HomeMy WebLinkAboutORD 11(2013)ORDINANCE NO. 11 (2013)
AN ORDINANCE OF THE CITY COUNCIL OF THE CITY
OF DIAMOND BAR, CALIFORNIA, AMENDING DIVISION
5 OF CHAPTER 8.12 OF THE DIAMOND BAR MUNICIPAL
CODE RELATING TO STANDARD URBAN STORM
WATER MITIGATION PLAN (SUSMP) REQUIREMENTS
BY IMPOSING RAINWATER LOW IMPACT
DEVELOPMENT (LID) STRATEGIES ON PROJECTS
THAT REQUIRE BUILDING, GRADING AND
ENCROACHMENT PERMITS
THE CITY COUNCIL OF THE CITY OF DIAMOND BAR, CALIFORNIA,
HEREBY FINDS AND DETERMINES AS FOLLOWS:
A. The federal Clean Water Act establishes Regional Water Quality
Control Boards in order to prohibit the discharge of pollutants in stormwater runoff to
waters of the United States.
B. The City is a permittee under the permit issued by the California
Regional Water Quality Control Board, Los Angeles Region Order No. R4-2012-0175,
on_November_ 08,_20'L2whic1i_per_mitestablisties_Waste__ Discharge__ Requirements for
-- - -- -----
Municipal Separate Storm Sewer Systems (MS4) Discharges within the Coastal
Watersheds of Los Angeles County, except discharges originating from the City of Long
Beach MS4.
C. Order No. R4-2012-0175 ("Order") contains requirements for the
City to establish a Low Impact Development (LID) Ordinance in order to participate in a
Watershed Management Program and/or Enhanced Watershed Management Program.
D. The Regional Board has adopted Total Maximum Daily Loads
(TMDLs) for pollutants which are numerical discharge limits that must be achieved
effectively through LID implementation.
E. The City has the authority under the California Water Code to adopt
and enforce ordinances imposing conditions, restrictions and limitations with respect to
activity that might degrade waters of the State.
F. The City has a stormwater management program that protects
water quality and water supply by employing watershed -based approaches that balance
environmental and economic considerations.
G. Urbanization has led to increased impervious surface areas
resulting in increased water runoff and less percolation to groundwater aquifers causing
the transport of pollutants to downstream receiving waters.
H. As required by the Order the City is expanding the applicability of
the existing LID requirements by providing stormwater and rainwater LID strategies for
all projects development and redevelopment projects.
1
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF DIAMOND BAR,
CALIFORNIA, DOES HEREBY ORDAIN AS FOLLOWS:
Section 1: Subsection (d) of Section 8.12.1620 entitled "Findings", is deleted in its
entirety and replaced with the following:
"(d) The City is a permittee under the permit issued by the California Regional
Water Quality Control Board, Los Angeles Region Order No. R44-2012-0175, on
November 08, 2012, which permit establishes Waste Discharge Requirements for
Municipal Separate Storm Sewer Systems (MS4) Discharges within the Coastal
Watersheds of Los Angeles County, except discharges originating from the City of Long
Beach MS4 and as a permittee the City is required to implement procedures with
respect to the entry of specifiedwater discharges into the municipal storm water
system."
Section 2: Section 8.12.1640 entitled "Definitions", is amended to add or replace the
following definitions, which definitions shall be placed in alphabetical order along with
the existing definitions of Section 8.12.1640. The following existing definitions in
Section 8.12.1640 shall be deleted in their entirety: Automotive service facilities, Best
Management Practice, Construction, Discharge, Municipal NPDES Permit, Municipal
Separate Storm Sewer System or MS4, Parking lot, Pollutant, Project, Redevelopment,
Standard Urban Storm Water Mitigation Plan or SUSMP and Urban runoff. If the
definition of any term contained in Section 8.12.1640 conflicts with the definition of the
same term in Order No. R4-2012-0175, then the definition contained in Order No. R4-
2012-0175 shall govern.
