HomeMy WebLinkAbout20190910_WQMP COMPLETEWater Quality
Management Plan (WQMP)
City of Newport Beach / Santa Ana Region
Priority Project
119 Shorecliff Road, Corona del Mar
Prepared for:
Gregory Bentley
600 S. Indian Hill Blvd.
Claremont, CA 91711
Prepared on: August 21, 2019
Prepared by:
CivilScapes Engineering, Inc.
Engineer: Civil Registration No. 76698
28052 Camino Capistrano, Suite 213
Laguna Niguel, CA 92677
(949) 464-8115
will@civilscapes.com
Water Quality Management Plan (WQMP)
Owner’s Certification
Project Owner’s Certification
Permit/Application No. TBD Grading Permit No. TBD
Tract/Parcel Map No. Lot 116/Tract 1116 Building Permit No. TBD
CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract) APN 052-210-09
This Water Quality Management Plan (WQMP) has been prepared for the homeowner by
CivilScapes Engineering Incorporated. The WQMP is intended to comply with the
requirements of the local NPDES Stormwater Program requiring the preparation of the plan.
The undersigned, while it owns the subject property, is responsible for the implementation of
the provisions of this plan and will ensure that this plan is amended as appropriate to reflect
up-to-date conditions on the site consistent with the current Orange County Drainage Area
Management Plan (DAMP) and the intent of the non-point source NPDES Permit for Waste
Discharge Requirements for the County of Orange, Orange County Flood Control District and
the incorporated Cities of Orange County within the Santa Ana Region. Once the undersigned
transfers its interest in the property, its successors-in-interest shall bear the aforementioned
responsibility to implement and amend the WQMP. An appropriate number of approved and
signed copies of this document shall be available on the subject site in perpetuity.
Owner: Gregory Bentley
Title Owner
Company
Address 600 S. Indian Hill Blvd., Claremont, CA 91711
Email
Telephone #
Signature Date
Bentley Residence
19027.WQMP.docx
Contents Page No.
Section I Discretionary Permit(s) and Water Quality Conditions ................................ 3
Section II Project Description ..................................................................................... 4
Section III Site Description ........................................................................................ 8
Section IV Best Management Practices (BMPs) ........................................................ 13
Section V Inspection/Maintenance Responsibility for BMPs ..................................... 30
Section VI Site Plan and Drainage Plan .................................................................... 32
Section VII Educational Materials ............................................................................. 32
Attachments
Educational Materials and Fact Sheets
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section I
19027.WQMP.docx Page 3
Section I Discretionary Permit(s) and
Water Quality Conditions
Provide discretionary permit and water quality information. Refer to Section 2.1 in the Technical
Guidance Document (TGD) available from the Orange County Stormwater Program (ocwatersheds.com).
Project Infomation
Permit/Application No. TBD Tract/Parcel Map No. Lot 116, Tract 1116
Additional Information/
Comments: APN 052-210-09
Water Quality Conditions
Water Quality
Conditions
(list verbatim)
No conditions of approval have been issued at this time.
Watershed-Based Plan Conditions
Provide applicable
conditions from watershed
- based plans including
WIHMPs and TMDLS.
There are no TMDLs for Little Corona Del Mar Beach
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section II
19027.WQMP.docx Page 4
Section II Project Description
II.1 Project Description
Provide a detailed project description including:
• Project areas; Land uses; Land cover; Design elements; A general description not broken
down by drainage management areas (DMAs).
Include attributes relevant to determining applicable source controls. Refer to Section 2.2 in the TGD
for information that must be included in the project description.
Description of Proposed Project
Development Category
(Verbatim from WQMP):
Priority Project Categories:
1. Detached Residential Development
Project Area (ft2): 12,927 Number of Dwelling Units: One single-
family residence
SIC Code: N/A -
Residential
Narrative Project
Description:
The project proposes to demolish the existing house and site work. A
new single family house with rear yard terracing will be constructed on
the site.
Project Area
Pervious Impervious
Area
(acres or sq ft)
Percentage Area
(acres or sq ft)
Percentage
Pre-Project Conditions 2,585 20% 10,342 80%
Post-Project Conditions 2,996 23% 9,931 77%
Drainage
Patterns/Connections
Drainage currently flows to down the slope to an existing offsite public
catch basin located in the sidewalk in the common area below the
property. The project proposes to maintain the existing drainage pattern
so it does not adversely impact the hydrology of the watershed and
downstream drainage systems.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section II
19027.WQMP.docx Page 5
II.2 Potential Stormwater Pollutants
Determine and list expected stormwater pollutants based on land uses and site activities. Refer to
Section 2.2.2 and Table 2.1 in the TGD for guidance.
Pollutants of Concern
Pollutant
Circle One:
E=Expected to
be of concern
N=Not Expected
to be of concern
Additional Information and Comments
Suspended-Solid/ Sediment E
Expected. The major source of sediments is
bare or poorly vegetated ground. Wind and
water have the potential to introduce sediments
in stormwater runoff
Nutrients E
Expected. Nutrients are generally associated
with poor landscaping practices, leaks from
sanitary systems, and animal wastes.
Heavy Metals N Not Expected.
Pathogens (Bacteria/Virus) E
Expected. Sources of pathogens include wild
bird and pet waste, garbage, and leaky sanitary
systems.
Pesticides E
Expected. Excessive application of pesticides
may result in runoff containing toxic levels of
its active ingredient.
Oil and Grease E Expected. Oil & grease are usually associated
with leaking vehicles in the driveways.
Toxic Organic Compounds N Not Expected.
Trash and Debris E
Expected. The major source for trash & debris
in stormwater is poorly managed trash
containers.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section II
19027.WQMP.docx Page 6
II.3 Hydrologic Conditions of Concern
Determine if streams located downstream from the project area are determined to be potentially
susceptible to hydromodification impacts. Refer to Section 2.2.3.1 in the TGD for NOC or Section
2.2.3.2 for <SOC>.
No – Show map
Yes – Describe applicable hydrologic conditions of concern below. Refer to Section 2.2.3 in the
TGD.
See as-built plans below showing offsite public storm drain system:
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section II
19027.WQMP.docx Page 7
II.4 Post Development Drainage Characteristics
Describe post development drainage characteristics. Refer to Section 2.2.4 in the TGD.
Existing land use consists of a single-family residence. The existing property is approximately 75%
impervious area. The proposed development will increase the impervious area to 75%. Overall peak
flows from the property compared below.
Q = C * I * A
C = (0.75*%IMP) +0.15
I=0.2 in/hr
Q(pre) = (0.75*0.80+0.15)*(0.2)*(12,927/43,560) = 0.045cfs
Q(post) = (0.75*0.77+0.15)*(0.2)*(12,927/43,560) = 0.043 cfs
II.5 Property Ownership/Management
Describe property ownership/management. Refer to Section 2.2.5 in the TGD.
GREGORY BENTLEY is the current owner of the property and will be responsible for maintenance of BMPs and
WQMP requirements. Upon sale of property maintenance of BMP and WQMP will be the responsibility of the
new owner. GREGORY BENTLEY shall provide this WQMP to new owner upon sale.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section III
19027.WQMP.docx Page 8
Section III Site Description
III.1 Physical Setting
Fill out table with relevant information. Refer to Section 2.3.1 in the TGD.
Planning Area/
Community Name Shorecliffs
Location/Address
119 Shorecliff Road, Corona del Mar 92625
APN: 052-210-09
Land Use Residential
Zoning R-1-6000 Single-Unit Family Residential
Acreage 0.30 acres
Predominant Soil Type Silty sand fill over terrace deposits.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section III
19027.WQMP.docx Page 9
III.2 Site Characteristics
Fill out table with relevant information and include information regarding BMP sizing, suitability, and
feasibility, as applicable. Refer to Section 2.3.2 in the TGD.
Precipitation Zone
24-hr, 85th percentile Rainfall, d = 0.65 inches
Topography The front and middle portions of the lot are level with a rear yard slope that
descends 10 to 11 feet.
Drainage
Patterns/Connectio
ns
Drainage currently flows to down the slope to an existing offsite public catch
basin located in the sidewalk in the common area below the property. The
project proposes to maintain the existing drainage pattern so it does not
adversely impact the hydrology of the watershed and downstream drainage
systems.
Soil Type, Geology,
and Infiltration
Properties
Silty sand fill over terrace deposits.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section III
19027.WQMP.docx Page 10
Site Characteristics (continued)
Hydrogeologic
(Groundwater) Conditions High groundwater is not expected.
Geotechnical Conditions
(relevant to infiltration) Infiltration is not recommended due to slope.
Off-Site Drainage There is no drainage onto the site from offsite areas. The project does
not propose to drain across property lines.
Utility and Infrastructure
Information All drainage systems shall be privately maintained
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section III
19027.WQMP.docx Page 11
III.3 Watershed Description
Fill out table with relevant information and include information regarding BMP sizing, suitability,
and feasibility, as applicable. Refer to Section 2.3.3 in the TGD.
Receiving
Waters Existing storm drain outlets into Little Corona Del Mar Beach
2014/2016
303(d) Listed
Impairments
Indicator Bacteria
Applicable
TMDLs None
Pollutants of
Concern for
the Project
Suspended-Solid/ Sediment, Nutrients, Pathogens (Bacteria/Virus), Pesticides, Oil and
Grease, Trash and Debris
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section III
19027.WQMP.docx Page 12
Environmentall
y Sensitive and
Special
Biological
Significant
Areas
The project is located more than 200 feet buffer of Lower Newport Bay which is an
impaired water-body. See map below.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 13
Section IV Best Management Practices (BMPs)
IV. 1 Project Performance Criteria
Describe project performance criteria. Several steps must be followed in order to determine what
performance criteria will apply to a project. These steps include:
• If the project has an approved WIHMP or equivalent, then any watershed specific criteria
must be used and the project can evaluate participation in the approved regional or sub-
regional opportunities. The local Permittee planning or NPDES staff should be consulted
regarding the existence of an approved WIHMP or equivalent.
• Determine applicable hydromodification control performance criteria. Refer to Section 7.II-
2.4.2.2 of the Model WQMP.
• Determine applicable LID performance criteria. Refer to Section 7.II-2.4.3 of the Model WQMP.
• Determine applicable treatment control BMP performance criteria. Refer to Section 7.II-3.2.2 of
the Model WQMP.
• Calculate the LID design storm capture volume for the project. Refer to Section 7.II-2.4.3 of the
Model WQMP.
(NOC Permit Area only) Is there an approved WIHMP or equivalent
for the project area that includes more stringent LID feasibility
criteria or if there are opportunities identified for implementing LID
on regional or sub-regional basis?
YES NO
If yes, describe WIHMP
feasibility criteria or
regional/sub-regional LID
opportunities.
A Model WIHMP for Newport Bay-Newport Coast has not been approved by
the Regional Water Quality Control Board at this time.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 14
Project Performance Criteria (continued)
If HCOC exists,
list applicable
hydromodification
control
performance
criteria (Section
7.II-2.4.2.2 in
MWQMP)
List applicable LID
performance
criteria (Section
7.II-2.4.3 from
MWQMP)
The projected proposes to properly design on-site biotreatment systems, since
infiltration, harvest and use, and evapotranspiration cannot be feasibly implemented.
