditions encountered in the field differ from the conditions hypothesized in this report.

Plans and sections of the project specifications should be reviewed by Alta to evaluate conformance with the intent of the recommendations contained in this report. If the project description or final design varies from that described in herein, Alta must be consulted regarding the applicability of the recommendations contained herein and whether any changes are required. Alta accepts no liability for any use of its recommendations if the project description or final design varies and Alta is not consulted regarding the alterations.

10.2 Limitations
This report is based on the following: 1) the project as presented on the attached plan; 2) the information obtained from Alta's laboratory testing included herein; and 3) from the information presented in the referenced reports. The findings and recommendations are based on the results of the subsurface investigation, laboratory testing, and office analysis combined with an interpolation and extrapolation of conditions between and beyond the subsurface excavation locations. However, the materials adjacent to or beneath those observed may have different characteristics than those observed, and no precise Item #6. Page 1498
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representations are made as to the quality or extent of the materials not observed. The results reflect an interpretation of the direct evidence obtained.

Work performed by Alta has been conducted in a manner consistent with the level of care and skill ordinarily exercised by members of the geotechnical profession currently practicing in the same locality under similar conditions. The methods used to develop the recommendations do not comprise an exact science and are not a guarantee that the interaction between the soils and proposed structures shall perform as planned. No other representation, either expressed or implied, and no warranty or guarantee is included or intended.

The recommendations presented in this report are based on the assumption that an appropriate level of field review will be provided by a geotechnical consultant who is familiar with the design and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and corresponding recommendations presented in this report.

The conclusions and recommendations included in this report are applicable to the specific design of this project as discussed in this report. They have no applicability to any other project or to any other location and any and all subsequent users accept any and all liability resulting from any use or reuse of the data, opinions, and recommendations without the prior written consent of Alta.

Alta has no responsibility for construction means, methods, techniques, sequences, procedures, safety precautions, programs in connection with the construction, acts or omissions of the CONTRACTOR or any other person performing any of the construction, or for the failure of any of them to carry out the construction in accordance with the final design drawings and specifications.

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APPENDIX A

REFERENCES
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APPENDIX A
Selected References
California Geological Survey, 2018, Earthquake Fault Zones, A Guide for Government Agencies, Property Owners/Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California, Special Publication 42, Revised 2018.

California Division of Mines and Geology, 1998, Seismic Hazard Zone Report for the Glendora

7.5‐Minute Quadrangle, Los Angeles County, California, Seismic Hazard Zone Report 025.

California Geological Survey, 1999, Earthquake Zones of Required Investigation Glendora Quadrangle, Scale 1:24,000, Official Map Released March 25, 1999.

California Code of Regulations, 2019, California Building Code, Title 24, Part 2, Volume 2, Based on the 2015 International Building Code, Effective Date January 1, 2020.

California Department of Water Resources, Water Data Library (WDL) Station Map, https://wdl.water.ca.gov/, accessed September 2022.

Jennings, C. W., 1985, An explanatory text to accompany the 1:750,000 scale fault and geologic maps of California: California Division of Mines and Geology, Bulletin 201, 197 p.

Jennings, C.W., and Bryant, W.A., 2010, Fault Activity Map of California: California Geological Survey Geologic Data Map No. 6, map scale 1:750,000.

Jennings, C. W., and Bryant, W.A., 2010, An explanatory text to accompany the 1:750,000 scale fault and geologic map of California: California Division of Mines and Geology, special publication 42, revised 1985, 24 p.

Romanoff, Melvin, 1989, Underground Corrosion, NBS Circular 579, Reprinted by NACE, Houston, TX, 1989.

U.S. Geological Survey, 2013, Seismic Design Maps,
http://earthquake.usgs.gov/hazards/designmaps/usdesign.php U.S. Geological Survey, 2008, National Seismic Hazards Maps – Source Parameters, http://geohazards.usgs.gov/cfusion/hazfaults_2008_search/query_main.cfm.

Item #6. Page 1501
Meeting Date: 9/24/2024 / Packet Page #: 1637
ALTA CALIFORNIA GEOTECHNICAL, INC.

APPENDIX B
Subsurface Investigation
Item #6. Page 1502
Meeting Date: 9/24/2024 / Packet Page #: 1638
Project Number 1‐0486 Page B‐1
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

APPENDIX B
Subsurface Investigation
Alta's subsurface investigation consisted of excavating, logging, and sampling four (4) hollow‐ stem auger borings. Details of the subsurface investigation are presented in Table B. The approximate location of the exploratory excavation is shown on the accompanying Plate 1 and the Geotechnical Logs are attached.

TABLE B

SURFACE INVESTIGATION DETAILS
Equipment Range of
Depths
Sampling Methods Sample Locations
Hollow‐
stem auger
Up to 26 feet 1. Bulk

2. Ring Samples

1. Bulk‐Select Depth

2. Every 2.5 to 5‐feet
Item #6. Page 1503
Meeting Date: 9/24/2024 / Packet Page #: 1639

UNIFIED SOI L CLASSIFIICATION SYSTEM
Major Divisions lfl tr Description Major Divisions an tr Coarse
Grained
Soils
N4ore than
50%
retained on
No 200
steve
Gravel
and
Sravelly
Soils
han 50%
frachon
relained
on No, 4
'l
ts
*
,-l*
EIF
GW
Well-graded grcvels or gravel sand
mixtures, little or no fines
Fine
(lrained
isoils
l\lore than
Silts
And
Clays
LL,<50
n
ML
Inorganic silts and very fine sands,
rock flour, silty or clayey fine sands
or clavev silts with slioht olasticitv
GP
Poorly-graded gravels or gravel
sand mixture, little or no fines CL
Inorganic clays of low to medium
plasticity, gravelly clays, sandy
clays, silty clays, lean clays Silty gravels, gravel-sand-silt mixtures
OL
Organic silts and organic silt-clays
of low plasticity
Clayey gravels, gravel-sand-clay
mixtures
Silts
And
Clays
LL,<50
MF
Inorganic silts, micaceous or
diatomaceous fine or silty soils,
elastic silts Sand
and
Sandy
Soils
than 50%
fraclion
Passes
on No, 4
i'+.
3_'. JV!
Well-graded sands or gravelly
sands, little or no fines
on No 200
steve VH
Inorganic clays of high plasticity,
fat clays SP
Poorly-graded sands or gravelly
sands, little or no fines
SM Silty sands, sarrd-silt mixtures OF
Organic clays of medium to high
plasticity
sc Clayey sands, and-clay mixtures Highly Organic
Soils PT Peat and other highly organic soils
BoUNDARY CLASSIFICATIoN: Soils possessing characteristics of two groups are designated by combinations of group symbols PARTICLE SIZ:E LIMITS
U.S. STANDA,RD SiERIES SIEVE
200 40 10 4

CLEAR SQUARE SIEVE OPENINGS
3t4" 3,, ,t2"

LABORATORY TESTS
Symbol Tesl
DS
DSR
cc)N
SA
MAX
RV
EI
SE
AL
CHEM
HY
Direct Shear
Direct Shear
(Remolded)
Sieve Analysis
Maximum Density
Resistance (R) Value
Expansion Index
Sand Equivalent
Atterberg Limits
Chemical Analysis
Hydrometer Analysis

SOIL MOISTURE

SIZE PROPORTIONS
Trace - <5%
Few-5to10%
Some - 15 to 25%
Increasing \/isual Moisture Content
Silts
an0
Clays
Sand Gravel
Cobbles Boulders
Fine Medium Coarsi€r Fine Coarse

RELATIVE DENSITY
Sands and Gravels Blows/Foot (SPT)
Very Loose
Loose
Medium Dense
Dense
Very Dense
<4
4-10
11-30
31 -50
>50

CON SI STENCY C IASSI FI CATI ON
Silts and Clays Criteria
Very Soft
Soft
Firm
stiff
Very Stiff
Thumb penetrates soil >1 in.

Thumb penetrates soil 1 in,
Thumb penetrates soil 1/4 in
Readily indented with thumbnail
Thumbnail will not indent soil

HARDNESS
KEY TO EXPLORATORY BORING LOGS}
,n
/L>//J, ALTA CALIFORNTA GEOTECHNTCAL tNC.
/\

PI-ATE B
Item #6. Page 1504
Meeting Date: 9/24/2024 / Packet Page #: 1640
ARTIFICIAL FILL-UNDOCUMENTED (afu): SILTY SAND, very fine to fine grained, brown, slightly moist, medium dense.
@2.5ft.: GRAVELLY SAND, fine to coarse grained, brown, slightly moist, dense, fine to coarse gravel < 1".

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse grained, dense, coarse gravel < 3".
@10.0ft.: dark brown, very dense.
@15.0ft.: greyish brown,
@20.0ft.: SILTY SAND/CLAYEY SAND, very fine to fine grained, slightly moist, reddish brown, medium dense.
@25.0ft.: GRAVELLY SAND, fine to coarse grained, dark brown, slightly moist, fine to coarse gravel < 1".

TOTAL DEPTH: 26 FEET.

NO GROUNDWATER ENCOUNTERED.

R
R
R
R
R
R
39 65
59 50 for 6"
18 50 for 6"

2.1 2.9

4.2 2.9

13.6 2.6
13 16
19 85
117
112
118
116
SM
SP
SP
SM/SC
SP
5 10
15 20
25 TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
770
765
760
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
140 lbs.
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
783 B-1
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
30 in.

Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-1
Item #6. Page 1505
Meeting Date: 9/24/2024 / Packet Page #: 1641
ASPHALT: 1 inch of asphaltic concrete over no aggregate base.

ARTIFICIAL FILL - UNDOCUMENTED: (afu): GRAVELLY SAND,
fine to coarse grained, tannish brown, slightly moist, some fine to coarse gravel < 1".

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse grained, brown, slughtly moist, some gravel < 1". @ 10.0ft.: dark brown, gravel < 3/4".
@15.0ft.: no recovery.
@20.0ft.: no recovery.
@25.0ft.: orange brown, slightly moist, dense, gravel < 1/2".

TOTAL DEPTH: 26 FEET.

NO GROUNDWATER ENCOUNTERED.

R
R
R
R
R
R
40 23
61 50 for

5.5"
50 for 4"
50 for 4"

2.5 8.5

2.3 3.1
12 51
12 17
108
115
109
111
SP
SP
5 10
15 20
25 TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
770
765
760
755
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
140 lbs.
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
781 B-2
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
30 in.

Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-2
Item #6. Page 1506
Meeting Date: 9/24/2024 / Packet Page #: 1642
ASPHALT: 1 inch of asphaltic concrete over no aggregate base.

ARTIFICIAL FILL - UNDOCUMENTED (afu): GRAVELLY SAND,
fine to medium grained, tannish brown, slightly moist, gravel < 3". @2.5ft.: no recovery.

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse grained, brown, dry, fine to coarse gravel < 3". @10.0ft.: medium to coarse grained, fine gravel < 3/4". @15.0ft.: no recovery.
@20.0ft.: reddish brown.
@22.0ft.: GRAVEL/COBBLE LAYER ENCOUNTERED.

TOTAL DEPTH: 26 FEET.

NO GROUNDWATER ENCOUNTERED.

R
R
R
R
R
R
54 50 for 6"
38 81
66 50 for 6"

2.6 2.4

3.7 3.6
10 9
14 21
96 97
97 113
SP
SP 5
10 15
20 25

TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
770
765
760
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
140 lbs.
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
782 B-3
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
30 in.

Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-3
Item #6. Page 1507
Meeting Date: 9/24/2024 / Packet Page #: 1643
ARTIFICIAL FILL - UNDOCUMENTED (afu): SILTY SAND, very
fine to fine grained, tannish brown, slightly moist, medium dense, some fine gravel< 3/4".

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse gravel, brown, slightly moist, dense, cobble <6". @5.0ft.: no recovery
@7.0ft.: GRAVEL/COBBLE LAYER ENCOUNTERED.
@10.0ft.: no recovery.
@13.0ft.: GRAVEL/COBBLE LAYER ENCOUNTERED.
@15.0ft.: no recovery.
@17.0ft.: REFUSAL.

TOTAL DEPTH: 17 FEET.

NO GROUNDWATER ENCOUNTERED.

R
R
R
R
50 for 6"
44 50 for 6"
50 for 3"
SM
SP
5 10
15 TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
770
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
140 lbs.
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
784 B-4
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
30 in.

Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-4
Item #6. Page 1508
Meeting Date: 9/24/2024 / Packet Page #: 1644
ARTIFICIAL FILL-UNDOCUMENTED (afu): SILTY SAND, very fine to fine grained, brown, slightly moist, medium dense.
@2.5ft.: GRAVELLY SAND, fine to coarse grained, brown, slightly moist, dense, fine to coarse gravel < 1".

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse grained, dense, coarse gravel < 3".

TOTAL DEPTH: 10 FEET.

NO GROUNDWATER ENCOUNTERED.

SM
SP
SP 5
10 TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
N/A
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
782 P-1
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
N/A
Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-5
Item #6. Page 1509
Meeting Date: 9/24/2024 / Packet Page #: 1645
ASPHALT: 1 inch of asphaltic concrete over no aggregate base.

ARTIFICIAL FILL - UNDOCUMENTED (afu): GRAVELLY SAND,
fine to medium grained, tannish brown, slightly moist, gravel < 3".

YOUNG ALLUVIAL FAN DEPOSITS (Qyf): GRAVELLY SAND, fine
to coarse grained, brown, dry, fine to coarse gravel < 3".

TOTAL DEPTH: 10 FEET.

NO GROUNDWATER ENCOUNTERED.

SP
SP 5
10 TYPE OF DRILL RIG
DRILLER SAT- MOISTURE CONT (%)
5/24/23
(%) URATION
DATE STARTED 5/24/23
780
775
GEOTECHNICAL DESCRIPTION SAMPLE OTHER ELEV DRY (pcf) DENSITY BORING DESIG.

DROP
DRIVE WT.

GW DEPTH (FT)

PROJECT NAME

DATE FINISHED LM DEPTH
N/A
723-731 E. Route 66 TESTS

S SPT (SPLIT SPOON) SAMPLE

R RING (DRIVE) SAMPLE
SAMPLE TYPES:

SHEET
NOTE

LOGGED BY GROUP
J: JOINTING
B: BEDDING
S: SHEAR
C: CONTACT
F: FAULT
RS: RUPTURE SURFACE
1-0486

GROUNDWATER

SEEPAGE
(Feet)
784 P-2
PROJECT NO.

GEOTECHNICAL BORING LOG
GROUND ELEV.
8" Hollow Stem Auger
2R Drilling Inc. SYMBOL LITHOLOGY BLOWS

B BULK SAMPLE T TUBE SAMPLE TYPE
1 OF 1
N/A
Alta California Geotechnical, Inc.

P.N. 1-0486 PLATE B-6
Item #6. Page 1510
Meeting Date: 9/24/2024 / Packet Page #: 1646
ALTA CALIFORNIA GEOTECHNICAL, INC.