Automotive Service Facility means a facility that is categorized in any one
of the following Standard Industrial Classification (SIC) and North American Industry
Classification System (NAICS) codes. For inspection purposes, Permittees need not
inspect facilities with SIC codes 5013, 5014, 5511, 5541, 7532-7534, and 7536-7539
provided that these facilities have no outside activities or materials that may be exposed
to stormwater.
Basin Plan means the Water Quality Control Plan, Los Angeles Region,
Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties, adopted
by the Regional Water Board on June 13, 1994 and subsequent amendments.
Best Management Practice (BMP) means practices or physical devices or
systems designed to prevent or reduce pollutant loading from stormwater or non-
stormwater discharges to receiving waters, or designed to reduce the volume of
stormwater or non-stormwater discharged to the receiving water.
Biofiltration means a LID BMP that reduces stormwater pollutant
discharges by intercepting rainfall on vegetative canopy, and through incidental
infiltration and/or evapotranspiration, and filtration. Incidental infiltration is an important
factor in achieving the required pollutant load reduction. Therefore, the term
"biofiltration" as used in this Chapter 8.12 is defined to include only systems designed to
facilitate incidental infiltration or achieve the equivalent pollutant reduction as
biofiltration BMPs with an underdrain (subject to approval by the Regional Board's
2
Executive Officer). Biofiltration BMPs include bioretention systems with an underdrain
and bioswales.
Bioretention means a LID BMP that reduces stormwater runoff by
intercepting rainfall on vegetative canopy, and through evapotranspiration and
infiltration. The bioretention system typically includes a minimum 2 -foot top layer of a
specified soil and compost mixture underlain by a gravel -filled temporary storage pit dug
into the in-situ soil. As defined in this Ordinance, a bioretention BMP may be designed
with an overflow drain, but may not include an underdrain. When a bioretention BMP is
designed or constructed with an underdrain it is regulated by Order No. R4-2012-0175
as biofiltration.
Bioswale means a LID BMP consisting of a shallow channel lined with
grass or other dense, low -growing vegetation. Bioswales are designed to collect
stormwater runoff and to achieve a uniform sheet flow through the dense vegetation for
a period of several minutes.
Commercial Malls means any development on private land comprised of
one or more buildings forming a complex of stores which sells various merchandise,
with interconnecting walkways enabling visitors to easily walk from store to store, along
with parking area(s). A commercial mall includes, but is not limited to: mini -malls, strip
other retad complexes, arra-enclosed-shoppiirrgnulls-orshoppbecenter�-_-_ _-- -- --- __-
Construction Activity means any construction or demolition activity,
clearing, grading, grubbing, or excavation or any other activity that result in land
disturbance. Construction does not include emergency construction activities required to
immediately protect public health and safety or routine maintenance activities required
to maintain the integrity of structures by performing minor repair and restoration work,
maintain the original line and grade, hydraulic capacity, or original purposes of the
facility. See "Routine Maintenance" definition for further explanation. Where clearing,
grading or excavating of underlying soil takes place during a repaving operation, State
General Construction, Permit coverage by the State of California General Permit for
Storm Water Discharges Associated with Industrial Activities or for Stormwater
Discharges Associated with Construction Activities is required if more than one acre is
disturbed or the activities are part of a larger plan.
Discharge means any release, spill, leak, pump, flow, escape, dumping, or
disposal of any liquid, semi-solid, or solid substance.
Flow-through treatment BMPs means a modular, vault type "high flow
biotreatment" devices contained within an impervious vault with an underdrain or
designed with an impervious liner and an underdrain.
Full Capture System means any single device or series of devices,
certified by the Executive Officer, that traps all particles retained by a 5 mm mesh
screen and has a design treatment capacity of not less than the peak flow rate Q
resulting from a one-year, one-hour storm in the sub -drainage area.
General Construction Activities Storm Water Permit (GCASP) means the
general NPDES permit adopted by the State Board which authorizes the discharge of
stormwater from construction activities under certain conditions.
General Industrial Activities Storm Water Permit (GIASP) means the
general NPDES permit adopted by the State Board which authorizes the discharge of
stormwater from certain industrial activities under certain conditions.