The performance criteria for LID for this project is as follows:
Infiltrate, harvest and use, evapotranspire, or biofilter the 85th percentile, 24-
hour storm event (design capture volume)
List applicable
treatment control
BMP performance
criteria (Section
7.II-3.2.2 from
MWQMP)
Performance criteria is met with LID. See above.
Calculate LID
design storm
capture volume
for Project.
𝐶𝑐𝑟𝑖𝑐𝑙 𝐶𝑎𝑙𝑟𝑟𝑟𝑐 𝑉𝑙𝑙𝑟𝑙𝑐,𝐶𝐶𝑉=𝐶 𝑥 𝑐 𝑥 𝐴 𝑥 43560 𝑟𝑐/𝑎𝑐 𝑥1
12 𝑖𝑙/𝑐𝑟
Where:
V = runoff volume during the design storm event, cu-ft
C = runoff coefficient = (0.75 × imp + 0.15)
imp = impervious fraction of drainage area (ranges from 0 to 1)
d = storm depth (inches)
A = tributary area to BMPs (acres)
𝐶𝐶𝑉=(0.75 ∗0.77 +0.15)𝑥 0.67 𝑥 12,997
𝑥1
12 𝑖𝑙
𝑐𝑟=𝟒𝟐𝟒 𝒃𝒕𝒃𝒊𝒃 𝒆𝒆𝒆𝒕
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 15
IV.2. SITE DESIGN AND DRAINAGE PLAN
Describe site design and drainage plan including
• A narrative of site design practices utilized or rationale for not using practices;
• A narrative of how site is designed to allow BMPs to be incorporated to the MEP
• A table of DMA characteristics and list of LID BMPs proposed in each DMA.
• Reference to the WQMP plot plan.
• Calculation of Design Capture Volume (DCV) for each drainage area.
• A listing of GIS coordinates for LID and Treatment Control BMPs (unless not required by
local jurisdiction).
Refer to Section 2.4.2 in the TGD.
Minimizing a development’s effects on water quality and the environment can be most effectively achieved by
using a combination of BMPs which include Low Impact Development (LID) Site Design, Source Control and
Treatment Control measures. These design and control measures employ a multi-level strategy. The strategy
consists of: 1) reducing or eliminating post-project runoff; 2) controlling sources of pollutants; and 3) treating
storm water runoff before discharging it to the storm drain system or to receiving waters.
The most effective means of avoiding or reducing water quality and hydrologic impacts is through
incorporation of measures into the project design. These measures should be taken into consideration early in
the planning of a project as they can affect the overall design of a project.
LID BMPs are intended to collectively minimize directly connected impervious areas, limit loss of existing
infiltration capacity, and protect areas that provide important water quality benefits neces sary to maintain
riparian and aquatic biota, and/or are particularly susceptible to erosion and sediment loss, as feasible. The
design of the proposed project has incorporated site design concepts as described below.
Draught tolerant plants will be employed in conformance with the city’s development code and water
conservation ordinances.
The site will also disconnect impervious surfaces. The rooftops will drain to bioretention planters before
connecting to the offsite storm drain system.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 16
IV.3 LID BMP SELECTION AND PROJECT CONFORMANCE ANALYSIS
Each sub-section below documents that the proposed design features conform to the applicable
project performance criteria via check boxes, tables, calculations, narratives, and/or references to
worksheets. Refer to Section 2.4.2.3 in the TGD for selecting LID BMPs and Section 2.4.3 in the TGD for
conducting conformance analysis with project performance criteria.
IV.3.1 Hydrologic Source Controls
If required HSCs are included, fill out applicable check box forms. If the retention criteria are
otherwise met with other LID BMPs, include a statement indicating HSCs not required.
Name Included?
Localized on-lot infiltration
Impervious area dispersion (e.g. roof top
disconnection)
Street trees (canopy interception)
Residential rain barrels (not actively managed)
Green roofs/Brown roofs
Blue roofs
Impervious area reduction (e.g. permeable
pavers, site design)
Other:
No Hydrologic Source Controls (HSCs) are proposed for this project.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 17
IV.3.2 Infiltration BMPs
Identify infiltration BMPs to be used in project. If design volume cannot be met state why BMPs
cannot be met
Name Included?
Bioretention without underdrains
Rain gardens
Porous landscaping
Infiltration planters
Retention swales
Infiltration trenches
Infiltration basins
Drywells
Subsurface infiltration galleries
French drains
Permeable asphalt
Permeable concrete
Permeable concrete pavers
Other:
Other:
Show calculations below to demonstrate if the LID Design Strom Capture Volume can be met with
infiltration BMPs. If not document how much can be met with infiltration and document why it is
not feasible to meet the full volume with infiltration BMPs.
Infiltration BMPs are infeasible due to the existing slope. Bioretention with underdrains are being
implemented.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 18
IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs
If the full Design Storm Capture Volume cannot be met with infiltration BMPs, describe any
evapotranspiration, rainwater harvesting BMPs. <Delete or leave blank if not used>
Name Included?
All HSCs; See Section IV.3.1
Surface-based infiltration BMPs
Biotreatment BMPs
Above-ground cisterns and basins
Underground detention
Other:
Other:
Other:
Show calculations below to demonstrate if the LID Design Strom Capture Volume can be met with
evapotranspiration, rainwater harvesting BMPs in combination with infiltration BMPs. If not
document how much can be met with either infiltration BMPs, evapotranspiration, rainwater
harvesting BMPs, or a combination, and document why it is not feasible to meet the full volume
with either of these BMPs categories.
Insufficient irrigation demand. Bioretention with underdrains are being implemented.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 19
IV.3.4 Biotreatment BMPs
If the full Design Storm Capture Volume cannot be met with infiltration BMPs, and/or
evapotranspiration and rainwater harvesting BMPs, describe biotreatment BMPs. Include sections
for selection, suitability, sizing, and infeasibility, as applicable.
Name Included?
Bioretention with underdrains
Stormwater planter boxes with underdrains
Rain gardens with underdrains
Constructed wetlands
Vegetated swales
Vegetated filter strips
Proprietary vegetated biotreatment systems
Wet extended detention basin
Dry extended detention basins
Other:
Other:
Show calculations below to demonstrate if the LID Design Strom Capture Volume can be met with
infiltration, evapotranspiration, rainwater harvesting and/or biotreatment BMPs. If not document
how much can be met with either infiltration BMPs, evapotranspiration, rainwater harvesting
BMPs, or a combination, and document why it is not feasible to meet the full volume with either of
these BMPs categories.
SEE CALCULATIONS ON FOLLOWING PAGE
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 20
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 21
IV.3.5 Hydromodification Control BMPs
Describe hydromodification control BMPs. See Section 5 TGD. Include sections for selection,
suitability, sizing, and infeasibility, as applicable. Detail compliance with Prior Conditions of
Approval.
Hydromodification Control BMPs
BMP Name BMP Description
Not Applicable
IV.3.6 Regional/Sub-Regional LID BMPs
Describe regional/sub-regional LID BMPs in which the project will participate. Refer to Section 7.II-
2.4.3.2 of the Model WQMP.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 22
Regional/Sub-Regional LID BMPs
Not Applicable
IV.3.7 Treatment Control BMPs
Treatment control BMPs can only be considered if the project conformance analysis indicates that it is not
feasible to retain the full design capture volume with LID BMPs. Describe treatment control BMPs including
sections for selection, sizing, and infeasibility, as applicable.
Treatment Control BMPs
BMP Name BMP Description
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 23
IV.3.8 Non-structural Source Control BMPs
Fill out non-structural source control check box forms or provide a brief narrative explaining if non-
structural source controls were not used.
Non-Structural Source Control BMPs
Identifier Name
Check One
If not applicable, state brief
reason Included Not
Applicable
N1 Education for Property Owners,
Tenants and Occupants
N2 Activity Restrictions
N3 Common Area Landscape
Management
N4 BMP Maintenance
N5 Title 22 CCR Compliance (How
development will comply) N/A. No hazardous waste
N6 Local Industrial Permit Compliance N/A. IGP does not apply to
this SIC code
N7 Spill Contingency Plan N/A. Materials are stored
indoors
N8 Underground Storage Tank
Compliance N/A. No record of USTs onsite
N9 Hazardous Materials Disclosure
Compliance N/A. No hazardous waste
N10 Uniform Fire Code Implementation
N11 Common Area Litter Control
N12 Employee Training
N13 Housekeeping of Loading Docks N/A. No loading docks
N14 Common Area Catch Basin Inspection
N15 Street Sweeping Private Streets and
Parking Lots
N16 Retail Gasoline Outlets N/A. No retail gas outlets
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 24
N1 Education for Property Owners, Tenants and Occupants: Practical informational materials are
provided to residents, occupants, or tenants to increase the public’s understanding of stormwater
quality, sources of pollutants, and what they can do to reduce pollutants in stormwater. The Owner
will be educated on general housekeeping practices that contribute to the protection of stormwater
quality. See Attachment ‘A’ in this WQMP for educational materials.
N2 Activity Restrictions: Per the city’s municipal code no person shall construct or maintain an
illicit connection. Illicit discharges are not allowed.
N3 Common Area Landscape Management: Specific practices are followed and ongoing
maintenance is conducted to minimize erosion and over-irrigation, conserve water, and reduce
pesticide and fertilizer applications.
The Owner will be responsible for ongoing landscape maintenance of the project consistent with
the City’s Water-Efficient Landscaping Code, Chapter 14.17 of NBMC and County BMP Fact Sheet
IC7. Both of these references are included in Attachment ‘A’.
N4 BMP Maintenance: In order to ensure adequate and comprehensive BMP implementation, all
responsible parties are identified for implementing all non-structural BMPs and for structural
BMPs, cleaning, inspection, and other maintenance activities are specified including responsible
parties for conducting such activities.
The Owner will be responsible for implementation of each non-structural BMP and scheduled
cleaning of all structural BMP facilities in perpetuity or until ownership is transferred. Prior to
transfer of ownership, the Transfer of Responsibility Form must be submitted and approved by the
City.
N10 Uniform Fire Code Implementation: If the project includes a hazardous material storage
facility or other area regulated by Article 80 and therefore implements measures to comply with
this section of the Uniform Fire Code.
The project will comply with the Uniform Fire Code.
N11 Common Area Litter Control: Trash management and litter control procedures are specified,
including responsible parties, and implemented to reduce pollution of drainage water.
The Owner will be responsible for litter patrol and emptying of trash receptacles and pet waste
weekly and as needed.
N12 Contractor/Employee Training: Practical informational materials and/or training are
provided to contractors to increase their understanding of stormwater quality, sources of
pollutants, and their responsibility for reducing pollutants in stormwater.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 25
The Owner will be responsible for educating contractors on general housekeeping practices that
contribute to the protection of stormwater quality. Educational materials are included in Appendix
A of this report. Educational materials will be provided to contractors at the time of hiring.
N14 Drainage Facility Inspection: Inspection procedures, schedules, and responsibilities are
established for drainage facilities to ensure regular cleaning, inspection, and maintenance.
The Owner will be responsible for having the catch basins inspected and cleaned prior to the storm
season, October 1st of each year and as needed.
N15 Street Sweeping Private Streets and Parking Lots: Driveways shall be swept using “dry
sweeping” (i.e. mechanical, vacuuming) and will be conducted to reduce pollution of drainage
water.
The Owner will be responsible for having driveways swept immediately prior to the storm season,
October 1st of each year and as needed.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 26
IV.3.9 Structural Source Control BMPs
Fill out structural source control check box forms or provide a brief narrative explaining if
Structural source controls were not used.