APPENDIX C
Laboratory Testing
Item #6. Page 1511
Meeting Date: 9/24/2024 / Packet Page #: 1647
Project Number 1‐0486 Page C‐1
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

LABORATORY TESTING
The following laboratory tests were performed on a representative sample in accordance with the applicable latest standards or methods from the ASTM, California Building Code (CBC) and California Department of Transportation.

Classification
Soils were classified with respect to the Unified Soil Classification System (USCS) in accordance with ASTM D‐2487 and D‐2488.

Particle Size Analysis
Modified hydrometer testing was conducted to aid in classification of the soil. The results of the particle size analysis are presented in Table C.

Maximum Density/Optimum Moisture
The maximum dry density and optimum moisture content of one representative bulk sample was evaluated in accordance with ASTM D‐1557. The results are summarized in Table C.

Expansion Index Tests
One (1) expansion index test were performed to evaluate the expansion potential of typical on‐ site soil. Testing was carried out in general conformance with ASTM Test Method D‐4829. The results are presented in Table C.

Consolidation Tests
Consolidation testing was performed on two (2) relatively “undisturbed” soil samples at their natural moisture content in accordance with procedures outlined in ASTM D‐2435.  The samples were placed in a consolidometer and loads were applied incrementally in geometric progression.  The samples (2.42‐inches in diameter and 1‐inch in height) were permitted to consolidate under each load increment until the slope of the characteristic linear secondary compression portion of the thickness versus log of time plot was apparent.  The percent Item #6. Page 1512
Meeting Date: 9/24/2024 / Packet Page #: 1648
Project Number 1‐0486   Page C‐2
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.
consolidation for each load cycle was recorded as the ratio of the amount of vertical compression to the original 1‐inch height.  The consolidation test results are shown on Plates C‐ 1 and C‐2.

Chemical Analyses
Chemical testing was performed on one select sample by Alta. The results of these tests (sulfate content, resistivity, chloride content and pH) are presented on Table C.

Item #6. Page 1513
Meeting Date: 9/24/2024 / Packet Page #: 1649
B-2 5 Gravelly Sand (Qyf) SP 10 78 9 3 SEE PLATE
C-1
B-3 2.5 Gravelly Sand (afu) SP 125.3 8.7 15 78 4 3 0 MinResist:13,860-OHMCM pH:8.8,Chl:115ppm,So4:<0.01%
B-3 5 Gravelly Sand (Qyf) SP 3 95 1 1 SEE PLATE
C-2

OTHER TESTS

REMARKS

BORING DEPTH
(FEET)

SOIL DESCRIPTION GROUP
SYMBOL
DIRECT
SHEAR

EXPANSION
INDEX
UBC 18-2

MAXIMUM

DENSITY
(PCF)

TABLE C

SUMMARY OF LABORATORY TEST DATA
P.N. 1-0486

OPTIMUM

MOISTURE

CONTENT
(%)
CONSOL
SILT
(0.075mm-0.005mm)
(%)
SAND
(4.76mm-0.075mm)
(%)
PLUS NO.4 SEIVE
(plus 4.76mm)
(%)
CLAY
(minus 0.005mm)
(%)
Alta California Geotechnical, Inc.

Item #6. Page 1514
Meeting Date: 9/24/2024 / Packet Page #: 1650
-2.0
-1.0
0 1.0

2.0 3.0

4.0 5.0

6.0 7.0

8.0 0.1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 910
REMARKS: WATER ADDED AT 1.07 TSF

CONSOLIDATION CURVE PERCENT CHANGE IN HEIGHT
PLATE C-1

COMPRESSIVE STRESS IN TSF
satur. (%)
115
-200
SP Gravelly Sand (Qyf)
boring in situ
51 group typical names density (pcf) sieve (%) symbol

8.5 moist. (%)
dry in situ depth (ft.)
B-2 5.0 12
Alta California Geotechnical, Inc.

P.N. 1-0486
Item #6. Page 1515
Meeting Date: 9/24/2024 / Packet Page #: 1651
-2.0
-1.0
0 1.0

2.0 3.0

4.0 5.0

6.0 7.0

8.0 0.1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 910
REMARKS: WATER ADDED AT 1.07 TSF

CONSOLIDATION CURVE PERCENT CHANGE IN HEIGHT
PLATE C-2

COMPRESSIVE STRESS IN TSF
satur. (%)
96 -200
SP Gravelly Sand (Qyf)
boring in situ
10 group typical names density (pcf) sieve (%) symbol

2.6 moist. (%)
dry in situ depth (ft.)
B-3 5.0 2
Alta California Geotechnical, Inc.

P.N. 1-0486
Item #6. Page 1516
Meeting Date: 9/24/2024 / Packet Page #: 1652
ALTA CALIFORNIA GEOTECHNICAL, INC.

APPENDIX D
Maintenance and Improvement Considerations
Item #6. Page 1517
Meeting Date: 9/24/2024 / Packet Page #: 1653
Project Number 1‐0486 Page D‐1
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

MAINTENANCE AND IMPROVEMENT CONSIDERATIONS
General
Owners purchasing property must assume a certain degree of responsibility for improvements and for maintaining conditions around their home. Of primary importance from a geotechnical standpoint are maintaining drainage patterns and minimizing the soil moisture variation below all improvements. Such design, construction and owner maintenance provisions may include:
 Employing contractors for improvements who design and build in recognition of local building codes and specific site soils conditions.
 Establishing and maintaining positive drainage away from all foundations, walkways, driveways, patios, and other improvements.
 Avoiding the construction of planters adjacent to structural improvements.

Alternatively, planter sides/bottoms can be sealed with an impermeable membrane and drained away from the improvements via subdrains into approved disposal areas.  Sealing and maintaining construction/control joints within concrete slabs and walkways to reduce the potential for moisture infiltration into the subgrade soils.  Utilizing landscaping schemes with vegetation that requires minimal watering. Watering should be done in a uniform manner, as equally as possible on all sides of the foundation, keeping the soil "moist" but not allowing the soil to become saturated.  Maintaining positive drainage away from structures and providing roof gutters on all structures with downspouts that are designed to carry roof runoff directly into area drains or discharged well away from the foundation areas.  Avoiding the placement of trees closer to the proposed structures than a distance of one‐half the mature height of the tree.
 Observation of the soil conditions around the perimeter of the structure during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to maintain relatively uniform moisture conditions.

Item #6. Page 1518
Meeting Date: 9/24/2024 / Packet Page #: 1654
Project Number 1‐0486 Page D‐2
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.

Sulfates
Owners should be cautioned against the import and use of certain inorganic fertilizers, soil amendments, and/or other soils from offsite sources in the absence of specific information relating to their chemical composition. Some fertilizers have been known to leach sulfate compounds into soils and increase the sulfate concentrations to potentially detrimental levels.

Site Drainage
 The owners should be made aware of the potential problems that may develop when drainage is altered through construction of hardscape improvements. Ponded water, drainage over the slope face, leaking irrigation systems, overwatering, or other conditions which could lead to ground saturation must be avoided.  No water should be allowed to flow over the slopes. No alteration of pad gradients should be allowed that would prevent pad and roof runoff from being directed to approved disposal areas.
 Drainage patterns have been established at the time of the fine grading should be maintained throughout the life of the structure. No alterations to these drainage patterns should be made unless designed by qualified professionals in compliance with local code requirements and site‐specific soils conditions.

Slope Drainage
 Residents should be made aware of the importance of maintaining and cleaning all interceptor ditches, drainage terraces, down drains, and any other drainage devices, which have been installed to promote slope stability.
 Subsurface drainage pipe outlets may protrude through slope surfaces and/or wall faces. These pipes, in conjunction with the graded features, are essential to slope and wall stability and must be protected in‐place. They should not be altered or damaged in any way.

Planting and Irrigation of Slopes
 Seeding and planting of the slopes should be planned to achieve, as rapidly as possible, a well‐established and deep‐rooted vegetal cover requiring minimal watering.  It is the responsibility of the landscape architect to provide such plants initially and of the residents to maintain such planting. Alteration of such a planting scheme is at the resident's risk.
 The resident is responsible for proper irrigation and for maintenance and repair of properly installed irrigation systems. Leaks should be fixed immediately.

Item #6. Page 1519
Meeting Date: 9/24/2024 / Packet Page #: 1655
Project Number 1‐0486 Page D‐3
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.
 Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wasteful runoff and serious ground saturation must be avoided.
 If automatic sprinkler systems are installed, their use must be adjusted to account for seasonal and natural rainfall conditions.

Burrowing Animals
 Residents must undertake a program to eliminate burrowing animals. This must be an ongoing program in order to promote slope stability.

Owner Improvement
Owner improvements (pools, spas, patio slabs, retaining walls, planters, etc.) should be designed to account for the terrain of the project, as well as expansive soil conditions and chemical characteristics. Design considerations on any given lot may need to include provisions for differential bearing materials, ascending/descending slope conditions, bedrock structure, perched (irrigation) water, special geologic surcharge loading conditions, expansive soil stresses, and long‐term creep/settlement.

All owner improvements should be designed and constructed by qualified professionals utilizing appropriate design methodologies, which account for the on‐site soils and geologic conditions.

Each lot and proposed improvement should be evaluated on an individual basis.

Setback Zones
Manufactured slopes may be subject to long‐term settlement and creep that can manifest itself in the form of both horizontal and vertical movement. These movements typically are produced as a result of weathering, erosion, gravity forces, and other natural phenomenon. A setback adjacent to slopes is required by most building codes, including the California Building Code.

This zone is intended to locate and support the residential structures away from these slopes and onto soils that are not subject to the potential adverse effects of these natural phenomena.

The owner may wish to construct patios, walls, walkways, planters, swimming pools, spas, etc. within this zone. Such facilities may be sensitive to settlement and creep and should not be constructed within the setback zone unless properly engineered. It is suggested that plans for Item #6. Page 1520
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Project Number 1‐0486 Page D‐4
June 22, 2023
ALTA CALIFORNIA GEOTECHNICAL, INC.
such improvements be designed by a professional engineer who is familiar with grading ordinances and design and construction requirements. In addition, we recommend that the designer and contractor familiarize themselves with the site specific geologic and geotechnical conditions on the specific lot.

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APPENDIX E
Earthwork Specifications
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APPENDIX F
Grading Details
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Initial Study/Mitigated Negative Declaration July 2024
Brandywine Route 66 Residential – PLN 23-0027

Page 167 ends

Appendix J
Noise Assessment, 723-731 East Route 66 Development
Project, City of Glendora, CA
Ldn Consulting, Inc.

February 9, 2024
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Project: 23-67 723-745 Route 66 Glendora Noise

NOISE ASSESSMENT
723-745 Route 66 Development Project
City of Glendora, CA
Prepared for:

Brandywine Homes
2355 Main Street, Suite 220
Irvine, CA 92614
Prepared By:
23811 Washington Ave, C110-333
Murrieta, California 92562
760-473-1253

February 9, 2024
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TABLE OF CONTENTS

TABLE OF CONTENTS .......................................................................................................................................... II LIST OF FIGURES ................................................................................................................................................ III LIST OF TABLES .................................................................................................................................................. III GLOSSARY OF COMMON TERMS ....................................................................................................................... IV EXECUTIVE SUMMARY ....................................................................................................................................... V

1.0 PROJECT INTRODUCTION ........................................................................................................................... 1

1.1 PURPOSE OF THIS STUDY ........................................................................................................................................ 1

1.2 PROJECT LOCATION .............................................................................................................................................. 1

1.3 PROJECT DESCRIPTION AND PURPOSE ....................................................................................................................... 1

2.0 FUNDAMENTALS........................................................................................................................................ 4

2.1 ACOUSTICAL FUNDAMENTALS ................................................................................................................................. 4

2.2 VIBRATION FUNDAMENTALS ................................................................................................................................... 4

3.0 SIGNIFICANCE THRESHOLDS AND STANDARDS ........................................................................................... 7

3.1 FEDERAL ............................................................................................................................................................. 7

3.2 STATE OF CALIFORNIA ........................................................................................................................................... 8

3.3 LOCAL REGULATIONS .......................................................................................................................................... 11

4.0 ENVIRONMENTAL SETTINGS & EXISTING CONDITIONS .............................................................................. 14

4.1 SETTINGS & LOCATIONS ...................................................................................................................................... 14

4.2 EXISTING NOISE CONDITIONS ............................................................................................................................... 14

4.3 NOISE MEASURING METHODOLOGY AND PROCEDURES ............................................................................................ 14

5.0 CONSTRUCTION NOISE ............................................................................................................................. 17

5.1 CONSTRUCTION NOISE PREDICTION METHODOLOGY ................................................................................................ 17

5.2 CONSTRUCTION NOISE FINDINGS ........................................................................................................................... 17

5.3 CONSTRUCTION VIBRATION FINDINGS .................................................................................................................... 19

6.0 TRANSPORTATION NOISE LEVELS .............................................................................................................. 20

6.1 GUIDELINES FOR THE DETERMINATION OF SIGNIFICANCE ............................................................................................ 20

6.2 FUTURE ONSITE ROADWAY NOISE ......................................................................................................................... 20

6.3 ONSITE RAIL LINE NOISE ...................................................................................................................................... 20

6.4 CUMULATIVE ONSITE NOISE LEVELS ....................................................................................................................... 22

6.5 INTERIOR NOISE ................................................................................................................................................. 23

6.6 TRAIN VIBRATION ............................................................................................................................................... 24

7.0 REFERENCES ............................................................................................................................................. 25 Item #6. Page 1551
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LIST OF FIGURES
FIGURE 1-A: PROJECT VICINITY MAP ................................................................................................................... 2 FIGURE 1-B: CONCEPTUAL SITE PLAN .................................................................................................................. 3 FIGURE 3-A: LAND USE – NOISE COMPATIBILITY GUIDELINES ............................................................................. 12 FIGURE 4-A: NOISE MEASUREMENT LOCATIONS ................................................................................................ 16 FIGURE 6-A: MODELED RECEPTOR LOCATIONS .................................................................................................. 21 FIGURE 6-B: FUTURE UNMITIGATED EXTERIOR NOISE LEVELS ............................................................................ 22

LIST OF TABLES
TABLE 2-1: HUMAN REACTION TO TYPICAL VIBRATION LEVELS ........................................................................... 6 TABLE 3-1: GROUNDBORNE VIBRATION AND NOISE IMPACT CRITERIA (HUMAN ANNOYANCE) ........................... 8 TABLE 3-2: GROUNDBORNE VIBRATION IMPACT CRITERIA (STRUCTURAL DAMAGE) ........................................... 8 TABLE 3-3: CALTRANS VIBRATION THRESHOLD CRITERIA FOR BUILDING DAMAGE ............................................. 11 TABLE 3-4: CALTRANS VIBRATION THRESHOLD CRITERIA FOR HUMAN RESPONSE .............................................. 11 TABLE 4-1: LONG-TERM NOISE LEVEL SUMMARY ............................................................................................... 15 TABLE 5-1: CONSTRUCTION PHASES AND NOISE LEVELS ..................................................................................... 18 TABLE 5-2: CONSTRUCTION NOISE LEVELS ......................................................................................................... 18 TABLE 5-3: VIBRATION LEVELS FROM CONSTRUCTION ACTIVITIES (RESIDENTIAL RECEPTORS) ............................ 19 Item #6. Page 1552
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GLOSSARY OF COMMON TERMS
Sound Pressure Level (SPL): a ratio of one sound pressure to a reference pressure (Lref) of 20 μPa. Because of the dynamic range of the human ear, the ratio is calculated logarithmically by 20 log (L/Lref).

