Press Alt + R to read the document text or Alt + P to download or print.
This document contains no pages.
CC - Item 3A - Attachment H - Appendix I. Preliminary LID PlanPRELIMINARY
LOW IMPACT DEVELOPMENT (LID) REPORT
TENTATIVE TRACT NO. 82875
3133-3141 Willard Avenue
Rosemead, CA 91770
Prepared for:
THE OLSON COMPANY
3010 Old Ranch Parkway, Suite 100
Seal Beach, CA 92740-2751
(562) 596-4770
Prepared by:
ALAN R. SHORT, P.E.
25911 Pinewood Lane
Laguna Hills, CA 92653
(949) 586-5200
Date Prepared: September 30, 2019
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
AUGUST 5, 2017
ROSEMEAD TENTATIVE TRACT NO. 82875 i
TABLE OF CONTENTS
SECTION PAGE
I. INTRODUCTION .................................................................................................................. 1
II. EXISTING SITE AND WATERSHED DESCRIPTION ................................................................. 3
SITE DESCRIPTION............................................................................................................... 3
GEOTECHNICAL CONDITIONS ............................................................................................. 3
WATERSHED DESCRIPTION ................................................................................................. 4
III. PROJECT DESCRIPTION ....................................................................................................... 6
IV. SITE ASSESSMENT AND DESIGN CONSIDERATIONS ......................................................... 12
SOURCE CONTROL BMPS .................................................................................................. 16
SITE DESIGN BMPS ............................................................................................................ 17
VI. STORMWATER QUALITY CONTROL MEASURES ............................................................... 18
STORMWATER QUALITY DESIGN CALCULATIONS ............................................................ 20
DESIGN STANDARDS FOR STORMWATER QUALITY CONTROL MEASURES/LID BMPS ..... 22
STORMWATER QUALITY CONTROL MEASURES/LID BMP SIZING..................................... 22
VII. HYDROLOGIC CONDITIONS OF CONCERN ........................................................................ 24
VIII. STORMWATER QUALITY CONTROL MEASURE MAINTENANCE ........................................ 25
RESPONSIBLE PARTY ......................................................................................................... 25
MAINTENANCE PLAN ........................................................................................................ 26
IX. APPENDICES ...................................................................................................................... 27
Appendix 1: Hydrocalc Calculations
Appendix 2: Geotechnical/Infiltration Report
Appendix 3: Modular Wetlands System O&M Manual
Appendix 4: Source Control BMP Fact Sheets
Appendix 5: Public Education Materials
Appendix 6: Master Covenant and Agreement (placeholder for Final LID Report only)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
AUGUST 5, 2017
ROSEMEAD TENTATIVE TRACT NO. 82875 ii
OWNER CERTIFICATION
LOW IMPACT DEVELOPMENT PLAN
This Low Impact Development Report has been prepared for The Olson Company, by ALAN R.
SHORT, P.E. It is intended to comply with the requirements of the County of Los Angeles National
Pollution Discharge Elimination Permit (Order No. R4-2012-0175-A01) issued by the Los Angeles
Regional Water Quality Control Board. The undersigned is authorized to approve implementation
of the provisions of this plan as appropriate and will strive to have the plan carried out by
successors consistent with the City of Rosemead Low Impact Development Ordinance and the
intent of the NPDES storm water program 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 gathering 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.
Signature Date
Name Title
THE OLSON COMPANY
3010 Old Ranch Parkway, Suite 100
Seal Beach, CA 92740-2751
(562) 596-4770
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
AUGUST 5, 2017
ROSEMEAD TENTATIVE TRACT NO. 82875 1 INTRODUCTION
I. INTRODUCTION
This LID Report covers the post-construction operations on Tentative Tract No. 82875, in the City
of Rosemead, California (see Figure 1, Vicinity Map). It has been developed as required under
State Water Resources Control Board (SWRCB) Municipal NPDES Storm Water Permit for the
County of Los Angeles and the Incorporated Cities of Los Angeles County, the County of Los
Angeles Department of Public Works Low Impact Development Standards Manual dated February
2014 (LID Standards Manual), and in accordance with good engineering practices.
This LID Report shall identify, at a minimum, the routine resources specified in the City of
Rosemead Low Impact Development Ordinance and the County of Los Angeles Department of
Public Works Low Impact Development Standards Manual, which details implementation of Low
Impact Development (LID) BMPs whenever they are applicable to a project; the assignment of
long-term maintenance responsibilities; and show the Design Plan that will be implemented in
order to mitigate post-construction stormwater runoff pollution.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 2 Figure 1 Vicinity Map (3133-3141 Willard Avenue)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 3
II. EXISTING SITE AND WATERSHED DESCRIPTION
SITE DESCRIPTION
The site is located at 3133, 3141 & 3149 Willard Avenue in the city of Rosemead, California. The
site is bordered by single-family residences to the north and south, Willard Avenue to the east,
and a utility easement to the west. The location of the site and its relationship to the surrounding
areas are shown on Figure 1, Vicinity Map.
The site is irregular in shape and comprises approximately 1.19 acres of land. The site is currently
occupied by two one-story residential buildings. The residential building at the northeast corner
of the site is unoccupied. Remnants of building foundations were also observed at certain portions
of the site. Other site improvements include a detached garage and a storage shed.
Under existing conditions, the site is approximately 9.2% impervious (see page 8). Topography
within the site varies with elevations of approximately 263 to 266 feet above mean sea level
(MSL), based on google earth. Site drainage is via sheet flow directed to east toward Willard
Avenue. Vegetation within the site consist of grass and medium size trees scattered throughout
the site.
SOIL CONDITIONS & INFILTRATION CHARACTERISTICS
Soils encountered at the site consist of artificial fill materials overlying alluvial deposits. The
artificial fill materials typically consist of brown silty sand. The artificial fill was typically moist and
loose to medium dense. Pores were observed within the central and western portions of the site.
The maximum thickness of the fill encountered varied from approximately 5 to 6 feet below
existing grades. The project site is comprised of Soil Group No. 007 soils, according to the Los
Angeles County Department of Public Works web-based Hydrology Map
(http://dpw.lacounty.gov/wrd/hydrologygis/)
The alluvial deposits were encountered below the artificial fill materials to the maximum depth
of exploration, 51.5 feet below the ground surface. The alluvial deposits consisted predominantly
of coarse-grained material and with occasional layers of fine-grained material at depth. The
coarse-grained material was typically brown sand with varying amounts of silt.
A review of the CDMG Seismic Hazard Zone Report 024 indicates that historical high groundwater
levels for the general site area is as shallow as 10 feet below the existing ground surface.
Groundwater was not encountered during this firm’s subsurface exploration to the maximum
depth explored, approximately 51.5 feet below the existing ground surface. Existing groundwater
in the past 10 years has fluctuated from 60 to 95 feet below the existing ground surface. It is
therefore concluded that groundwater can at least be as shallow as 60 feet below the existing
ground surface.
Percolation testing was performed on May 2, 2019, in general conformance with the constant-
head test procedures outlined in the referenced Well Permeameter Method (USBR 7300-89).
Based on the subsurface exploration and percolation testing, infiltration of storm water is not
considered to be feasible due to the estimated permeability being less than 0.3 in/hr, at 0.22 in/hr
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 4
and less than 0.09 in/hr in the tests performed. Percolation characteristics of site soils are not
anticipated to meet the minimum requirements of the Los Angeles County guidelines. This is
likely attributed to the presence of fine-grained material throughout the subsurface materials.
Although the subsurface materials can be considered a silty sand, pockets of cohesive materials
were observed. The infiltration study is provided in Appendix 2.
WATERSHED DESCRIPTION
The proposed project resides within the Los Angeles River Watershed, which covers an area of
approximately 834 square miles. The watershed encompasses and is shaped by the path of the
Los Angeles River, which flows from its headwaters in the mountains eastward to the northern
corner of Griffith Park. Here the channel turns southward through the Glendale Narrows before
it flows across the coastal plain and into San Pedro Bay near Long Beach. The Los Angeles River
has evolved from an uncontrolled, meandering river providing a valuable source of water for early
inhabitants to a major flood protection waterway.
The proposed project discharges south into the City MS4 along Willard Avenue. The storm drain
then ties into the line at Garvey Avenue flowing east. This line then discharges into the Rio Hondo
Channel approximately 1.3 miles from the project site. The Rio Hondo Channel then flows
southwest until it reaches the Los Angeles River approximately 15 miles downstream.
Los Angeles River Watershed Management Area is 303(d) listed for Ammonia, Coliform Bacteria,
Copper, Lead, Nutrients, Oil, and Trash. Of those pollutants, Trash, Nutrients/Ammonia, Lead,
Copper, and Bacteria are addressed in TMDLs that have been established and approved by USEPA.