Structural Source Control BMPs
Identifier Name
Check One
If not applicable, state brief
reason Included Not
Applicable
S1 Provide storm drain system stenciling
and signage No catch basins on-site
S2
Design and construct outdoor material
storage areas to reduce pollution
introduction
No outdoor material storage areas
S3
Design and construct trash and waste
storage areas to reduce pollution
introduction
S4
Use efficient irrigation systems &
landscape design, water conservation,
smart controllers, and source control
S5 Protect slopes and channels and
provide energy dissipation
Incorporate requirements applicable to
individual priority project categories
(from SDRWQCB NPDES Permit)
S6 Dock areas N/A
S7 Maintenance bays N/A
S8 Vehicle wash areas N/A
S9 Outdoor processing areas N/A
S10 Equipment wash areas N/A
S11 Fueling areas N/A
S12 Hillside landscaping N/A
S13 Wash water control for food
preparation areas N/A
S14 Community car wash racks N/A
Water Quality Management Plan (WQMP)
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Bentley Residence Section IV
19027.WQMP.docx Page 27
S3 Design and construct outdoor material storage areas to reduce pollution introduction: The
trash area will be inspected in conjunction with Litter Control (N11) on a weekly basis. The area
will be inspected for loose debris and to make sure bins are closed.
S4 Use efficient irrigation systems & landscape design, water conservation, smart controllers,
and source control: The project must comply with City’s landscape ordinance. The Owner will be
responsible for ongoing landscape maintenance of the project consistent with the City’s Water-
Efficient Landscaping Code, Chapter 14.17 of NBMC and County BMP Fact Sheet IC7. Both of
these references are included in Attachment ‘A’.
S5 Protect slopes and channels and provide energy dissipation: The project will maintain
drainage channels and provide splash blocks where roof drains outlet to grade. See project plans
for more information.
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 28
IV.4 ALTERNATIVE COMPLIANCE PLAN (IF APPLICABLE)
IV.4.1 Water Quality Credits
Determine if water quality credits are applicable for the project. Refer to Section 3.1 of the Model
WQMP for description of credits and Appendix VI of the TGD for calculation methods for applying water
quality credits.
Description of Proposed Project
Project Types that Qualify for Water Quality Credits (Select all that apply):
Redevelopment
projects that reduce the
overall impervious
footprint of the project
site.
Brownfield redevelopment, meaning
redevelopment, expansion, or reuse of real
property which may be complicated by the
presence or potential presence of hazardous
substances, pollutants or contaminants, and
which have the potential to contribute to
adverse ground or surface WQ if not
redeveloped.
Higher density development projects which
include two distinct categories (credits can only
be taken for one category): those with more than
seven units per acre of development (lower credit
allowance); vertical density developments, for
example, those with a Floor to Area Ratio (FAR)
of 2 or those having more than 18 units per acre
(greater credit allowance).
Mixed use development, such as a
combination of residential, commercial,
industrial, office, institutional, or other land
uses which incorporate design principles
that can demonstrate environmental benefits
that would not be realized through single
use projects (e.g. reduced vehicle trip traffic
with the potential to reduce sources of water
or air pollution).
Transit-oriented developments, such as a mixed
use residential or commercial area designed to
maximize access to public transportation; similar to
above criterion, but where the development center is
within one half mile of a mass transit center (e.g. bus,
rail, light rail or commuter train station). Such
projects would not be able to take credit for both
categories, but may have greater credit assigned
Redevelopment
projects in an established
historic district, historic
preservation area, or
similar significant city
area including core City
Center areas (to be
defined through
mapping).
Developments with
dedication of undeveloped
portions to parks,
preservation areas and
other pervious uses.
Developments
in a city center
area.
Developments
in historic
districts or
historic
preservation
areas.
Live-work developments, a
variety of developments designed
to support residential and
vocational needs together –
similar to criteria to mixed use
development; would not be able
to take credit for both categories.
In-fill projects, the
conversion of empty lots
and other underused
spaces into more
beneficially used spaces,
such as residential or
commercial areas.
Calculation of
Water Quality
Credits
(if applicable)
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section IV
19027.WQMP.docx Page 29
IV.4.2 Alternative Compliance Plan Information
Describe an alternative compliance plan (if applicable). Include alternative compliance obligations
(i.e., gallons, pounds) and describe proposed alternative compliance measures. Refer to Section 7.II
3.0 in the WQMP.
Not Applicable
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section V
19027.WQMP.docx Page 30
Section V Inspection/Maintenance
Responsibility for BMPs
Fill out information in table below. Prepare and attach an Operation and Maintenance Plan.
Identify the mechanism through which BMPs will be maintained. Inspection and maintenance
records must be kept for a minimum of five years for inspection by the regulatory agencies. Refer to
Section 7.II 4.0 in the Model WQMP.
BMP Inspection/Maintenance
BMP Reponsible
Party(s)
Inspection/
Maintenance
Activities
Required
Minimum
Frequency of
Activities
Bioretention Planter
with Underdrain Owner
Plant materials should
be tolerant of summer
drought, ponding
fluctuations, and
saturated soil
conditions for 48
hours. Inspect for
standing water and
ruts. The area should
be maintained with 2-
4 inches of mulch at
startup and an
additional placement
of 1-2 inches of mulch
should be added
annually.
Annually in
July/August before
each rainy season
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section VI
19027.WQMP.docx Page 31
Section VI Site Plan and Drainage Plan
VI.1 SITE PLAN AND DRAINAGE PLAN
Include a site plan and drainage plan sheet set containing the following minimum information:
• Project location
• Site boundary
• Land uses and land covers, as applicable
• Suitability/feasibility constraints
• Structural BMP locations
• Drainage delineations and flow information
• Drainage connections
• BMP details
Water Quality Management Plan (WQMP)
119 Shorecliff Road, Corona del Mar
Bentley Residence Section VII
19027.WQMP.docx Page 32
Section VII Educational Materials
Refer to the Orange County Stormwater Program (ocwatersheds.com) for a library of materials
available. For the copy submitted to the Permittee, only attach the educational materials specifically
applicable to the project. Other materials specific to the project may be included as well and must
be attached.
Education Materials
Residential Material
(http://www.ocwatersheds.com)
Check If
Applicable
Business Material
(http://www.ocwatersheds.com)
Check If
Applicable
The Ocean Begins at Your Front Door Tips for the Automotive Industry
Tips for Car Wash Fund-raisers Tips for Using Concrete and Mortar
Tips for the Home Mechanic Tips for the Food Service Industry
Homeowners Guide for Sustainable
Water Use Proper Maintenance Practices for Your
Business
Household Tips
Other Material Check If
Attached Proper Disposal of Household
Hazardous Waste
Recycle at Your Local Used Oil
Collection Center (North County) R-1 Automobile Repair & Maintenance
Recycle at Your Local Used Oil
Collection Center (Central County) R-2 Automobile Washing
Recycle at Your Local Used Oil
Collection Center (South County) R-3 Automobile Parking
Tips for Maintaining a Septic Tank
System R-4 Home & Garden Care Activities
Responsible Pest Control R-5 Disposal of Pet Waste
Sewer Spill R-6 Disposal of Green Waste
Tips for the Home Improvement Projects R-7 Household Hazardous Waste
Tips for Horse Care R-8 Water Conservation
Tips for Landscaping and Gardening
Tips for Pet Care
Tips for Pool Maintenance
Tips for Residential Pool, Landscape and
Hardscape Drains
Tips for Projects Using Paint
Chapter 14.17
WATER-EFFICIENT LANDSCAPING
Sections:
14.17.005 Purpose.
14.17.010 Definitions.
14.17.020 Applicability.
14.17.030 Landscape Water Use Standards.
14.17.040 Implementation Procedures.
* Prior history: Ords. 92-54, 92-55 and 96-22.
14.17.005 Purpose.
The purpose of this chapter and the related design standards is to establish an alternative model
acceptable under Governor Brown’s April 1, 2015, Drought Executive Order (B-29-15) as being at least as
effective as the State Model Water Efficient Landscape Ordinance in the context of conditions in the City
to:
A. Promote the benefits of consistent landscape ordinances with neighboring local and regional
agencies;
B. Promote the values and benefits of landscapes while recognizing the need to invest water and other
resources as efficiently as possible;
C. Establish a structure for planning, designing, installing, and maintaining and managing water-
efficient landscapes in new construction and rehabilitated projects;
D. Establish provisions for water management practices and water waste prevention for existing
landscapes;
E. Use water efficiently without waste by setting a maximum applied water allowance as an upper limit
for water use and reduce water use to the lowest practical amount; and
F. Encourage the use of economic incentives that promote the efficient use of water, such as providing
rebate incentives and offering educational programs. (Ord. 2015-34 § 1 (part), 2016: Ord. 2010-1 § 1
(part), 2010)
14.17.010 Definitions.
For the purposes of this chapter, the following words and phrases shall have the meanings set forth in
this section:
A. “Aggregate landscape areas” pertains to the areas undergoing development as one project or for
production home neighborhoods or other situations where multiple parcels are undergoing
development as one project, but will eventually be individually owned.
B. “Applied water” means the portion of water supplied by the irrigation system to the landscape.
C. “Budget-based tiered-rate structure” means tiered or block rates for irrigation accounts charged by
the retail water agency in which the block definition for each customer is derived from lot size or
irrigated area and the evapotranspiration requirements of landscaping.
D. “Design standards” refers to the Design Standards for Implementation of the Water Efficient
Landscape Ordinance, which are hereby adopted by reference and may be amended from time-to-time,
which describe procedures, calculations, and requirements for landscape projects subject to this
chapter.
E. “Ecological restoration project” means a project where the site is intentionally altered to establish a
defined, indigenous, historic ecosystem.
F. “Estimated applied water use” or “EAWU” means the average annual total amount of water
estimated to be necessary to keep plants in a healthy state. EAWU is based on the reference
evapotranspiration rate, the size of the landscape area, plant water use factors, and the irrigation
efficiency within each hydrozone.
G. “ET adjustment factor” or “ETAF” of 0.55 (fifty-five (55) percent) for residential areas and 0.45
(forty-five (45) percent) for nonresidential areas, that, when applied to reference evapotranspiration,
adjusts for plant factors and irrigation efficiency, two major influences upon the amount of water that
needs to be applied to the landscape. The ETAF for new and existing (nonrehabilitated) special
landscape area shall not exceed 1.0 (one hundred (100) percent). The ETAF for existing nonrehabilitated
landscapes is 0.8 (eighty (80) percent).
H. “Hardscapes” means any durable material or feature (pervious and nonpervious) installed in or
around a landscape area, such as pavements or walls. Surface area of pools and other water features is
considered part of the landscape area and not considered hardscape for purposes of this chapter.
I. “Irrigation efficiency” means the measurement of the amount of water beneficially used divided by
the amount of water applied. Irrigation efficiency is derived from measurements and estimates of
irrigation system characteristics and management practices. The minimum average irrigation efficiency
for purposes of this chapter is 0.75 (seventy-five (75) percent) for overhead spray devices and 0.81
(eighty-one (81) percent) for drip systems with an overall irrigation efficiency of 0.71 (seventy-one (71)
percent). Greater irrigation efficiency can be expected from well designed and maintained systems.
J. “Landscape area” means all the planting areas, turf areas, and water features in a landscape design
plan subject to the maximum applied water allowance and estimated applied water use calculations.
