Chico Municipal Code Ch. 15.50 Storm Water Management and Discharge Controls

The purposes of this chapter are:

A. To protect and enhance the water quality of the City’s watercourses, water bodies and wetlands pursuant to, and consistent with, the federal Water Pollution Control Act (Clean Water Act) (33 U.S.C. § 1251 et seq.), the Porter-Cologne Water Quality Control Act (Wat. Code § 13000 et seq.) and the City’s National Pollutant Discharge Elimination System (NPDES) permit, as such permit is amended and/or renewed by the California Regional Water Quality Control Board (Regional Board).

B. To protect and promote the health, safety and general welfare of the citizens of the City by prescribing regulations to effectively prohibit non-storm water discharges to the City’s storm drain system and to reduce the discharge of pollutants in storm water to the maximum extent practicable by:

1. Regulating non-storm water discharges to the City’s storm drain system;

2. Controlling the discharge to the City’s storm drain system from spills, overland flow, dumping or disposal of materials other than storm water;

3. Reducing pollutants in storm water discharges from the City’s storm drain system to the maximum extent practicable;

4. Minimizing degradation of the water quality of watercourses and the disruption or pollution of natural or City-authorized drainage flows caused by the activities of clearing and grubbing, grading, filling and excavating of land, as well as sediment and pollutant run off from other construction-related activities; and

5. Controlling industrial and commercial pollutant discharges to the City’s storm drain system.

The following words and phrases, when used in this chapter, shall have the following meanings. Words and phrases used in this chapter and not otherwise defined shall be interpreted as defined in the regulations of the United States Environmental Protection Agency to implement the provisions of the federal Clean Water Act and as defined by the California Water Resources Control Board to implement the Porter- Cologne Water Quality Control Act.

A. “Best management practices” or “BMPs” means physical, structural and/or managerial practice that when used singly or in combination, prevent or reduce pollution of storm water.

B. “Construction site” means any project, including projects requiring coverage under the general construction permit, that involves soil disturbing activities including, but not limited to, clearing, grading, paving, disturbances to ground such as stockpiling, and excavation.

C. “Development or project” means any construction activity or alteration of the landscape, its terrain, contour or vegetation, including the erection or alteration of single or multiple structures, and any grading.

D. “Director” means the director of public works - engineering or his or her designee who is authorized to enforce compliance with this chapter.

E. “Direct discharge” means a discharge that is routed directly to waters of the United States by means of a pipe, channel, or ditch including through the storm sewer system, or through surface runoff.

F. “Discharge” means any release, spill, leak, pumping, flow, escape or leaching, including subsurface migration to groundwater, dumping or disposal of any gas, liquid, semi-solid or solid substance, whether accidental or intentional.

G. “Discharge of a pollutant” means the addition of any pollutant or combination of pollutants to waters of the United States from any point source. The term includes additions of pollutants to waters of the United States from: surface runoff which is collected or channeled by man; discharges through pipes, sewers, or other conveyances owned by a state, municipality, or other person which do not lead to a treatment works; and discharges through pipes, sewers, or other conveyances, leading into privately owned treatment works.

H. “Illicit discharge” means any discharge to the storm drain system that is prohibited under local, state, or federal statutes, ordinances, codes or regulations that is not composed entirely of storm water except discharges pursuant to a NPDES permit or discharges excepted under Section 15.50.050 of this chapter.

I. “Incidental runoff” is unintended amounts (volume) of runoff, such as unintended, minimal over-spray from sprinklers that escapes the area of intended use. Water leaving an intended use area is not considered incidental if it is part of the facility design, if it is due to excessive application, if it is due to intentional overflow or application, or if it is due to negligence.

J. “Linear underground/overhead projects (LUPs)” means any conveyance, pipe, or pipeline for the transportation of any gaseous, liquid (including water and wastewater for domestic municipal services), liquescent, or slurry substance; and cable line or wire for the transmission of electrical energy; and cable line or wire for communications (e.g. telephone, telegraph, radio, or televisions messages); and associated ancillary facilities. Construction activities associated with LUPs include, but are not limited to, (a) those activities necessary for the installation of underground and overhead linear facilities (e.g., conduits, substructures, pipelines, towers, poles, cables, wires, connectors, switching, regulating and transforming equipment, and associated ancillary facilities); and include, but are not limited to, (b) underground utility mark-out, potholing, concrete and asphalt cutting and removal, trenching, excavation, boring and drilling, access road and pole/tower pad and cable/wire pull station, substation construction, substructure installation, construction of tower footings and/or foundations, pole and tower installations, pipeline installations, welding, concrete and/or pavement repair or replacement, and stockpile/borrow locations.

K. “Low impact development” means a sustainable practice that benefits water supply and contributes to water quality protection. Unlike traditional storm water management, which collects and conveys storm water runoff through storm drains, pipes, or other conveyances to a centralized storm water facility, low impact development (LID) takes a different approach by using site design and storm water management to maintain the site’s pre-development runoff rates and volumes. The goal of LID is to mimic a site’s predevelopment hydrology by using design techniques that infiltrate, filter, store, evaporate, and detain runoff close to the source of rainfall.