Green Roof means a LID BMP using planter boxes and vegetation to
intercept rainfall on the roof surface. Rainfall is intercepted by vegetation leaves and
through evapotranspiration. Green roofs may be designed as either a bioretention BMP
or as a biofiltration BMP. To receive credit as a bioretention BMP, the green roof system
planting medium shall be of sufficient depth to provide capacity within the pore space
volume to contain the design storm depth and may not be designed or constructed with
an underdrain.
Industrial/Commercial Facility means any facility involved and/or used in
the production, manufacture, storage, transportation, distribution, exchange or sale of
goods and/or commodities, and any facility involved and/or used in providing
professional and non-professional services. This category of facilities includes, but is
not limited to, any facility defined by either the Standard Industrial Classifications (SIC)
or the North American Industry Classification System (NAICS). Facility ownership
(federal, state, municipal, private) and profit motive of the facility are not factors in this
definition).
Industrial Park means land development that is set aside for industrial
development. Industrial parks are usually located close to transport facilities, especially
where more than one transport modalities coincide: highways, railroads, airports, and
navigable rivers. It includes office parks, which have offices and light industry.
Infiltration BMP means a LID BMP that reduces stormwater runoff by
capturing and infiltrating the runoff into in-situ soils or amended onsite soils. Examples
of infiltration BMPs include infiltration basins, dry wells, and pervious pavement.
Low Impact Development (LID) consists of building and landscape
features designed to retain or filter stormwater runoff.
Municipal Separate Storm Sewer System (MS4) means a conveyance or
system of conveyances (including roads with drainage systems, municipal streets, catch
basins, curbs, gutters, ditches, manmade channels, or storm drains):
(i) Owned or operated by a State, city, town, borough, county, parish,
district, association, or other public body (created by or pursuant to
State law) having jurisdiction over disposal of sewage, industrial
wastes, stormwater, or other wastes, including special districts
under State law such as a sewer district, flood control district or
drainage district, or similar entity, or an Indian tribe or an authorized
Indian tribal organization, or a designated and approved
management agency under section 208 of the CWA that
discharges to waters of the United States,
Designed or used for collecting or conveying stormwater;
Which is not a combined sewer; and
4
(iv) Which is not part of a Publicly Owned Treatment Works (POTW) as
defined at 40 CFR Section 122.2.
(40 CFR Section 122.26(b) (8)).
National Pollutant Discharge Elimination System (NPDES) means the
national program for issuing, modifying, revoking and reissuing, terminating, monitoring
and enforcing permits, and imposing and enforcing pretreatment requirements, under
CWA Section 307, 402, 318, and 405. The term includes an "approved program".
Natural Drainage System means a drainage system that has not been
improved (e.g., channelized or armored). The clearing or dredging of a natural drainage
system does not cause the system to be classified as an improved drainage system.
Outfall means a point source as defined by 40 CFR 122.2 at the point
where a municipal separate storm sewer discharges to waters of the United States and
does not include open conveyances connecting two municipal separate storm sewers,
or pipes, tunnels or other conveyances with connect segments of the same stream or
other waters of the United Sates and are used to convey waters of the United States.
(40 CFR Section 122.26(b) (9)).
cility for the parking or storage of motor
vehicles used for businesses, commerce, industry, or personal use, with a lot size of
5,000 square feet or more of surface area, or with 25 or more parking spaces.
Pollutant means any "pollutant" defined in Section 502(6) of the Federal
Clean Water Act or incorporated into the California Water Code Section 1337.
Project means all development, redevelopment, and land disturbing
activities. The term is not limited to "Project" as defined under CEQA (Pub. Resources
Code Section 21065).
Rainfall Harvest and Use means a LID BMP system designed to capture
runoff, typically from a roof but can also include runoff capture from elsewhere within the
site, and to provide for temporary storage until the harvested water can be used for
irrigation or non -potable uses. The harvested water may also be used for potable water
uses if the system includes disinfection treatment and is approved for such use by the
local building department.
Receiving Water means "water of the United States" into which waste
and/or pollutants are or may be discharged.