The landscape area does not include footprints of buildings or structures, sidewalks, driveways, parking
lots, decks, patios, gravel or stone walks, other pervious or nonpervious hardscapes, and other
nonirrigated areas designated for nondevelopment (e.g., open spaces and existing native vegetation).
K. “Landscape documentation package” means the documents required to be provided to the City for
review and approval of landscape design projects, as described in the design standards.
L. “Landscape project” means the total area of landscape in a project, as provided in the definition of
“landscape area.”
M. “Landscape rehabilitation project” means any relandscaping project that meets the applicability
criteria of Section 14.17.020, where the modified landscape area is greater than twenty-five hundred
(2,500) square feet.
N. “Licensed professional” means a licensed landscape architect, California licensed landscape
contractor, civil engineer, architect, or any other person authorized to design or construct a landscape
pursuant to Sections 5500.1, 5615, 5641, 5641.1, 5641.2, 5641.3, 5641.4, 5641.5, 5641.6, 6701, and
7027.5 of the California Business and Professions Code, Section 832.27 of Title 16 of the California Code
of Regulations, and Section 6721 of the California Food and Agriculture Code, or any successor statutes.
O. “Local water supplier” means any entity, including, but not limited to, a public agency, city, county,
or private water company that provides retail water service.
P. “Maximum applied water allowance” or “MAWA” is the upper limit of annual applied water for the
established landscape area as specified in Section 2.2 of the design standards. It is based upon the area’s
reference evapotranspiration, the ET adjustment factor, and the size of the landscape area. The
estimated applied water use shall not exceed the maximum applied water allowance. MAWA = (ETo)
(0.62) [(ETAF x LA) + ((1 - ETAF) x SLA)]
Q. “Ministerial permit” means an authorizing document issued by the City’s Community Development
Department in conjunction with a landscape project which may include, but is not limited to: grading,
pools, spas, fountains, ponds, retaining walls, fences and walls, shade structures, trellis structures,
barbecues, outdoor fireplaces, etc.
R. “New landscape installation project” means a landscape installed in conjunction with any type of
new development, whether or not the new development includes construction of new building(s) (e.g.,
parks, playgrounds, greenbelts, etc.).
S. “Nonpervious” means any surface or natural material that does not allow for the passage of water
through the material and into the underlying soil.
T. “Pervious” means any surface or material that allows the passage of water through the material and
into the underlying soil.
U. “Plant factor” or “plant water use factor” is a factor, when multiplied by ETo, which estimates the
amount of water needed by plants. For purposes of this chapter, the plant factor range for very low
water use plants is zero (0) to 0.1 (ten (10) percent); the plant factor for low water use plants is 0.1 (ten
(10) percent) to 0.3 (thirty (30) percent); the plant factor range for moderate water use plants is 0.4
(forty (40) percent) to 0.6 (sixty (60) percent); and the plant factor range for high water use plants is 0.7
(seventy (70) percent) to 1.0 (one hundred (100) percent). Plant factors cited in this chapter are derived
from the Department of Water Resources publication “Water Use Classification of Landscape Species.”
Plant factors may also be obtained from horticultural researchers from academic institutions or
professional associations as approved by the California Department of Water Resources (DWR).
V. “Recycled water” or “reclaimed water” means a wastewater which, as a result of treatment, is
suitable for nonpotable uses not intended for human consumption such as landscape irrigation and
water features.
W. “Reference evapotranspiration” or “ETo” means a standard measurement of environmental
parameters which affect the water use of plants. ETo is given expressed in inches per day, month, or
year as represented in Appendix D of the design standards and is an estimate of the evapotranspiration
of a large field of four- to seven-inch-tall, cool-season grass that is well watered. Reference
evapotranspiration is used as the basis of determining the maximum applied water allowance.
X. “Smart automatic irrigation controller” means an automatic timing device used to remotely control
valves that operate an irrigation system and which schedules irrigation events using either
evapotranspiration (weather-based) or soil moisture data with nonvolatile memory shall be required for
irrigation scheduling in all irrigation systems, recommending U.S. EPA WaterSense labeled devices as
applicable.
Y. “Special landscape area” or “SLA” means an area of the landscape dedicated solely to edible plants
such as orchards and vegetable gardens, areas irrigated with recycled water, water features using
recycled water, or areas dedicated to active play such as community pools and spas, parks, sports fields,
golf courses, or areas where turf provides a playing surface. These areas may have an ET adjustment
factor (ETAF) up to 1.0 (one hundred (100) percent).
Z. “Turf” means a ground cover surface of mowed grass. Annual bluegrass, Kentucky bluegrass,
perennial ryegrass, red fescue, and tall fescue are cool-season grasses. Bermuda grass, Kikuyu grass,
seashore paspalum, St. Augustine grass, zoysia grass, and Buffalo grass are warm-season grasses.
AA. “Valve” means a device used to control the flow of water in an irrigation system.
BB. “Water feature” means a design element where open water performs an aesthetic or recreational
function. Water features include ponds, lakes, waterfalls, fountains, artificial streams, spas, and
swimming pools (where water is artificially supplied). The surface area of water features is included in
the high water use hydrozone of the landscape area. Constructed wetlands used for on-site wastewater
treatment, habitat protection or storm water best management practices that are not irrigated and used
solely for water treatment or storm water retention are not water features and, therefore, are not
subject to the water budget calculation. (Ord. 2015-34 § 1 (part), 2016: Ord. 2013-11 § 84, 2013; Ord.
2010-1 § 1 (part), 2010)
14.17.020 Applicability.
A. Beginning February 1, 2016, and consistent with Executive Order No. B-29-15, this chapter shall
apply to the following landscape projects:
1. New landscape projects with an aggregate landscape area equal to or greater than five hundred
(500) square feet which require discretionary or ministerial permits from the City.
2. Rehabilitated landscape projects with an aggregate landscape area equal to or greater than twenty-
five hundred (2,500) square feet which require discretionary or ministerial permits from the City.
3. New or rehabilitated landscape projects with an aggregate landscape area of twenty-five hundred
(2,500) square feet or less may comply with the performance requirements of this chapter or conform
to the prescriptive measures contained in Appendix H of the Design Standards (Prescriptive Compliance
Option);
4. New or rehabilitated projects using treated or untreated graywater or rainwater captured on site,
any lot or parcels within the project that has less than twenty-five hundred (2,500) square feet of
landscape area and meets the lot or parcel’s landscape water requirement (estimated total water use)
entirely with the treated or untreated graywater or through stored rainwater capture on site is subject
only to Appendix H of the Design Standards (Prescriptive Compliance Option);
5. New landscape installation projects or landscape rehabilitation projects installed at cemeteries shall
be subject to the following sections of the design standards: Sections 2.2, Water Efficient Landscape
Calculations and Alternatives; 2.8, Post-Installation Irrigation Scheduling; and 2.9, Post-Installation
Landscape and Irrigation Maintenance, but shall not require a landscape documentation package
(Design Standards Section 2.1).
B. This chapter does not apply to:
1. Landscape rehabilitation projects that consist of replacement plantings with equal or lower water
needs and the irrigation system is designed, operable and programmed to comply with the City’s water
conservation regulations;
2. Registered local, State, or Federal historical sites;
3. Ecological restoration projects that do not require a permanent irrigation system;
4. Plant collections, as part of botanical gardens and arboretums open to the public; or
5. Landscape in hazard reduction and fuel modification zones, where applicable.
C. Section 14.17.030(B) (requiring compliance with the City’s water conservation ordinance) shall apply
to all landscape areas, whether installed prior to (existing landscapes) or after adoption of the ordinance
codified in this chapter. (Ord. 2015-34 § 1 (part), 2016: Ord. 2010-1 § 1 (part), 2010)
14.17.030 Landscape Water Use Standards.
A. For new landscape installation or rehabilitation projects subject to Section 14.17.020, the estimated
applied water use allowed for the landscape area shall not exceed the MAWA calculated using an ET
adjustment factor of 0.55 (fifty-five (55) percent) for residential areas and 0.45 (forty-five (45) percent)
for nonresidential areas, except for special landscape areas where the MAWA is calculated using an ET
adjustment factor of 1.0 (one hundred (100) percent); or the design of the landscape area shall
otherwise be shown to be equivalently water efficient in a manner acceptable to the City, as provided in
the design standards.
B. Irrigation of all landscape areas shall be conducted in a manner conforming to the rules and
requirements, and shall be subject to penalties and incentives for water conservation and water waste
prevention, as determined and implemented by the City’s water conservation ordinance. (Ord. 2015-34
§ 1 (part), 2016: Ord. 2010-1 § 1 (part), 2010)
14.17.040 Implementation Procedures.
A. A landscape documentation package shall be submitted to the City for review and approval of all
landscape projects subject to the provisions of this chapter. Any landscape documentation package
submitted to the City shall comply with the provisions of the design standards.
B. The landscape documentation package shall include a certification of design by a professional
appropriately licensed in the State of California stating that the landscape design and water use
calculations have been prepared by or under the supervision of a licensed professional and are certified
to be in compliance with the provisions of this chapter and the design standards.
1. Landscape and irrigation plans shall be submitted to the City for review and approval with
appropriate water use calculations. Water use calculations shall be consistent with the procedures and
calculations provided in the design standards document.
2. Verification of compliance of the landscape installation with the approved plans shall be obtained
through a certification of completion, which shall be submitted to the City prior to final of the permit,
per the procedures provided in the design standards document. (Ord. 2015-34 § 1 (part), 2016: Ord.
2010-1 § 1 (part), 2010)
IC7. LANDSCAPE MAINTENANCE MINIMUM BEST MANAGEMENT PRACTICES
Pollution Prevention/Good Housekeeping
• Properly store and dispose of gardening wastes.
• Use mulch or other erosion control measures on
exposed soils.
• Properly manage irrigation and runoff.
• Properly store and dispose of chemicals.
• Properly manage pesticide and herbicide use.
• Properly manage fertilizer use.
Stencil storm drains
Training
• Train employees on these BMPs, storm water
discharge prohibitions, and wastewater discharge
requirements.
• Provide on-going employee training in pollution
prevention.
Best Management Practices (BMPs)
A BMP is a technique, measure or structural control that is
used for a given set of conditions to improve the quality of
the stormwater runoff in a cost effective manner 1 . The
minimum required BMPs for this activity are outlined in the
box to the right. Implementation of pollution
prevention/good housekeeping measures may reduce or
eliminate the need to implement other more costly or
complicated procedures. Proper employee training is key
to the success of BMP implementation.
The BMPs outlined in this fact sheet target the following
pollutants:
Targeted Constituents
Sediment x
Nutrients x
Floatable Materials x
Metals
Bacteria x
Oil & Grease
Organics & Toxicants
Pesticides x
Oxygen Demanding x
Provided below are specific procedures associated with each of the minimum BMPs along with procedures for
additional BMPs that should be considered if this activity takes place at a facility located near a sensitive
waterbody. In order to meet the requirements for medium and high priority facilities, the owners/operators must
select, install and maintain appropriate BMPs on site. Since the selection of the appropriate BMPs is a site-
specific process, the types and numbers of additional BMPs will vary for each facility.
1. Take steps to reduce landscape maintenance requirements.
• Where feasible, retain and/or plant native vegetation with features that are determined to be
beneficial. Native vegetation usually requires less maintenance than planting new vegetation.
• When planting or replanting consider using low water use flowers, trees, shrubs, and groundcovers.