L. “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, man-made channels, or storm drains): (i) owned or operated by the City of Chico; (ii) designed or used for collecting or conveying storm water; and (iii) which is not part of a publicly owned treatment works as defined at 40 C.F.R. 122.2.

M. “National Pollutant Discharge Elimination System (NPDES) permit” or “NPDES permit” means a discharge permit issued by the State Water Resources Control Board, the Regional Water Quality Control Board or the United States Environmental Protection Agency.

N. “Non-storm water discharge” means any discharge to the storm drain system that is not entirely composed of storm water.

O. “Pollutant” means any contaminant that can degrade the quality of the receiving waters by altering pH, total suspended or settleable solids, biochemical oxygen demand, chemical oxygen demand, nutrients or temperature.

P. “Redevelopment” means land-disturbing activity that results in the creation, addition or replacement of exterior impervious surface area on a site which some past development has occurred. Redevelopment does not include trenching, excavation and resurfacing associated with LUPs; pavement grinding and resurfacing of existing roadways; construction of new sidewalks, pedestrian ramps, or bike lanes on existing roadways; or routine replacement of damaged pavement such as pothole repair or replacement of short, non-contiguous sections of roadway.

Q. “Storm drain system” means a conveyance or system of conveyances owned, operated or controlled by the city designed or used to convey storm water to waters of the United States. The conveyance system may include, but is not limited to, any roads with drainage systems, streets, catch basins, natural and artificial channels, aqueducts, stream beds, gullies, curbs, gutters, ditches, open fields, parking lots, impervious surfaces used for parking, and storm drains.

R. “Storm water” means water that originates from atmospheric moisture (rainfall, hail, snow or snowmelt) that falls onto land, water or other surfaces and any surface flow, runoff or drainage associated with such atmospheric events.

S. “Storm water pollution prevention plan” or “SWPPP” means a plan required by the State Water Resources Control Board, the Regional Water Quality Control Board or the United States Environmental Protection Agency which sets forth the site map, identifies the activities that have the potential to pollute storm water which may enter the city’s storm drain system, describes the proposed BMPs to be implemented by the discharger, and contains a description of any other requirements that the State Water Resources Control Board, the Regional Water Quality Control Board or the United States Environmental Protection Agency requires the discharger to list in the SWPPP.

(Ord. 2439 §111, Ord. 2468 §1)

The city has the legal authority to:

A. Effectively prohibit non-storm water discharges through the municipal separate storm sewer system (MS4). Exceptions to this prohibition are listed under Section 15.50.050.

B. Detect and eliminate illicit discharges and illegal connections to the MS4. Illicit connections include pipes, drains, open channels, or other conveyances that have the potential to allow an illicit discharge to enter the MS4. Illicit discharges include all non-storm water discharges not otherwise authorized in Section 15.50.050, including, but not limited to, discharges from privately owned septic systems; discharges of runoff from material storage areas; discharges from spills; and discharges from organized car washes, mobile cleaning and pressure wash operations.

C. Respond to the discharge of spills, and prohibit dumping or disposal of materials other than storm water into the MS4.

D. Require parties responsible for runoff in excess of incidental runoff to:

• 1. Detect leaks and correct the leaks within 72 hours of learning of the leak;
• 2. Properly design and aim sprinkler heads;
• 3. Not irrigate during precipitation events; and

4. Manage pond containing recycled water such that no discharge occurs unless the discharge is a result of a 25-year, 24-hour storm event or greater, and the appropriate regional water board is notified by email no later than 24 hours after the discharge. The notification is to include identifying information, including the permittee’s name and permit identification number.

E. Require operators of construction sites, new or redeveloped land, and industrial and commercial facilities to minimize the discharge of pollutants to the MS4 through the installation, implementation, or maintenance of best management practices (BMPs) consistent with the California Storm Water Quality Association (CASQA) Best Management Practice Handbooks or equivalent.

F. Require information deemed necessary to assess compliance with this municipal code.

G. Review designs and proposals for new development and redevelopment to determine whether adequate BMPs will be installed, implemented, and maintained during construction and after final stabilization (post construction).

H. Require any discharger, engaged in activities or operations, or owning facilities or property which will or may result in pollutants entering storm water, the storm drain system, or waters of the U.S. to perform all necessary maintenance activities to the storm water control system as prescribed by the operation and maintenance (“O&M”) plan and certificate of responsibility form applicable. If the system is not functioning as designed and permitted, the discharger, engaged in activities or operations, or owning facilities or property must perform the required maintenance immediately to restore the system.

I. Enter private property for the purpose of inspecting, at reasonable times, any facilities, equipment practices, or operations for active or potential storm water discharges, or non-compliance with Chapter 15.