The proposed project, therefore, must minimize these pollutants of concern should they be
anticipated or expected from the project’s land use.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 5 Los Angeles County Storm Drain System (https://pw.lacounty.gov/fcd/StormDrain/index.cfm)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 6
III. PROJECT DESCRIPTION
The proposed Tentative Tract 82875 project will develop 29 single-family attached residential
units on the 1.20-acre property. There will be 8 buildings with a T-shaped driveway providing six
uncovered surface parking stalls and one handicap space. Under proposed conditions, the project
site will be approximately 74.7% impervious, an increase from 9.2% impervious in existing
conditions.
The proposed project will generally be drained via area drains as well as curb and gutter flows
along the drive aisles of the property to drop inlet catch basins. Storm water runoff flows will
generally drain in a southeasterly direction towards Willard Avenue. Prior to discharge offsite,
the LID stormwater runoff flows will be treated by a Modular Wetlands System (MWS-L-8-16)
proprietary biofiltration BMP that will be in the south side front setback area between Residential
Unit #7 and Willard Avenue. For peak flow detention, approximately 50 feet of 60-inch diameter
HDPE pipe will be located at north side front setback area between Residential Unit #6 and Willard
Avenue. LID treated flows and peak flows will be discharged via storm drain tie-in to the existing
48-inch RCP LACDPW storm drain along Willard Avenue.
An HOA will be formed upon project completion. All driveways within the project site are
considered private, to be maintained by the HOA. All storm water BMPs specified in this LID
Report will also be maintained by the HOA. There are no trash enclosures or community trash
bins, as each individual homeowner will be responsible for their respective homes, with regularly
scheduled trash pickup at each home.
TTRTRP2P2TRTRP2P215RUP15RUP CABLEELECF.R
.TRTRTR15RUP15RUPCABLEELECF.R.P1P5P1XP4P3P5P1P5P1XP4P3TRTR P2P2TR TRP2 P2 TRTR P2P2P1P515RUP15RUPCABLEELECF.R.P1XTRTRP4P3P5TRTR P2P21BLDG 2002BLDG 3003BLDG 1004BLDG 1005BLDG 1006BLDG 1007BLDG 1008BLDG 100WILLARD AVEMin. 8' Side Setback RequiredMin. 20' FrontSetbackRequiredMin. 8' Side Setback RequiredMin. 8' Side Setback Required100’ Setback fromHigh VoltagePower LinesMin. 20' RearSetbackRequiredADA Accessible Path13'-0"20'-0"30'-0"
26'-0"8'-0"10'-0"100'-0"6'-0"6'-0"30'-0"26'-0"
20'-0"
28'-6"
9'-0"
13'-0"24'-0"7'-6"12'-5"8'-0"
5'-0"9'-4"Open Space "E" 931 SQ. FT.Open Space "B"2645 SQ. FT.Open Space "A" 2849 SQ. FT.EXISTING RESIDENTIALEXISTING RESIDENTIALOpen Space "C"2315 SQ. FT.8'-11"Open Space "D"1376 SQ. FT.26' Fire Laneand HammerheadArchitecture + Planning17911 Von Karman Ave,Suite 200Irvine, CA 92614949.851.2133ktgy.com#ROSEMEAD - WILLARD & GARVEYRosemead, CA2018-1210The Olson Company3010 Old Ranch Parkway,Suite 100Seal Beach, CA 90704Plot Date:09.25.20190102040SCALE: 1"=20'-0"A1.0CONCEPTUALSITE PLAN
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 12
IV. SITE ASSESSMENT AND DESIGN CONSIDERATIONS
When implementing storm water control measures for a project, the project is required to provide
treatment to remove pollutants of concern for the project. The BMP matrix labeled Table 7.3 on
the following page lists the land use categories and their pollutants of concern for the Los Angeles
River Watershed. This report is responsible for determining, evaluating, and selecting the
appropriate and applicable measures to treat the targeted pollutants to the MEP standard. One
or a combination of two or more suggested LID/treatment control BMPs can be selected as
deemed applicable.
The proposed project is considered a High-Density Single-Family Residential land use at 24.2
Dwelling Units per acre. The anticipate pollutants for the project include suspended solids, total
phosphorus, copper, lead, and zinc. See table 7.3 below. Based on the TMDLs and 303(d) listed
impairments for the Los Angeles River Watershed, the projects primary pollutants of concern are,
therefore, (1) nutrients, (2) trash, and (3) oil and grease, and (4) metals. LID Report treatment
control BMPs must address these pollutants to the MEP.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 13 BMP MATRIX TABLES FOR LID REPORT PROJECT CATEGORIES (Excerpted from County of Los Angeles Department of Public Works, Low Impact Development Standards Manual, February 2014)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 14
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 15
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 16
SOURCE CONTROL BMPS
Source control BMPs are required to be incorporated in all new development and redevelopment
projects unless not applicable. The table below indicates all BMPs to be incorporated in the
project. For those designated as not applicable (N/A), a brief explanation why is provided.
The specific source control BMPs for the Tentative Tract No. 82875 Project include:
INCORPORATED SOURCE
CONTROL BMP: YES N/A DESCRIPTION
Storm Drain Message and
Signage (S-1) Inlets will be stenciled with the
appropriate message.
Outdoor Material Storage Area
(S-2) None proposed.
Outdoor Trash Storage/Waste
Handling Area (S-3) None proposed.
Outdoor Loading/Unloading
Dock Area (S-4) None proposed.
Outdoor Vehicle/Equipment
Repair/Maintenance Area (S-5) None proposed.
Outdoor Vehicle/Equipment/
Accessory Wash Area (S-6) None proposed.
Fuel & Maintenance Area (S-7) None proposed.
Landscape Irrigation Practices
(S-8) Efficient irrigation systems and smart
controllers are proposed.
Building Materials (S-9) None proposed.
Animal Care and Handling
Facilities (S-10) None proposed.
Outdoor Horticulture Areas
(S-11) None proposed.
The following source control BMP fact sheets are provided in Appendix 4 of this report as a
reference to the design plans and/or specifications for the Tentative Tract No. 82875 Project:
· Storm Drain Message and Signage (S-1)
· Landscape Irrigation Practices (S-8)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 17
SITE DESIGN BMPS
The following table describes the site design BMPs used in this project and the methods used to
incorporate them. Careful consideration of site design is a critical first step in storm water
pollution prevention from new developments and redevelopments.
SITE DESIGN PRINCIPLES
DESIGN CONSIDERED: SPECIFIC BMP YES NO DESCRIPTION
Site Planning
Building roof runoff will be directed to
landscaping prior to discharge onto
pavement or into area drains.
Protect and Restore Natural Areas There are no natural areas to
conserve. Site is already developed.
Minimize Land Disturbance
The project site is in an area that is
considered built-out and is on an
existing developed property.
Minimize Impervious Area
Approximately 10,000 square feet of
common open space is provided,
contributing to the majority of the
25.3% pervious area (0.3 acres) for the
project.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 18
VI. STORMWATER QUALITY CONTROL MEASURES
This section describes the storm water quality control measures or LID BMPs proposed to treat
the project site’s storm water runoff. Low Impact Development (LID) BMPs are required in
addition to site design measures and source controls to reduce pollutants in stormwater
discharges. LID BMPs are engineered facilities that are designed to retain or biofilter runoff on the
project site. The Los Angeles County MS4 Stormwater Permit (Order No. R4-2012-0715) requires
the evaluation and use of LID features using the following hierarchy of treatment: infiltration,
harvest/reuse, and biofiltration.
The design storm, from which the SWQDv is calculated, is defined as the greater of:
The 0.75-inch, 24-hour rain event; or
The 85th percentile, 24-hour rain event as determined from the Los Angeles County 85th
percentile precipitation isohyetal map.1
Per the Los Angeles County 85th percentile precipitation isohyetal map, the 85th percentile, 24-
hour storm event is 0.9-inch (see Figure 2). BMPs selected for the site shall rely on infiltration,
bioretention, rainfall storage and reuse, and/or biofiltration, as feasible. In addition, any
biofiltration features will be designed to biofiltrate 1.5 times the portion of the SWQDv that is not
retained onsite (1.35-inch storm).
INFILTRATION BMP FEASIBILITY
As described in Section II, the soil percolation tests conducted on the site found infiltration rates
of 0.22 in/hr and 0.09 in/hr. Since the measured rates fall below the LID Standards Manual’s
minimum requirement for feasibility of 0.3 inches per hour, infiltration on the project site is
therefore considered infeasible. Infiltration test results are included in Appendix 2.