• Consider alternative landscaping techniques such as naturescaping and xeriscaping.
2. Properly store and dispose of gardening wastes.
• Dispose of grass clippings, leaves, sticks, or other collected vegetation as garbage at a permitted
landfill or by composting.
• Do not dispose of gardening wastes in streets, waterways, or storm drainage systems.
• Place temporarily stockpiled material away from watercourses and storm drain inlets, and berm
and/or cover.
3. Use mulch or other erosion control measures on exposed soils.
1 EPA " Preliminary Data Summary of Urban Stormwater Best Management Practices”
IC7 Landscape Maintenance 1
4. Properly manage irrigation and runoff.
• Irrigate slowly or pulse irrigate so the infiltration rate of the soil is not exceeded.
• Inspect irrigation system regularly for leaks and to ensure that excessive runoff is not occurring.
• If re-claimed water is used for irrigation, ensure that there is no runoff from the landscaped area(s).
• If bailing of muddy water is required (e.g. when repairing a water line leak), do not put it in the storm
drain; pour over landscaped areas.
• Use automatic timers to minimize runoff.
• Use popup sprinkler heads in areas with a lot of activity or where pipes may be broken. Consider
the use of mechanisms that reduce water flow to broken sprinkler heads.
5. Properly store and dispose of chemicals.
• Implement storage requirements for pesticide products with guidance from the local fire department
and/or County Agricultural Commissioner.
• Provide secondary containment for chemical storage.
• Dispose of empty containers according to the instructions on the container label.
• Triple rinse containers and use rinse water as product.
6. Properly manage pesticide and herbicide use.
• Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of
pesticides and herbicides and training of applicators and pest control advisors.
• Follow manufacturers’ recommendations and label directions.
• Use pesticides only if there is an actual pest problem (not on a regular preventative schedule).
When applicable use less toxic pesticides that will do the job. Avoid use of copper-based pesticides
if possible. Use the minimum amount of chemicals needed for the job.
• Do not apply pesticides if rain is expected or if wind speeds are above 5 mph.
• Do not mix or prepare pesticides for application near storm drains. Prepare the minimum amount of
pesticide needed for the job and use the lowest rate that will effectively control the targeted pest.
• Whenever possible, use mechanical methods of vegetation removal rather than applying herbicides.
Use hand weeding where practical.
• Do not apply any chemicals directly to surface waters, unless the application is approved and
permitted by the state. Do not spray pesticides within 100 feet of open waters.
• Employ techniques to minimize off-target application (e.g. spray drift) of pesticides, including
consideration of alternative application techniques.
• When conducting mechanical or manual weed control, avoid loosening the soil, which could lead to
erosion.
• Purchase only the amount of pesticide that you can reasonably use in a given time period.
• Careful soil mixing and layering techniques using a topsoil mix or composted organic material can
be used as an effective measure to reduce herbicide use and watering.
7. Properly manage fertilizer use.
• Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of
fertilizers.
• Follow manufacturers’ recommendations and label directions.
• Employ techniques to minimize off-target application (e.g. spray drift) of fertilizer, including
consideration of alternative application techniques. Calibrate fertilizer distributors to avoid
excessive application.
• Periodically test soils for determining proper fertilizer use.
• Fertilizers should be worked into the soil rather than dumped or broadcast onto the surface.
• Sweep pavement and sidewalk if fertilizer is spilled on these surfaces before applying irrigation
water.
• Use slow release fertilizers whenever possible to minimize leaching
IC7 Landscape Maintenance 2
8. Incorporate the following integrated pest management techniques where appropriate:
• Mulching can be used to prevent weeds where turf is absent.
• Remove insects by hand and place in soapy water or vegetable oil. Alternatively, remove insects
with water or vacuum them off the plants.
• Use species-specific traps (e.g. pheromone-based traps or colored sticky cards).
• Sprinkle the ground surface with abrasive diatomaceous earth to prevent infestations by soft-bodied
insects and slugs. Slugs also can be trapped in small cups filled with beer that are set in the ground
so the slugs can get in easily.
• In cases where microscopic parasites, such as bacteria and fungi, are causing damage to plants,
the affected plant material can be removed and disposed of (pruning equipment should be
disinfected with bleach to prevent spreading the disease organism).
• Small mammals and birds can be excluded using fences, netting, and tree trunk guards.
• Promote beneficial organisms, such as bats, birds, green lacewings, ladybugs, praying mantis,
ground beetles, parasitic nematodes, trichogramma wasps, seedhead weevils, and spiders that
prey on detrimental pest species.
Training
1. Train employees on these BMPs, storm water discharge prohibitions, and wastewater discharge
requirements.
2. Educate and train employees on the use of pesticides and pesticide application techniques.
Only employees properly trained to use pesticides can apply them.
3. Train and encourage employees to use integrated pest management techniques.
4. Train employees on proper spill containment and cleanup.
• Establish training that provides employees with the proper tools and knowledge to immediately
begin cleaning up a spill.
• Ensure that employees are familiar with the site’s spill control plan and/or proper spill cleanup
procedures.
• Fact sheet IC17 discusses Spill Prevention and Control in detail.
5. Establish a regular training schedule, train all new employees, and conduct annual refresher
training.
6. Use a training log or similar method to document training.
Stencil storm drains
Storm drain system signs act as highly visible source controls that are typically stenciled directly adjacent to
storm drain inlets. Stencils should read “No Dumping Drains to Ocean”.
References
California Storm Water Best Management Practice Handbook. Industrial and Commercial. 2003.
www.cabmphandbooks.com
California Storm Water Best Management Practice Handbooks. Industrial/Commercial Best Management
Practice Handbook. Prepared by Camp Dresser& McKee, Larry Walker Associates, Uribe and Associates,
Resources Planning Associates for Stormwater Quality Task Force. March 1993.
King County Stormwater Pollution Control Manual. Best Management Practices for Businesses. King County
Surface Water Management. July 1995. On-line: http://dnr.metrokc.gov/wlr/dss/spcm.htm
Stormwater Management Manual for Western Washington. Volume IV Source Control BMPs. Prepared by
Washington State Department of Ecology Water Quality Program. Publication No. 99-14. August 2001.
IC7 Landscape Maintenance 3
Water Quality Handbook for Nurseries. Oklahoma Cooperative Extension Service. Division of Agricultural
Sciences and Natural Resources. Oklahoma State University. E-951. September 1999.
For additional information contact:
County of Orange/ OC Watersheds
Main: (714) 955-0600
24 hr Water Pollution Hotline: 1-877-89-SPILL
or visit our website at www.ocwatersheds.com
IC7 Landscape Maintenance 4
R-1
AUTOMOBILE REPAIR AND
MAINTENANCE
Automobile repair and maintenance activities have the potential to
contribute directly to storm drain systems primarily through spills or
the dumping of waste fluids being conveyed to the storm drain.
Automotive fluids, such as oils, greases, and solvents, are
hydrocarbon based, and may contain metals, chlorinated
hydrocarbons, and other toxic compounds. Removal of caked dirt
and grime from an automobile increases the sediment load to the
storm drain system. The pollution prevention activities outlined in
this fact sheets are used to prevent the discharge of pollutants to the
storm drain system.
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients
Bacteria
Foaming Agents
Metals x
Hydrocarbons x
Hazardous Materials x
Pesticides and
Herbicides
Other Think before conducting automobile repair and maintenance
activities. Remember - The ocean starts at your front door.
Required Activities
• Recycle used oil and antifreeze by taking them to service stations and other
recycling centers. Never pour oil in storm drains or other areas.
• Do not perform repair and maintenance activities during rain events.
• Immediately clean up and contain any spills. Dispose of all waste and adsorbent
materials properly.
• Store hazardous materials and wastes (including, but not limited to, fluids, solvents,
parts containing fluids, batteries) indoors, under cover, or in watertight containers.
• Perform automobile maintenance and repairs over impervious surfaces such as concrete,
so spills and waste material should be readily cleaned up. Use drip pans, plastic
sheeting, etc. to contain spills and waste material.
• Dispose of cleaning solvents at the designated hazardous waste center.
Recommended Activities
• Conduct auto repair activities at a commercial repair facility
• Perform automobile repair and maintenance activities under a covered area.
• Do not buy fluids containing target pollutants (e.g. degreasers containing PERC).
• Monitor parked or stored vehicles and equipment for leaks and place pans under leaks
to collect fluids for proper disposal or recycling.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600 Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-2
AUTOMOBILE WASHING
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients X
Bacteria
Foaming Agents X
Metals X
Hydrocarbons X
Hazardous Materials x
Pesticides and
Herbicides
Other
Automobile washing activities have the potential to contribute
pollutants because road dust washed from vehicles may contain
metals and hydrocarbons. Any leaking fluids washed from the
automobile may be carried to the storm drain by the wash water.
Detergents used for automobile washing may also contain
phosphorus and foaming agents, which contribute to the
eutrophication of receiving waterbodies. The pollution prevention
activities outlined in this fact sheets are used to prevent the discharge
of pollutants to the storm drain system.
Think before conducting automobile washing activities. Remember - The ocean starts at your
front door.
Required Activities
• Shake floor mats into trashcan or vacuum to clean. Do not shake over ground.
• If using cleaners (such as acid based wheel cleaners) use a rag to wipe them on and off,
do not rinse them off with water.
• If possible, divert runoff from automobile washing to a grassy surface large enough to
contain and allow complete infiltration
• Dispose of excess wash water into the sanitary sewer (i.e. via sink, or toilet) or onto a
landscaped area that will allow for complete infiltration.
• Conduct engine degreasing at a commercial facility that is set up to handle that type of
waste.
Recommended Activities
• When possible, use commercial wash facilities
• Wash vehicles over pervious surfaces such as lawns and gravel areas
• Choose soaps, cleaners, or detergents labeled “non-toxic”, “phosphate free”, or
“biodegradable”. Vegetable and citrus-based products are typically safest for the
environment.
• Turn off water when not actively washing down automobile.
• If available, use established neighborhood wash areas, where runoff is properly
controlled and managed.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-3
AUTOMOBILE PARKING
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients
Bacteria
Foaming Agents
Metals X
Hydrocarbons X
Hazardous Materials x
Pesticides and
Herbicides
Other
Parked automobiles may contribute pollutants to the storm
drain because poorly maintained vehicles may leak fluids
containing hydrocarbons, metals, and other pollutants. In
addition, heavily soiled automobiles may drop clods of dirt
onto the parking surface, contributing to the sediment load
when runoff is present. During rain events, or wash-down
activities, the pollutants may be carried into the storm drain
system. The pollution prevention activities outlined in this
fact sheets are used to prevent the discharge of pollutants to
the storm drain system.
Think before parking your car. Remember - The ocean starts at your front door.
Required Activities
• If required, vehicles have to be removed from the street during designated street
sweeping/cleaning times.
• If the automobile is leaking, place a pan or similar collection device under the
automobile, until such time as the leak may be repaired.
• Use dry cleaning methods to remove any materials deposited by vehicles (e.g.
adsorbents for fluid leaks, sweeping for soil clod deposits).
Recommended Activities
• Park automobiles over permeable surfaces (e.g. gravel, or porous cement).
• Limit vehicle parking to covered areas.