J. Require that dischargers promptly cease and desist discharging and/or cleanup and abate a discharge, including the ability to:

1. Effectively require the discharger to abate and clean up their discharge, spill, or pollutant release within 72 hours of notification; high risk spill should be cleaned up as soon as possible.

2. Require abatement within 30 days of notification, for uncontrolled sources of pollutants that could pose an environmental threat.

3. Perform the clean-up and abatement work and bill the responsible party, if necessary;

4. Provide the option to order the cessation of activities until such problems are adequately addressed if a situation persists where pollutant-causing sources or activities are not abated; and/or

5. Require a new timeframe and notify the Central Valley Regional Water Board when all parties agree that clean-up activities cannot be completed within the original timeframe and notify the Central Valley Regional Water Board in writing within five business days of the determination that the timeframe requires revision.

K. Levy citations or administrative fines against responsible parties either immediately at the site or within a few days.

L. Require recovery and remediating costs from responsible parties.

M. Impose more substantial civil or criminal sanctions and escalate corrective response for persistent non-compliance, repeat or escalating violations, or incidents of major environmental harm.

N. Require compliance with Section 15.50.075 Construction site storm water runoff control.

O. Require compliance with Section 15.50.080 Post construction storm water management.

P. The city has the legal authority to inspect public and private construction projects and conduct enforcement as necessary.

(Ord. 2468 §2)

This chapter shall be administered by the Director and shall be construed to assure consistency with the requirements of the federal Clean Water Act, applicable implementing regulations, and any City NPDES permits as amended, revised or reissued. In the event of any conflict between this chapter and any federal or state law, regulation, order or permit, the requirement that establishes the higher standard for public health or safety shall govern. Nothing in this chapter shall preclude enforcement of any other applicable law, regulation, order or permit. Nothing in this chapter is intended to diminish or preempt the authority of the fire department to investigate, clean-up or abate the effects of any hazardous materials under state law or applicable sections of this code, and any such actions of the fire department shall be in addition to, and not in place of, measures set forth in this chapter.

A. Illicit Discharge. Non-storm water discharges to the City’s storm drain system are prohibited except as specifically permitted under Section 15.50.050.

B. Discharge in Violation of Permit. Any discharge that would result in, or contribute to, a violation of the City’s NPDES permit as amended, revised or reissued, either separately considered or when combined with other discharges, is a violation of this chapter and is prohibited. Liability for any such discharge shall be the responsibility of the person causing or responsible for the discharge as well as the property owner from whose property the discharge occurs or originates. Such responsible persons shall be strictly liable for discharges in violation of the City’s NPDES permit and such persons shall defend, indemnify and hold harmless the City in any administrative or judicial enforcement act relating to such discharge.

The following discharges are exempt from the prohibitions set forth in Section 15.50.040 above:

A. Any discharge regulated under a NPDES permit issued to the discharger provided that the discharger is in compliance with all requirements of the permit and all other applicable laws and regulations.

B. Discharges from the following non-storm water activities unless identified by either the city or the Regional Water Quality Control Board as a significant source of pollutants to waters of the United States:

• 1. Water line flushing;
• 2. Diverted stream flows;
• 3. Rising ground waters;

4. Uncontaminated ground water infiltration (as defined at 40 C.F.R. § 35.2005(20)) to separate storm sewers;

• 5. Uncontaminated pumped ground water;
• 6. Discharges from potable water sources;
• 7. Foundation drains;
• 8. Air conditioning condensation;
• 9. Springs;
• 10. Water from crawl space pumps;
• 11. Footing drains;
• 12. Individual residential car washing;
• 13. Flows from riparian habitats and wetlands;
• 14. Dechlorinated swimming pool discharges;
• 15. Discharges or flows from fire fighting activities;
• 16. City municipal storm drain maintenance line clearing activities; and
• 17. Incidental runoff from landscaped areas (in accordance with below):

a. Discharges in excess of an amount deemed to be incidental runoff shall be controlled.

b. Non-storm water runoff discharge that is not incidental is prohibited, unless otherwise listed above in B.1 - B.17.

c. Incidental runoff may be regulated by waste discharge requirements or, where necessary, waste discharge requirements that serve as a NPDES permit, including MS4 permits.

(Ord. 2468 §3)

Any person subject to a construction activity NPDES storm water discharge permit shall comply with all provisions of such permit. Proof of compliance with the permit shall be submitted to the Director or his or her designee, if so requested. Proof of compliance shall include a copy of the notice of intent (NOI) submitted to the State Water Resources Control Board, the SWPPP for the construction project, and the waste discharge identification (WDID) number provided by the State Water Resources Control Board. Construction activity permits are required for construction projects disturbing one acre or more of land. Construction activities of any size are also subject to the City’s grading regulations at Titles 16 and 16R of this code.

The Director or his or her designee shall, at any time, have the authority to inspect construction sites to ensure compliance with the measures outlined in the SWPPP for the projects and to implement the enforcement measures of this chapter and Chapters 1.12 and 1.14 of this code.