A-weighted Sound Pressure Level (dBA): Some frequencies of noise are more noticeable than others. To compensate for this fact, different sound frequencies are weighted more.

Minimum Sound Level (Lmin): Minimum SPL or the lowest SPL measured over the time interval using the A-weighted network and slow time weighting.

Maximum Sound Level (Lmax): Maximum SPL or the highest SPL measured over the time interval the A-weighted network and slow time weighting.

Equivalent sound level (Leq): the true equivalent sound level measured over the run time. Leq is the A-weighted steady sound level that contains the same total acoustical energy as the actual fluctuating sound level.

Day Night Sound Level (Ldn): Representing the Day/Night sound level, this measurement is a 24 –hour average sound level where 10 dB is added to all the readings that occur between 10 pm and 7 am. This is primarily used in community noise regulations where there is a 10 dB “Penalty” for nighttime noise. Typically, Ldn’s are measured using A weighting.

Community Noise Exposure Level (CNEL): The accumulated exposure to sound measured in a 24-hour sampling interval and artificially boosted during certain hours. For CNEL, samples taken between 7 pm and 10 pm are boosted by 5 dB; samples taken between 10 pm and 7 am are boosted by 10 dB.

Octave Band: An octave band is defined as a frequency band whose upper band-edge frequency is twice the lower band frequency.

Third-Octave Band: A third-octave band is defined as a frequency band whose upper bandedge frequency is 1.26 times the lower band frequency.

Response Time (F,S,I): The response time is a standardized exponential time weighting of the input signal according to fast (F), slow (S) or impulse (I) time response relationships. Time response can be described with a time constant. The time constants for fast, slow and impulse responses are 1.0 seconds, 0.125 seconds and 0.35 milliseconds, respectively.

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EXECUTIVE SUMMARY
This noise study has been completed to determine the noise impacts to and from the proposed multi-family residential project. The project proposes the construction of six 3-story multi-family residential buildings consisting of 39 townhomes/flats. The project is located at 723-745 East Route 66 in the City of Glendora within the San Gabriel Valley in the County of Los Angeles.

Construction Noise and Vibration
Project construction noise levels are considered exempt if activities occur within the hours specified in the City of Glendora Municipal Code, Section 9.44.110 of 7:00 a.m. and 9:00 p.m., if located within a residential zone or within a radius of five hundred feet therefrom unless approval is obtained from the City Building Official or City Engineer.

Nonetheless, in addition to complying with the City’s noise standards regarding construction working hours and noise levels, construction noise should be minimized through the implementation of best management practices (BMPs) that may include, but are not limited to, the following:
• Proper maintenance and tuning of all construction equipment engines to minimize noise emissions.
• Proper maintenance and functioning of the mufflers on all internal combustion and equipment engine.
• Locate fixed and/or stationary equipment as far as possible from noise-sensitive receptors. • Appoint a public liaison for Project construction that would be responsible for addressing public concerns about construction activities, including excessive noise. As needed, the liaison would determine the cause of concern (e.g., starting too early, bad muffler) and implement measures to address the concern. These BMPs would further reduce construction noise levels.

Construction activities would generate levels of vibration that would not exceed the FTA or City criteria for nuisance for nearby residential uses. Therefore, vibration impacts would be less than significant.

Transportation Noise
The results of this analysis indicate that future vehicle noise from Route 66 to the south and train noise from the Foothill Gold Line extension to the north are the principal sources of community noise that could impact the site. Based upon the findings, the outdoor use areas were determined to be below the City’s Noise compatibility threshold of 70 dBA CNEL without attenuation measures.

Therefore, no impacts are anticipated and no mitigation (i.e., noise walls) are required.

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Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise The City of Glendora noise guidelines also state, consistent with Title 24 of the California Code of Regulations (CCR), that a project is required to perform an interior assessment on the portions of a project site where building façade noise levels are above the normally compatible noise level in order to ensure that acceptable interior noise levels can be achieved. The buildings would be exposed to noise levels up to 69 dBA CNEL at the facades; thus, the proposed project would be required to prepare an interior noise study for all units to reduce interior noise levels to 45 dBA CNEL.

Basic calculations show that a windows open condition will typically reduce the interior noise levels 10-15 dBA CNEL and not provide adequate interior noise mitigation. To meet the 45 dBA CNEL interior noise standard, an overall minimum interior noise level reduction of 24 dBA CNEL is needed for the proposed project. Therefore, a closed window condition with an STC rating of 28 or better is required to reduce interior noise levels to comply with CCR Title 24 and City of Glendora requirements.

Additionally, ground mounted mechanical ventilation units (HVAC) will be installed at the proposed residential units and could potentially be located near windows. Typically, 3 to 5-ton HVAC units could generate noise levels between 70 to 74 dBA, therefore, upgraded windows would be required to mitigate the noise levels from the HVAC units. Depending on the type and where the HVAC units are located near a window, upgraded glass assemblies of up to STC 33 could be required to reduce the interior noise levels to below the 45 dBA CNEL noise standard. Once the final site plans showing the locations of the HVAC units and final architectural plans are available, a final interior noise study should be conducted to ensure interior noise reductions.

Transportation Vibration
According to the Metro Gold Line Foothill Extension EIR, the Metro Gold Foothill Extension project is proposing the use of floating slab, ballast mat, TDC, and reduced speeds to reduce vibration levels to less than significant levels. Based on the Metro Gold Foothill Extension design features and the setbacks from the rail alignment, no additional project related mitigation measures are required.

Due to the close proximity to the railroad, special consideration should be taken to minimize effects of vibration on the existing buildings. The use of vibration dampening materials such as carpeting as well as upgraded windows and doors can significantly reduce the effects of groundborne vibration within the buildings.

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1.0 PROJECT INTRODUCTION

1.1 Purpose of this Study
The purpose of this Noise study is to determine noise impacts, if any, to the Project from off-site sources (i.e., traffic, train) and from the project (i.e., construction, operational) onto surrounding uses. Should impacts be determined, the intent of this study would be to recommend suitable mitigation measures to bring those impacts to a level that would be considered less than significant.

1.2 Project Location
The proposed 723-745 Route 66 Multi-Family Residential development is located on an approximate 1.85-acre project site located at 723-745 East Route 66 in the City of Glendora, CA.

The project is generally located north of Interstate 210 (I-210) and east of State Route 39 (SR39) between Glendora Avenue and Lone Hill Avenue. Glendora Avenue and Lone Hill Avenue provide regional access to the project site via I-210 to the south. The project site is surrounded by existing retail uses to the east and west, existing single-family residences to the north, and East Route 66 to the south. Existing multi-family residential uses are located across Route 66 to the south. The Foothill Gold Line within the Los Angeles Metro Rail system is located adjacent to the project to the north and is currently under construction to build an extension to the light rail system. A project vicinity map and location map are shown in Figure 1-A.

1.3 Project Description and Purpose
The project proposes the construction of six 3-story multi-family residential buildings consisting of 39 townhomes/flats. The residential units will consist of one, two, and three-bedroom floor plans. The conceptual site plan is shown on Figure 1-B of this report.

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2 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Figure 1-A: Project Vicinity Map
Project
Location
Source: (Google, 2023)
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3 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Figure 1-B: Conceptual Site Plan
Source: (KTGY Architecture + Planning, 2023)
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2.0 FUNDAMENTALS

2.1 Acoustical Fundamentals
Noise is defined as unwanted or annoying sound which interferes with or disrupts normal activities. Exposure to high noise levels has been demonstrated to cause hearing loss. The individual human response to environmental noise is based on the sensitivity of that individual, the type of noise that occurs and when the noise occurs.

Sound is measured on a logarithmic scale consisting of sound pressure levels known as a decibel (dB). The sounds heard by humans typically do not consist of a single frequency but of a broadband of frequencies having different sound pressure levels. The method for evaluating all the frequencies of the sound is to apply an A-weighting to reflect how the human ear responds to the different sound levels at different frequencies. The A-weighted sound level adequately describes the instantaneous noise whereas the equivalent sound level depicted as Leq represents a steady sound level containing the same total acoustical energy as the actual fluctuating sound level over a given time interval.

The U.S. Environmental Protection Agency (U.S. EPA) has compiled data regarding the noise generating characteristics of specific types of construction equipment. Noise levels generated by heavy construction equipment can range from 60 dBA to in excess of 100 dBA when measured at 50 feet. However, these noise levels diminish rapidly with distance from the construction site at a rate of approximately 6 dBA per doubling of distance. For example, a noise level of 75 dBA measured at 50 feet from the noise source to the receptor would be reduced to 69 dBA at 100 feet from the source to the receptor and reduced to 63 dBA at 200 feet from the source. The most effective noise reduction methods consist of controlling the noise at the source, blocking the noise transmission with barriers or relocating the receiver. Any or all of these methods may be required to reduce noise levels to an acceptable level.

The most effective noise reduction methods consist of controlling the noise at the source, blocking the noise transmission with barriers or relocating the receiver. Any or all of these methods may be required to reduce noise levels to an acceptable level.

2.2 Vibration Fundamentals
Vibration is a trembling or oscillating motion of the ground. Like noise, vibration is transmitted in waves, but in this case through the ground or solid objects. Unlike noise, vibration is typically felt rather than heard. Vibration can be either natural as in the form of earthquakes, volcanic eruptions, or manmade as from explosions, heavy machinery, or trains. Both natural and Item #6. Page 1559
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5 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise manmade vibration may be continuous, such as from operating machinery; or infrequent, as from an explosion.

As with noise, vibration can be described by both its amplitude and frequency. Amplitude may be characterized in three ways: displacement, velocity, and acceleration. Particle displacement is a measure of the distance that a vibrated particle travels from its original position and for the purposes of soil displacement is typically measured in inches or millimeters. Particle velocity is the rate of speed at which soil particles move in inches per second or millimeters per second.

Particle acceleration is the rate of change in velocity with respect to time and is measured in inches per second or millimeters per second. Typically, particle velocity (measured in inches or millimeters per second) and/or acceleration (measured in gravities) are used to describe vibration.

Table 2-1 shows the human reaction to various levels of peak particle velocity.

Vibrations also vary in frequency and this affects perception. Typical construction vibrations fall in the 10 to 30 Hz range and usually occurring around 15 Hz. Traffic vibrations exhibit a similar range of frequencies; however, due to their suspension systems, it is less common, to measure traffic frequencies above 30 Hz.

Propagation of ground-borne vibrations is complicated and difficult to predict because of the endless variations in the soil through which the waves travel. There are three main types of vibration propagation: surface, compression, and shear waves. Surface waves, or Rayleigh waves, travel along the ground’s surface. These waves carry most of their energy along an expanding circular wave front, similar to ripples produced by dropping an object into water. P-waves, or compression waves, are waves that carry their energy along an expanding spherical wave front.

The particle motion in these waves is longitudinal. S-waves, or shear waves, are also body waves that carry energy along an expanding spherical wave front. However, unlike P-waves, the particle motion is transverse, or side-to-side and perpendicular to the direction of propagation.

As vibration waves propagate from a source, the energy is spread over an ever-increasing area such that the energy level is reduced with the distance from the energy source. This geometric spreading loss is inversely proportional to the square of the distance. Wave energy is also reduced with distance as a result of material damping in the form of internal friction, soil layering, and special voids. The amount of attenuation provided by material damping varies with soil type and condition as well as the frequency of the wave.

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6 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Table 2-1: Human Reaction to Typical Vibration Levels
Vibration Level
Peak Particle Velocity
(in/sec)
Human Reaction Effect on Buildings

0.006–0.019 Threshold of perception, possibility of
intrusion
Vibrations unlikely to cause damage of any
type

0.08 Vibrations readily perceptible
Recommended upper level of vibration to
which ruins and ancient monuments should
be subjected

0.10 Level at which continuous vibration
begins to annoy people
Virtually no risk of “architectural” (i.e., not
structural) damage to normal buildings

0.20 Vibrations annoying to people in
buildings
Threshold at which there is a risk to
“architectural” damage to normal dwelling –
houses with plastered walls and ceilings

0.4–0.6
Vibrations considered unpleasant by
people subjected to continuous
vibrations and unacceptable to some
people walking on bridges
Vibrations at a greater level than normally
expected from traffic, but would cause
“architectural” damage and possibly minor
structural damage
Source: Caltrans, Division of Environmental Analysis, Transportation Related Earthborne Vibration, Caltrans Experiences, Technical Advisory, Vibration, TAV-02-01-R9601, 2020 (Caltrans, 2020).

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3.0 SIGNIFICANCE THRESHOLDS AND STANDARDS
To limit population exposure to physically and/or psychologically damaging as well as intrusive noise levels, the federal government, the State of California, various county governments, and most municipalities in the state have established standards and ordinances to control noise.

Roadway, Air and rail traffic, and commercial and industrial activities are typically the major sources of noise in some areas. Federal, state, and local agencies regulate different aspects of environmental noise. Federal and state agencies generally set noise standards for mobile sources such as aircraft and motor vehicles. Local agencies generally set noise standards or regulations of stationary sources.

3.1 Federal
Federal Transit Administration (FTA)
No federal regulations apply to noise or vibration from the proposed project, but the United States Department of Transportation Federal Transit Administration (FTA) provides criteria for acceptable levels of groundborne vibration for various types of special buildings that are sensitive to vibration (Federal Transit Administration, 2018). For purposes of identifying potential projectrelated vibration impacts, the FTA criteria will be used. The human reaction to various levels of vibration is highly subjective. The upper end of the range shown for the threshold of perception, or roughly 65 VdB, may be considered annoying by some people. Vibration below 65 VdB may also cause secondary audible effects, such as a slight rattling of doors, suspended ceilings/fixtures, windows, and dishes, any of which may result in additional annoyance. Table 3-1 on the following page, shows the FTA groundborne vibration and noise impact criteria for human annoyance.

In addition to the vibration annoyance standards presented above, the FTA also applies the following standards for construction vibration damage. As shown in Table 3-2 on the following page, structural damage is possible for typical residential construction when the peak particle velocity (PPV) exceeds 0.2 inch per second (in/sec). This criterion is the threshold at which there is a risk of damage to normal dwellings.

In the context of this analysis, the noise and vibration impacts associated with the construction operations will be conditioned to comply with the thresholds stated above. The potential noise and vibration impacts are analyzed separately below.