• Perform routine maintenance to minimize fluid leaks, and maximize fuel
efficiency.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-4
HOME AND GARDEN CARE
ACTIVITIES
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients
Bacteria x
Foaming Agents x
Metals x
Hydrocarbons x
Hazardous Materials x
Pesticides and
Herbicides
Other x
HOME CARE
Many hazardous materials may be used in and around
residences during routine maintenance activities (such as: oils,
paints, cleaners, bleaches, pesticides, glues, solvents, and other
products). Improper or excessive use of these products can
increase the potential for pollutants to be transported to the
storm drain by runoff. The pollution prevention activities
outlined in this fact sheets are used to prevent the discharge of
pollutants to the storm drain system.
Think before conducting home care activities. Remember - The
ocean starts at your front door.
Required Activities
• Clean out painting equipment in an area where the waste can be contained and properly
disposed of (latex – sewer, oil based – household hazardous waste center).
• Rinse off cement mixers and cement laden tools in a contained washout area. Dispose
of dried concrete waste in household trash.
• If safe, contain, clean up, and properly dispose all household hazardous waste spills. If
an unsafe condition exists, call 911 to activate the proper response team.
• Household hazardous materials must be stored indoors or under cover, and in closed
and labeled containers. Dispose of them at a household hazardous waste center.
• Household wash waters (e.g. washer machine effluent, mop water, etc.) must be
disposed of in the sanitary sewer.
• Pool and spa water may be discharged to the storm drain if residual chlorine is less than
0.1 mg/L, the pH is between 6.5 and 8.5, and the water is free from any unusual
coloration. (Call 714-834-6107 to obtain information on a pool drain permit). Pool filter
media must be contained and disposed of properly.
Recommended Activities
• Only purchase the types and amounts of materials needed.
• Share unused portions of products with neighbors or community programs (latex paint)
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
GARDEN CARE
Garden activities may contribute pollutants via soil erosion,
green waste, fertilizer and pesticide use. Plant and garden
care activities such as landscape maintenance, fertilization,
and pesticide application have the potential to discharge
significant quantities of pollutants to the storm drain system.
Nonvegetated surfaces may allow for significant erosion
leading to high sediment loads. Other pollutants such as
pesticides may adsorb onto the soil particles and be
transported off site. Excess fertilizer and pesticide pollutants
from over application may be carried to the storm drain by
dissolving in irrigation runoff or rainwater. Green wastes
may also contain organic matter and may have adsorbed
fertilizers and pesticides.
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients x
Bacteria x
Foaming Agents
Metals
Hydrocarbons
Hazardous Materials
Pesticides and
Herbicides
x
Other x
Excessive irrigation is often the most significant factor in home and garden care activities.
Pollutants may dissolve in irrigation water and then be transported to the storm drain, or
particles and materials coated with fertilizers and pesticides may be suspended in the irrigation
flow and carried to the storm drain. The pollution prevention activities outlined in this fact
sheets are used to prevent the discharge of pollutants to the storm drain system.
Think before conducting garden care activities. Remember - The ocean starts at your front door.
Required Activities
• Irrigation systems must be properly adjusted to reflect seasonal water needs.
• Minimize the use of pesticides and fertilizers. Read the labels and follow directions to
avoid improper use. Do not apply chemicals if it is windy or about to rain.
• Properly clean up and dispose of spills of gardening chemicals, fertilizes, or soils. If
possible, return the spilled material to the container for future use.
• Lawn and garden care products must be stored in closed labeled containers, in covered
areas, or off-ground and under protective tarps.
• Household hazardous waste must be properly disposed at a household hazardous waste
center.
• Cover nonvegetated surfaces to prevent erosion.
Recommended Activities
• Utilize xeroscaping and use of drought and insect resistant landscaping.
• Cultivate garden often to control weeds
• Use integrated pest management (IPM). Planting pest repelling plants (e.g. Marigolds)
or using pest eating insects (e.g. ladybugs) may reduce the need for pesticides.
• Do not leave food (human or pet) outside overnight
• Remove fruit and garden waste
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-5
DISPOSAL OF PET WASTES
Pet wastes left in the environment may introduce solids,
bacteria, and nutrients to the storm drain. The type and
quantity of waste will dictate the proper disposal
method. Small quantities of waste are best disposed
with regular trash or flushed down a toilet. Large
quantities of wastes from herbivore animals may be
composted for subsequent use or disposal to landfill.
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients x
Bacteria x
Foaming Agents
Metals
Hydrocarbons
Hazardous Materials
Pesticides and
Herbicides
Other
Pick up after your pet! It’s as easy as 1-2-3. 1) Bring a
bag. 2) Clean it up. 3) Dispose of it properly (toilet or
trash). The pollution prevention activities outlined in
this fact sheets are used to prevent the discharge of
pollutants to the storm drain system.
Think before you dispose of any pet wastes. Remember - The ocean starts at your front
door.
Required Activities
• All pet wastes must be picked up and properly disposed of. Pet waste should be
disposed of in the regular trash, flushed down a toilet, or composted as type and
quantities dictate.
• Properly dispose of unused flea control products (shampoo, sprays, or collars).
• Manure produced by livestock in uncovered areas should be removed at least
daily for composting, or storage in water-tight container prior to disposal. Never
hose down to stream or storm drain. Composting or storage areas should be
configured and maintained so as not to allow contact with runoff. Compost may
be donated to greenhouses, nurseries, and botanical parks. Topsoil companies
and composting centers may also accept composted manure.
• Line waste pits or trenches with an impermeable layer, such as thick plastic
sheeting.
• When possible, allow wash water to infiltrate into the ground, or collect in an
area that is routed to the sanitary sewer.
• Confine livestock in fenced in areas except during exercise and grazing times.
Restrict animal access to creeks and streams, preferably by fencing.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
• Install gutters that will divert roof runoff away from livestock areas.
Recommended Activities
• In order to properly dispose of pet waste, carry bags, pooper-scooper, or
equivalent to safely pick up pet wastes while walking with pets.
• Bathe pets indoors and use less toxic shampoos. When possible, have pets
professionally groomed.
• Properly inoculate your pet in order to maintain their health and reduce the
possibility of pathogens in pet wastes.
• Maintain healthy and vigorous pastures with at least three inches of leafy
material.
• Consider indoor feeding of livestock during heavy rainfall, to minimize manure
exposed to potential runoff.
• Locate barns, corrals, and other high use areas on portions of property that either
drain away from or are located distant form nearby creeks or storm drains.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-6
DISPOSAL OF GREEN WASTES
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients x
Bacteria x
Foaming Agents
Metals
Hydrocarbons
Hazardous Materials x
Pesticides and
Herbicides
x
Other
Green wastes entering the storm drain may clog the
system creating flooding problems. Green wastes washed
into receiving waters create an oxygen demand as they are
decomposed, reducing the available oxygen for aquatic
life. Pesticide and nutrient residues may be carried to the
receiving water with the green wastes. The pollution
prevention activities outlined in this fact sheets are used to
prevent the discharge of pollutants to the storm drain
system.
Think before disposing of any green wastes – Remember - The ocean starts at your front
door.
Required Activities
• Green wastes can not be disposed of in the street, gutter, public right-of-way,
storm drain, or receiving water. Dispose of green wastes as a part of the
household trash. If the quantities are too large, arrange a pick up with the local
waste hauler.
• After conducting yard or garden activities sweep the area and properly dispose of
the clippings and waste. Do not sweep or blow out into the street or gutter.
Recommended Activities
• Utilize a commercial landscape company to conduct the landscape activities and
waste disposal.
• Utilize native plants and drought tolerant species to reduce the water use and
green waste produced.
• Use a lawn mower that has a mulcher so that the grass clippings remain on the
lawn and do not have to be collected and disposed of.
• Compost materials in a designated area within the yard.
• Recycle lawn clippings and greenery waste through local programs if available.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
R-7
HOUSEHOLD HAZARDOUS
WASTE
Household hazardous wastes (HHW) are defined as
waste materials which are typically found in homes or
similar sources, which exhibit characteristics such as:
corrosivity, ignitability, reactivity, and/or toxicity, or
are listed as hazardous materials by EPA.
Many types of waste can be
recycled, however options
for each waste type are
limited. Recycling is always
preferable to disposal of
unwanted materials. All
gasoline, antifreeze, waste oil, and lead-acid batteries
can be recycled. Latex and oil-based paint can be
reused, as well as recycled. Materials that cannot be
reused or recycled should be disposed of at a properly
permitted landfill.
The activities outlined in this fact
sheet target the following
pollutants:
Sediment
Nutrients
Bacteria
Foaming Agents x
Metals x
Hydrocarbons x
Hazardous Materials x
Pesticides and
Herbicides
x
Other x
List of most common HHW
products:
Drain openers
Oven cleaners
Wood and metal cleaners and
polishes
Automotive oil and fuel additives
Grease and rust solvents
Carburetor and fuel injection
cleaners
Starter fluids
Batteries
Paint Thinners
Paint strippers and removers
Adhesives
Herbicides
Pesticides
Fungicides/wood preservatives
Think before disposing of any household hazardous
waste. Remember - The ocean starts at your front door.
Required Activities
• Dispose of HHW at a local collection facility. Call (714) 834-6752 for the
household hazardous waste center closest to your area.
• Household hazardous materials must be stored indoors or under cover, and in
closed and labeled containers.
• If safe, contain, clean up, and properly dispose all household hazardous waste
spills. If an unsafe condition exists, call 911 to activate the proper response
team.
Recommended Activities
• Use non-hazardous or less-hazardous products.
• Participate in HHW reuse and recycling. Call (714) 834-6752 for the
participating household hazardous waste centers.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
The California Integrated Waste Management Board has a Recycling Hotline (800) 553-2962, that provides information and recycling locations for
used oil.
R-8
WATER CONSERVATION
Excessive irrigation and/or the overuse of water is often
the most significant factor in transporting pollutants to
the storm drain system. Pollutants from a wide variety of
sources including automobile repair and maintenance,
automobile washing, automobile parking, home and
garden care activities and pet care may dissolve in the
water and be transported to the storm drain. In addition,
particles and materials coated with fertilizers and
pesticides may be suspended in the flow and be
transported to the storm drain.
Hosing off outside areas to wash them down not only
consumes large quantities of water, but also transports any pollutants, sediments, and
waste to the storm drain system. The pollution prevention activities outlined in this fact
sheets are used to prevent the discharge of pollutants to the storm drain system.
The activities outlined in this fact
sheet target the following
pollutants:
Sediment x
Nutrients x
Bacteria x
Foaming Agents x
Metals x
Hydrocarbons x
Hazardous Materials x
Pesticides and
Herbicides
x
Other x
Think before using water. Remember - The ocean starts at your front door.
Required Activities
• Irrigation systems must be properly adjusted to reflect seasonal water needs.
• Do not hose off outside surfaces to clean, sweep with a broom instead.
Recommended Activities
• Fix any leaking faucets and eliminate unnecessary water sources.
• Use xeroscaping and drought tolerant landscaping to reduce the watering needs.
• Do not over watering lawns or gardens. Over watering wastes water and
promotes diseases.
• Use a bucket to re-soak sponges/rags while washing automobiles and other
items outdoors. Use hose only for rinsing.
• Wash automobiles at a commercial car wash employing water recycling.