The City will require implementation of BMPs for any activity, operation or facility that may cause or contribute to pollution or the contamination of storm water, the storm drain system or waters of the United States. Where BMP requirements are promulgated by the City or any federal, state or regional agency for any activity, operation or facility which would otherwise cause the discharge of pollutants to the storm drain system or waters of the United States, every person undertaking such activity or operation, or owning or operating such facility, shall comply with such requirements.

A. Applicability. All projects that disturb soil are subject to the construction site storm water runoff control requirements. Projects that disturb one acre or more of soil or disturb less than one acre but are part of a larger common plan or development or sale are subject to the State Water Board’s construction general permit in addition to the construction site storm water runoff control requirements.

B. Construction Plan Review and Approval Procedures.

1. Prior to issuing a grading or building permit, the City of Chico shall require each operator of a construction activity within the city’s jurisdiction to prepare and submit for review and approval an erosion and sediment control plan (ESCP) per the city’s approved ESCP form. The ESCP shall contain appropriate site-specific construction site BMPs that meet the minimum requirements to control storm water pollution due to construction activities. The city holds the right to require additional specific BMPs before approving the ESCP.

a. The storm water pollution prevention plan (SWPPP) developed pursuant to the construction general permit may substitute for the ESCP for projects where a SWPPP is developed. The city holds the right to require additional BMPs before approving the SWPPP.

2. The ESCP shall include the rationale used for selecting BMPs including, if necessary, supporting soil loss calculations. The ESCPs shall contain, as needed, erosion and sediment controls, soil stabilization, dewatering, source controls, and pollution prevention measures per the CASQA Best Management Practices Handbooks or as approved by the city.

3. The ESCP shall list all applicable permits directly associated with any grading activity, including State Water Boards’ construction general permit, State Water Boards’ 401 water quality certification, U.S. Army Corps of Engineers 404 permit, and the California Department of Fish and Wildlife 1600 streambed alteration agreement. The responsible party shall submit evidence to the City of Chico that all permits directly associated with the grading activity have been obtained prior to commencing the soil disturbing activities authorized by the grading permit.

4. Construction sites are subject to Section 15.50.040 Prohibited activities.

C. Construction Site Inspection and Enforcement.

1. The city has the legal authority to inspect public and private construction projects and conduct enforcement as necessary.

(Ord. 2468 §4)

A. Site Design Measures.

1. All projects that create and/or replace (including projects with no net increase in impervious footprint) between 2,500 square feet and 5,000 square feet of impervious surface, including detached single family homes that create and/or replace 2,500 square feet or more of impervious surface and are not part of a larger plan of development are required to implement one or more of the following site design measures to reduce project site runoff:

a. Stream setbacks and buffers – a vegetated area including trees, shrubs, and herbaceous vegetation, that exists or is established to protect a stream system;

b. Soil quality improvement and maintenance – improvement and maintenance soil through soil amendments and creation of microbial community;

c. Tree planting and preservation – planting and preservation of healthy, established trees that include both evergreens and deciduous;

d. Porous pavement – pavement that allows runoff to pass through it, thereby reducing the runoff from a site and surrounding areas and filtering pollutants;

e. Green roofs – a vegetated, open-channel management practice designed specifically to treat and attenuate storm water runoff; and/or

f. Rain barrels and cisterns – system that collects and stores storm water runoff from a roof or other impervious surface.

2. This section is not applicable to linear underground/overhead projects.

3. Project proponents shall use the State Water Board SMARTS post-construction calculator to quantify and submit to the City of Chico the runoff reduction resulting from implementation of site design measures.

4. The plans for the site design measures required in this section shall be stamped by:

a. A California civil professional engineer for rooftop and impervious area disconnections, porous pavement, rain cisterns, bioretention and rain gardens, infiltration trenches, retention or detention basins, or green roofs; and

b. A California landscape architect for soil quality improvements, vegetated swales, or biorentention and rain gardens.

B. Regulated Projects – Projects that create and/or replace 5,000 square feet or more of impervious surface.

1. All projects that create and/or replace 5,000 square feet or more of impervious surface are required to implement measures for site design, source control, runoff reduction, storm water treatment and baseline hydromodification management. These projects are considered regulated projects.

a. Regulated projects do not include detached single family home projects that are not part of a larger plan of development; interior remodels; routine maintenance or repairs such as exterior wall surface replacement or pavement resurfacing within the existing footprint; and LUPs.

i. LUPs that have a discrete location of 5,000 square feet or more of newly constructed contiguous impervious surface are considered a regulated project for that specific discrete location.