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8 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Table 3-1: Groundborne Vibration and Noise Impact Criteria (Human Annoyance) Category
Groundborne Vibration
Impact Levels
(VdB re 1 microinch/second)
Groundborne Noise Impact Levels
(dB re 20 micropascals)
Frequent
Events1
Occasional
Events2
Infrequent
Events3
Frequent
Events1
Occasional
Events2
Infrequent
Events3
Category 1: Buildings where low
ambient vibration is essential for interior
operations.
65 VdB4 65 VdB4 65 VdB4 N/A4 N/A4 N/A4
Category 2: Residences and buildings
where people normally sleep. 72 VdB 75 VdB 80 VdB 35 dBA 38 dBA 43 dBA Category 3: Institutional land uses with
primarily daytime use. 75 VdB 78 VdB 83 VdB 40 dBA 43 dBA 48 dBA Source: (Federal Transit Administration, 2018)
1 “Frequent Events” are defined as more than 70 vibration events per day. Most rapid transit projects fall into this category. 2 “Occasional Events” are defined as between 30 and 70 vibration events of the same source per day. Most commuter truck lines have this many operations.
3 “Infrequent Events” are defined as fewer than 30 vibration events of the same kind per day. This category includes most commuter rail branch lines.
4 This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical microscopes.

Vibration-sensitive manufacturing or research will require detailed evaluation to define the acceptable vibration levels. Ensuring lower vibration levels in a building often requires special design of the HVAC systems and stiffened floors. 5 Vibration-sensitive equipment is not sensitive to groundborne noise.

Table 3-2: Groundborne Vibration Impact Criteria (Structural Damage) Building Category PPV (in/sec) VdB
I. Reinforced-concrete, steel, or timber (no plaster) 0.5 102 II. Engineered concrete and masonry (no plaster) 0.3 98 III. Non-engineered timber and masonry buildings 0.2 94 IV. Buildings extremely susceptible to vibration damage 0.12 90 Source: (Federal Transit Administration, 2018)
Notes: RMS velocity calculated from vibration level (VdB) using the reference of one microinch/second.

3.2 State of California
Community Noise Assessment Criteria
The following significance criteria are based on guidance provided by Appendix G of the California Environmental Quality Act (CEQA) Guidelines. For the purposes of this report, noise impacts would be potentially significant if the proposed Project is determined to result in or cause:

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9 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise • Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies; • A substantial permanent increase in ambient noise levels in the Project vicinity above existing levels without the proposed Project; or
• A substantial temporary or periodic increase in ambient noise levels in the Project vicinity above noise levels existing without the proposed Project.

While the CEQA Guidelines and City of Glendora noise standards provide direction on noise compatibility and establish noise standards by land use type, they do not define the levels at which increases above the ambient noise levels are considered substantial. However, the Federal Highway Administration and Caltrans both identify changes in noise levels of greater than 3 dBA as "barely perceptible," while changes of 5 dBA are considered "readily perceptible.” This is consistent with the community response to noise characteristics described in Section 3.3 below.

In a community situation, the noise exposure is extended over a long time period, and changes in noise levels occur over years rather than the immediate comparison made in a laboratory situation. The level at which changes in community noise levels become discernible is likely to be some value greater than 1 dBA, and 3 dBA appears to be appropriate for most people. On this basis, and for the purposes of this study, a substantial increase in noise levels attributable to operations of the Project would occur if:

1. Ambient conditions are below applicable standards, and project-generated noise at receptor land uses would result in:
• An exceedance of the suggested land uses/noise compatibility guidelines for surface transportation sources presented in the City of Glendora Noise Element (mobile sources); or
• An exceedance of the exterior noise standards defined in the City of Glendora Noise Ordinance (area/stationary sources);

2. If ambient noise conditions exceed applicable Noise Ordinance Standards and projectgenerated noise would create a “barely perceptible” 3 dBA or greater permanent increase in ambient exterior noise levels.

3. For construction noise, a substantial increase in noise would occur if project-related construction activities occur outside the hours of 7:00 a.m. and 9:00 p.m.

California Building Standards Code
The California Building Standards Code is contained in Title 24 of the California Code of Regulations and consists of 11 different parts that set various construction and building Item #6. Page 1564
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10 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise requirements. Part 2, California Building Code, Section 1207, Sound Transmission, establishes sound transmission standards for interior walls, partitions, and floor/ceiling assemblies.

Specifically, Section 1207.4 establishes that interior noise levels attributable to exterior noise sources shall not exceed 45 dBA DNL or CNEL (as set by the local General Plan) in any habitable room.

California Green Building Standards Code
The California Green Building Standards Code is Part 11 to the California Building Standards Code.

Chapter 5, Nonresidential Mandatory Standards, Section 5.507 establishes the following requirements for non-residential development that may be applicable to the proposed project. • 5.507.4.1.1 sets forth that buildings exposed to a noise level of 65 dB Leq (1-hour) during any hour of operation shall have exterior wall and roof-ceiling assemblies exposed to the noise source meeting a composting sound transmission class (STC) rating of at least 45 (or an outdoor indoor transmission class (OITC) of 35), with exterior windows of a minimum STC of 40.
• Section 5.507.4.2 sets forth that wall and roof assemblies for buildings exposed to a 65 dBA Leq pursuant to Section 5.507.4.1.1, shall be constructed to provide an interior noise environment attributable to exterior sources that does not exceed 50 dBA Leq in occupied areas during any hour of operation. This requirement shall be documented by preparing an acoustical analysis documenting interior sound levels prepared by personnel approved by the architect or engineer of record.

Caltrans
The California Department of Transportation’s (Caltrans) Transportation and Construction Vibration Guidance Manual provides a summary of vibration criteria that have been reported by researchers, organizations, and governmental agencies (Caltrans, 2020). Chapters Six and Seven of this manual summarize vibration detection and annoyance criteria from various agencies and provide Caltrans recommended guidelines and thresholds for evaluating potential vibration impacts on buildings and humans from transportation and construction projects. These thresholds are summarized in Table 3-3 and Table 3-4.

Item #6. Page 1565
Meeting Date: 9/24/2024 / Packet Page #: 1701
11 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Table 3-3: Caltrans Vibration Threshold Criteria for Building Damage Structural Integrity Maximum PPV (in/sec)
Transient Continuous
Extremely Fragile buildings, ruins, monuments 0.12 0.08 Fragile Buildings 0.2 0.1
Historic and some older buildings 0.50 0.25
Older residential structures 0.50 0.30
New residential structures 1.00 0.50
Modern industrial and commercial buildings 2.00 0.50
Source: (Caltrans, 2020)
Note: PPV = peak particle velocity
Table 3-4: Caltrans Vibration Threshold Criteria for Human Response Human Response
Maximum PPV (in/sec)
Transient Continuous
Barely perceptible 0.035 0.012
Distinctly perceptible 0.24 0.035
Strongly perceptible 0.90 0.10
Severely perceptible 2.00 0.40
Source: (Caltrans, 2020)
Note: PPV = peak particle velocity

3.3 Local Regulations
The City of Glendora General Plan and Municipal Code establishes the following applicable policies related to noise and vibration.

City of Glendora General Plan Noise Element
The City of Glendora Community Plan Noise Element states that the Noise and Land Use Compatibility Guidelines, (shown in Table N-1 of the Noise Element and provided below in Figure 3-A in this report) and the accompanying discussion should set forth the criteria for siting new development in the City of Glendora (City of Glendora, 2008). These guidelines state that any project which would be located in a normally unacceptable noise exposure area, based on the Land Use Compatibility Guidelines, shall require an acoustical analysis. Noise mitigation in the future shall be incorporated in the project as needed. As a condition of approval of a project, the City may require post-construction noise monitoring and sign off by an acoustician to ensure that City requirements have been met.

Item #6. Page 1566
Meeting Date: 9/24/2024 / Packet Page #: 1702
12 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Pursuant to the Noise and Land Use Compatibility Guidelines (Figure 3-A below), exterior noise levels ranging up to 65 dBA CNEL are classified as “normally acceptable” for multi-family residential development based upon the assumption that the homes are built with normal conventional construction. Noise levels ranging from 60 to 70 dBA CNEL are “conditionally acceptable”. “Conditionally acceptable” means that noise levels are acceptable only when a detailed noise analysis is conducted and needed noise insulation features are included in the design.

Conventional construction with closed windows and a fresh air supply system or air conditioning will normally suffice as "acceptable noise insulation" features. Noise levels in the 70 to 75 dBA Ldn range are classified as “normally unacceptable” and new construction or development is discouraged but may proceed if a detailed noise analysis is conducted and needed noise insulation features included in the design. Noise levels between 75-85 dBA CNEL are clearly unacceptable and development of these land uses should generally not be undertaken.

Figure 3-A: Land Use – Noise Compatibility Guidelines

Item #6. Page 1567
Meeting Date: 9/24/2024 / Packet Page #: 1703
13 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Interior noise levels should be mitigated to a maximum of 45 dBA CNEL in all habitual rooms when the exterior of the residences are exposed to levels of 60 dBA CNEL or more. If windows and doors are required to be closed to meet the interior noise standard, then mechanical ventilation shall be provided per City requirements.

City of Glendora Municipal Code
Construction Noise
Section 9.44.110 of the City of Glendora Noise Ordinance states that it is unlawful for any person within a residential zone, or within a radius of five hundred feet therefrom, to operate equipment or perform any outside construction or repair work on buildings, structures or projects or to operate any pile driver, power shovel, pneumatic hammer, derrick, power hoist or any other construction type device (between the hours of nine p.m. of one day and seven a.m. of the next day) in such a manner that a reasonable person of normal sensitiveness residing in the area is caused discomfort or annoyance unless beforehand a permit therefor has been duly obtained from the city. No permit shall be required to perform emergency work as defined in Section

9.44.020(c).

Item #6. Page 1568
Meeting Date: 9/24/2024 / Packet Page #: 1704
14 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise

4.0 ENVIRONMENTAL SETTINGS & EXISTING CONDITIONS

4.1 Settings & Locations
The project is located within the Route 66 Corridor Specific Plan which was established to improve the economic vitality and livability of the corridor through the establishment of a comprehensive strategy to retain existing business and attract additional commercial, industrial, office, retail, and residential opportunities. The residential aspect of the specific plan is intended to contribute to the mix of housing choices offered to Glendora residents and provide consistency with the Glendora General Plan 2013-2021 Housing Element.

The surrounding land uses to the east and west are zoned Commercial and the land uses to the north across the railroad tracks are zoned single-family residential (R-1). The apartments to the south across Route 66 are zoned multi-family residential (R-3). The Foothill Gold Line within the Los Angeles Metro Rail system is located adjacent to the project to the north and is currently under construction to build an extension to the light rail system.

4.2 Existing Noise Conditions
The project is adjacent to existing commercial uses to the east and west. The primary source of noise to the project site will be transportation noise from Route 66 to the south and the future commuter train noise from the Foothill Gold Line to the north.

4.3 Noise Measuring Methodology and Procedures
Long-term 24-hour measurements were taken at the project site having a relatively flat terrain and no obstruction from trees or structures. The noise measurements were recorded on Tuesday September 19th to Wednesday September 20th, 2023 by Ldn Consulting between approximately 1:00 p.m. and 1:00 p.m. the following day. Noise measurements were taken using a Larson-Davis Spark Model 706 Type 2 precision sound level meter, programmed, in "slow" mode, to record noise levels in "A" weighted form. The sound level meter and microphone were mounted on a tripod, five feet above the ground and equipped with a windscreen during all measurements. The sound level meter was calibrated before and after the monitoring using a Larson-Davis calibrator, Model CAL 200.

Table 4-1 provides the hourly noise levels along with the average and CNEL values. The noise measurement locations were determined based on site access and noise impact potential to the proposed sensitive uses. Long-term monitoring location 1 (LT-1) was located at the central portion of the project site. The noise monitoring locations are provided graphically in Figure 4-A.

Item #6. Page 1569
Meeting Date: 9/24/2024 / Packet Page #: 1705
15 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Table 4-1: Long-Term Noise Level Summary
LT-1
(Leq)
LT-1
(CNEL)
2:00 PM 53.2 53.2
3:00 PM 53.7 53.7
4:00 PM 54.4 54.4
5:00 PM 53.5 53.5
6:00 PM 56.6 56.6
7:00 PM 56.3 56.3
8:00 PM 53.8 53.8
9:00 PM 53.3 53.3
10:00 PM 53.0 53.0
11:00 PM 52.2 62.2
12:00 AM 49.2 59.2
1:00 AM 46.1 56.1
2:00 AM 45.4 55.4
3:00 AM 45.4 55.4
4:00 AM 45.2 55.2
5:00 AM 45.4 55.4
6:00 AM 49.5 59.5
7:00 AM 54.4 64.4
8:00 AM 55.3 55.3
9:00 AM 55.6 55.6
10:00 AM 54.0 54.0
11:00 AM 53.7 53.7
12:00 PM 53.6 53.6
1:00 PM 52.7 52.7
Overall 53.1 57.0
Item #6. Page 1570
Meeting Date: 9/24/2024 / Packet Page #: 1706
16 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Figure 4-A: Noise Measurement Locations
LT-1
Item #6. Page 1571
Meeting Date: 9/24/2024 / Packet Page #: 1707
17 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise

5.0 CONSTRUCTION NOISE

5.1 Construction Noise Prediction Methodology
Construction noise represents a short-term impact on the ambient noise levels. Noise generated by construction equipment includes haul trucks, water trucks, graders, dozers, loaders and scrapers can reach relatively high levels. Grading activities typically represent one of the highest potential sources for noise impacts. The most effective method of controlling construction noise is through local control of construction hours and by limiting the hours of construction to normal weekday working hours.

The project site is generally flat with an existing retail structure on site. Therefore, no significant grading activities are anticipated. Grading activities would be limited to minor grade adjustments required for the preparation of paving activities for the internal parking areas and drive aisles.

5.2 Construction Noise Findings
Construction of the proposed Project will require equipment such as loaders, pick-up trucks, backhoes, and an asphalt paver. Construction activities will take place between the hours of 7:00 a.m. and 9:00 p.m. in accordance with the City’s Noise Ordinance.

The development construction will consist of grading, building construction, and paving. The building construction activities will consist of trenching, paving, and building construction. Noise would typically occur during this phase due to the operation of backhoes, and front-end loaders as well as air compressors and hand-held power tools. The nearest residences to be impacted by construction are the single-family homes located to the north across the proposed train tracks and the existing apartments to the south across Route 66. Noise monitoring was conducted during the construction at a larger construction site to determine the noise levels from the associated equipment (Campus Park Multi-Family, LDN Consulting, 2017). A list of the anticipated noise levels for each phase of construction is shown in Table 5-1.