For additional information contact:
County of Orange, OC Watershed
Main: (714) 955-0600/ 24hr Water Pollution Discharge Hotline 1-877-89-SPILL
or visit our website at: www.ocwatersheds.com
TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-50 December 20, 2013
XIV.5. Biotreatment BMP Fact Sheets (BIO)
Conceptual criteria for biotreatment BMP selection, design, and maintenance are contained in
Appendix XII. These criteria are generally applicable to the design of biotreatment BMPs in
Orange County and BMP-specific guidance is provided in the following fact sheets. 24
Note: Biotreatment BMPs shall be designed to provide the maximum feasible infiltration and ET based on
criteria contained in Appendix XI.2.
BIO-1: Bioretention with Underdrains
Bioretention stormwater treatment facilities are landscaped
shallow depressions that capture and filter stormwater
runoff. These facilities function as a soil and plant-based
filtration device that removes pollutants through a variety of
physical, biological, and chemical treatment processes. The
facilities normally consist of a ponding area, mulch layer,
planting soils, and plants. As stormwater passes down
through the planting soil, pollutants are filtered, adsorbed,
biodegraded, and sequestered by the soil and plants.
Bioretention with an underdrain are utilized for areas with
low permeability native soils or steep slopes where the
underdrain system that routes the treated runoff to the storm
drain system rather than depending entirely on infiltration.
Bioretention must be designed without an underdrain in areas of
high soil permeability.
Feasibility Screening Considerations
If there are no hazards associated with infiltration (such as groundwater concerns, contaminant
plumes or geotechnical concerns), bioinfiltration facilities, which achieve partial infiltration,
should be used to maximize infiltration.
24 Not all BMPs presented in this section are considered “biofiltration BMPs” under the South Orange County
Permit Area. Biofiltration BMPs are vegetated treat-and-release BMPs that filter stormwater through amended soil
media that is biologically active, support plant growth, and also promote infiltration and/or evapotranspiration. For
projects in South Orange County, the total volume of storage in surface ponding and pores spaces is required to be at
least 75% of the remaining DCV that the biofiltration BMP is designed to address. This prevents significant down-
sizing of BMPs which otherwise may be possible via routing calculations. Biotreatment BMPs that do not meet this
definition are not considered to be LID BMPs, but may be used as treatment control or pre-treatment BMPs. See
Section III.7 and Worksheet SOC-1 for guidance.
Also known as:
Rain gardens with
underdrains
Vegetated media filter
Downspout planter boxes
Bioretention
Source: Geosyntec Consultants
TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-51 December 20, 2013
Bioretention with underdrain facilities should be lined if contaminant plumes or geotechnical
concerns exist. If high groundwater is the reason for infiltration infeasibility, bioretention facilities
with underdrains do not need to be lined.
Opportunity Criteria
Land use may include commercial, residential, mixed use, institutional, and subdivisions.
Bioretention may also be applied in parking lot islands, cul-de-sacs, traffic circles, road shoulders,
road medians, and next to buildings in planter boxes.
Drainage area is ≤ 5 acres.
Area is available for infiltration.
Site must have adequate relief between land surface and the stormwater conveyance system to
permit vertical percolation through the soil media and collection and conveyance in underdrain to
stormwater conveyance system.
OC-Specific Design Criteria and Considerations
□
Ponding depth should not exceed 18 inches; fencing may be required if ponding depth is
greater than 6 inches to mitigate drowning.
□ The minimum soil depth is 2 feet (3 feet is preferred).
□ The maximum drawdown time of the bioretention ponding area is 48 hours. The maximum
drawdown time of the planting media and gravel drainage layer is 96 hours, if applicable.
□
Infiltration pathways may need to be restricted due to the close proximity of roads, foundations,
or other infrastructure. A geomembrane liner, or other equivalent water proofing, may be placed
along the vertical walls to reduce lateral flows. This liner should have a minimum thickness of
30 mils.
□
If infiltration in bioretention location is hazardous due to groundwater or geotechnical concerns,
a geomembrane liner must be installed at the base of the bioretention facility. This liner should
have a minimum thickness of 30 mils.
□
The planting media placed in the cell shall be designed per the recommendations contained in
MISC-1: Planting/Storage Media
□
Plant materials should be tolerant of summer drought, ponding fluctuations, and saturated soil
conditions for 48 hours; native place species and/or hardy cultivars that are not invasive and do
not require chemical inputs should be used to the maximum extent feasible
□
The bioretention area should be covered with 2-4 inches (average 3 inches) or mulch at the
start and an additional placement of 1-2 inches of mulch should be added annually.
□
Underdrain should be sized with a 6 inch minimum diameter and have a 0.5% minimum slope.
Underdrain should be slotted polyvinyl chloride (PVC) pipe; underdrain pipe should be more
than 5 feet from tree locations (if space allows).
□
A gravel blanket or bedding is required for the underdrain pipe(s). At least 0.5 feet of washed
aggregate must be placed below, to the top, and to the sides of the underdrain pipe(s).
□ An overflow device is required at the top of the bioretention area ponding depth.
□
Dispersed flow or energy dissipation (i.e. splash rocks) for piped inlets should be provided at
basin inlet to prevent erosion.
□
Ponding area side slopes shall be no steeper than 3:1 (H:V) unless designed as a planter box
BMP with appropriate consideration for trip and fall hazards.
TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-52 December 20, 2013
Simple Sizing Method for Bioretention with Underdrain
If the Simple Design Capture Volume Sizing Method described in Appendix III.3.1 is used to size a
bioretention with underdrain facility, the user selects the basin depth and then determines the appropriate
surface area to capture the DCV. The sizing steps are as follows:
Step 1: Determine DCV
Calculate the DCV using the Simple Design Capture Volume Sizing Method described in Appendix
III.3.1.
Step 2: Verify that the Ponding Depth will Draw Down within 48 Hours
The ponding area drawdown time can be calculated using the following equation:
DDP = (dP / KMEDIA) × 12 in/ft
Where:
DDP = time to drain ponded water, hours
dP = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
KMEDIA = media design infiltration rate, in/hr (equivalent to the media hydraulic conductivity with a
factor of safety of 2; KMEDIA of 2.5 in/hr should be used unless other information is available)
If the drawdown time exceeds 48 hours, adjust ponding depth and/or media infiltration rate until 48
hour drawdown time is achieved.
Step 3: Determine the Depth of Water Filtered During Design Capture Storm
The depth of water filtered during the design capture storm can be estimated as the amount routed
through the media during the storm, or the ponding depth, whichever is smaller.
dFILTERED = Minimum [ ((KMEDIA × TROUTING)/12), dP]
Where:
dFILTERED = depth of water that may be considered to be filtered during the design storm event, ft
KMEDIA = media design infiltration rate, in/hr (equivalent to the media hydraulic conductivity with a
factor of safety of 2; KMEDIA of 2.5 in/hr should be used unless other information is available)
TROUTING = storm duration that may be assumed for routing calculations; this should be assumed to be
no greater than 3 hours. If the designer desires to account for further routing effects, the Capture
Efficiency Method for Volume-Based, Constant Drawdown BMPs (See Appendix III.3.2) should be
used.
dP = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
Step 4: Determine the Facility Surface Area
A = DCV/ (dP + dFILTERED)
Where:
A = required area of bioretention facility, sq-ft
DCV = design capture volume, cu-ft
dFILTERED = depth of water that may be considered to be filtered during the design storm event, ft
dP = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
In South Orange County, the provided ponding plus pore volume must be checked to demonstrate that it
is greater than 0.75 of the remaining DCV that this BMP is designed to address. See Section III.7 and
Worksheet SOC-1.
TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV-53 December 20, 2013
Capture Efficiency Method for Bioretention with Underdrains
If the bioretention geometry has already been defined and the user wishes to account more explicitly for
routing, the user can determine the required footprint area using the Capture Efficiency Method for
Volume-Based, Constant Drawdown BMPs (See Appendix III.3.2) to determine the fraction of the DCV
that must be provided to manage 80 percent of average annual runoff volume. This method accounts for
drawdown time different than 48 hours.
Step 1: Determine the drawdown time associated with the selected basin geometry
DD = (dp / KDESIGN) × 12 in/ft
Where:
DD = time to completely drain infiltration basin ponding depth, hours
dP = bioretention ponding depth, ft (should be less than or equal to 1.5 ft)
KDESIGN = design media infiltration rate, in/hr (assume 2.5 inches per hour unless otherwise proposed)
If drawdown is less than 3 hours, the drawdown time should be rounded to 3 hours or the Capture
Efficiency Method for Flow-based BMPs (See Appendix III.3.3) shall be used.
Step 2: Determine the Required Adjusted DCV for this Drawdown Time
Use the Capture Efficiency Method for Volume-Based, Constant Drawdown BMPs (See Appendix III.3.2)
to calculate the fraction of the DCV the basin must hold to achieve 80 percent capture of average annual
stormwater runoff volume based on the basin drawdown time calculated above.
Step 3: Determine the Basin Infiltrating Area Needed
The required infiltrating area (i.e. the surface area of the top of the media layer) can be calculated using
the following equation:
A = Design Volume / dp
Where:
A = required infiltrating area, sq-ft (measured at the media surface)
Design Volume = fraction of DCV, adjusted for drawdown, cu-ft (see Step 2)
dp = ponding depth of water stored in bioretention area, ft (from Step 1)
This does not include the side slopes, access roads, etc. which would increase bioretention footprint. If
the area required is greater than the selected basin area, adjust surface area or adjust ponding depth and
recalculate required area until the required area is achieved.
In South Orange County, the provided ponding plus pore volume must be checked to demon strate that it
is greater than 0.75 of the remaining DCV that this BMP is designed to address. See Section III.7 and
Worksheet SOC-1.
Configuration for Use in a Treatment Train
Bioretention areas may be preceeded in a treatment train by HSCs in the drainage area, which
would reduce the required design volume of the bioretention cell. For example, bioretention could
be used to manage overflow from a cistern.
Bioretention areas can be used to provide pretreatment for underground infiltration systems.
Additional References for Design Guidance
CASQA BMP Handbook for New and Redevelopment:
http://www.cabmphandbooks.com/Documents/Development/TC -32.pdf
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XIV-54 December 20, 2013
SMC LID Manual (pp 68):
http://www.lowimpactdevelopment.org/guest75/pub/All_Projects/SoCal_LID_Manual/SoCalL
ID_Manual_FINAL_040910.pdf
Los Angeles County Stormwater BMP Design and Maintenance Manual, Chapter 5:
http://dpw.lacounty.gov/DES/design_manuals/StormwaterBMPDesignandMaintenance.pdf
San Diego County LID Handbook Appendix 4 (Factsheet 7):
http://www.sdcounty.ca.gov/dplu/docs/LID -Appendices.pdf
Los Angeles Unified School District (LAUSD) Stormwater Technical Manual, Chapter 4:
http://www.laschools.org/employee/design/fs -studies-and-
reports/download/white_paper_report_material/Storm_Water_Technical_Manual_2009 -opt-
red.pdf?version_id=76975850
County of Los Angeles Low Impact Development Standards Manual, Chapter 5:
http://dpw.lacounty.gov/wmd/LA _County_LID_Manual.pdf
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XIV-15 December 20, 2013
XIV.2. Miscellaneous BMP Design Element Fact Sheets (MISC)
MISC-1: Planting/Storage Media
Planting and storage media is a critical design element for
several common BMP types, including bioretention,
bioinfiltration, swales, filter strips, and greenroofs. This
fact sheet is intended to be used as referenced from these
fact sheets.
General Design Criteria
Planting/storage media should be designed to achieve
the long term hydraulic design requirements associated
with the design of the facility (i.e., design Ksat).