2. Regulated projects include development projects. Development includes new and redevelopment projects on public or private land that fall under the permitting authority of the city. Redevelopment is any land-disturbing activity that results in the creation, addition, or replacement of exterior impervious surface area on a site on which some past development has occurred. Redevelopment does not include trenching, excavation and resurfacing associated with LUPs; pavement grinding and resurfacing of existing roadways; construction of new sidewalks, pedestrian ramps, or bike lanes on existing roadways; or routing replacement of damaged pavement such as a pothole repair or replacement of short, non-contiguous sections of roadway. The following describe specific regulated project requirements:

a. Redevelopment Projects –

i. Where a redevelopment project results in an increase of more than 50 percent of the impervious surface of a previously existing development, runoff from the entire project, consisting of all existing, new, and/or replaced impervious surfaces, must be included to the extent feasible.

ii. Where a redevelopment project results in an increase of less than 50 percent of the impervious surface of a previously existing development, only runoff from the new and/or replaced impervious surface of the project must be included.

b. Road Projects and LUPs – Any of the following types of road projects and LUPs that create 5,000 square feet or more of newly constructed contiguous impervious surface and that are public road projects and/or fall under the permitting authority of the city shall comply with Section 15.50.080(D) Low impact development design standards, except that treatment of runoff of the 85th percentile that cannot be infiltrated onsite shall follow U.S. Environmental Protection Agency’s guidance regarding green infrastructure to the extent feasible.

i. Construction of new streets or roads, including sidewalks and bicycle lanes built as part of the new streets or roads.

ii. Widening of existing streets or roads with additional traffic lanes.

a. Where the addition of traffic lanes result in an alteration of more than 50 percent of the impervious surface of an existing street or road, runoff from the entire project, consisting of all existing, new, and/or replaced impervious surfaces, must be included in the treatment system design.

b. Where the addition of traffic lanes result in an alteration of less than 50 percent (but 5,000 square feet or more) of the impervious surface of an existing street or road, only the runoff from new and/or replaced impervious surface of the project must be included in the treatment system design.

iii. Construction of linear underground/overhead projects (LUPs).

iv. Specific exclusions are:

a. Sidewalks built as part of new streets or roads and built to direct storm water runoff to adjacent vegetated areas.

b. Bicycle lanes that are built as part of new streets or roads that direct storm water runoff to adjacent vegetated areas.

c. Impervious trails built to direct storm water runoff to adjacent vegetated areas, or other non-erodible permeable areas, preferably away from creeks or towards the outboard side of levees.

d. Sidewalks, bicycle lanes, or trails constructed with permeable surfaces.

e. Trenching, excavation and resurfacing associated with LUPs; pavement grinding and resurfacing of existing roadways and parking lots; construction of new sidewalks, pedestrian ramps, or bike lanes on existing roadways; or routine replacement of damaged pavement such as pothole repair or replacement of short, non-contiguous sections of roadway.

C. Source Control Measures.

1. Regulated projects with pollutant-generating activities and sources are required to implement standard permanent and/or operation source control measures. The measures for the following pollutant generating activities and sources shall be designed consistent with recommendations from the CASQA Storm Water BMP Handbook for New Development and Redevelopment or equivalent manual:

a. Accidental spills or leaks

b. Interior floor drains

c. Parking/storage areas and maintenance

d. Indoor and structural pest control

e. Landscape/outdoor pesticide use

f. Pools, spas, ponds, decorative fountains, and other water features

g. Restaurants, grocery stores, and other food service operations

h. Refuse areas

i. Industrial processes

j. Outdoor storage of equipment or materials

k. Vehicle and equipment cleaning

l. Vehicle and equipment repair and maintenance

m. Fuel dispensing areas

n. Loading docks

o. Fire sprinkler test water

p. Drain or wash water from boiler drain lines, condensate drain lines, rooftop equipment, drainage sumps, and other sources

q. Unauthorized non-storm water discharges

r. Building and grounds maintenance

D. Low Impact Development (LID) Design Standards – All regulated projects are required to implement LID standards as listed below.

1. Site Assessment – Regulated projects are required to assess and evaluate how site conditions, such as soils, vegetation, and flow paths, will influence the placement of buildings and paved surfaces. The evaluation will be used to meet the goals of capturing and treating runoff and assuring these goals are incorporated into the project design. The following methods are required to be completed to optimize the site layout of the project site:

a. Define the development envelope and protected areas, identifying areas that are most suitable for development and areas to be left undisturbed.

b. Concentrate development on portions of the site with less permeable soils and preserve areas that can promote infiltration.

c. Limit overall impervious coverage of the site with paving and roofs.

d. Set back development from creeks, wetlands, and riparian habitats.

e. Preserve significant trees.

f. Conform the site layout along natural landforms.

g. Avoid excessive grading and disturbance of vegetation and soils.

h. Replicate the site’s natural drainage patterns.

i. Detain and retain runoff throughout the site.

2. Drainage Management Areas – Each regulated project is required to provide a map or diagram dividing the developed portions of the project site into discrete drainage management areas (DMAs), and to manage runoff from each DMA using site design measures, source controls and/or storm water treatment and baseline hydromodification measures.