STORMWATER CAPTURE & REUSE FEASIBILITY
In accordance with the County of Los Angeles Low Impact Development Standards Manual (LID
Standards Manual), storage and reuse shall be considered should infiltration be determined
infeasible. Since the primary use of captured runoff is for subsurface drip irrigation purposes, the
proposed onsite irrigation demand was calculated for wet season months (October through April)
to evaluate reuse feasibility. Demand requirements were calculated based on the proposed
landscaping area, 1.19 acres (74.7% site imperviousness), and compared with the minimum LID
design capture runoff volume of 2,700 ft3 for the project site.
At a minimum, storage and reuse BMPs must be designed and maintained to ensure adequate
capacity is available to capture the stormwater quality design volume (SWQDv) within 3 days (72
hours) of a likely storm event. The evaluation performed herein is derived from City of Los Angeles
feasibility screening guidelines for capture and use, which initially screens to see if the 7-month
wet season irrigation demand (ETWU7-month) is more than the LID design volume or SWQDv. Once
this threshold is met, a final determination is made by assessing the estimated daily average water
usage during the wet season, to ensure that there is enough irrigation demand from the project
1 County of Los Angeles Department of Public Works. (2004, February). Analysis of 85th Percentile 24-hour Rainfall
Depth Analysis within the County of Los Angeles (February 2004). Retrieved September 30, 2019, from
http://ladpw.org/wrd/hydrologygis/
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 19
site during the rainy season to effectively utilize and draw down the SWQDv during a 72-hour
period.2
Based on the initial screening method, storage and reuse of stormwater runoff is considered
potentially feasible since the SWQDv ≤ ETWU7-month. See calculations below.
Given for Proposed Project:
Impervious Area 0.89 acres
Pervious Area 0.30 acres
Total Tributary Area 1.19 acres
Total Site Irrigated Area 13,068 ft2
ETo Wet Season (Oct-April) 21.7 (Los Angeles area)3 = ET7
Planting Factor (PF) 0.5 = Medium Planting Type, moderate water use.
Step 1: Calculate the Design Volume in Gallons (for 72-hour holding time)
SWQDv = 2,700 ft3 x 7.48 gal/ft3 = 20,196 gallons
Step 2: Determine Planter Factor
Planter Factor (PF) = Planting Factor x Irrigated Area
= 0.5 x 13,068 ft2
= 6,534 ft2
Step 3: Determine the 7-Month (Oct 1 – April 30) Estimated Total Water Use (ETWU)
Wet Season Estimated Total Water Use (ETWU7-month) = ET7 x 0.62 x PF
= 21.7 x 0.62 x 6,534 ft2
= 87,908 gallons
Step 4: Determine if Captured Volume is Equal or Less Than Irrigation Demand (ETWU)
Is SWQDv ≤ ETWU7-month?
Yes – Demand (ETWU7-month) is greater than SWQDv. Storage and reuse is potentially
feasible.
STORAGE & REUSE FEASIBILITY SCREENING SUMMARY
Project
Acreage
Irrigated
Area SWQDv Plant Factor
(PF)
7-Month
ETWU
Meets Initial
Screening Criteria?
1.19 13,068 ft2 20,196 gal. 6,534 ft2 87,908 gal. Yes
2 City of Los Angeles Department of Public Works, Watershed Protection Division. (2011, June). Development Best
Management Practices Handbook Low Impact Development Manual Part B Planning Activities. 4th Edition.
3 Reference Evapotranspiration (ETo) Table from City of Los Angeles Irrigation Guidelines (Local Implementation of AB
1881).
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 20
Despite the feasibility screening resulted in stormwater storage and reuse being potentially
feasible, it is necessary to determine that the Stormwater Quality Design Volume can be
adequately drawn down within 72 hours in order for it to be implemented on the project. This is
determined by estimating the daily average water demand during the wet season. Since the
ETWU7-month is approximately 87,908 gallons, the average daily water demand is roughly 410
gallons per day (214 days). Over a 72 hour period, it appears that the daily average water usage
during the wet season is insufficient to utilize and draw down the onsite SWQDv, since the total
water demand is 820 gallons, assuming that the first 24 hours after a rain event there is no water
demand. Only 4% of the onsite SWQDv (820 gallons of 20,196 gallons) would be used for irrigation
of the landscaped area within the project site over a 72-hour period, with approximately 19,376
gallons remaining in storage and unutilized. A significant amount of runoff treatment would be
bypassed should a subsequent storm event follow shortly after the first. Therefore, stormwater
runoff storage and reuse is considered not feasible.
BIOFILTRATION
Due to the infeasibility of the project site for retention, the project site will be treated by
biofiltration, with a Modular Wetlands System (MWS-L-8-16) proprietary BMP. The entire 1.19-
acre property will be treated by the MWS unit and, therefore, the project site has one Drainage
Area.
The table below provides the retention and biofiltration (1.5x) volumes and flow-rates for the
project site under proposed conditions. BMPs selected for the project must be sized to provide
the equivalent or greater treatment capacities than the listed volumes/flow-rates below.
Calculations were performed utilizing the hydrologic calculator “HydroCalc” developed by the Los
Angeles County Department of Public Works. HydroCalc completes the full Modified Rational
Method (MODRAT) calculation process and produces the peak stormwater runoff flow rates and
volumes for single subareas. Detailed calculations for the proposed treatment control BMPs,
based on the HydroCalc tool, are provided in Appendix 1 of this report.
STORMWATER QUALITY DESIGN CALCULATIONS
Since stormwater retention is infeasible at the project site due to measured infiltration rates being
less than 0.3 inches/hour, the project will rely on biofiltration to treat the LID volume. As such,
the LID volume/rate to biofilter will be expressed as 1.5 times what would otherwise be retained.
The Hydrocalc calculations for the proposed Tract No. 82875 project site is summarized below.
SUMMARY OF STORMWATER QUALITY DESIGN CALCULATIONS
Drainage
Area Acres
Imp.
Ratio
Soil
No.
Slope
Length
(ft) Slope
Tc
(min)
Storm
Depth
1.5x (in.)
1.5x LID
SWQDv
(ft3)
1.5x LID
flow rate
(cfs)
1 1.19 0.75 007 335 0.0107 17 1.35 4,048 0.378
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 21 Figure 2 Project Site Predominant Soil Type Number = 007 | 85th Percentile, 24-hr Rainfall = 0.9 inch
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 22
DESIGN STANDARDS FOR STORMWATER QUALITY CONTROL MEASURES/LID BMPS
The Modular Wetlands System (MWS) proprietary biofiltration BMP is a flow-based treatment
system. As such, the project is required to treat a minimum of the 0.378 cfs. The various MWS
sizes are provided in the table below, along with their respective treatment flow rates.
STORMWATER QUALITY CONTROL MEASURES/LID BMP SIZING
LID BMPs are sized based on the tributary area draining to them. Based on the project site’s
grading and drainage design, the property is comprised of one drainage area that covers the entire
1.19-acre site. Therefore, the drainage area’s LID flow rate is equivalent to the project’s design
flow rate of 0.378 cfs. For this reason, an MWS-L-8-16 unit with a treatment flow rate capacity of
0.462 cfs is prescribed. See Section III LID Schematic Exhibit and MWS-L-8-16 standard detail
below for further details.
STANDARD DETAIL
STORMWATER BIOFILTRATION SYSTEM
MWS-L-8-16-V
PLAN VIEW
ELEVATION VIEW
RIGHT END VIEW
LEFT END VIEW
GENERAL NOTES
INSTALLATION NOTES
SITE SPECIFIC DATA
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 24
VII. HYDROLOGIC CONDITIONS OF CONCERN
There are no hydrologic conditions of concern for the project site. The project does not drain
into a natural drainage system. It drains to to the Rio Hondo Channel at Whittier Narrows Dam
and ultimately to the Los Angeles River. All downstream channels are considered engineered
channels with concrete side slopes. Therefore, the project will not have any hydromodification
impacts to any downstream channels and is exempt from hydromodification requirements.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 25
VIII. STORMWATER QUALITY CONTROL MEASURE MAINTENANCE
RESPONSIBLE PARTY
It has been determined that The Olson Company (owner) shall assume all BMP inspection and
maintenance responsibilities for the Tract No. 82875 Project until an HOA is established. An HOA
will be established for the property and the Owner will transition to an HOA Corporation. The
Owner will be responsible for maintenance of all storm drain inlets, collectors, v-ditches or any
other related flood control or storm water control device. Furthermore, all interior streets and/or
roadways, landscape, recreation areas, facilities and/or open space within the project limits will
be maintained by the Owner.