Redevelopment means land -disturbing activity that results in the creation,
addition, or replacement of 5,000 square feet or more of impervious surface area on an
already developed site. Redevelopment includes, but is not limited to: the expansion of
a building footprint; addition or replacement of a structure; replacement of impervious
surface area that is not part of routine maintenance activity; and land disturbing activity
related to structural or impervious surfaces. It does not include routine maintenance to
maintain original line and grade, hydraulic capacity, or original purpose of facility, nor
does it include emergency construction activities required to immediately protect public
health and safety.
Routine Maintenance" includes, but is not limited to projects conducted to:
1. Maintain the original line and grade, hydraulic capacity, or original
purpose of the facility.
2. Perform as needed restoration work to preserve the original design
grade, integrity and hydraulic capacity of flood control facilities.
3. Includes road shoulder work, regrading dirt or gravel roadways and
shoulders and performing ditch cleanouts.
4. Update existing lines* and facilities to comply with applicable codes,
standards, and regulations regardless if such projects result in
increased capacity.
5. Repair leaks
Routine maintenance does not include construction of new** lines or
facilities resulting from compliance with applicable codes, standards and
regulations.
* Update existing lines includes replacing existing lines with new materials
or pipes.
New lines are those that are not associated with existing facilities and
are not part of a project to update or replace existing lines.
Significant Ecological Areas (SERs) means an area that is determined to
possess an example of biotic resources that cumulatively represent biological diversity,
for the purposes of protecting biotic diversity, as part of the Los Angeles County
General Plan. Areas are designated as SEAS, if they possess one or more of the
following criteria:
1. The habitat of rare, endangered, and threatened plant and animal
species.
2. Biotic communities, vegetative associations, and habitat of plant and
animal species that are either one of a kind, or are restricted in
distribution on a regional basis.
3. Biotic communities, vegetative associations, and habitat of plant and
animal species that are either one of a kind or are restricted in
distribution in Los Angeles County.
4. Habitat that at some point in the life cycle of a species or group of
species, serves as a concentrated breeding, feeding, resting, migrating
grounds and is limited in availability either regionally or within Los
Angeles County.
5. Biotic resources that are of scientific interest because they are either
an extreme in physical/geographical limitations, or represent an
unusual variation in a population or community.
6. Areas important as game species habitat or as fisheries.
7. Areas that would provide for the preservation of relatively undisturbed
examples of natural biotic communities in Los Angeles County.
R
S. Special areas.
Storm Drain System means any facility or any parts of the facility,
including streets, gutters, conduits, natural or artificial drains, channels and watercourse
that are used for the purpose of collecting, storing, transporting or disposing of
stormwater and are located within the City.
Storm Water or Stormwater means runoff and drainage related to
precipitation events (pursuant to 40 CFR Section 122.26(b)(13); 55 Fed. Reg. 47990,
47995 (Nov. 16, 1990)),
Urban Runoff means surface water flow produced by storm and non -storm
events. Non -storm events include flow from residential, commercial or industrial
activities involving the use of potable and non -potable water."
Section 3: The second sentence of Section 8.12.1690(b) is amended to read as
follows:
"The following shall apply to all construction activities within the City not
otherwise governed by Section 8.12.1695 of this Code and such construction activities
shall be required from the time of land clearing, demolition or commencement of
construction until receipt of a certificate of occupancy:"
Section 4: Section 8.12.1695, entitled "Standard Urban Storm Water Mitigation Plan
((SUSMP"), is deleted in its entirety and replaced with the following:
"Section 8.12.1695. — Low Impact Development Measures for New Development and/or
Redevelopment Planning and Construction Activities.
(a) Objective. The provisions of this Section establish requirements for construction
activities and facility operations of Development and Redevelopment projects to
comply with the current "Order No. R4-2012-0175," lessen the water quality impacts
of development by using smart growth practices, and integrate LID practices and
standards for stormwater pollution mitigation through means of infiltration,
evapotranspiration, biofiltration, and rainfall harvest and use. LID shall be inclusive
of new development and/or redevelopment requirements.
(b) Scope. This Section contains requirements for stormwater pollution control
measures in Development and Redevelopment projects and authorizes the City to
further define and adopt stormwater pollution control measures, and to develop LID
principles and requirements, including but not limited to the objectives and
specifications for integration of LID strategies, grant waivers from the LID
requirements, and collect funds for Projects that are granted waivers. Except as
otherwise provided herein, the City shall administer, implement and enforce the
provisions of this Section.