3. Numeric Sizing Criteria for Storm Water Retention and Treatment – Facilities designed to evapotranspire, infiltrate, harvest/use, and biotreat storm water are required to meet at least one of the following hydraulic sizing design criteria:

a. Volumetric Criteria:

i. The maximized capture storm water volume for the tributary area, on the basis of historical rainfall records, determined using the formula and volume capture coefficients in Urban Runoff Quality Management, WEF Manual of Practice No. 23/ASCE Manual of Practice No. 87 (1998) pages 175-178 (that is, approximately the 85th percentile 24-hour storm runoff event); or

ii. The volume of annual runoff required to achieve 80 percent or more capture, determined in accordance with the methodology in Section 5 of the CASQA’s Storm Water Best Management Practice Handbook, New Development and Redevelopment (2003), using local rainfall data.

b. Flow-based Criteria:

i. The flow of runoff produced from a rain event equal to at least 0.2 inches per hour intensity; or

ii. The flow of runoff produced from a rain event equal to at least 2 times the 85th percentile hourly rainfall intensity as determined from local rainfall records.

4. Site design measures as defined in Section 15.50.080(A) above, site layout, and design measures shall be implemented on the objective of achieving infiltration, evapotranspiration and/or harvesting/reuse of the 85th percentile 24-hour storm runoff event. Site design measures shall be used to reduce the amount of runoff, to the extent technically feasible, for which retention and runoff is required. Any remaining runoff from impervious DMAs may then be directed to one or more bioretention facilities as specified in Section 15.50.080(D)(6) below.

5. Source Controls – All regulated projects shall implement source controls as defined in Section 15.50.080(C) above.

6. Storm Water Treatment Measures and Baseline Hydromodification Management Measures – After implementation of site design measures on regulated projects, the remaining runoff from impervious DMAs must be directed to one or more facilities designed to infiltrated, evapotranspire, and/or bioretain the amount of runoff specified in Section 15.50.080(D)(3) Numeric sizing criteria for storm water retention and treatment. The facilities must be demonstrated to be at least as effective as a bioretention system with the following design parameters:

a. Maximum surface loading rate of 5 inches per hour, based on the flow rates calculated. A sizing factor of 4% of tributary impervious area may be used.

b. Minimum surface reservoir volume equal to surface area times a depth of 6 inches.

c. Minimum planting medium depth of 18 inches. The planting medium must sustain a minimum infiltration rate of 5 inches per hour throughout the life of the project and must maximize runoff retention and pollutant removal. A mixture of sand (60%-70%) meeting the specifications of American Society for Testing and Materials (ASTM) C33 and compost (30%-40%) may be used.

d. Subsurface drainage/storage (gravel) layer with an area equal to the surface area and having a minimum depth of 12 inches.

e. Underdrain with discharge elevation at top of gravel layer.

f. No compaction of soils beneath the facility, or ripping/loosening of soils if compacted.

g. No liners or other barriers interfering with infiltration.

h. Appropriate plant palette for the specified soil mix and maximum available water use.

7. Alternative Designs – Facilities, or a combination of facilities, of a different design than in Section 15.50.080(D)(6) may be permitted if all of the following measures of equivalent effectiveness are demonstrated:

a. Equal or greater amount of runoff infiltrated or evapotranspired;

b. Equal or lower pollutant concentrations in runoff that is discharged after biotreatment;

c. Equal or greater protection against shock loadings and spills;

d. Equal or greater accessibility and ease of inspection and maintenance.

8. Allowed Variations for Special Site Conditions – The bioretention system design parameters Section 15.50.080(D)(6) may be adjusted for the following special site conditions:

a. Facilities located within 10 feet of structures or other potential geotechnical hazards established by the geotechnical expert for the project may incorporate an impervious cutoff wall between the bioretention facility and the structure or other geotechnical hazard.

b. Facilities with documented high concentrations of pollutants in underlying soil or groundwater, facilities located where infiltration could contribute to a geotechnical hazard, and facilities located on elevated plazas or other structures may incorporate an impervious liner and may located the underdrain discharge at the bottom of the subsurface drainage/storage layer (this configuration is commonly known as a “flow-through planter”).

c. Facilities located in areas of high groundwater, highly infiltrative soils or where connection of underdrain to a surface drain or to a subsurface storm drain are infeasible, may omit the underdrain.

d. Facilities serving high-risk areas such as fueling stations, truck stops, auto repairs, and heavy industrial sites may be required to provide additional treatment to address pollutants of concern unless these high-risk areas are isolated from storm water runoff or bioretention areas with little chance of spill migration.

9. Exceptions to Requirements of Bioretention Facilities –

Contingent on a demonstration that use of bioretention or a facility of equivalent effectiveness is infeasible, other types of biotreatment or media filters (such as tree-box-type biofilters or in-vault media filters) may be used for the following categories of regulated projects:

a. Projects creating or replacing an acre or less of impervious area, and located in a designated pedestrian-oriented commercial district, and having at least 85% of the entire project site covered by permanent structures;

b. Facilities receiving runoff solely from existing (pre-project) impervious areas; and

c. Historic sites, structures or landscapes that cannot alter their original configuration in order to maintain their historic integrity.