Item #6. Page 1572
Meeting Date: 9/24/2024 / Packet Page #: 1708
18 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Table 5-1: Construction Phases and Noise Levels
Construction
Phase
Source Level @
50’ (dBA)
Distance from
Property Line
(Feet)
Noise Reduction
from distance
(dBA)
Noise Reduction
from Duty Cycle
(dBA)
Resultant Noise
Level (dBA)
Site Grading 75.7 60 -1.6 -3.0 71.1
Building
Construction 68.2 60 -1.6 -3.0 63.6
Architectural
Coating 62.3 60 -1.6 -3.0 57.7
Paving Equipment 71.6 60 -1.6 -3.0 67.0
Due to the smaller site area, less equipment will be utilized compared to the previously referenced project. Due to the site constraints, the construction equipment would not be running continuously and would be moving near the property line to other portions of the project site for an average distance of 60-feet. Utilizing a duty-cycle of 30 minutes of any given hour that the equipment would be operating at a single location would reduce the noise levels a minimum of 3 dBA hourly.

Based on the EPA noise emissions, empirical data and the amount of equipment needed, worst-case noise levels from the construction equipment operations would occur during the base operations (grading/site preparation). The construction schedule identifies that grading activities will occur in a single phase all at the same time, with anticipated equipment including an excavator, a grader, a rubber tire dozer, and two tractors/backhoes. Due to physical constraints and normal site preparation operations, most of the equipment will be spread out over the site. A list of equipment used during grading is summarized in Table 5-2.

Table 5-2: Construction Noise Levels
Construction
Equipment Quantity
Source Level
@ 50-Feet
(dBA)*
Cumulative Noise Level
@ 100-Feet
(dBA)
Tractor/Loader/Backhoe 3 72 70.8
Rubber Tire Dozer 1 74 68.0
Grader 1 73 67.0
Excavator 1 79 73.0
*
Source: U.S. Environmental Protection Agency (U.S. EPA), 1971 and Empirical Data At any given time, a piece of construction equipment would only be within 100 feet of a sensitive receptor for a very short duration, after which it would move to another part of the project site, further from existing sensitive receptors. Construction activity noise levels are only expected to near 75 dBA at residential property lines when activity is taking place in close proximity to the property Item #6. Page 1573
Meeting Date: 9/24/2024 / Packet Page #: 1709
19 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise line, and at all other times will be less than 75 dBA. Due to the area of the site, this scenario is only expected to take place for very brief periods of time throughout the day, and for this reason, construction limited to the allowable hours of operation established within the code will comply with City of Glendora noise regulations. At the time of this analysis, no Project construction activity is planned outside of the specified hours, therefore, no impacts are anticipated.

At the time of this analysis, no Project construction activity is planned outside of the specified hours. Therefore, no impacts are anticipated and no mitigation is required during construction of the proposed Project. Additionally, all equipment should be properly fitted with mufflers and all staging and maintenance should be conducted as far away from the existing residence as possible.

5.3 Construction Vibration Findings
The nearest vibration-sensitive uses are the existing single-family homes to the north and the multi-family residential uses to the south located 200 feet or more from the center of the proposed construction. Table 6-3 lists the average vibration levels that would be experienced at the nearest vibration sensitive land uses from the temporary construction activities.

Table 5-3: Vibration Levels from Construction Activities (Residential Receptors) Equipment
Approximate
Velocity Level
at 25 Feet
(VdB)
Approximate
RMS Velocity
at 25 Feet
(in/sec)
Approximate
Velocity Level
at 200 Feet
(VdB)
Approximate
RMS Velocity
at 200 Feet
(in/sec)
Large Dozer 87 0.089 59.9 0.0039
Backhoe Ram 87 0.089 59.9 0.0039
Jackhammer 79 0.035 51.9 0.0015
Loaded Trucks 86 0.076 58.9 0.0034
Criteria 80 0.05
Significant Impact? No No
1 PPV at Distance D = PPVref x (25/D)1.5
The FTA has determined vibration levels that would cause annoyance to a substantial number of people and potential damage to building structures. The FTA criterion for infrequent vibration induced annoyance is 80 Vibration Velocity (VdB) for residential uses. For the purpose of this section of the municipal code, the perception threshold shall be presumed to be more than 0.05 inch per second RMS vertical velocity. Construction activities would generate levels of vibration that would not exceed the FTA or City criteria for nuisance for nearby residential uses. Therefore, vibration impacts would be less than significant.

Item #6. Page 1574
Meeting Date: 9/24/2024 / Packet Page #: 1710
20 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise

6.0 TRANSPORTATION NOISE LEVELS

6.1 Guidelines for the Determination of Significance
The Noise Element includes standards for land use compatibility for community noise exposure.

For the purposes of this project, the noise impacts associated with traffic are controlled by the Community Plan 2025. For noise sensitive multi-family residential areas, the exterior noise levels should remain below 70 dBA CNEL to be considered “conditionally acceptable” and the interior noise levels should remain below 45 dBA CNEL.

6.2 Future Onsite Roadway Noise
The primary source of roadway noise to the project site will be from vehicular traffic from adjacent Route 66 to the south. According to the City’s General Plan Projected Buildout Noise Contours, the 70 dBA CNEL noise contour of Route 66 is located 47-feet from the centerline of the roadway.

Therefore, at a distance of 66-feet, the patios and building facades of the front units adjacent to Route 66 are expected to be as high as 67.8 dBA CNEL. The modeled observer locations for the outdoor use areas are presented in Figure 6-A.

6.3 Onsite Rail Line Noise
The nearest building façade of the proposed Project is located approximately 86 feet from the centerline of the future light rail extension of the Foothill Gold Line of the Los Angeles Metro Rail system. According to the Metro Gold Line Foothill Extension EIR, noise levels in the vicinity of the project are expected to be as high as 67 dBA Ldn at a distance of 34-feet (ATS Consulting, 2013).

Noise levels would therefore be reduced to approximately 61.0 dBA CNEL at the nearest building façade due to the setback from the rail alignment. According to the EIR, the noise levels account for both light rail transit (LRT) trains and freight trains with horn noise. Additionally, outdoor usable space is provided by a central courtyard area that will be shielded from the future rail line by the proposed buildings that would provide additional noise reductions.

Item #6. Page 1575
Meeting Date: 9/24/2024 / Packet Page #: 1711
21 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Figure 6-A: Modeled Receptor Locations
3 Modeled Receptors
1 3
2 Item #6. Page 1576
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22 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise

6.4 Cumulative Onsite Noise Levels
The noise levels determined for the roadway and train activities were combined to determine the overall cumulative noise levels at the proposed receptors. Sound levels are logarithmic and so cannot be manipulated without being converted back to a linear scale. You must first antilog each number, add or subtract and then log them again in the following way.

𝐿ൌ 10 ∗ 𝐿𝑜𝑔 ∑ 10
ಽ೔
భబ ௡
௜ 𝑜𝑟 𝐿ൌ 10 ∗ 𝐿𝑜𝑔 ሾ10ఱర
భబ ൅ 10ఱవభబሿ =60 dBA CNEL
A spreadsheet calculation was used which computes equivalent noise levels for each of the time periods used in the calculation of CNEL. Weighting these equivalent noise levels and summing them gives the CNEL for the traffic projections. The modeling results for Route 66 and the cumulative noise levels from the train noise are provided in Figure 6-B.

Figure 6-B: Future Unmitigated Exterior Noise Levels
Item #6. Page 1577
Meeting Date: 9/24/2024 / Packet Page #: 1713
23 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise Based upon these findings, the outdoor use and open space areas would meet the City’s 70 dBA CNEL noise threshold to be considered “conditionally acceptable” without mitigation. Additionally, three decibels of attenuation is allowed for the first row of buildings when they block 40 to 65% of the line of sight to the noise source, and five decibels of attenuation is allowed when the buildings obstruct more than 65% of the line of sight (Source: (Caltrans, 2006)). The line of sight to the roadway and the rail line from the outdoor courtyard areas between the buildings are blocked by the proposed structures therefore it is anticipated that the cumulative noise levels from these sources will be lower than what is shown in Figure 6-B.

Additional noise modeling was done to determine the noise levels at the nearest building facades. It was determined that the building facades with line of sight to Route 66 would experience noise levels as high as 69 dBA CNEL. Units with line of sight to the rail line would be exposed to noise levels as of 66 dBA CNEL.

6.5 Interior Noise
The City of Glendora noise guidelines also state, consistent with Title 24 of the California Code of Regulations (CCR), that a project is required to perform an interior assessment on the portions of a project site where building façade noise levels are above the normally compatible noise level in order to ensure that acceptable interior noise levels can be achieved. The buildings would be exposed to noise levels up to 69 dBA CNEL at the facades; thus, the proposed project would be required to prepare interior noise studies for all units.

The windows/doors closed condition does not require the windows or doors to be non-operable but does requires that mechanical ventilation is installed to move air within the structure and control temperatures when the windows are closed. The mechanical ventilation must meet the jurisdictional Item #6. Page 1578
Meeting Date: 9/24/2024 / Packet Page #: 1714
24 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise requirements for these dwelling units. Once the final site plans showing the locations of the HVAC units and final architectural plans are available, a final interior noise study should be conducted to ensure interior noise reductions.

6.6 Train Vibration
The project site is located approximately 90 feet south of the future light rail extension of the Foothill Gold Line of the Los Angeles Metro Rail system. Rail-related noise comes from several potential sources. A locomotive engine’s propulsion system generates noise from mechanical and electrical systems. The interaction of wheels with the track produces various noises, particularly where the wheel encounters a flaw or defect along smooth wheel/track surfaces. Finally, train horn or bells and railroad crossing warning devices generate short but loud alerts pursuant to federal safety regulations.

According to the Metro Gold Line Foothill Extension EIR, vibration levels in the vicinity of the project are expected to be as high as 73 VdB at a distance of 86-feet and accounts for both LRT trains and freight trains (ATS Consulting, 2013). The nearest building is located approximately 90-feet from the centerline of the railroad and therefore could experience vibration levels in excess of the FTA’s vibration threshold of 72 VdB. The mitigate the potential impacts of train vibration, the Metro Gold Foothill Extension project is proposing the use of floating slab, ballast mat, TDC, and reduced speeds to reduce vibration levels to less than significant levels. Based on the Metro Gold Foothill Extension design features and the setbacks from the rail alignment, no additional project related mitigation measures are required.

Item #6. Page 1579
Meeting Date: 9/24/2024 / Packet Page #: 1715
25 Ldn Consulting, Inc. 2/9/24 23-67 723-745 Route 66 Glendora Noise

7.0 REFERENCES
ATS Consulting. (2013). Metro Gold Line Foothill Extension - Azusa to Montclair Final Environmental Impact Report.

California, S. o. (2017). State of California General Plan Guidelines.

Caltrans. (2020). Transportation Related Earthborne Vibration, Caltrans Experiences. Retrieved from https://dot.ca.gov/-/media/dot-media/programs/environmentalanalysis/documents/env/tcvgm-apr2020-a11y.pdf City of Glendora. (2008). Glendora Community Plan 2025.

City of Glendora Municipal Code. (1972). Retrieved from https://library.qcode.us/lib/glendora_ca/pub/municipal_code/ Federal Transit Administration. (2018). Transit Noise and Vibration Impact Assessment Manual.

Google. (2023). Retrieved from maps.google.com
KTGY Architecture + Planning. (2023). Concept Design.

Item #6. Page 1580
Meeting Date: 9/24/2024 / Packet Page #: 1716
Initial Study/Mitigated Negative Declaration July 2024
Brandywine Route 66 Residential – PLN 23-0027

Page 168 ends

Appendix K
731 East Route 66 Townhomes Project Vehicle Miles Traveled Analysis Screening and Trip Generation Memorandum
Ldn Consulting, Inc.

April 16, 2024
Item #6. Page 1581
Meeting Date: 9/24/2024 / Packet Page #: 1717

CARLSBAD
CLOVIS
IRVINE

LOS ANGELES

PALM SPRINGS

POINT RICHMOND

RIVERSIDE

ROSEVILLE

SAN LUIS OBISPO
1500 Iowa Avenue, Suite 200, Riverside, California 92507 951.781.9310 www.lsa.net

MEMORANDUM
DATE:

TO:

FROM:

SUBJECT:

April 16, 2024
Chris Courtney, Senior Project Manager, Brandywine Homes Ambarish Mukherjee, P.E., AICP, Principal
731 E Route 66 Townhomes Project Vehicle Miles Traveled Analysis Screening and Trip Generation Memorandum (LSA Project No. 20231358)
LSA Associates, Inc. (LSA) has prepared this Trip Generation and Vehicle Miles Traveled (VMT) Memorandum (Memo) for the 731 E Route 66 Townhomes Project (project) located at the northwest corner of S Glenwood Avenue and E Historic Route 66 in the City of Glendora (City). The proposed project consists of 39 townhomes. The project site is located between the future Los Angeles Metro A Line (previously Gold Line) Foothill Extension light rail tracks to the north and Historic Route 66 to the south. Figure 1 illustrates the regional and project location (All figures and tables attached). Figure 2 illustrates a conceptual site plan for the project.

BACKGROUND
On December 28, 2018, the California Office of Administrative Law cleared the revised California Environmental Quality Act (CEQA) guidelines for use. Among the changes to the guidelines was removal of vehicle delay and level of service (LOS) from consideration under CEQA. With the adopted guidelines, transportation impacts are to be evaluated based on a project’s effect on vehicle miles traveled (VMT).

As mentioned above, the project is located within the jurisdiction of City of Glendora, which is within the South Los Angeles County region. The city has adopted its own VMT policy and has its own tool to determine VMT impacts. Therefore, as recommended by the City staff, the CEQA Transportation Analysis Screening Tool for Development Projects (VMT calculator) was used to calculate the project VMT.

METHODOLOGY
Senate Bill 743 (SB 743) required changes be made to CEQA regulations introducing VMT as the new metric for determining project traffic impacts. As previously mentioned, the VMT analysis has been prepared based on the results from the city’s VMT Calculator tool.

Project VMT Analysis
The first step for preparing a VMT analysis is to evaluate whether a development is eligible to be screened out from preparing a detailed VMT analysis. The VMT calculator requires the user to enter the address and Assessor’s Parcel Number (APN) of the proposed project followed by the number of units based on the type of project. The Project falls under the category of “Residential – Item #6. Page 1582
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4/15/24 (P:\20231358 Glendora Rte 66 Townhomes\Traffic\GlendoraRoute 66 Townhomes ‐ Trip Gen and VMT Screening Memo_April 2024.docx) 2 Townhouse” and consists of 39 dwelling units. The VMT calculator requires an input of the number of affordable housing units which in this case is zero. The VMT calculator also requires other inputs such as, if the project belongs to certain category of land‐uses (Library, School, Park, Community Center, or Local Serving Project). Since the project is a residential project, these categories do not apply.

Upon entering all required inputs in the city’s VMT calculator, it was determined that the project is screened out from a detailed VMT analysis and presumed to have a less than significant VMT impact. The results of this analysis using the VMT Calculator is included in Appendix A.