Long-term funding for BMP maintenance will be provided by the Owner or HOA. Maintenance
will be funded through HOA fees.
RESPONSIBLE PARTY CONTACT INFORMATION
Name: The Olson Company
Contact: Tom Moore, Senior Director of Operations
Address: 3010 Old Ranch Parkway, Suite 100
Seal Beach, CA 92740-2751
Phone: (562) 596-4770
Email:
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 26
MAINTENANCE PLAN
Proper O&M is an important element of a stormwater mitigation plan to ensure BMPs remove
pollution effectively. Routine maintenance or service also contributes to the efficiency and
continuous operation of a system. The post development BMP maintenance responsibility and
frequency matrix provided in this section detail the specific party to perform the inspection and
maintenance of each BMP for the Tentative Tract No. 82875 Project and details the maintenance
and inspection activities to be performed, and the frequency with which each shall be performed.
Structural BMP Maintenance Responsibility / Frequency Matrix
BMP
Responsibility
Maintenance Frequency
Catch Basin
Cleaning Owner / HOA
Minimum Frequency: Catch basin/storm drain inlets
within the project site will be cleaned out at least once
per year, prior to the rainy season (October 1).
Storm Drain
Stenciling Owner / HOA
Minimum Frequency: Storm drain inlet stenciling and
signage will be inspected for legibility at least once per
year. Any illegible stencils/signage will be replaced
immediately.
Modular
Wetlands
System
(MWS-L-8-16)
Owner / HOA
Minimum Frequency: 1x per Year.
The MWS unit shall be maintained in accordance with
manufacturer’s specifications provided in Appendix 3.
HPDE
Underground
Detention Pipe
Owner/HOA
Minimum Frequency: 1x per Year.
The underground detention system for peak flow
mitigation shall be inspected through the risers annually
and after major storm events, and cleaned at a minimum
of once per year, prior to the start of the rainy season
(October 1st). Cleaning and maintenance will be
performed per manufacturer specifications and will
typically include removal of any trash and debris and
excess sediment within the pipes. Sediment shall be
removed when deposits approach within 6 inches of the
invert heights of the connecting pipe or inlet structures.
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875 27
IX. APPENDICES
Appendix 1: Hydrocalc Calculations
Appendix 2: Geotechnical / Infiltration Report
Appendix 3: Modular Wetlands System O&M Manual
Appendix 4: Source Control BMP Fact Sheets
Appendix 5: Public Education Materials
Appendix 6: Master Covenant and Agreement (Placeholder for Final LID Report)
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875
APPENDIX 1
HYDROCALC CALCULATIONS
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875
APPENDIX 2
GEOTECHNICAL / INFILTRATION REPORT
September 19, 2019
J.N.: 2783.00
Mr. Steve Armanino
The Olson Company
3010 Old Ranch Parkway, Suite 100
Seal Beach, California 90740
Subject: Infiltration Study for Storm Water Quality, Proposed Multi-Family Residential
Development, 3133, 3141 & 3149 Willard Avenue, Rosemead, California.
Dear Mr. Armanino,
Albus-Keefe & Associates, Inc. has completed a geotechnical investigation of the site for evaluation
of the percolation characteristics of the site soils. The scope of this investigation consisted of the
following:
• Exploratory drilling, soil sampling and percolation test well installation
• Field percolation testing
• Laboratory testing of selected soil samples
• Engineering analysis of the data
• Preparation of this report
SITE DESCRIPTION AND PROPOSED DEVELOPMENT
Site Location and Description
The site is located at 3133, 3141 & 3149 Willard Avenue in the city of Rosemead, California. The
site is bordered by single-family residences to the north and south, Willard Avenue to the east, and a
utility easement to the west. The location of the site and its relationship to the surrounding areas are
shown on Figure 1, Site Location Map.
The site is irregular in shape and comprises approximately 1.2 acres of land. The site is currently
occupied by two one-story residential buildings. The residential building at the northeast corner of
the site is unoccupied. Remnants of building foundations were also observed at certain portions of
the site. Other site improvements include a detached garage and a storage shed.
Topography within the site varies with elevations of approximately 263 to 266 feet above mean sea
level (MSL), based on google earth. Site drainage is via sheet flow directed to east toward Willard
Avenue. Vegetation within the site consist of grass and medium size trees scattered throughout the
site.
The Olson Company September 19, 2019
J.N.: 2783.00
Page 2
ALBUS-KEEFE & ASSOCIATES, INC.
© 2018 Google
N
SITE LOCATION MAP
The Olson Company
Proposed Residential Development
3133, 3141 & 3149 Willard Avenue
Rosemead, California
NOT TO SCALE
FIGURE 1
SITE
Loca
tion
The Olson Company September 19, 2019
J.N.: 2783.00
Page 3
ALBUS-KEEFE & ASSOCIATES, INC.
Proposed Development
We understand the site will be developed for residential use consisting of 29 units of three- story
townhomes. It is anticipated that all proposed structures will be constructed on grade (i.e. no
subterranean elements). Associated interior driveways, perimeter/retaining walls, underground
utilities and a storm water infiltration system are also planned.
No grading or structural plans were available in preparing of this report. However, we anticipate
that minor rough grading of the site will be required to achieve future surface configuration and we
expect the proposed residential dwellings will be wood-framed structures with concrete slabs on
grade yielding relatively light foundation loads.
SUMMARY OF FIELD AND LABORATORY WORK
Subsurface Investigation
Subsurface exploration for this investigation was conducted at the site on April 30, 2019 and
consisted of drilling three (3) exploratory borings. The borings were drilled to maximum depths of
approximately 51.5 feet below the existing ground surface utilizing a truck-mounted, hollow-stem-
auger drill rig. Representatives of Albus-Keefe & Associates, Inc. logged the exploratory
excavations. Visual and tactile identifications were made of the materials encountered, and their
descriptions are presented on the Exploration Logs in Appendix A. The approximate locations of the
exploratory excavations completed by this firm are shown on the enclosed Geotechnical Map, Plate
1.
Bulk, relatively undisturbed and Standard Penetration Test (SPT) samples were obtained at selected
depths within the exploratory boring for subsequent laboratory testing. Relatively undisturbed
samples were obtained using a 3-inch O.D., 2.5-inch I.D., California split-spoon soil sampler lined
with brass rings. SPT samples were obtained from the boring using a standard, unlined SPT soil
sampler. During each sampling interval, the sampler was driven 18 inches with successive drops of
a 140-pound automatic hammer falling 30 inches. The number of blows required to advance the
sampler was recorded for each six inches of advancement. The total blow count for the lower 12
inches of advancement per soil sample is recorded on the exploration log. Samples were placed in
sealed containers or plastic bags and transported to our laboratory for analyses. The borings were
backfilled with auger cuttings upon completion of sampling.
In addition, two percolation test boring, P-1 and P-2, were also excavated to an approximate depth of
25 and 10 feet in the vicinity of exploratory boring B-1 for subsequent percolation testing. The
percolation test well was later backfilled with auger cuttings upon completion of testing.
Percolation Testing
Percolation testing was performed on May 2, 2019, in general conformance with the constant-head
test procedures outlined in the referenced Well Permeameter Method (USBR 7300-89). A water
hose attached to a water source on site was connected to an inline flowmeter to measure the water
flow. The flowmeter is capable of measuring flow rates up to 13 gallons per minute and as low as
0.06 gallons per minute. A valve was connected in line with the flowmeter to control the flow rate.
The Olson Company September 19, 2019
J.N.: 2783.00
Page 4
ALBUS-KEEFE & ASSOCIATES, INC.
A filling hose was used to connect the flowmeter and the test well. Water was then introduced by
the filling hose near the bottom of the test well. A water level meter with 1/100-foot divisions was
used to measure the depths to water surface from the top of well casings.
Flow to the well was terminated upon either completion of testing of all the pre-determined water
levels or if the flow rate exceeded the maximum capacity of the flowmeter. Measurements obtained
during the percolation testing are provided on Appendix C, Plates C-1 and C-2.
Laboratory Testing
Selected soil samples of representative earth materials were tested to assist in the formulation of
conclusions and recommendations presented in this report. Tests consisted of in-situ moisture
content and dry density, and grain-size analysis. Results of laboratory testing relevant to percolation
characteristics are presented in the Appendix B.
ANALYSIS OF DATA
Subsurface Conditions
Descriptions of the earth materials encountered during our investigation are summarized below and
are presented in detail on the Exploration Logs presented in Appendix A.