E. Hydromodification Management – Hydromodification management projects are regulated projects that create and/or replace one acre or more of impervious surface. A project that does not increase impervious surface area over the pre-project condition is not a hydromodification management project. Post-project runoff for hydromodification management projects shall not exceed estimated pre-project flow rate for the 2-year, 24-hour storm.

F. Operations and Maintenance of Post-Construction Storm Water Management Measures – All regulated projects shall at a minimum, require from all project proponents and their successors in control of the project or successors in fee title:

1. The property owner or responsible party shall sign a statement of responsibility accepting responsibility for the on-going operation, inspection, and maintenance of the treatment control measures until the property and/or responsibility is legally transferred to another entity. The statement of responsibility shall be on a form approved by the city.

a. The transfer of property to a new owner shall contain conditions requiring the recipient to assume responsibility for maintenance of any treatment control measures to be included in the sales or lease agreement for that property and will be the owner’s responsibility. The new owner or responsible party will be obligated to maintain the operations and maintenance of the treatment control measures.

2. The city will send the responsible party an operation and maintenance self- certification form. The responsible party will certify that the operations and maintenance program is being implemented and that the treatment control measures are in an effective operational condition. The responsible party will have sixty (60) days to complete and return the annual operation and maintenance self-certification form.

a. If the operation and maintenance self-certification form is not received within the sixty (60) day period, the city will perform the inspection and assessment. The responsible party will be billed for the inspection and assessment as applicable.

G. All projects subject to this section shall submit a completed post construction storm water worksheet to the city.

(Ord. 2468 §5)

All grading work shall be performed in compliance with Titles 16 and 16R of this code and all construction or development activity, including clearing, grading or excavation, whether requiring a grading permit or not, shall be undertaken in accordance with all requirements of this chapter.

A. Whenever necessary to make an inspection of any building or property to enforce any of the provisions of this chapter, or whenever the Director has reasonable cause to believe that there exists in any building or upon any property any condition that constitutes a violation of this chapter, the Director may enter such building or property at all reasonable times to perform an inspection as well as any of the other activities authorized by this chapter. If an owner, tenant, occupant, agent or other responsible party refuses to grant the City permission to enter or inspect, the City may seek an inspection warrant pursuant to the Code of Civil Procedure.

B. Routine or area inspections shall be based upon such reasonable selection processes as may be deemed necessary to carry out the objectives of this chapter, including but not limited to, random sampling and/or sampling in areas with evidence of storm water contamination, illicit discharges, discharge of non-storm water to the storm drain system or similar evidence.

C. The Director may enter and inspect property for which a grading permit has been applied to determine the applicability of, or compliance with, this chapter and City specifications. The Director may also inspect any and all property on which grading, filling, clearing, and grubbing or excavating activities are occurring to ensure compliance with this chapter.

A. During any inspection the Director may collect samples as necessary in order to implement and enforce the provisions of this chapter. This authority shall include the right to require the installation of sampling and metering devices on private property or to require the person owning or occupying the property to supply samples.

B. During any inspection the Director may require the person owning or occupying the property to provide any and all records relating to any potential storm water contamination, illegal discharge, non-storm water discharge or other violation of this chapter for review and copying.

C. Whenever the Director has reasonable cause to believe that there may exist on any property a condition that constitutes a violation of this chapter, the Director may require monitoring, analysis and/or reporting of discharges from the property to the storm drain system by serving a written notice of such requirement(s) on the owner of the property or on the operator of a facility or activity on the property. The cost of complying with these requirements shall be borne by the owner of the property or the operator of the facility or activity for which monitoring, analysis and/or reporting has been required, to the extent permitted by law.

Any person owning, occupying or responsible for property or responsible for emergency response for a facility or activity has a personal responsibility to train facility personnel and maintain notification procedures to assure immediate notification is provided to the City of any suspected, confirmed or unconfirmed release of materials, pollutants or wastes creating a risk of discharge to the City’s storm drain system. As soon as any person owning, occupying or responsible for the property or responsible for emergency response for a facility or activity has knowledge of any suspected, confirmed or unconfirmed release, such person shall take all necessary steps to ensure the discovery, containment and clean-up of such release and shall immediately notify the Director by telephone of the release and shall confirm the notification by written correspondence within 24 hours of such knowledge.

The Director may utilize any enforcement actions authorized or provided in this code including, but not limited to, administrative remedies as set forth in Chapter 1.14 of this code. The Director may also exercise any of the following enforcement actions deemed necessary:

A. Abatement

1. Any discharge or condition violating any provisions of this chapter is a threat to the public health, safety and welfare and constitutes a public nuisance.