Active Transportation and Public Transit Analysis
The project was examined for any conflicts with adopted plans, policies, or programs regarding active transportation or public transit facilities, or otherwise decreases the performance or safety of such facilities in Glendora's General Plan, known as "Community Plan 2025".

Currently, there are no existing bicycle facilities within the project vicinity. Based on the Community Plan 2025 Circulation Element, there are no bike lanes proposed along the project roadways.

The existence of sidewalks provides more transportation choices for non‐work trips, which can replace some auto trips, reducing growth in congestion and air pollution. Within the project vicinity, paved sidewalks are present along Route 66 located on the south of the project site. According to the Community Plan 2025 Circulation Element, the project will not affect any existing sidewalks and will add sidewalks along the project frontage on Route 66.

The City of Glendora is well served by public transit systems. The Foothill Transit (FTA) and the Glendora Mini‐Bus both operate routes that extend into or through the City of Glendora. While the Glendora Mini‐Bus offers curb‐to‐curb transportation services for senior citizens and permanently disabled persons, the operates several routes in the City. FTA fixed bus route 187 operates within the project vicinity. Service is provided every day with a frequency of one bus every twenty minutes in each direction, except that the frequency is decreased to one bus every one‐half hour during the weekends and holidays.

In addition, the project site is located about 2.3 miles from APU/Citrus College Station which is a light rail station of Los Angeles Metro Rail system station located on the A Line. As per the City’s General Plan Community Circulation Element, Foothill Extension of the Metro Gold Line is proposed to follow an alignment from its current terminus in Pasadena to its proposed eastern terminus in the City of Montclair, passing through many Foothill cities, including Glendora. But this does not fall in the project vicinity.

The project does not conflict with existing or proposed bicycle, pedestrian, and public transit facilities. Therefore, it can be considered to conform to all adopted policies, plans, or programs concerning these facilities and will not have a significant impact.

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TRIP GENERATION ANALYSIS
This trip generation analysis has been prepared consistent with the City of Glendora Traffic Impact Analysis Guidelines, revised October 2015 (TIA Guidelines). The City’s TIA Guidelines states Traffic Impact Analysis (TIA) will not be required for a project if it adds less than 50 peak hour net project trips to roadways, or if it adds less than 150 peak hour net project trips to freeways.

The trip generation for the project was developed using rates from the Institute of Transportation Engineers (ITE) Trip Generation Manual (11th Edition) for Land Use 220 – “Multifamily Housing (Low‐Rise) Not Close to Rail Transit”. Table A summarizes the project trip generation and shows that the proposed project is anticipated to generate 16 trips in the a.m. peak hour, 19 trips in the p.m. peak hour, and 263 daily trips. Since the proposed project is anticipated to generate less than 50 peak hour trips during either the a.m. or p.m. peak hours, a TIA is not required for this project.

ATTACHMENTS
Tables
Table A: Project Trip Generation
Figures
Figure 1: Regional and Project Location
Figure 2: Conceptual Site Plan
Appendix
Appendix A: VMT Calculator Tool Results
Item #6. Page 1584
Meeting Date: 9/24/2024 / Packet Page #: 1720
4/15/24 (P:\20231358 Glendora Rte 66 Townhomes\Traffic\GlendoraRoute 66 Townhomes ‐ Trip Gen and VMT Screening Memo_April 2024.docx) 4

FIGURES

Item #6. Page 1585
Meeting Date: 9/24/2024 / Packet Page #: 1721
SOURCE: Google Earth, 2022.

P:\20231358 Glendora Rte 66 Townhomes\Traffic\Google Earth\Glendora.aprx (1/8/2024) FIGURE 1
Glendora Route 66 Townhomes Project
Vehicle Miles Traveled Analysis and Trip Generation Memorandum

L O S A N G E L E S

C O U N T Y
Ã57
§¨¦210
Project Vicinity
0 100 200 300
FEET
LEGEND
Project Location
Regional and Project Location
Project Location
Project
Location
ROUTE 66

E LEMON AVE

E WALNUT AVE
Item #6. Page 1586
Meeting Date: 9/24/2024 / Packet Page #: 1722
N
FEET
SOURCE: Brandywine Homes, January, 2024.

P:\20231358 Glendora Rte 66 Townhomes\Traffic\Graphics\fig2_SitePlan.ai 0 20 40
FIGURE 2
Conceptual Site Plan
Glendora Route 66 Townhomes Project
Vehicle Miles Traveled Analysis and Trip Generation Memorandum Route 66
Front
Setback
15'-0"
Side Setback 10'-0"
26'-0"
26'-0"
26'-0"
49'-0"
33'-6"
27'-0"
20'-10"
Trash Enclosure
w/ Refuse and Recycling
288.26'
150' N 0°37'45"E
227.84' N 89°36'42"E
279.33'
128.39'
Side Setback 10'-0"
58'-6"
58'-6"
20'-6"
33'-6"
Perimeter Wall
Mail
Patio
Patio Single Level Unit
at Ground Floor
Private Drive and
Fire Lane
Single Level Unit
at Ground Floor
Single Level Unit
at Ground Floor Single Level Unit
at Ground Floor
Single Level Unit
at Ground Floor
Single Level Unit
at Ground Floor
Rear
Setback
15'-0"
287.26'
20'-9"
22'-3"
15'-9"
10'-8"
10'-9"
18'-0"
9'-0"
18'-0"
9'-0"
Condensers to be screened.

See landscape sheet for details.
0 10 20 40
Architecture + Planning
888.456.5849
ktgy.com
723-745 E. ROUTE 66
GLENDORA, CA #2022-1093

ENTITLEMENT SUBMITTAL
JANUARY 10, 2024
Item #6. Page 1587
Meeting Date: 9/24/2024 / Packet Page #: 1723
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Item #6. Page 1588
Meeting Date: 9/24/2024 / Packet Page #: 1724
Land Use In Out Total In Out Total
Multifamily Housing (Low‐Rise) Not Close to Rail Transit 39 DU Trips/Unit1 0.10 0.30 0.40 0.32 0.19 0.51 6.74
Trip Generation 4 12 16 12 7 19 263
Notes:

DU = Dwelling Unit
Rates from Institute of Transportation Engineers (ITE) Trip Generation Manual, (11th Edition) Land Use 220 ‐ "Multifamily Housing (Low‐Rise) Not Close to Rail Transit", Setting/Location ‐ 'General Urban/Suburban'.
1 Table A ‐ Project Trip Generation
A.M. Peak Hour P.M. Peak Hour Daily Units
P:\20231358 Glendora Rte 66 Townhomes\Traffic\TripGen.xlsx\Trip Gen (1/12/2024) Item #6. Page 1589
Meeting Date: 9/24/2024 / Packet Page #: 1725
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APPENDIX A
Item #6. Page 1590
Meeting Date: 9/24/2024 / Packet Page #: 1726
CEQA Transportation Analysis Screening Tool for Development Projects Legend
User Input xxxx
Calculated Value xxxx
1 Project Information
Applicant Name
Project Name
Number Street (no street suffix, e.g. Ave., Blvd.)
Address 731
2 Project Description
Type Unit Existing Project Change
Emploment ‐ Office Building 1000s Sq Feet ‐                 Library No Employment ‐ Hospital 1000s Sq Feet ‐                 School No Employment ‐ Medical/Dental Office 1000s Sq Feet ‐                 Park No Employment ‐ Movie Theater 1000s Sq Feet ‐                 Community Center No Hotel Rooms ‐                 Other locally serving No
Industrial ‐ Heavy 1000s Sq Feet ‐
Industrial ‐ Light 1000s Sq Feet ‐
Industrial ‐ Warehouse 1000s Sq Feet ‐
Retail ‐ Store 1000s Sq Feet 5.303                   (5) Retail ‐ Restaurant 1000s Sq Feet ‐
Residential ‐ Apartment Units ‐
Residential ‐ Assisted Living Beds ‐
Residential ‐ Single Family Units ‐
Residential ‐ Townhouse Units 039 3                   9 Number of Affordable Housing Units Units 00 ‐
3 Checklist Screening
Screened to be Presumed as Less Than Significant? Yes Project Below Size Threshold 4 Threshold Estimate
If not screened, would the Proposed Project have VMT that is Less than the Thresholds of Significance? Threshold VMT Project Est.

Residential VMT Yes 19.3 15.3 Employment VMT ‐ ‐ 24.5 If "No" for either, the following Potential Mitigation Measures could be implemented to reduce to less than significant 5 Mitigation Measures
Strategy Implementation Number VMT Reductions
On‐Site Bikeshare Yes 10 Residential Employment
Unbundled Parking Costs Yes ‐ (0.9) Neighborhood Electric Vehicle
Infrastructure Yes 10
Provide Parking Cash‐Out Program Yes
TDM Information >25 ksft non‐residential Yes
Preferential Parking >50 ksft non‐residential Yes
Multimodal Site Improvements >100 ksft non‐residential Yes Implement Transportation Demand
Management Program – Required
Implementation/Monitoring Yes
Implement Subsidized or Discounted
Transit Program Yes
Telecommuting and Alternative Work
Schedules Yes
Fair Share contribution to First/Last Mile
project or other intrastructure Yes Threshold VMT Project Est.

Residential 19.3 14.4 Presumed Less Than Significant CEQA Transportation Impact After Mitigation Yes Employment ‐ 24.5 5 This tool is to estimate the potential of a land use
development project, where the City of Glendora is the
CEQA lead agency
Install electrical charging equipment
Separates parking cost from property
costs
Implement bikeshare program
To support non‐vehicle trips
Encouraging telecommuting and
alternative work schedules reduces the
Encourage transit use by providing
subsidy
Reduce drive‐alone travel mode share
and encourage alternative modes of
travel
Incentives for alternative transportation
Brandywine Homes
731 E Route 66 Townhomes Project
ROUTE 66
Is this project a:

Purpose
Item #6. Page 1591
Meeting Date: 9/24/2024 / Packet Page #: 1727
Initial Study/Mitigated Negative Declaration July 2024
Brandywine Route 66 Residential – PLN 23-0027

Page 169 ends

Appendix L
Will Serve Letters
Item #6. Page 1592
Meeting Date: 9/24/2024 / Packet Page #: 1728
12/5/2023
John Koser
Koser Consulting, LLC on behalf of Brandywine
31805 Temecula Pkwy, #737
Temecula, CA 92592
RE: Will Serve Letter Request for Job I.D.#41-2023-11-00137 Location: AREA WEST OF ROUTE 66 & GLENWOOD AVE, CITY OF GLENDORA Dear John Koser:

Thank you for inquiring about the availability of natural gas service for your project. We are pleased to inform you that Southern California Gas Company (SoCalGas) has facilities in the area where the above-named project is being proposed.

The service would be in accordance with SoCalGas’ policies and extension rules on file with the California Public Utilities Commission (Commission) at the time contractual arrangements are made.

This letter should not be considered a contractual commitment to serve the proposed project and is only provided for informational purposes only. The availability of natural gas service is based upon natural gas supply conditions and is subject to changes in law or regulation. As a public utility, SoCalGas is under the jurisdiction of the Commission and certain federal regulatory agencies, and gas service will be provided in accordance with the rules and regulations in effect at the time service is provided. Natural gas service is also subject to environmental regulations, which could affect the construction of a main or service line extension (for example, if hazardous wastes were encountered in the process of installing the line). Applicable regulations will be determined once a contract with SoCalGas is executed.

If you need assistance choosing the appropriate gas equipment for your project, or would like to discuss the most effective applications of energy efficiency techniques, please contact our area Service Center at 800-427-2200.

Thank you again for choosing clean, reliable, and safe natural gas, your best energy value.

Sincerely,
Randolph Darnell
Randolph Darnell
Technical GIS Supervisor
RD/SV
enc.

Southern California Gas Company
1981 West Lugonia Avenue
Redlands, CA 92374
Mailing Address:

PO Box 3003
Redlands, CA 92373-0306
Item #6. Page 1593
Meeting Date: 9/24/2024 / Packet Page #: 1729
Item #6. Page 1594
Meeting Date: 9/24/2024 / Packet Page #: 1730
DOC 6942022.D22 A Century of Service
June 26, 2023
Ref. DOC 6941926
Mr. Michael Reyes
Design Engineer
C&V Consulting, Inc.
9830 Irvine Center Drive
Irvine, CA 92618
Dear Mr. Reyes:

Will Serve Letter for BWHX-047
The Los Angeles County Sanitation Districts (Districts) received your will serve letter request for the subject project located in the City of Glendora on June 6, 2023. The proposed project is located within the jurisdictional boundary of District No. 22. We offer the following comments regarding sewerage service:

1. The wastewater flow originating from the proposed project will discharge to a local sewer line, which is not maintained by the Districts, for conveyance to the Districts’ Base Line Trunk Sewer, located in Grand Avenue at Route 66. The Districts’ 15-inch diameter trunk sewer has a capacity of 4.4 million gallons per day (mgd) and conveyed a peak flow of 1.5 mgd when last measured in 2015.

2. The wastewater generated by the proposed project will be treated at the San Jose Creek Water Reclamation Plant (WRP) located adjacent to the City of Industry, which has a capacity of 100 mgd and currently processes an average recycled flow of 62.7 mgd. All biosolids and wastewater flows that exceed the capacity of the San Jose Creek WRP are diverted to and treated at the Joint Water Pollution Control Plant in the City of Carson.

3. The expected increase in average wastewater flow from the project, described in the application as 43 attached townhomes, is 7,856 gallons per day, after all structures on the project site are demolished. For a copy of the Districts’ average wastewater generation factors, go to www.lacsd.org, under Services, then Wastewater Program and Permits and select Will Serve Program, and click on the Table 1, Loadings for Each Class of Land Use link.

4. The Districts are empowered by the California Health and Safety Code to charge a fee to connect facilities (directly or indirectly) to the Districts’ Sewerage System or to increase the strength or quantity of wastewater discharged from connected facilities. This connection fee is used by the Districts for its capital facilities. Payment of a connection fee may be required before this project is permitted to discharge to the Districts’ Sewerage System. For more information and a copy of the Connection Fee Information Sheet, go to www.lacsd.org, under Services, then Wastewater (Sewage) and select Rates & Fees. In determining the impact to the Sewerage System and applicable connection fees, the Districts will determine the user category (e.g. Condominium, Single Family Home, etc.) that best represents the actual or anticipated use of the parcel(s) or facilities on the parcel(s) in the development. For more specific information regarding the connection fee application procedure and fees, please contact the Districts’ Wastewater Fee Public Counter at (562) 908-4288, extension 2727.