(c) Applicability. Development projects subject to Permittee conditioning and
approval for the design and implementation of post -construction controls to mitigate
storm water pollution, prior to completion of the project(s), are:
(1) All development projects equal to 1 acre or greater of disturbed area that
adds more than 10,000 square feet of impervious surface area.
(2) Industrial parks 10,000 square feet or more of surface area.
(3) Commercial malls 10,000 square feet or more of surface area.
(4) Retail gasoline outlets with 5,000 square feet or more of surface area.
(5) Restaurants (Standard Industrial Classification (SIC) of 5812) with 5,000
. square feet or more of surface area.
(6) Parking lots with 5,000 square feet or more of impervious surface area, or
with 25 or more parking spaces.
(7) Streets and roads construction of 10,000 square feet or more of impervious
surface area. Street and road construction applies to standalone streets,
roads, highways, and freeway projects, and also applies to streets within
larger projects.
(8) Automotive service facilities (Standard Industrial Classification (SIC) of 5013,
5014, 5511, 5541, 7532-7534 and 7536-7539) 5,000 square feet or more of
surface area.
(9) Projects located in or directly adjacent to, or discharging directly to an
Environmentally Sensitive Area (ESA), where the development will:
a. Discharge stormwater runoff that is likely to impact a sensitive biological
species or habitat; and
b. Create 2,500 square feet or more of impervious surface area
(10) Single-family hillside homes.
(11) Redevelopment Projects
a. Land disturbing activity that results in the creation or addition or
replacement of 5,000 square feet or more of impervious surface area on
an already developed site on Planning Priority Project categories.
b. Where Redevelopment results in an alteration to more than fifty percent of
impervious surfaces of a previously existing development, and the existing
development was not subject to post -construction stormwater quality
control requirements, the entire project must be mitigated.
c. Where Redevelopment results in an alteration of less than fifty percent of
impervious surfaces of a previously existing development, and the existing
development was not subject to post -construction stormwater quality
control requirements, only the alteration must be mitigated, and not the
entire development.
d. Redevelopment does not include routine maintenance activities that are
conducted to maintain original line and grade, hydraulic capacity, original
purpose of facility or emergency redevelopment activity required to protect
public health and safety. Impervious surface replacement, such as the
reconstruction of parking lots and roadways which does not disturb
additional area and maintains the original grade and alignment, is
0
considered a routine maintenance activity. Redevelopment does not
include the repaving of existing roads to maintain original line and grade.
e.. Existing single-family dwelling and accessory structures are exempt from
the Redevelopment requirements unless such projects create, add, or
replace 10,000 square feet of impervious surface area.
(d) Effective Date. The Planning and Land Development requirements contained in
Section 7 of Order No. R4-2012-0175 shall become effective 90 days from the
adoption of the Order (February 6, 2013). This includes Planning Priority Projects
that are discretionary permit projects or project phases that have not been deemed
complete for processing, or discretionary permit projects without vesting tentative
maps that have not requested and received an extension of previously granted
approvals within 90 days of adoption of the Order. Projects that have been deemed
complete within 90 days of adoption of the Order are not subject to the requirements
of Section 7.
(e) Specific Requirements. The Site for every Project shall be designed to control
pollutants, pollutant loads, and runoff volume to the maximum extent feasible by
minimizing impervious surface area and controlling runoff from impervious surfaces
through infiltration, evapotranspiration, bioretention and/or rainfall harvest and use.
(1) A new single-family hillside home development shall include mitigation
measures to:
a. Conserve natural areas;
b. Protect slopes and channels;
c.' Provide storm drain system stenciling and signage;
d. Divert roof runoff to vegetated areas before discharge unless the diversion
would result in slope instability; and
e. Direct surface flow to vegetated areas before discharge, unless the
diversion would result in slope instability.
(2) Street and road construction of 10,000 square feet or more of impervious
surface shall follow USEPA guidance regarding Managing Wet Weather with
Green Infrastructure: Green Streets (December 2008 EPA -833-F-08-009) to
the maximum extent practicable.