2. The Director may abate any discharge or condition that violates any provision of this chapter in accordance with the provisions of Chapter 1.14 of this code and such action by the Director shall be subject to appeal as provided for in that chapter. In addition, any notice and order issued by the Director under Chapter 1.14 of this code may require the owner and/or occupant of the subject property to take any or all of the following actions:

a. Submit and implement a plan approved by the Director for the correction and prevention of the discharge or condition violating any provision of this chapter;

b. Cease and desist all activities that may cause or contribute to any discharge or condition violating any provision of this chapter;

c. Clean-up any release of pollutants causing or resulting from the violation of any provision of this chapter;

d. Mitigate any circumstances that may cause or contribute to any discharge or condition violating any provision of this chapter; and

e. Adopt and implement BMPs and/or a storm water pollution prevention plan approved by the Director.

3. If any violation of this chapter constitutes a seasonal and recurrent nuisance, the Director shall so declare in the notice and order issued pursuant to subsection 2 above. Thereafter, the owner or occupant of the subject property shall abate such seasonal and recurrent nuisance every year without the necessity of any further notice and order. If at any time following the issuance of the notice and order the nuisance is not abated as required, the Director may summarily abate the condition in accordance with provisions of Chapter 1.14 of this code.

4. When, in the opinion of the Director, any discharge from any source to the storm drain system causes or threatens to cause a condition that presents an imminent hazard to the public health, safety or welfare or the environment, or a violation of the City’s NPDES permit, the Director may issue a notice requiring the owner or occupant of the property where the discharge is occurring to immediately abate the discharge. In any case where the discharge is not immediately abated or the Director determines that time constraints are such that abatement must occur without providing the notice, the Director may summarily abate the condition in accordance with the provisions of Chapter 1.14 of this code.

5. The owner of any property from which a discharge is made in violation of this chapter and any person making or causing the discharge, if different from the owner, shall be jointly and severally liable for the costs incurred by the City for any abatement, clean-up or restoration, including any related inspection and testing costs arising from the discharge and the costs shall be invoiced to the owner of the property and any responsible persons. If the invoice is not paid within sixty (60) days, the Director may commence proceedings for recovery of these costs in accordance with the provisions of Chapter 1.14 of this code.

B. Civil Actions

In addition to any other remedies or penalties provided in this chapter, any violation of this chapter may be enforced by civil action brought by the City Attorney. In any such action the City may seek, as appropriate, any or all available equitable and legal remedies including but not limited to:

1. A temporary or permanent injunction;

2. Assessment upon the violator for the costs of any investigation, inspection, testing or monitoring related to the violation and for the reasonable costs of preparing and bringing legal action under this subsection including attorney fees, whether for in- house or outside counsel;

3. Costs incurred in removing, correcting, abating, cleaning-up or terminating the adverse effects resulting from the violation;

4. Compensatory damages for damage, loss or destruction to water quality, wildlife, fish and aquatic life, or public health and safety;

5. Payment or reimbursement of any governmental fines or penalties imposed on the City as a result of the violation; and

6. Payment of a fine of up to $5,000 for each day or portion of a day that the discharge occurs.

C. Criminal Violations

A violation of any of the provisions of this chapter shall constitute a misdemeanor, except that notwithstanding any other provision of this code, any such violation may, at the discretion of the City Attorney, be charged and prosecuted as an infraction.

If a decision or action by the Director is not subject to an appeal procedure under any other provision of this code, any person who is affected by the Director’s decision or action may appeal the decision or action to the City Manager within ten (10) days following the effective date of the decision or action by filing a written appeal with the City Manager. Upon receipt of such appeal, the City Manager may request a report and recommendation from the Director and shall set the matter for an informal hearing at the earliest practical date. Not less than seven (7) days prior to the date of the hearing, the City Manager shall provide written notice of the hearing to the person appealing the decision or action. At the hearing, the appellant may be represented by any person of appellant’s choice. The City Manager shall hear any additional evidence presented by the appellant or the Director and may reject, affirm or modify the Director’s decision or action. The City Manager’s decision shall be the City’s final administrative determination of the matter.

The provisions of Sections 1094.5 and 1094.6 of the Code of Civil Procedure set forth the sole procedure for judicial review of any action taken pursuant to this chapter. Parties seeking judicial review of any final action taken pursuant to this chapter shall file such action within ninety (90) calendar days after the occurrence of any event or receipt of any decision constituting the evaluation of administrative remedies provided in this chapter for which review is sought.

The standards established by this chapter are minimum standards and do not imply that compliance by any discharger will ensure that there will not be any contamination, pollution nor unauthorized discharge of pollutants to the City’s storm drain system or waters of the United States. This chapter shall not create liability on the part of the City or any city employee for any damages that result from any discharger’s reliance on this chapter or any lawful administrative decision.

The remedies provided in this chapter shall be cumulative and not exclusive and shall be in addition to any and all remedies available to the City.

(Ord. 2384)