Item #6. Page 1595
Meeting Date: 9/24/2024 / Packet Page #: 1731
Mr. Michael Reyes 2 June 26, 2023
DOC 6942022.D22 A Century of Service

5. In order for the Districts to conform to the requirements of the Federal Clean Air Act (CAA), the capacities of the Districts’ wastewater treatment facilities are based on the regional growth forecast adopted by the Southern California Association of Governments (SCAG). Specific policies included in the development of the SCAG regional growth forecast are incorporated into clean air plans, which are prepared by the South Coast and Antelope Valley Air Quality Management Districts in order to improve air quality in the South Coast and Mojave Desert Air Basins as mandated by the CAA. All expansions of Districts’ facilities must be sized and service phased in a manner that will be consistent with the SCAG regional growth forecast for the counties of Los Angeles, Orange, San Bernardino, Riverside, Ventura, and Imperial. The available capacity of the Districts’ treatment facilities will, therefore, be limited to levels associated with the approved growth identified by SCAG. As such, this letter does not constitute a guarantee of wastewater service, but is to advise the applicant that the Districts intend to provide this service up to the levels that are legally permitted and to inform the applicant of the currently existing capacity and any proposed expansion of the Districts’ facilities.

If you have any questions, please contact the undersigned at (562) 908-4288, extension 2708 or at [email protected].

Very truly yours,
Donna J. Curry
Customer Service Specialist
Facilities Planning Department
DC:sw
Item #6. Page 1596
Meeting Date: 9/24/2024 / Packet Page #: 1732
Appendix B
As your Southern California Edison (SCE) Design Representative for this project, I am committed to providing you with excellent customer service. The following information is intended to help explain SCE’s planning and permitting process for the electric infrastructure needed to serve your Project.

Depending on the scope of work necessary to serve your project (electric facility installation, removal, relocation, rearrangement and/or replacement), it may be necessary for you to submit an Advanced Engineering Fee. This Fee will be applied to certain expenses associated with preliminary design and engineering work required to estimate the cost for SCE to perform the electric work associated with your project. Please note: Depending on factors such as resource constraints, construction or relocation of SCE facilities requirements, the need for environmental review, and so forth, delays in meeting your projected completion date may occur. To help minimize the potential for delays it is imperative that you provide all requested information as early as possible.

If the project results in the need for SCE to perform work on SCE electrical facilities that operate at between 50 and 200 kilovolts (kV), please be advised these facilities are subject to the California Public Utilities Commission’s (CPUC's) General Order 131-D (GO 131-D) Permit to Construct (PTC) requirements. For the CPUC PTC review, the CPUC acts as the lead agency under the California Environmental Quality Act (CEQA). Depending on the scope of SCE’s work, certain exemptions to the PTC requirements may be available. If no exemptions are available, the PTC application preparation and environmental approval process could take a minimum of 24 - 48 months.

If you anticipate that your project will require work to be performed on SCE electrical facilities operated at between 50 kV and 200 kV, please inform me at your earliest possible convenience for further assistance to determine the potential G.O.131-D permitting requirements and/or permitting exemption(s).

In order for SCE to determine the required electrical utility work necessary to support your project, and to determine any permitting requirements and costs associated with constructing these facilities, project plans and a completed Customer Project Information Sheet will need to be submitted.

If you have any additional questions, please feel free to call me at Sincerely,
SCE Design Representative
Rev. 07/09/12 DS-125-1
Item #6. Page 1597
Meeting Date: 9/24/2024 / Packet Page #: 1733
Initial Study/Mitigated Negative Declaration July 2024
Brandywine Route 66 Residential – PLN 23-0027

Page 170 ends

Appendix M
Sewer System Analysis, TTM No. 84292, Sewer Plan
Assessment District No. 4, SMD Index E-2298 and E-2341
C&V Consulting, Inc
June 2024
Item #6. Page 1598
Meeting Date: 9/24/2024 / Packet Page #: 1734
1 SEWER SYSTEM ANALYSIS
TTM No. 84292
Sewer Plan Assessment District No. 4
SMD Index E-2298 and E-2341
Prepared for:

Brandywine Homes
16580 Aston St.

Irvine, CA 92606
Contact: Chris Courtney
(949) 336-2298
Property:
723-731 E. Route 66
Glendora, CA 91740
Tract No. 84292
APN: 8646-029-024
Prepared by:

C&V Consulting, Inc.
9830 Irvine Center Drive
Irvine, CA 92618
(949) 916-3800
Contact: Dane McDougall, P.E., P.L.S.

Dane P. McDougall R.C.E. 80705
Prepared: June 2024
Item #6. Page 1599
Meeting Date: 9/24/2024 / Packet Page #: 1735
2 Table of Contents

SECTION PAGE
INTRODUCTION 3
SITE DESCRIPTION 4
PROJECT DESCRIPTION 5
METHODOLOGY 6
SEWER PIPE CAPACITY ANALYSIS 7
CONCLUSION 8
Appendices
A. SEWER MONITORING STUDY EXHIBIT
B. SEWER MONITORING STUDY TABLE & DEPTH OF FLOW CALCULATIONS C. FLOW MONITORING DATA
D. SEWER AS-BUILTS
E. REFERENCES
Item #6. Page 1600
Meeting Date: 9/24/2024 / Packet Page #: 1736
3 INTRODUCTION
The following study has been prepared by C&V Consulting, Inc. to determine and illustrate:

A. The capacity of the existing sewer segments from the proposed development site to the flow monitored City maintained 10” sewer main in E. Route 66.

B. If the existing sewer facilities will adequately service the proposed development.

This study utilizes a sewer monitoring method to determine the depth results of the existing conditions with the addition of the proposed site. The existing sewer system was analyzed to determine the sewer capacity and its ability to adequately service the proposed development. The analysis includes all existing tributary flows to the sewer system and future flow from the proposed development to the existing system, located at MH 314 in E. Route 66.

Item #6. Page 1601
Meeting Date: 9/24/2024 / Packet Page #: 1737
4 SITE DESCRIPTION
The project is located at 723-731 E. Route 66., in the City of Glendora, California. The site is bounded by E. Rout 66 to the south, A.T. & S.F. Railroad to the north, and commercial buildings to the east and west.

The existing project site is comprised of an existing abandoned commercial building along with a parking lot.

Figure 1: Source (Google Maps)
Item #6. Page 1602
Meeting Date: 9/24/2024 / Packet Page #: 1738
5 PROJECT DESCRIPTION
The proposed development has an area approximately 1.845 acres. The project proposes the construction of thirty-nine (39) dwelling units, private garages, private drive aisles, hardscape, associated landscaping, and guest parking areas. The private drive aisle provides access to the residences via one driveway entrance/exit along E Route 66. Drive aisles and parking areas will be composed of asphalt concrete pavement, and landscaping will be incorporated in open space areas. The proposed sewer system will be gravity fed and flow will be towards a local sewer line located along E.

Route 66, which conveys and connects to the 15” LACSD Base Line Trunk Sewer located in Grand Avenue at E. Route 66.

Item #6. Page 1603
Meeting Date: 9/24/2024 / Packet Page #: 1739
6 METHODOLOGY/EXISTING CONDITIONS
The study will investigate the sewerage discharge route along E. Route 66 from the proposed development (TTM No. 84292) to the existing 10” sewer main at MH 314.

Sewer Monitoring Method
As part of this study for the sewer monitoring analysis, the project was conditioned to flow monitor the existing conditions at Manhole #314 on the 10” local main, located in E. Route 66 by US3. The sewer segment upstream of MH 314 was analyzed because it was flow monitored per the US3 report. The upstream segment also has a flatter slope than the downstream segment so this will provide a more conservative analysis. The City of Glendora selected this manhole to be flow-monitored which is +/- 5,400 feet away from the project site. The flow monitoring took place from 5/31/2024 to 6/18/2024. Proposed peak project flows were calculated and added to the existing site peak flows to obtain the proposed development conditions using LACPW standards; see Appendix E. See Appendix C for the as-built provided by the City which shows the analyzed segment’s pipe size and slope. See appendix A for Sanitary Sewer Analysis Exhibit for reference.

Item #6. Page 1604
Meeting Date: 9/24/2024 / Packet Page #: 1740
7 SEWER PIPE CAPACITY ANALYSIS
Sewer Monitoring Method
The existing sewer pipes were analyzed per LA County Standard S-C4 for a maximum design depth at halffull for pipes less than 15” and three-fourths full for pipes 15” and greater; see Appendix E. Based on the monitoring data collected by US3, existing peak flow for MH 314 was measured at .229 mgd (0.3543 cfs), with a peak depth flow of 2.010 inches (d/D = 0.2010). The data shows that the 10” sewer pipe system capacity is capable of maintaining an adequate flow well below 50% of its flow depth capacity with the additional flow from the proposed development. Refer to the field data enclosed in Appendix C.

The “Loadings for each Class of Land Use” per the Los Angeles County Department of Public Works was utilized for this method to obtain the peak flow generated from the proposed residential project site.

Condominiums are 0.001 cfs/unit; see Appendix E. The project will produce 0.039 cfs of effluent for the 39 proposed condominium units.

To approximate the real-world conditions of the pipe, a new Manning’s n-value was calculated based on the existing max flow rate and depth of flow observed. This new Manning’s n-value was used to calculate the depth of flow for the combined proposed flow rate and the existing flow rate.

The project site will contribute 0.039 cfs to the trunk main, which results in a 4.8% increase to the sewer main with a total flowrate of 0.3933 cfs. The existing 10” sewer main will then flow with a projected d/D =0.2112, which is below the d/D=0.50 criteria and indicates that the proposed development will not have a significant impact on the existing condition of its’ capacity. Refer to the Sewer Monitoring Study Table in Appendix B for calculation details.

Item #6. Page 1605
Meeting Date: 9/24/2024 / Packet Page #: 1741
8 CONCLUSION
The results from this study using methods provided by the US3, Los Angeles Department of Public Works, and Manning’s equation demonstrate that the proposed flows, in addition to the observed flows, create a proposed depth of flow that does not impact the existing surrounding sanitary sewer systems. Based on sewer monitoring data collected by US3, the sewer systems located in E. Route 66 indicated good flow, along with hydraulics and relatively low depths. Refer to Appendix B for calculations and tabulated results.

The proposed residential development project onsite system flows will increase the overall downstream system of the local main by approximately 4.8% at peak flow and the volume of flow does not exceed 50% of the capacity of the pipes (d/D<0.50). Based on the analysis above, we conclude that effluent volumes produced by the proposed development should not significantly impact or exceed the existing sewer capacity in the public system, and that the existing sewer system along E. Route 66 has adequate capacity for the proposed development.

Item #6. Page 1606
Meeting Date: 9/24/2024 / Packet Page #: 1742
9 Appendix A

SEWER MONITORING STUDY EXHIBIT
Item #6. Page 1607
Meeting Date: 9/24/2024 / Packet Page #: 1743
Item #6. Page 1608
Meeting Date: 9/24/2024 / Packet Page #: 1744
10 Appendix B

SEWER MONITORING STUDY TABLE &

DEPTH OF FLOW CALCULATIONS
Item #6. Page 1609
Meeting Date: 9/24/2024 / Packet Page #: 1745
Sewer Monitoring Study Table
TTM 84292
723-731 E. Route 66
Monitored MH Metered (MGD) Calc (cfs) Diameter (in) Slope (ft/ft) Metered (in) d/D *Delta (cfs) Future (cfs) Calc (in) d/D MH 314 0.2290 0.3543 10 0.0160 2.01 0.2010 0.009 0.039 0.3933 2.112 0.2112 4.8% *Use 0.001 (cfs/unit) for condominiums per Estimated Average Daily Sewage Flows for Various Occupancies % Increase Calculated With Project Peak Flow (cfs)
Manning's n
Existing Monitored Peak Flow Upstream Pipeline Existing Peak Flow Depth Item #6. Page 1610
Meeting Date: 9/24/2024 / Packet Page #: 1746
11 Appendix C

FLOW MONITORING DATA
Item #6. Page 1611
Meeting Date: 9/24/2024 / Packet Page #: 1747
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
Methods & Procedures & Equipment
Methods and Procedures
Utility Systems Science & Software provided C&V Consulting, Inc with an off the shelf, nonproprietary flow monitoring solution that included one state of the art Hach Flo-Dar® AV Sensor system and one CCTV inspection from manhole (MH) 52 to MH 50. The project course of action is listed below. The US3team:
• Assessed permitting and traffic control at the site on Rte 66, Glendora, CA. • Prepared the traffic control plan and obtained a City Encroachment Permit. • Installed and removed traffic control in accord with site-specific California Temporary Traffic Control Handbook (CATTCH) requirements for the installation, calibration and removal of equipment
• Coordinated with the Los Angeles County Department of Public Works and the East Maintenance Yard Supervisor for installation and removal of equipment. • On 05/31/2024, Innerline Engineering performed the CCTV inspection of one length of pipe from MH 52 to MH 50.
o High-water marks between MH 52 and MH 50 were at a constant 5% of the pipe’s depth.
o No blockages, debris or build up was observed during the CCTV inspection. • Validated the sites for suitability for sewer flow monitoring. o The Rte 66 MH 341 had no laterals with moderate to rapid open channel hydraulics. Monitoring began on the upstream line as it provided the best hydraulics during inspection.
o Installed and calibrated the flow monitoring equipment at the site per manufacturer recommendations on 5/31/2024.
o Follow-up on the installation confirmed equipment was reading properly. o Collect 15-minute interval depth and velocity data points over the entire monitoring period.
o Removed the equipment on 6/18/2024 and validated the data. o All of the equipment went through diagnostic testing before and after the study with less than a 1% deviation between manual and meter level readings and less than a 5% deviation between manual and meter velocity readings. o Equipment calibration was verified in accordance with manufacturer specifications.
• Prepared the data reports.
o The table below contains a summary of the average (Avg) and maximum (Max) velocities (Vel) and levels (Lev) collected during this study as well as the calculated flow rates (Flow) and depth versus diameter ratios (d/D).