Soils encountered at the site consist of artificial fill materials overlying alluvial deposits. The
artificial fill materials typically consist of brown silty sand. The artificial fill was typically moist and
loose to medium dense. Pores were observed within the central and western portions of the site. The
maximum thickness of the fill encountered varied from approximately 5 to 6 feet below existing
grades. Deeper fills associated with the previously existing improvements may also be present on
site.
The alluvial deposits were encountered below the artificial fill materials to the maximum depth of
exploration, 51.5 feet below the ground surface. The alluvial deposits consisted predominantly of
coarse-grained material and with occasional layers of fine-grained material at depth. The coarse-
grained material was typically brown sand with varying amounts of silt. These deposits are slightly
moist to moist and loose to very dense. The fine-grained material consisted of brown clay and silt.
These deposits are typically was typically moist and very stiff. The upper alluvium was also
observed to contain pores within the central and western portions of the site.
Groundwater
A review of the CDMG Seismic Hazard Zone Report 024 indicates that historical high groundwater
levels for the general site area is as shallow as 10 feet below the existing ground surface.
Groundwater was not encountered during this firm’s subsurface exploration to the maximum depth
explored, approximately 51.5 feet below the existing ground surface. A review of the Los Angeles
County monitoring well database indicates well number 2924E is approximately 0.4 miles to the
southeast with data indicating historic groundwater has been in a downward trend since 1957.
Existing groundwater in the past 10 years has fluctuated from 60 to 95 feet below the existing
The Olson Company September 19, 2019
J.N.: 2783.00
Page 5
ALBUS-KEEFE & ASSOCIATES, INC.
ground surface. It is therefore concluded that groundwater can at least be as shallow as 60 feet below
the existing ground surface.
Percolation Data
An analysis was performed to evaluate permeability using the flow rate obtained at the end of the
constant-head stage of field percolation testing. The analysis was performed in accordance with the
procedures provided in the referenced USBR 7300-89. The procedure essentially uses a closed-form
solution to the percolation out of a small-diameter well. Using this method, we calculated a
composite permeability value for the head condition maintained in each well. Since the flow to the
well was less than the lower limit of our equipment, the minimum flow rate of the equipment was
used. The result is summarized in Table 1 below and the supporting analysis is included in
Appendix C, Plates C-3 and C-4.
TABLE 1
Summary of Back-Calculated Permeability Coefficient
Location
Total Depth
of Well
(ft)
Depth to
Water in
Well
(ft)
Height of
Water in
Well
(ft)
Static Flow
Rate
(gal./min.)
Estimated
Permeability,
ks
(in/hr.)
P-1 25.0 20.0 5.0 0.15 0.22
P-2 10.0 5.0 5.0 < 0.06 < 0.09
CONCLUSIONS AND RECOMMENDATIONS
Based on the subsurface exploration and percolation testing at 3133, 3141 & 3149 Willard Avenue,
infiltration of storm water is not considered to be feasible due to the estimated permeability being
less than 0.3 in/hr (less than 10-6 m/s). Percolation characteristics of site soils are not anticipated to
meet the minimum requirements of the Los Angeles County guidelines. This is likely attributed to
the presence of fine-grained material throughout the subsurface materials. Although the subsurface
materials can be considered a silty sand, pockets of cohesive materials were observed.
LIMITATIONS
This report is based on the geotechnical data as described herein. The materials encountered in our
boring excavations and utilized in our laboratory testing for this investigation are believed
representative of the project area, and the conclusions and recommendations contained in this report
are presented on that basis. However, soil and bedrock materials can vary in characteristics between
points of exploration, both laterally and vertically, and those variations could affect the conclusions
and recommendations contained herein. As such, observations by a geotechnical consultant during
the construction phase of the storm water infiltration systems are essential to confirming the basis of
this report.
The Olson Company September 19, 2019
J.N.: 2783.00
Page 6
ALBUS-KEEFE & ASSOCIATES, INC.
This report has been prepared consistent with that level of care being provided by other professionals
providing similar services at the same locale and time period. The contents of this report are
professional opinions and as such, are not to be considered a guaranty or warranty.
This report should be reviewed and updated after a period of one year or if the site ownership or
project concept changes from that described herein.
This report has been prepared for the exclusive use of The Olson Company to assist the project
consultants in the design of the proposed development. This report has not been prepared for use by
parties or projects other than those named or described herein. This report may not contain
sufficient information for other parties or other purposes.
This report is subject to review by the controlling governmental agency.
We appreciate this opportunity to be of service to you. If you should have any questions regarding
the contents of this report, please do not hesitate to call.
Sincerely,
ALBUS-KEEFE & ASSOCIATES, INC.
Mark Principe Paul Hyun Jin Kim
Staff Engineer Associate Engineer
P.E. 77214
Enclosures: Plate 1- Geotechnical Map
Appendix A - Exploratory Logs
Appendix B – Relevant Soil Laboratory Testing
Appendix C - Percolation Testing and Analyses
The Olson Company September 19, 2019
J.N.: 2783.00
Page 7
ALBUS-KEEFE & ASSOCIATES, INC.
REFERENCES
Publications and Reports
California Department of Conservation, Division of Mines and Geology, Seismic Hazard Report
027, “Seismic Hazard Zone Report for the El Monte 7.5-Minute Quadrangles, Los Angeles
County, California”, 1998.
“Procedure for Performing Field Permeability Testing by the Well Permeameter Method”, United
States Department of The Interior, Bureau of Reclamation (USBR 7300-89).
Saxton, K.E., W.J. Rawls, J.S. Romberger, and R.I. Papendick. 1986, “Estimating generalized soil-
water characteristics from texture”, Soil Sci. Soc. Am. J. 50(4):1031-103
WILLARD AVE.PROJECT SITE LIMITSB-1B-2B-3P-1P-2EARL AVE.- Exploratory BoringEXPLANATION(Locations Approximate)ALBUS-KEEFE & ASSOCIATES, INC.GEOTECHNICAL CONSULTANTSGEOTECHNICAL MAP2783.00Job No.:Date:Plate:105/14/190 20 40 80APPROX SCALE : 1" = 40'- Exploratory Percolation Test Boring
ALBUS-KEEFE & ASSOCIATES, INC.
APPENDIX A
EXPLORATORY LOGS
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
WaterCoreBulk5
10
15
20
EXPLANATION
Solid lines separate geologic units and/or material types.
Dashed lines indicate unknown depth of geologic unit change or
material type change.
Solid black rectangle in Core column represents California
Split Spoon sampler (2.5in ID, 3in OD).
Double triangle in core column represents SPT sampler.
Vertical Lines in core column represents Shelby sampler.
Solid black rectangle in Bulk column respresents large bag
sample.
Other Laboratory Tests:
Max = Maximum Dry Density/Optimum Moisture Content
EI = Expansion Index
SO4 = Soluble Sulfate Content
DSR = Direct Shear, Remolded
DS = Direct Shear, Undisturbed
SA = Sieve Analysis (1" through #200 sieve)
Hydro = Particle Size Analysis (SA with Hydrometer)
200 = Percent Passing #200 Sieve
Consol = Consolidation
SE = Sand Equivalent
Rval = R-Value
ATT = Atterberg Limits
Albus-Keefe & Associates, Inc.Plate A-1
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
MPHollow-Stem Auger
The Olson Company
B-1
271.5
WaterCoreBulk140 lbs / 30 in
5
10
15
20
ARTIFICIAL FILL (Af)
Silty Sand (SM): Dark brown, moist, medium dense, fine to
medium grained sand, organics, trace fine grained sand, pores,
pocket of sand
@ 4 ft, loose, increased sand, no pores
ALLUVIUM (Qal)
Silty Sand (SM): Light reddish brown, moist, loose, fine to
medium grained sand, pores, decreased clay
@ 10 ft, mottled reddish brown and gray, slightly moist,
medium dense, fine grained sand, trace fine gravel, iron oxide,
decreased fines
@ 20 ft, dense
27
30
34
25
14
11
9.2
8.9
10.1
11
16.5
114.7
106.6
125.2
115.3
110.7
Consol SA
Hydro
Consol
Albus-Keefe & Associates, Inc.Plate A-2
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
MPHollow-Stem Auger
The Olson Company
B-1
271.5
WaterCoreBulk140 lbs / 30 in
30
35
40
45
@ 30 ft, light brown, very dense, fine to medium grained sand
@ 35 ft, dense, fine to coarse grained sand, clay nodules
Silty Sand (SM): Mottled light grayish brown and reddish
brown, moist, dense, fine grained sand, mica present
Silt (ML): Mottled light grayish brown and reddish brown,
moist, very stiff, mica present
23
34
31
28
17
SA Hydro
Albus-Keefe & Associates, Inc.Plate A-3
25
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
MPHollow-Stem Auger
The Olson Company
B-1
271.5
WaterCoreBulk140 lbs / 30 in
Silty Sand (SM): Mottled light brown and reddish brown, moist,
dense, fine grained sand, mica present, 2" layer of silt
End of boring at depth of 51.5 ft. Backfilled with soil cutting.