(3) The remainder of Projects shall prepare a LID Plan to comply with the
following:
a. Retain stormwater runoff onsite for the Stormwater Quality Design Volume
(SWQDv) defined as the runoff from:
i. The 85th percentile 24-hour runoff event as determined from the Los
Angeles County 85th percentile precipitation isohyetal map; or
ii. The volume of runoff produced from a 0.75 inch, 24-hour rain event,
whichever is greater.
9
b. Minimize hydromodification impacts to natural drainage systems as defined
in Order No. R4-2012-0175.
G. To demonstrate technical infeasibility, the project applicant must
demonstrate that the Project cannot reliably retain 100 percent of the
SWQDv on-site, even with the maximum application of green roofs and
rainwater harvest and use, and that compliance with the applicable post -
construction requirements would be technically infeasible by submitting a
site-specific hydrologic and/or design analysis conducted and endorsed by
a registered professional engineer, geologist, architect, and/or landscape
architect. Technical infeasibility may result from conditions including the
following:
i. The infiltration rate of saturated in-situ soils is less than 0.3 inch per
hour and it is not technically feasible to amend the in-situ soils to attain
an infiltration rate necessary to achieve reliable performance of
infiltration or bioretention BMPs in retaining the SWQDv onsite.
ii. Locations where seasonal high groundwater is within five to ten feet of
surface grade;
iii. Locations within 100 feet of a groundwater well used for drinking water;
iv. Brownfield development sites or other locations where pollutant
mobilization is a documented concern;
V. Locations with potential geotechnical hazards;
vi. Smart growth and infill or redevelopment locations where the density
and/ or nature of the project would create significant difficulty for
compliance with the onsite volume retention requirement.
d. If partial or complete onsite retention is technically infeasible, the project
Site may biofiltrate 1.5 times the portion of the remaining SWQDv that is
not reliably retained onsite. Biofiltration BMPs must adhere to the design
specifications provided in Order No. R4-2012-0175.
i. Additional alternative compliance options such as offsite infiltration and
groundwater replenishment projects may be available to the project
Site. The Project Site should contact the City to determine eligibility.
e. The remaining SWQDv that cannot be retained or biofiltered onsite must be
treated onsite to reduce pollutant loading. BMPs must be selected and
designed to meet pollutant -specific benchmarks as required per Order No.
R4-2012-0175. Plow -through BMPs may be used to treat the remaining
SWQDv and must be sized based on a rainfall intensity of:
0.2 inches per hour, or
The one year, one-hour rainfall intensity as determined from the most
recent Los Angeles County isohyetal map, whichever is greater."
Section 5: VALIDITY. If any provision of this Ordinance is found to be unconstitutional
or otherwise invalid by any court of competent jurisdiction, such invalidity shall not affect
10
the remaining provisions of this Ordinance which provisions are declared to be
severable from those found to be unconstitutional or otherwise invalid.
Section 6: EFFECTIVE DATE. This ordinance shall go into effect and be in full force
and operation from and after thirty (30) days after its final passage and adoption.
Section 7: The City Clerk shall certify to the passage and adoption of this Ordinance
and shall post a certified copy of this Ordinance, together with the vote for and against
the same, in the Office of the City Clerk.
PASSED, APPROVED AND ADOPTED THIS 5th DAY OF November , BY
THE CITY COUNCIL OF THE CITY OF DIAMOND BAR.
Jack Tanaka, Mayor
I, Tommye Cribbins, City Clerk of the City of Diamond Bar, do hereby certify that the
foregoing Ordinance was duly introduced at a regular meeting of the City Council of the
City of Diamond Bar held on the 15t4lay ofQc_t _ , 2013 and was finally passed at a
regular meeting of the City Council held on the 5t�h day of c)c 2013, by the following
vote-,
AYES: Council Members: Chang, Herrera, Tye,
MPT/Everett, M/Tanaka
NOES: Council Members: None
ABSENT: Council Members: None
ABSTAIN: Council Members: None
ATTEST:y —�
Tommye Cribbins, City Clerk
City of Diamond Bar
11