Item #6. Page 1612
Meeting Date: 9/24/2024 / Packet Page #: 1748
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
MH
Pipe
Size
(in)
Avg
Vel
(fps)
Max
Vel
(fps)
Avg
Lev
(in)
Max
Lev
(in)
Avg
Flow
(gpm)
Max
Flow
(gpm)
Avg
d/D
Max
d/D
341 10 3.66 4.52 1.66 2.01 101.11 158.86 0.17 0.20
Equipment
Figure above: Equipment installed for the Sewer Flow Monitoring Study Figure above: Web-Enabled Flo-Dar® AV Sensor, Radar-Based Velocity/Area Flow Meter Item #6. Page 1613
Meeting Date: 9/24/2024 / Packet Page #: 1749
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
FloDar® AV Sensor Specifications:
• Enclosure
o IP68 Waterproof rating, Polystyrene
• Dimensions
o 160.5 W x 432.2 L x 297 D mm (6.32 x 16.66 x 11.7 in.), o With SVS, D = 387 mm (15.2 in.)
• Weight
o 4.8 kg (10.5 lbs.)
• Operating Temperature
o -10 to 50°C (14 to 122°F)
• Storage Temperature
o -40 to 60°C (-40 to 140°F)
• Power Requirements
o Supplied by FL900 Flow Logger, Flo-Logger, or Flo-Station • Interconnecting Cable
o Disconnect available at both sensor and logger or Flo-Station o Polyurethane, 0.400 (±0.015) in. diameter; IP68
o Standard length 9 m (30 ft), maximum 305 m (1000 ft)
• Cables – available in two styles:
o connectors at both ends
o connector from sensor with open leads to desiccant hub, desiccant hub with connector to logger. A potting/sealant kit will be included. This can be used to run the cable through conduit.
• Certification
o Certified to: FCC Part 15.245: FCC ID: VIC-FLODAR24
o Industry Canada Spec. RSS210. v7: IC No.: 6149A-FLODAR24

SURCHARGE DEPTH MEASUREMENT
o Auto zero function maintains zero error below 0.5 cm (0.2 in.) • Method
o Piezo-resistive pressure transducer with stainless steel diaphragm • Range
o 3.5 m (138 in.), overpressure rating 2.5 x full scale

VELOCITY MEASUREMENT
• Method
o Radar
• Range
o 0.23 to 6.10 m/s (0.75 to 20 ft/s)
Item #6. Page 1614
Meeting Date: 9/24/2024 / Packet Page #: 1750
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
• Frequency Range
o 24.075 to 24.175 GHz, 15.2 mW (max.)
• Accuracy
o ±0.5%; ±0.03 m/s (±0.1 ft/s)

DEPTH MEASUREMENT
• Method
o Ultrasonic
• Standard Operating Range from Flo-Dar® Housing to Liquid o 0 to 152.4 cm (0 to 60 in.)
• Optional Extended Level Operating Range from Transducer Face to Liquid o 0 to 6.1 m (0 to 20 ft.) with 43.18 cm (17 in.) dead band, temperature compensated. • Accuracy
o ±1%; ±0.25 cm (±0.1 in.)

FLOW MEASUREMENT
• Method
o Based on Continuity Equation
• Accuracy
o ±5% of reading typical where flow is in a channel with uniform flow conditions and is not surcharged, ±1% full scale max.

SURCHARGE CONDITIONS DEPTH/VELOCITY DEPTH (Std with Flo-Dar® Sensor) • Surcharge depth supplied by Flo-Dar® sensor.

VELOCITY (Optional Surcharge Velocity Sensor)
• Method
o Electromagnetic
• Range
o ±4.8 m/s (±16 ft/s)
• Accuracy
o ±0.15 ft/s or 4% of reading, whichever is greater.
• Zero Stability
o ±0.05 ft/s
The Flo-Dar® Open Channel Flow Meters provide an innovative approach to open channel flow monitoring. Combining digital Doppler radar velocity sensing with ultrasonic pulse echo level sensing Flo-Dar® provides accurate open channel flow monitoring without the fouling problems associated with submerged sensors.

Item #6. Page 1615
Meeting Date: 9/24/2024 / Packet Page #: 1751
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
Perfect Solution for Difficult Flow Conditions:
• Flows with High Solids Content
• High Temperature Flows
• Caustic Flows
• Large Man-Made Channel
• High Velocities
• Shallow Flows
Benefits:

1. Personnel have no contact with the flow during installation.

2. Maintenance caused by sensor fouling is eliminated

3. Field Replaceable/Interchangeable Sensors and Monitors Item #6. Page 1616
Meeting Date: 9/24/2024 / Packet Page #: 1752
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
How It Works
Flo-Dar® transmits a digital Doppler radar beam that interacts with the fluid and reflects back signals at a different frequency than that which was transmitted. These reflected signals are compared with the transmitted frequency. The resulting frequency shift provides an accurate measure of the velocity and the direction of the flow. Level is detected by ultrasonic pulse echo. Flow is then calculated based on the Continuity Equation:

Q = V x A, Where Q = Flow, V = Average Velocity and A = Area Accurate Flow Measurements
Flo-Dar® provides the user with highly accurate flow measurements under a wide range of flows and site conditions. By measuring the velocity of the fluid from above, Flo-Dar® eliminates accuracy problems inherent with submerged sensors including sensor disturbances, high solids content and distribution of reflectors.

Figure above: US3 utilizes exclusively Hach March-McBirney Flo-Dar® Meters Item #6. Page 1617
Meeting Date: 9/24/2024 / Packet Page #: 1753
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
US3 Company Information
US3is a California Corporation Federal ID No. 33-0729605 and qualifies as a Minority Business Enterprise. US3 has certified as an MBE with the California Public Utility Commission’s authorized clearinghouse, Verification Number: 97ES0008.

US3is a specialty service company for the Water & Waste Water industry, providing monitoring and control for Utilities since 1996. US3is in the forefront of this industry by taking the proven technological approaches developed in other high-tech industries and applying them to protect one of our most precious natural resources - our water.

US3 engineers and technical personnel have applied advanced instrumentation system technology to water/wastewater open channel flow monitoring, pipeline evaluation, engineering, and data analysis, all coupled to the power of the Internet. This unique integrated systems approach allows the company to bring greater insight and intelligence to gathering information about water/wastewater system performance of our clients, and in turn, to support the fulfillment of their commitments to manage and cost effectively design, operate, and maintain these systems.

Moreover, US3 supports Municipalities, Consulting Engineering firms and other water/waste water systems integrators by providing temporary technical services for engineering, software programming and technical site maintenance and calibration site support work, primarily in the Water and Waste Water industries.

Figure at right: All US3
technicians are certified
for Confined Space Entry.

Item #6. Page 1618
Meeting Date: 9/24/2024 / Packet Page #: 1754
2024.05.31-06.18 Temporary Sewer Flow Monitoring C&V Consulting Utility Systems Science & Software
Key Personnel Assigned
US3 provided the necessary resources to fully implement this project. Primary in support of this effort were the following personnel:

Mr. Mark Serres: Mr. Serres is a degreed electrical engineer with over 30 years of experience with fresh/wastewater systems, project management, and systems integration in relation to complex industrial systems. This includes experience in industrial automation and water/wastewater industries. Mr. Serres is responsible for assuring client satisfaction and marshalling the required resources to meet the project requirements.

Mr. Thomas Williams: Mr. Williams is an Engineering Manager with over 25 years of experience in complex systems development for wastewater monitoring. This experience includes hydraulic compatibility, instrumentation, communications and analysis. Mr. Williams is responsible for assuring that the required equipment is designed and calibrated to meet the project requirements.

Darlene Szczublewski, PE: Mrs. Szczublewski is a licensed Civil Engineer in multiple states. She has over 20 years of engineering experience with stormwater/wastewater related projects. She assisted in the completion of several Sanitary Sewer Evaluation Surveys and Capacity Analysis projects to meet Consent Decrees as well as completing numerous Infiltration and Inflow (I&I) studies for other clients. Mrs. Szczublewski has developed numerous flow data analysis techniques to present a clear informative picture of flow in a monitored system. Her work also includes the development of training programs for clients describing I&I and capacity analysis methodologies. Mrs. Szczublewski is responsible for analyzing the data as well as the data collection process and assuring that the reports meet the project requirements.

Name, title, address and telephone number of persons to contact regarding this US3 project.

Darlene Szczublewsk i , PE
Senior Civil Engineer
[email protected]
1300 Hill Street
El Cajon, CA 92020
619-546-4281 (work)
619-246-5304 (cell)
Tom Willia ms
Engineering Manager
[email protected]
1300 Hill Street
El Cajon, CA 92020
619-546-4281 (work)
619-398-7799 (cell)
Item #6. Page 1619
Meeting Date: 9/24/2024 / Packet Page #: 1755
2024.06 Rte 66 MH 314
MH at ~535 W. Rte 66
MH SE of address in WB lanes of
Historic Rte 66.

X
Install Date: 5/31/2024
Access: System Type:

Sanitary Storm
Map
Sewer Map
Flow Meter
Meter Depth: 77.69"
MH Coordinates: 34.128832, -117.871836
Moderate to rapid open channel hydraulics.

Avg Velocity Avg Measured Level Multiplier

3.66 fps 1.66" 1.0
Gas
O2 H2S CO LEL

20.9 0 0 0
Notes
No laterals; monitored the upstream line as it
provided the best hydraulics during inspection.

Traffic Safety
Used arrow board, cones & signs in accord
w/approved TCP per site-specific CATTCH
requirements.

Land Use
Residential Commercial Industrial Trunk
X
West
Manhole Depth
10"
94"
Round
10"/10"
Good
Concrete
None observed
Passed

0.4 2-D

16.31"

6.31"
Upstream
Flow Heading
Sensor Direction
Sensor Dist. to Crown
Sensor Offset
Velocity Profile Data
Velocity Profile Taken
Silt
Manhole Material
Pipe Condition
Pipe Shape
Inner Pipe Size (In/Out)
Monitored Pipe Size
C&V Consulting
Glendora, CA 91740
MH # 314
Site Report
Confidential Proprietary Information
6/18/2024
Item #6. Page 1620
Meeting Date: 9/24/2024 / Packet Page #: 1756
2024.06 Rte 66 MH 314
MH at ~535 W. Rte 66
Glendora, CA 91740
Meter Site Document
Manhole Before Install
Installed
Upstream Pipe Size
Site
Installation Process
Upstream
Item #6. Page 1621
Meeting Date: 9/24/2024 / Packet Page #: 1757
Temporary Flow Study
C&V Consulting
2024.06 Rte 66 MH 314
Utility Systems, Science and Software
Santa Ana, CA 92705
601 N. Parkcenter Dr, Suite 209
Meter Start Date From 5/31/2024
Meter Stop Date To 6/18/2024
Velocity (fps) Level (in) Flow (mgd)
Average 3.669 1.662 0.146
Maximum 4.520 2.010 0.229
Minimum 2.170 1.190 0.052
Pipe Size 10.000
Estimated Capacity (mgd) Not Calculated
Capacity Used Not Calculated
Sensor Type Hach - Flodar
El Cajon, CA 92020
1300 Hill St
Item #6. Page 1622
Meeting Date: 9/24/2024 / Packet Page #: 1758
Velocity (fps) Level (in) Flow (gpm)
Average 3.751 1.687 106.213 RainFall Inches
Maximum 4.510 1.980 153.580
Minimum 2.370 1.210 39.640 6/18/2024
Item #6. Page 1623
Meeting Date: 9/24/2024 / Packet Page #: 1759
Velocity (fps) Level (in) Flow (gpm)
Average 3.657 1.659 101.139 RainFall Inches
Maximum 4.450 2.010 156.240
Minimum 2.170 1.190 35.780 6/18/2024
Item #6. Page 1624
Meeting Date: 9/24/2024 / Packet Page #: 1760
Velocity (fps) Level (in) Flow (gpm)
Average 3.670 1.659 101.466 RainFall Inches
Maximum 4.520 2.010 158.860
Minimum 2.240 1.210 37.570 6/18/2024
Item #6. Page 1625
Meeting Date: 9/24/2024 / Packet Page #: 1761
Velocity (fps) Level (in) Flow (gpm)
Average 3.600 1.644 97.787 RainFall Inches
Maximum 4.410 2.010 153.560
Minimum 2.480 1.220 42.420 6/18/2024
Item #6. Page 1626
Meeting Date: 9/24/2024 / Packet Page #: 1762
6/18/2024 1:44:39 PM
5/31/2024 thru 6/18/2024
Item #6. Page 1627
Meeting Date: 9/24/2024 / Packet Page #: 1763
2024.06 Rte 66 MH 314:
05/31/2024 thru 6/18/2024
Report Date: 06/18/2024
Customer: C&V Consulting
Group: 723-745 E. Route 66
Site: 2024.06 Rte 66 MH 314
Item #6. Page 1628
Meeting Date: 9/24/2024 / Packet Page #: 1764
12 Appendix D

SEWER AS-BUILTS
Item #6. Page 1629
Meeting Date: 9/24/2024 / Packet Page #: 1765
SITE

SEWER AREA STUDY

MAINLINE TO THE FLOW
MONITORED MH 314 (CONT.

NEXT PAGE)
Item #6. Page 1630
Meeting Date: 9/24/2024 / Packet Page #: 1766
FLOW MONITORED MH 314
Item #6. Page 1631
Meeting Date: 9/24/2024 / Packet Page #: 1767
MH 314 - FLOW

MONITORED
Item #6. Page 1632
Meeting Date: 9/24/2024 / Packet Page #: 1768
13 Appendix E

REFERENCES
Item #6. Page 1633
Meeting Date: 9/24/2024 / Packet Page #: 1769
Item #6. Page 1634
Meeting Date: 9/24/2024 / Packet Page #: 1770
Occupancy Abbreviation *Average daily flow
Apartment Buildings:

Bachelor or Single dwelling units Apt 150 gal/D.U.
1 bedroom dwelling units Apt 200 gal/D.U.
2 bedroom dwelling units Apt 250 gal/D.U.
3 bedroom or more dwelling units Apt 300 gal/D.U.

Auditoriums, churches, etc. Aud 5 gal/seat
Automobile parking P 25 gal/1000 sq ft gross floor area Bars, cocktails lounges, etc. Bar 20 gal/seat
Commercial Shops & Stores CS 100 gal/1000 sq ft gross floor area Hospitals (surgical) HS 500 gal/bed
Hospitals (convalescent) HC 85 gal/bed
Hotels H 150 gal/room
Medical Buildings MB 300 gal/1000 sq ft gross floor area Motels MB 150 gal/unit
Office Buildings Off 200 gal/1000 sq ft gross floor area Restaurants, cafeterias, etc. R 50 gal/seat
Schools:

Elementary or Jr. High S 10 gal/student
High Schools HS 15 gal/student
Universities or Colleges U 20 gal/student
College Dormitories CD 85 gal/student
Zone Coefficient (cfs/Acre)
Agriculture ---------------------------------- 0.001
Residential*:

R-1 -------------------------------------------- 0.004
R-2 -------------------------------------------- 0.008
R-3 -------------------------------------------- 0.012
R-4 -------------------------------------------- 0.016* Commercial:

C-1 through C-4 ---------------------------- 0.015*
Heavy Industrial:

M-1 through M-4 -------------------------- 0.021*
exceed the coefficients shown
* Use 0.001 (cfs/unit) for condominiums only
Estimated Average Daily Sewage Flows for Various Occupancies *Multiply the average daily flow by 2.5 to obtain the peak flow Zoning Coefficients
* Individual building, commercial or industrial plant capacities shall be the determining factor when they SOURCE LINK:
https://dpw.lacounty.gov/ldd/lddservices/sewerAreaStudy/docs/Estimated%20A verage%20Daily%20Sewage%20Flow%20for%20Various%20Occupancies.pdf Item #6. Page 1635
Meeting Date: 9/24/2024 / Packet Page #: 1771
Initial Study/Mitigated Negative Declaration July 2024
Brandywine Route 66 Residential – PLN 23-0027

Page 171 ends

Glendora City CouncilSeptember 24, 2024

Glendora City Council
September 24, 2024