No groundwater encountered.
29
Albus-Keefe & Associates, Inc.Plate A-4
50
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
SDHollow-Stem Auger
The Olson Company
B-2
272.5
WaterCoreBulk140 lbs / 30 in
5
10
15
20
ARTIFICIAL FILL (Af)
Silty Sand (SM): Medium brown, moist, loose, fine to
medium grained sand, some pores, organics, debris, trace
gravel, with clay
@ 4 ft, reddish brown, very moist, very loose, increased pores
ALLUVIUM (Qal)
Silty Sand (SM): Brown, medium dense, fine to coarse grained
sand, trace gravel, organics, pocket of medium grained sand,
some pores
@ 10 ft, reddish brown, loose, some clay, decreased pores
@ 15 ft, light brown, medium dense, trace fine gravel, iron
oxide
@ 20 ft, dense, decreased gravel
End of boring at depth of 23 ft. No groundwater encountered.
Backfilled with soil cutting.
9
19
10
22
5
22
9.6
8.5
9.2
10.3
114.1
114.9
110.3
120.9
SO4 DS
pH
Resist ChMax, EI
Consol
Consol
Albus-Keefe & Associates, Inc.Plate A-5
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
SDHollow-Stem Auger
The Olson Company
B-3
273.3
WaterCoreBulk140 lbs / 30 in
5
10
15
20
ARTIFICIAL FILL (Af)
Silty Sand (SM): Brown, moist, medium dense, fine to
coarse grained sand, organics, trace coarse gravel
@ 4 ft, loose, increased sand, trace fine to medium gravel, mica
present
ALLUVIUM (Qal)
Silty Sand (SM): Light brown, very moist, medium dense,
coarse grained sand
Sand with Silt (SP-SM): Light brown gray, moist, medium
dense, fine to coarse grained sand, with fine to coarse gravel
Silty Sand (SM): Light brown, dense, fine to coarse grained sand, trace gravel
@ 16.5 ft, gravel layer
@ 20 ft, 2 inch layer of clayey silt, no gravel
22
28
17
20
13
23
4.2
5.2
6.6
4.4
111
89.2
113.4
115.2
Albus-Keefe & Associates, Inc.Plate A-6
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
SDHollow-Stem Auger
The Olson Company
B-3
273.3
WaterCoreBulk140 lbs / 30 in
30
35
40
45
Lean Clay (CL): Brown, moist, very stiff, fine to medium
grained sand, trace coarse grained sand, iron oxide, mica present,
some silt
Silty Sand (SM): Light brown, moist, dense, fine to
medium grained sand, trace gravel, mica present, iron oxide
Silty Sand with Gravel (SM): Light brown, slightly moist, very
dense, fine to coarse grained sand, fine to coarse gravel, mica
present
Silty Sand (SM): Reddish brown, moist, medium dense, fine to
coarse grained sand, mica present
Silt (ML): Grayish brown, moist, very stiff, trace fine grained
sand, mica present, iron oxide specs, some clay
@ 45 ft, hard
13
29
50
9
10
200 ATT
200
200 ATT
Albus-Keefe & Associates, Inc.Plate A-7
25
Project:
Address:
Job Number:
Drill Method:
Client:
Driving Weight:
Location:
Elevation:
Date:
Logged By:
Depth
(feet)
Lith-
ology
Blows
Per
Foot
Moisture
Content
(%)
Dry
Density
(pcf)
Other
Lab Tests
Laboratory TestsSamples
Material Description
E X P L O R A T I O N L O G
Rosemead (Willard & Garvey)
3122 Delta Pl, Rosemead, CA 91770
2783.00 4/30/2019
SDHollow-Stem Auger
The Olson Company
B-3
273.3
WaterCoreBulk140 lbs / 30 in
Silty Sand (SM): Reddish brown, moist, dense, mica present
Clay (CL): Brown, moist, hard, mica present, trace sand, few silt,
iron oxide
End of boring at depth of 51.5. No groundwater encountered.
backfilled with soil cutting.
24
32.7
Albus-Keefe & Associates, Inc.Plate A-8
50
ALBUS-KEEFE & ASSOCIATES, INC.
APPENDIX B
RELEVANT SOIL LABORATORY TESTING
COARSE FINE COARSE MEDIUM FINE
Description
Silty Sand (SM)
Albus-Keefe & Associates, Inc.Plate B-1
2783.00
GRAIN SIZE DISTRIBUTION
Job Number Location
B-1
GRAVELCOBBLES SILT AND CLAYSAND
10
Depth
6"3"1.5"3/4"3/8"4 10 20 40 60 100 200
0
10
20
30
40
50
60
70
80
90
1000
10
20
30
40
50
60
70
80
90
100
0.00010.0010.010.1110100
U.S. Standard Sieve Sizes
Percent RetainedPercent PassingGrain Size in Millimeters
COARSE FINE COARSE MEDIUM FINE
Description
Silty Sand (SM)
Albus-Keefe & Associates, Inc.Plate B-2
2783.00
GRAIN SIZE DISTRIBUTION
Job Number Location
B-1
GRAVELCOBBLES SILT AND CLAYSAND
25
Depth
6"3"1.5"3/4"3/8"4 10 20 40 60 100 200
0
10
20
30
40
50
60
70
80
90
1000
10
20
30
40
50
60
70
80
90
100
0.00010.0010.010.1110100
U.S. Standard Sieve Sizes
Percent RetainedPercent PassingGrain Size in Millimeters
ALBUS-KEEFE & ASSOCIATES, INC.
APPENDIX C
PERCOLATION TESTING AND ANALYSES
Client:Job. No.: 2783.00
Date Tested:Test by: MP
Location:
Top of Casing to Bottom of Well (ft): 25
Elev. of Ground Surface (ft): 271.5
Diam. of Test Hole (in): 8
Diam. of Casing (in): 3
Ht. to Top of Casing (ft): 0
Water Tempurature (C°): 21
Elapsed Time Depth to H2O Flow Rate Total H2O used
(minutes)(ft)(gal./min.) (gal)
0 11:58 20 0.30 0.00
1 11:59 20 0.20 0.25
2 12:00 20 0.10 0.50
4 12:02 20 0.15 0.80
6 12:04 20 0.15 1.05
8 12:06 20 0.15 1.35
12 12:10 20 0.15 1.95
17 12:15 20 0.15 2.70
22 12:20 20 0.15 3.45
32 12:30 20 0.15 4.95
42 12:40 20 0.15 6.45
72 13:10 20 0.15 10.95
Constant Head
Time
Field Percolation Testing - Constant Head
5/2/2019
P-1
The Olson Company
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0 1020304050607080Accumulated Flow ‐GallonsTime ‐Minutes
ALBUS-KEEFE ASSOCIATES, INC.Plate C-1
Client:Job. No.: 2783.00
Date Tested:Test by: MP
Location:
Top of Casing to Bottom of Well (ft): 10
Elev. of Ground Surface (ft): 271.5
Diam. of Test Hole (in): 8
Diam. of Casing (in): 3
Ht. to Top of Casing (ft): 0
Water Tempurature (C°): 21
Elapsed Time Depth to H2O Flow Rate Total H2O used
(minutes)(ft)(gal./min.) (gal)
0 13:25 5 0.20 0.00
1 13:26 5 0.10 0.15
2 13:27 5 < 0.06 0.30
Time
Field Percolation Testing - Constant Head
The Olson Company
5/2/2019
P-2
Constant Head
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
011223Accumulated Flow ‐GallonsTime ‐Minutes
ALBUS-KEEFE ASSOCIATES, INC.Plate C-2
J.N.: 2783.00
Client: Olson
Well No.: P‐1
Condition 1
Condition 2
Condition 3
Units:
1
25 feet
20 feet
5 feet
4.0 Inches
Minimum Volume Required: 1473.4 Gal.
0.15 Gal/min.
21 Celsius
0.9647 ft^3/min.
Ignore Tᵤ
1
3.07E‐04 ft/min.
0.22 in./hr.
ALBUS-KEEFE & ASSOCIATES, INC.Plate C-3
High water Table with Water Above the Well Bottom
High Water Table & Water Below Bottom of Well
Low Water Table
INFILTRATION WELL DESIGN
Constant Head
USBR 7300‐89 Method
The presence or absence of a water table or
impervious soil layer within a distance of less than
three times that of the water depth in the well
(measured from the water surface) will enable the
water table to be classified as Condition I,
Condition II, Condtion III.