The planting media shall be designed to address
pollutants of concern at the design hydraulic capacity.
Bioretention soil shall also support vigorous plant growth.
Planting media should consist of 60 to 80% fine sand
and 20 to 40% compost.
Planting media for projects draining to nutrient sensitive receiving water should adhere to
recommendations for nutrient sensitive planting media provided below.
Sand
Sand should be free of wood, waste, coating such as clay, stone dust, carbonate, etc., or any
other deleterious material. All aggregate passing the No. 200 sieve size should be non-plastic.
Sand for bioretention should be analyzed by an accredited lab using #200, #100, #40, #30, #16,
#8, #4, and 3/8 sieves (ASTM D 422 or as approved by the local permitting authority) and me et
the following gradation (Note: all sands complying with ASTM C33 for fine aggregate comply with
the gradation requirements below):
Sieve Size (ASTM D422)
% Passing (by weight)
Minimum Maximum
3/8 inch 100 100
#4 90 100
#8 70 100
#16 40 95
#30 15 70
#40 5 55
#100 0 15
#200 0 5
Also known as:
Bioretention soil media
(BSM)
Street-end biofiltration with
planting/storage media
Source: City of Portland
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XIV-16 December 20, 2013
Note: the gradation of the sand component of the media is believed to be a major factor in the
hydraulic conductivity of the media mix. If the desired hydraulic conductivity of the media cannot
be achieved within the specified proportions of sand and compost (#2), then it may be necessary
to utilize sand at the coarser end of the range specified in the table above (“minimum” column).
Compost
Compost should be a well decomposed, stable, weed free organic matter source d erived from waste
materials including yard debris, wood wastes, or other organic materials not including manure or
biosolids meeting standards developed by the US Composting Council (USCC). The product shall be
certified through the USCC Seal of Testing Assurance (STA) Program (a compost testing and
information disclosure program). Compost quality should be verified via a lab analysis to be:
Feedstock materials shall be specified and include one or more of the following: landscape/yard
trimmings, grass clippings, food scraps, and agricultural crop residues.
Organic matter: 35-75% dry weight basis.
Carbon and Nitrogen Ratio: 15:1 < C:N < 25:1
Maturity/Stability: shall have dark brown color and a soil-like odor. Compost exhibiting a sour or
putrid smell, containing recognizable grass or leaves, or is hot (120 F) upon delivery or rewetting
is not acceptable.
Toxicity: any one of the following measures is sufficient to indicate non-toxicity:
o NH4:NH3 < 3
o Ammonium < 500 ppm, dry weight basis
o Seed Germination > 80% of control
o Plant trials > 80% of control
Solvita® > 5 index value
Nutrient content:
o Total Nitrogen content 0.9% or above preferred
o Total Boron should be <80 ppm, soluble boron < 2.5 ppm
Salinity: < 6.0 mmhos/cm
pH between 6.5 and 8 (may vary with plant palette)
Compost for bioretention should be analyzed by an accredited lab using #200, ¼ inch, ½ inch,
and 1 inch sieves (ASTM D 422 or as approved by the local permitting authority) and meet the
following gradation:
Sieve Size (ASTM D422)
% Passing (by weight)
Minimum Maximum
1 inch 99 100
½ inch 90 100
¼ inch 40 90
#200 2 10
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XIV-17 December 20, 2013
Tests should be sufficiently recent to represent the actual material that is anticipated to be
delivered to the site. If processes or sources used by the supplier have chang ed significantly
since the most recent testing, new tests should be requested.
Note: the gradation of compost used in bioretention media is believed to play an important role in
the saturated hydraulic conductivity of the media. To achieve a higher saturat ed hydraulic
conductivity, it may be necessary to utilize compost at the coarser end of this range (“minimum”
column). The percent passing the #200 sieve (fines) is believed to be the most important factor in
hydraulic conductivity. In addition, a coarser compost mix provides more heterogeneity of the
bioretention media, which is believed to be advantageous for more rapid development of soil
structure needed to support health biological processes. This may be an advantage for plant
establishment with lower nutrient and water input.
Mulch
Planting area should generally be covered with 2 to 4 inches (average 3 inches) of mulch at the
start and an additional placement of 1 to 2 inches of mulch should be added annually. The
intention is that to help sustain the nutrient levels, suppress weeds, retain moisture, and maintain
infiltration capacity.
For nutrient-sensitive planting/storage media design, inorganic mulch such as gravel, may be
used.
Planting/Storage Media Design for Nutrient Sensitive Receiving Waters
Where the BMP discharges to receiving waters with nutrient impairments or nutrient TMDLs, the planting
media placed should be designed with the specific goal of minimizing the potential for initial and long
term leaching of nutrients from the media.
In general, the potential for leaching of nutrients can be minimized by:
o Utilizing stable, aged compost (as required of media mixes under all conditions).
o Utilizing other sources of organic matter, as appropriate, that are safe, non-toxic, and have
lower potential for nutrient leaching than compost.
o Reducing the content of compost or other organic material in the media mix to the minimum
amount necessary to support vigorous plant growth and healthy biological processes.
A landscape architect should be consulted to assist in the design of planting/storage media to
balance the interests of plant establishment, water retention capacity (irrigation demand), and the
potential for nutrient leaching. The following practices should be considered in developing the
media mix design:
o The actual nutrient content and organic content of the selected compost source should
be considered when specifying the proportions of compost and sand. The compost
specification allows a range of organic content over approximately a factor of 2 and
nutrient content may vary more widely. Therefore determining the actual organic content
and nutrient content of the compost expected to be supplied is important in determining
the proportion to be used for amendment.
o A commitment to periodic soil testing for nutrient content and a commitment to adaptive
management of nutrient levels can help reduce the amount of organic amendment that
must be provided initially. Generally, nutrients can be added planting areas through the
addition of organic mulch, but cannot be removed.
o Plant palettes and the associated planting mix should be designed with native plants
where possible. Native plants generally have a broader tolerance for nutrient content, and
can be longer lived in leaner/lower nutrient soils. An additional benefit of lower nutrient
levels is that native plants will generally have less competition from weeds.
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XIV-18 December 20, 2013
o Nutrients are better retained in soils with higher cation exchange capacity (CEC). CEC
can be increased through selection of organic material with naturally high CEC, such as
peat, and/or selection of inorganic material with high CEC such as some sands or
engineered minerals (e.g., low P-index sands, zeolites, rhyolites, etc). Including higher
CEC materials would tend to reduce the net leaching of nutrients.
o Soil structure can be more important than nutrient content in plant survival and biologic
health of the system. If a good soil structure can be created with very low amounts of
compost, plants survivability should still be provided. Soil structure is loosely defined as
the ability of the soil to conduct and store water and nutrients as well as the degree of
aeration of the soil. While soil structure generally develops with time, planting/storage
media can be designed to promote earlier development of soil structure. Soil structure is
enhanced by the use of amendments with high hummus content (as found in well-aged
organic material). In addition, soil structure can be enhanced through the use of
compost/organic material with a distribution of particle sizes (i.e., a more heterogeneous
mix). Finally, inorganic amendments such as polymer beads may be useful for promoting
aeration and moisture retention associated with a good soil structure. An example of
engineered soil to promote soil structure can be found here:
http://www.hort.cornell.edu/uhi/outreach/pdfs/custructuralsoilwebpdf.pdf
o Younger plants are generally more tolerant of lower nutrient levels and tend to help
develop soil structure as they grow. Starting plants from smaller transplants can help
reduce the need for organic amendments and improve soil structure. The project should
be able to accept a plant mortality rate that is somewhat higher than starting from larger
plants and providing high organic content.
With these considerations, it is anticipated that less than 10 percent compost amendment could
be used, while still balancing plant survivability and water retention.
We wish to express our gratitude to following individuals for their feedback on the design of
planting/storage media for nutrient sensitive receiving waters in Southern California.
Deborah Deets, City of Los Angeles Bureau of Sanitation
Drew Ready, LA and San Gabriel Rivers Watershed Council
Rick Fisher, ASLA, City of Los Angeles Bureau of Engineering
Dr. Garn Wallace, Wallace Laboratories
Glen Dake, GDML
Jason Schmidt, Tree People
The guidance provided herein does not reflect the individual opinions of any individual listed above and
should not be cited or otherwise attributed to those listed.
Selecting Plants for Planting/Storage Media
Plant materials should be tolerant of summer drought, ponding fluctuations, and saturated soil
conditions for 48 to 96 hours.
It is recommended that a minimum of three types of tree, shrubs, and/or herbaceous groundcover
species be incorporated to protect against facility failure due to disease and insect infestations of
a single species.
Native plant species and/or hardy cultivars that are not invasive and do not require chemical
inputs should be used to the maximum extent feasible.
SHORECLIFFN46°25'51"E 74.99'N02°15'35"E 253.41'25.18'N04°01'25"E239.25'L=54.64'Δ=14°43'50"R=175.00' L=44.99'CPROPOSED RESIDENCEFF=72.50146 SFBIORETENTIONPLANTER (18"DEEP)106 SFBIORETENTIONPLANTER (18"DEEP)A-112,927 SF(9,931 IMP)BENTLEY RESIDENCEPROJECT: 19027 | DATE: SEPTEMBER 4, 2019WATER QUALITY MANAGEMENT PLAN FOR119 SHORECLIFF DRIVE, CORONA DEL MARNOTES:1.SOIL AND VEGETATION TO BE INCORPORATED SHALL BE SELECTED BY THE PROJECT'S LANDSCAPE ARCHITECT.DROUGHT AND FLOOD RESISTANT PLANT SPECIES NATIVE TO SOUTHERN CALIFORNIA SHOULD BE SELECTED WHENPOSSIBLE. SOIL MEDIA SHOULD FACILITATE VIGOROUS PLANT GROWTH AND NOT RESTRICT PERFORMANCEREQUIREMENTS. REFER TO TECHNICAL GUIDANCE DOCUMENT FACT SHEET MISC-1 FOR ADDITIONAL INFORMATION.2.UNIFORM MIX OF SAND AND ORGANIC MATERIAL (COMPOST) MINIMUM INFILTRATION RATE 5" PER HOUR.3.PERFORATED PIPE SHALL BE 1" FROM BOTTOM OF FACILITY.LONGITUDINAL 4" DIAMETERWIDTH = 4.65'6"PERFORATED COLLECTION PIPEWATER PROOFINGON SIDES AND BOTTOM3" LAYER OFMULCH OR COBBLEPLANTING PERLANDSCAPE PLANPER LANDSCAPE PLANDRAINS TO STREET24"
SEE NOTES 1 & 2WASHEDSLOPING TO DRAINBIO-1: BIORETENTION W/UNDERDRAINSSECTION VIEW | NO SCALEDRAIN INLET FOROVERFLOW. ELEV PER PLANPLANTER BOXELEVATION PERPLANGRAVEL30 MIL MIN THICKNEESSDRAIN PIPEPER GRADINGPLAN SHEET C3WATER SURFACEELEVATIONP=VARIESPIPE OUTLET ABOVESURFACE OF BASIN(INV PER PLAN)LEGENDSUB-AREA DELINEATIONBIORETENTION AREALANDSCAPE AREASUB-AREA DESIGNATIONSUB-AREA SQUARE FOOTAGEA-52,786 SF(1,786 IMP)IMPERVIOUS AREASUB-AREA IMPERVIOUS SQUARE FOOTAGE