Low Water Table‐When the distance from the
water surface in the test well to the ground water
table, or to an impervious soil layer which is
considered for test puposes to be equivalent to a
water table, is greater than three times the depth
of water in the well, classify as Condition I.
High Water Table‐When the distance from the
water surface in the test well to the ground water
table or to an impervious layer is less than three
times the depth of water in the well, a high water
table condition exists. Use Condition II when the
water table or impervious layer is below the well
bottom. Use Condition III when the water table or
impervious layer is above the well bottom.
(Viscosity of Water @ Temp. T) / (Viscosity of water @ 20° C) (V):
Unsaturated Distance Between the Water Surface in the Well and
the Water table (Tᵤ):
Factor of Safety:
Coefficient of Permeability @ 20° C (k₂₀):
Design k₂₀:
Temperature (T):
Depth to Water (h₂):
Enter Condition (1, 2 or 3):
Ground Surface to Bottom of Well (h₁):
Height of Water in the Well (h₁‐h₂=h):
Radius of Well (r):
Discharge Rate of Water Into Well for Steady‐State Condition (q):
J.N.: 2783.00
Client: Olson
Well No.: P‐2
Condition 1
Condition 2
Condition 3
Units:
1
10 feet
5 feet
5 feet
4.0 Inches
Minimum Volume Required: 1473.4 Gal.
< 0.06 Gal/min.
21 Celsius
0.9647 ft^3/min.
Ignore Tᵤ
1
1.23E‐04 ft/min.
< 0.09 in./hr.
ALBUS-KEEFE & ASSOCIATES, INC.Plate C-4
Discharge Rate of Water Into Well for Steady‐State Condition (q):
INFILTRATION WELL DESIGN
Constant Head
USBR 7300‐89 Method
Low Water Table
High Water Table & Water Below Bottom of Well
High water Table with Water Above the Well Bottom
Enter Condition (1, 2 or 3):
Ground Surface to Bottom of Well (h₁):
Depth to Water (h₂):
Height of Water in the Well (h₁‐h₂=h):
Radius of Well (r):
The presence or absence of a water table or
impervious soil layer within a distance of less than
three times that of the water depth in the well
(measured from the water surface) will enable the
water table to be classified as Condition I,
Condition II, Condtion III.
Low Water Table‐When the distance from the
water surface in the test well to the ground water
table, or to an impervious soil layer which is
considered for test puposes to be equivalent to a
water table, is greater than three times the depth
of water in the well, classify as Condition I.
High Water Table‐When the distance from the
water surface in the test well to the ground water
table or to an impervious layer is less than three
times the depth of water in the well, a high water
table condition exists. Use Condition II when the
water table or impervious layer is below the well
bottom. Use Condition III when the water table or
impervious layer is above the well bottom.
Temperature (T):
(Viscosity of Water @ Temp. T) / (Viscosity of water @ 20° C) (V):
Unsaturated Distance Between the Water Surface in the Well and
the Water table (Tᵤ):
Factor of Safety:
Coefficient of Permeability @ 20° C (k₂₀):
Design k₂₀:
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875
APPENDIX 3
MODULAR WETLANDS SYSTEM O&M MANUAL
www.modularwetlands.com
Maintenance Guidelines for
Modular Wetland System - Linear
Maintenance Summary
o Remove Trash from Screening Device – average maintenance interval is 6 to 12 months.
(5 minute average service time).
o Remove Sediment from Separation Chamber – average maintenance interval is 12 to 24 months.
(10 minute average service time).
o Replace Cartridge Filter Media – average maintenance interval 12 to 24 months.
(10-15 minute per cartridge average service time).
o Replace Drain Down Filter Media – average maintenance interval is 12 to 24 months.
(5 minute average service time).
o Trim Vegetation – average maintenance interval is 6 to 12 months.
(Service time varies).
System Diagram
Access to screening device, separation
chamber and cartridge filter
Access to drain
down filter
Pre-Treatment
Chamber
Biofiltration Chamber
Discharge
Chamber
Outflow
Pipe
Inflow Pipe
(optional)
www.modularwetlands.com
Maintenance Procedures
Screening Device
1. Remove grate or manhole cover to gain access to the screening device in the Pre-
Treatment Chamber. Vault type units do not have screening device. Maintenance
can be performed without entry.
2. Remove all pollutants collected by the screening device. Removal can be done
manually or with the use of a vacuum truck. The hose of the vacuum truck will not
damage the screening device.
3. Screening device can easily be removed from the Pre-Treatment Chamber to gain
access to separation chamber and media filters below. Replace grate or manhole
cover when completed.
Separation Chamber
1. Perform maintenance procedures of screening device listed above before
maintaining the separation chamber.
2. With a pressure washer spray down pollutants accumulated on walls and cartridge
filters.
3. Vacuum out Separation Chamber and remove all accumulated pollutants. Replace
screening device, grate or manhole cover when completed.
Cartridge Filters
1. Perform maintenance procedures on screening device and separation chamber
before maintaining cartridge filters.
2. Enter separation chamber.
3. Unscrew the two bolts holding the lid on each cartridge filter and remove lid.
4. Remove each of 4 to 8 media cages holding the media in place.
5. Spray down the cartridge filter to remove any accumulated pollutants.
6. Vacuum out old media and accumulated pollutants.
7. Reinstall media cages and fill with new media from manufacturer or outside
supplier. Manufacturer will provide specification of media and sources to purchase.
8. Replace the lid and tighten down bolts. Replace screening device, grate or
manhole cover when completed.
Drain Down Filter
1. Remove hatch or manhole cover over discharge chamber and enter chamber.
2. Unlock and lift drain down filter housing and remove old media block. Replace with
new media block. Lower drain down filter housing and lock into place.
3. Exit chamber and replace hatch or manhole cover.
www.modularwetlands.com
Maintenance Notes
1. Following maintenance and/or inspection, it is recommended the maintenance
operator prepare a maintenance/inspection record. The record should include any
maintenance activities performed, amount and description of debris collected, and
condition of the system and its various filter mechanisms.
2. The owner should keep maintenance/inspection record(s) for a minimum of five
years from the date of maintenance. These records should be made available to
the governing municipality for inspection upon request at any time.
3. Transport all debris, trash, organics and sediments to approved facility for disposal
in accordance with local and state requirements.
4. Entry into chambers may require confined space training based on state and local
regulations.
5. No fertilizer shall be used in the Biofiltration Chamber.
6. Irrigation should be provided as recommended by manufacturer and/or landscape
architect. Amount of irrigation required is dependent on plant species. Some plants
may require irrigation.
www.modularwetlands.com
Maintenance Procedure Illustration
Screening Device
The screening device is located directly
under the manhole or grate over the
Pre-Treatment Chamber. It’s mounted
directly underneath for easy access
and cleaning. Device can be cleaned by
hand or with a vacuum truck.
Separation Chamber
The separation chamber is located
directly beneath the screening device.
It can be quickly cleaned using a
vacuum truck or by hand. A pressure
washer is useful to assist in the
cleaning process.
www.modularwetlands.com
Cartridge Filters
The cartridge filters are located in the
Pre-Treatment chamber connected to
the wall adjacent to the biofiltration
chamber. The cartridges have
removable tops to access the
individual media filters. Once the
cartridge is open media can be
easily removed and replaced by hand
or a vacuum truck.
Drain Down Filter
The drain down filter is located in the
Discharge Chamber. The drain filter
unlocks from the wall mount and hinges
up. Remove filter block and replace with
new block.
www.modularwetlands.com
Trim Vegetation
Vegetation should be maintained in the
same manner as surrounding vegetation
and trimmed as needed. No fertilizer shall
be used on the plants. Irrigation
per the recommendation of the
manufacturer and or landscape
architect. Different types of vegetation
requires different amounts of
irrigation.
www.modularwetlands.com
Inspection Form
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. Info@modularwetlands.com
For Office Use Only
(city) (Zip Code)(Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( )_
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Yes
Depth:
Yes No
Modular Wetland System Type (Curb, Grate or UG Vault):Size (22', 14' or etc.):
Other Inspection Items:
Storm Event in Last 72-hours? No Yes Type of Inspection Routine Follow Up Complaint Storm
Office personnel to complete section to
the left.
2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176
Inspection Report
Modular Wetlands System
Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system?
Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber?
Any signs of improper functioning in the discharge chamber? Note issues in comments section.
Chamber:
Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly?
Structural Integrity:
Working Condition:
Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the
unit?
Is there standing water in inappropriate areas after a dry period?
Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)?
Project Name
Project Address
Inspection Checklist
CommentsNo
Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes,
specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber.
Is there a septic or foul odor coming from inside the system?
Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)?
Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below.
Sediment / Silt / Clay
Trash / Bags / Bottles
Green Waste / Leaves / Foliage
Waste:Plant Information
No Cleaning Needed
Recommended Maintenance
Additional Notes:
Damage to Plants
Plant Replacement
Plant Trimming
Schedule Maintenance as Planned
Needs Immediate Maintenance
www.modularwetlands.com
Maintenance Report
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. Info@modularwetlands.com
For Office Use Only
(city) (Zip Code)(Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( )_
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Site
Map #
Comments:
2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176
Inlet and Outlet
Pipe Condition
Drain Down Pipe
Condition
Discharge Chamber
Condition
Drain Down Media
Condition
Plant Condition
Media Filter
Condition
Long:
MWS
Sedimentation
Basin
Total Debris
Accumulation
Condition of Media
25/50/75/100
(will be changed
@ 75%)
Operational Per
Manufactures'
Specifications
(If not, why?)
Lat:MWS
Catch Basins
GPS Coordinates
of Insert
Manufacturer /
Description / Sizing
Trash
Accumulation
Foliage
Accumulation
Sediment
Accumulation
Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes
Office personnel to complete section to
the left.
Project Address
Project Name
Cleaning and Maintenance Report
Modular Wetlands System
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875
APPENDIX 4
SOURCE CONTROL BMP FACT SHEETS
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.
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
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.1 The
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.
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
PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019
ROSEMEAD TENTATIVE TRACT NO. 82875
APPENDIX 5
PUBLIC EDUCATION MATERIALS
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.
PP ickick UpUp AfterAfter YourYour Pooch!Pooch!
Dog owners can help so
l
v
e
t
h
e
s
t
o
r
m
w
a
t
e
r
p
o
l
l
u
t
i
o
n
problem by taking thes
e
e
a
s
y
s
t
e
p
s
…
• Clean up after your
d
o
g
e
v
e
r
y
s
i
n
gle 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 do
g.
• Carry extra bags when walking your dog and make
them available to other
p
e
t
o
w
n
e
r
s
w
h
o
a
r
e
w
i
t
h
o
u
t
.
• Teach children how
t
o
p
r
o
p
e
r
l
y
c
l
e
a
n
u
p
a
f
ter a pet.
Encourage them to throw
t
h
e
u
s
e
d
b
a
g
s
i
n
t
h
e
nearest trash receptacl
e
i
f
t
h
e
y
a
re away from home.
• Put a friendly message on the bulletin board at
the local dog park to
r
e
m
i
n
d
p
et owners to clean
up after their dogs.
• Te ll friends and neighbors abo
u
t
t
h
e
i
ll effects of
animal waste on the environment.
E
n
c
o
u
r
a
g
e
them to clean up after t
h
e
i
r
p
e
t
s
a
s
w
e
l
l
.
Tips for Dog Owners:
AA YardYard is ais a Terrible Terrible
ThingThing toto Waste!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.
Tips For Yard Care:
L.A. County residents
c
a
n
h
e
l
p
solve the stormwater
pollution problem by tak
i
n
g
t
h
e
s
e
e
a
s
y
s
t
e
p
s
…
• Do not over-fertilize and do not use fertilizer or
p
e
s
ticides
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 tha
n
“
b
l
a
n
k
e
t
”
a
p
ply.
• When watering your lawn, use the least amount of
water possible so it do
e
s
n
’
t
r
u
n
i
n
t
o
t
h
e
s
t
r
e
e
t
c
a
r
r
y
i
n
g
pesticides and other chemicals with it.
• Use non-toxic products for your garden and
l
awn
whenever possible.
• If you must store pesticides or fertilizer, make sur
e
they are in a sealed, w
a
t
e
r
-
p
r
o
o
f
c
o
n
t
a
i
n
e
r
i
n
a
covered area to prevent ru
n
o
ff.
• Do not blow, sweep, hose o
r
r
a
k
e
l
e
a
v
e
s
o
r
o
t
h
e
r
yard trimmings into the street, gutter
o
r
s
t
o
r
m
d
r
a
i
n
.
A message from the Cou
n
t
y
o
f
L
o
s
A
n
g
e
l
e
s
D
e
p
a
r
t
m
e
n
t
o
f Public Works.
Printed on recycled paper.
DoDon’t Paint the’t Paint the Town Red!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.
Tips for Paint Clean-Up:
L.A. County residents
c
a
n
h
e
l
p
s
o
l
v
e
t
h
e
s
t
o
r
m
w
a
t
e
r
pollution problem by t
a
k
i
n
g
t
h
e
s
e
e
a
s
y
s
t
e
p
s
w
h
e
n
working with paint an
d
p
a
i
n
t
-
r
e
l
a
t
e
d
p
r
o
d
u
c
t
s
…
• Never dispose of paint or paint-relat
e
d
p
r
o
d
u
c
t
s
i
n
t
h
e
gutters or storm drains. This is called illegal dumping.
Take them to a House
h
o
l
d
H
a
z
a
r
d
o
u
s
W
a
s
t
e
/
E
-
W
a
s
t
e
collection event. Ca
l
l
1
(
8
8
8
)
C
L
E
A
N
L
A
o
r
visit
www.888CleanLA.com
t
o
l
o
c
a
t
e
a
n
e
v
e
n
t
n
e
a
r
y
o
u
.
• Buy only what you need. Reuse leftover paint for
touch-ups or donate
i
t
t
o
a
l
o
c
a
l
g
r
a
f
f
i
t
i
a
b
a
t
e
m
e
n
t
program. Recycle or u
s
e
e
x
c
e
s
s
p
a
i
n
t
.
• Clean water-based pa
i
n
t
b
r
u
s
h
es in the sink.
• Oil-based paints shou
l
d
b
e
c
l
e
a
n
e
d
w
i
t
h
p
a
i
n
t
t
h
inner.
Filter and reuse paint
t
h
i
n
n
e
r
.
S
e
t
t
h
e
u
s
e
d
t
h
i
n
n
e
r
aside in a closed jar t
o
s
e
t
t
l
e
-
o
u
t
p
a
i
n
t
p
a
r
t
i
c
l
e
s
.
• Store paints and pain
t
-
r
e
l
a
t
e
d
p
r
o
d
u
c
t
s
i
n
r
i
g
i
d
,
durable and watertight co
n
t
a
i
n
e
r
s
w
i
t
h
tight-fitting covers.
A message from the Cou
n
t
y
o
f
L
o
s
A
n
g
e
l
e
s
D
e
p
a
r
t
m
e
n
t
o
f Public Works.
Printed on recycled paper.
Are You a Litter B
u
g
A r e Y o u a L i t t e r B u g
and a n d DoDo n’t Know It?t K n o w I t ?
Take our quiz!
Have you ever...
• Dropped a cigarette butt or trash on the grou
n
d
?
• Failed to pick up after your dog while out on
a
w
a
l
k
?
• Overwatered your lawn after ap
p
l
y
i
ng
fertilizers/pesticides?
• Disposed of used motor oil in the s
t
r
e
e
t
,
gutter or garbage?
If you answered yes to any of these action
s
,
t
h
e
n
YOU ARE A LITTER BUG!
Each of these behaviors contribute to stor
m
w
a
t
e
r
pollution, which contaminates o
u
r
o
c
e
a
n
a
n
d
waterways, kills marine life and causes beach
c
l
o
s
u
r
e
s
.
You can become part of the solution!
To find out how, flip this card over.
For more information, c
a
l
l
o
r
v
i
s
i
t
:
Follow these simple steps to
prevent stormwater pollution
• Put your garbage wh
e
r
e
i
t
b
e
l
o
n
g
s
—
i
n
t
h
e
t
r
ash can.
• Pick up after your dog
w
h
e
n
out on a walk.
• Reduce pesticide and
f
e
r
t
i
l
i
z
e
r
u
s
e
;
d
o
n
’
t
o
v
e
r
w
a
t
e
r
after application or apply if rain is
f
o
r
e
c
a
s
t
.
• Dispose of used motor oil at an oil
r
e
c
y
c
l
i
n
g
c
e
n
t
e
r
or at a free Househo
l
d
H
a
z
a
r
d
o
u
s
W
aste/E-Waste
collection event.
A message from the Cou
n
t
y
o
f
Los Angeles Department of Public Works.
Printed on recycled paper.
Follow these simple step
s
t
o
F ol lo w t h es e s i m p l e s t e p s t o
prevent stormwater po
l
l
u
t
i
o
n
:
pre v e n t s to rmw a te r p ol lu t i on:
