El Cajon Municipal Code Ch. 16.60 Standard Urban Storm Water Mitigation Plan

The ordinance codified in this chapter shall be known as the "Standard Urban Storm Water Mitigation Plan ("SUSMP") ordinance of the City of El Cajon."

(Ord. 5034 § 2, 2015)

A. The municipal storm water NPDES permit (Order No. R9-2013-0001, as subsequently modified by amendment or renewal order, NPDES No. CAS0109266, hereinafter collectively referred to as "Municipal Permit") issued to the municipal agencies within the San Diego region, including the City of El Cajon ("City"), by the San Diego RWQCB on May 8, 2013, requires the development and implementation of a program addressing urban runoff pollution related development issues for both public and private projects.

B. The requirement to implement a program for development planning is based on federal and state statutes including: Section 402 (p) of the Clean Water Act, Section 6217 of the Coastal Zone Act Reauthorization Amendments of 1990 ("CZARA"), and the California Water Code. The Clean Water Act amendments of 1987 established a framework for regulating urban runoff discharges from municipal, industrial, and construction activities under the NPDES program. The municipal permit requires the implementation of a local BMP Design Manual that incorporates the minimum Low Impact Development (LID)/Site Design, and Permanent BMP Design requirements developed in the Countywide Model BMP Design Manual.

(Ord. 5034 § 2, 2015)

The regulations of this chapter were developed to address post-construction urban runoff pollution from new development and redevelopment projects. The goal of this chapter is to develop and implement practicable policies to ensure, to the maximum extent practicable ("MEP") that development does not increase pollutant loads from a project site or result in increased erosion in channels or streams downstream of the development.

(Ord. 5034 § 2, 2015)

The regulations set forth in this chapter shall apply to the development plan approval process for discretionary development applications, and prior to issuing development permits for ministerial projects. All "development projects" must include control measures to reduce the discharge of storm water pollutants to the MEP. Development projects are construction, rehabilitation, redevelopment, or reconstruction activities that have the potential to contact storm water and contribute an anthropogenic source of pollutants or reduce the natural absorption and infiltration abilities of the land. Each development project is classified as either a "standard development project" ("SDP") or a "priority development project" ("PDP"). This chapter includes regulations that apply to all development projects as well as additional regulations that apply only to priority development projects. Projects that meet any of the criteria in section 16.60.050 are not considered development projects and are not subject to the requirements of this chapter. All development projects are subject to the requirements of this chapter, subject to the lawful prior approval provisions of the municipal permit.

(Ord. 5034 § 2, 2015)

The following activities are not considered "development projects," and the requirements of this chapter do not apply to them:

A. Replacement of impervious surfaces that are part of a routine maintenance activity, such as:

1. Replacing roof material on an existing building;

2. Rebuilding a structure to original design after damage from earthquake, fire or similar disasters;

3. Restoring pavement or other surface materials affected by trenches from utility work;

4. Resurfacing existing roads and parking lots, including slurry, overlay, and restriping;

5. Routine replacement of damaged pavement, including full depth replacement, if the sole purpose is to repair the damage;

6. Constructing new sidewalk, pedestrian ramps, bicycle lanes, or trails (within existing impervious street right-of-way); and

7. Restoring a historic building to its original historic design.

B. Repair or improvements to an existing building or structure that do not alter the size:

1. Plumbing, electrical and HVAC work;

2. Interior alterations including major interior remodels and tenant build-out within an existing commercial building; and

3. Exterior alterations that do not change the general dimensions and structural framing of the building (does not include building additions or projects where the existing building is demolished).

(Ord. 5034 § 2, 2015)

The following types of development projects, except those excluded in accordance with section 16.60.070, are considered priority development projects:

A. New development projects that create 10,000 square feet or more of impervious surfaces (collectively over the entire project site). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

B. Redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

C. New and redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site), and support one or more of the following uses:

D. Restaurants. This category is defined as a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption described in Standard Industrial Classification ("SIC") code 5812.

1. Hillside development projects. This category includes development on any natural slope that is 25% or greater.

2. Parking lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce.

3. Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles.

E. New or redevelopment projects that create or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area ("ESA"). "Discharging directly to" includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).

F. New development projects, or redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface, that support one or more of the following uses:

1. Automotive repair shops. This category is defined as a facility that is categorized in any one of the following SIC codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.

2. Retail gasoline outlets ("RGOs"). This category includes RGOs that meet the following criteria (a) 5,000 square feet or more in size or (b) a projected Average Daily Traffic ("ADT") of 100 or more vehicles per day.

(Ord. 5034 § 2, 2015)

The following development projects are considered standard projects, even if they otherwise meet the criteria to be considered a priority development project category in section 16.60.060:

A. New or retrofit paved sidewalks, pedestrian ramps, bicycle lanes, or trails that meet at least one of the following criteria:

1. Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other nonerodible permeable areas;

2. Designed and constructed to be hydraulically disconnected[1] from paved streets or roads; and

[1]

A sidewalk, bicycle lane or trail is considered to be hydraulically disconnected from paved streets or roads if they drain via separate drainage pathways (e.g., separate inlets) such that overland flows do not comingle with street or road runoff.

3. Designed and constructed with permeable pavements or surfaces.

B. Retrofit or redevelopment of existing paved alleys, streets, or roads that are designed and constructed in accordance with USEPA Green Streets guidance, as defined in the El Cajon BMP Design Manual.

(Ord. 5034 § 2, 2015)

The following areas may be excluded in the calculation of amount of impervious area added or replaced when determining if the project is a priority development project:

A. Areas of a project that are considered exempt from storm water requirements in accordance with section 16.60.050.

B. Swimming pools and decorative ponds with adequate freeboard or an overflow structure that does not release to the MS4 storm drain system.

(Ord. 5034 § 2, 2015)

All development projects, as defined in sections 16.60.040 and 16.60.050, that are not priority development projects are standard development projects.

(Ord. 5034 § 2, 2015)

The provisions of chapter 13.10 (Storm Water Management and Discharge Control), including the definitions and enforcement provisions, shall be applicable to this chapter as though fully set forth herein.

(Ord. 5034 § 2, 2015)

Interpretation of this chapter shall assure consistency with the purpose and intent of this chapter and shall implement the requirements of the municipal permit. This chapter is not intended to interfere with, abrogate or annul any other chapter, rule or regulation, statute, or other provision of law. The requirements of this chapter should be considered minimum requirements, and where any provision of this chapter imposes restrictions different from those imposed by any other chapter, rule or regulation, or other provision of law, whichever provisions are more restrictive or impose higher protective standards for human health or the environment shall take precedence.

(Ord. 5034 § 2, 2015)

The requirements of this chapter shall be incorporated into the project design and shown on the project plans prior to approval of discretionary permits. For projects requiring only ministerial permits, the requirements of this chapter shall be incorporated into the project design and shown on the project plans prior to the issuance of any ministerial permits. City departments carrying out public projects that are not required to obtain permits shall be responsible for ensuring the requirements of this chapter are incorporated into the project design and shown on the project plans prior to bidding for construction contracts, or equivalent. For public projects, the requirements of this chapter must be incorporated into the project design and shown on the plans before allowing the project to commence. In addition, all qualifying public and private standard and priority development projects, shall submit a Storm Water Mitigation Plan ("SWMitP") documenting how the project design complies with the requirements of this chapter before permits are issued for both private and public projects and before projects are allowed to commence. The City of El Cajon BMP Design Manual, which shall be made available on the City's website, is incorporated herein by reference and made a part of this chapter's requirements.

(Ord. 5034 § 2, 2015)

All development projects shall implement source control and Low Impact Development (LID) site design BMPs. Furthermore, all priority development projects shall implement structural BMPs. Storm water BMPs shall be considered and implemented where expressly required by this chapter and if not so required where determined applicable and feasible by the City Engineer/Director of Public Works. The storm water BMPs shall adhere to the requirements of this chapter, and shall be correctly designed in accordance with the requirements of the El Cajon BMP Design Manual so as to remove pollutants to the MEP. Priority projects must also be designed so that runoff rates and durations are controlled to maintain or reduce downstream erosion conditions and protect stream habitat. Design criteria and procedures for hydromodification management are identified in section 16.60.240 and further outlined in the City of El Cajon BMP Design Manual.

(Ord. 5034 § 2, 2015)

All development projects must meet the following requirements:

A. Onsite BMPs shall be located so as to remove pollutants from runoff prior to its discharge to any receiving waters, and as close to the source as possible;

B. Structural BMPs shall not be constructed within the Waters of the U.S.; and

C. Onsite BMPs shall be designed and implemented with measures to avoid the creation of nuisances or pollutions associated with vectors (e.g. mosquitoes, rodents, or flies).

(Ord. 5034 § 2, 2015)

All development projects must implement site design BMPs, which incorporate LID principles, and source control BMPs. Additional technical details and guidelines for selection of appropriate site design and source control BMPs are provided in the City of El Cajon BMP Design Manual.

A. Site design performance standards define minimum requirements for how a site must incorporate site design BMPs, including the location of BMPs and the use of integrated site design practices. The following site design practices must be implemented at all development projects, where applicable and feasible:

1. Maintenance or restoration of natural storage reservoirs and drainage corridors (including topographic depressions, areas of permeable soils, natural swales, and ephemeral and intermittent streams). If development projects propose to disturb water bodies shall also comply with all applicable requirements of other agencies, including, but not limited to, the U.S. Army Corps of Engineers, the California Department of Fish and Wildlife, and the San Diego Regional Water Quality Control Board;

2. Buffer zones for natural water bodies (where buffer zones are technically infeasible, the project applicant shall include other buffers such as trees, access restrictions, or similar measures);

3. Conservation of natural areas within the project footprint including existing trees, other vegetation, and soils;

4. Construction of streets, sidewalks, or parking lot aisles to the minimum widths necessary, provided public safety is not compromised;

5. Minimization of the impervious footprint of the project;

6. Minimization of soil compaction to landscaped areas;

7. Disconnection of impervious surfaces through distributed pervious areas;

8. Landscaped or other pervious areas designed and constructed to effectively receive and infiltrate, retain and/or treat runoff from impervious areas, prior to discharging to the MS4;

9. Small collection strategies located at, or as close as possible to, the source (i.e. the point where storm water initially meets the ground) to minimize the transport of runoff and pollutants to the MS4 and receiving waters;

10. Use of permeable materials for projects with low traffic areas and appropriate soil conditions;

11. Landscaping with native or drought tolerant species; and

12. Harvesting and using precipitation.

B. Source control BMPs shall be implemented at all development projects in accordance with sections 16.60.160 through 16.60.220, where applicable and feasible.

(Ord. 5034 § 2, 2015)

Development projects shall design projects to prevent illicit discharges in accordance with the requirements of El Cajon Municipal Code chapter 13.10. BMPs required to prevent discharges include, but are not limited to, those listed below. BMPs to prevent illicit discharges shall be incorporated into the project design where applicable.

A. Interior floor drains and elevator shaft pumps shall be plumbed to the sanitary sewer system.

B. Drains within indoor parking garages, except for drains that receive runoff from areas exposed to precipitation, shall be plumbed to the sanitary sewer system.

C. Fire sprinkler systems shall be designed to drain fire sprinkler system test water to the sanitary sewer.

D. Boiler drain lines shall be directly or indirectly connected to the sanitary sewer system and may not discharge to the storm drain system.

E. Condensate, including air conditioning condensate, drain lines may discharge to landscaped areas or other pervious areas stabilized to prevent erosion if the flow is small enough that runoff will not occur. Condensate drain lines may not discharge to the storm drain system.

F. Rooftop mounted equipment with potential to produce pollutants shall have overhead coverage and/or have secondary containment.

G. Any drainage sumps onsite shall feature a sediment sump to reduce the quantity of sediment in pumped water.

H. Roofing, gutters, and trim made of copper or other unprotected metals that may leach into runoff shall be avoided, where feasible.

I. Vehicle and equipment wash areas shall be designed in accordance with section 16.60.220(B).

(Ord. 5034 § 2, 2015)

Storm drain stencils are highly visible source control messages, typically placed directly adjacent to storm drain inlets. The stencils contain a brief statement that explains that the dumping of improper materials into the storm water conveyance system is prohibited. Graphical icons, either illustrating anti-dumping symbols or images of receiving water fauna, are effective supplements to the anti-dumping message. Development projects shall include the following requirements in the project design:

A. Provide stenciling or labeling of all storm drain inlets and catch basins within the project area with prohibitive language (such as: "NO DUMPING DRAINS TO THE OCEAN – NO TIRE DESECHOS HABITO EN EL AGUA") and/or graphical icons to discourage illegal dumping;

B. Post signs and prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area; and

C. Maintain legibility of stencils and signs.

D. Contact the City of El Cajon at (619) 441-1653 for a stencil.

(Ord. 5034 § 2, 2015)

Improper storage of materials outdoors may increase the potential for toxic compounds, oil and grease, heavy metals, nutrients, suspended solids, and other pollutants to enter the storm water conveyance system. Where the development project plans include outdoor areas for storage of materials that may contribute pollutants to the storm water conveyance system, the following storm water BMPs are required:

A. Materials with the potential to contribute pollutants to storm water runoff or non-storm water discharges shall be stored in a covered area protected from run-on, such as, but not limited to, a cabinet, shed, or area with a permanent roof or awning and graded or bermed to prevent run-on, where feasible. Where not feasible, berms, dikes, curbs, or other containment structures shall be placed around the perimeter of the storage area to divert run-on around the storage area and reduce the potential for runoff from the storage area. In all cases, runoff from roofs and downspouts shall be directed away from storage areas.

B. Effective secondary containment shall be provided and maintained for all containers of liquid with the potential to leak or to spill onto outdoor areas to prevent leaks or spills from discharging pollutants to the storm water conveyance structure. Secondary containment may also be required for non-liquid materials where necessary to prevent discharges of pollutants to the storm water conveyance system. Where secondary containment is proposed, the storage area in which the secondary containment structure is located shall have a roof or awning that extends beyond the limits of the storage area to minimize collection of precipitation within the secondary containment system, where feasible. A manufactured shed or equivalent may be used to satisfy this requirement in cases where the shed or equivalent provides sufficient storage capacity.

C. Bollards, traffic barriers, fences, curbs, or other equivalent measures shall be installed to protect material storage containers stored in locations accessible to vehicles. These measures are intended to prevent damage to containers that could result in spills or leaks.

D. Storage areas for hazardous materials shall meet all applicable requirements for storage of hazardous materials.

(Ord. 5034 § 2, 2015)

Where the development project plans include outdoor work areas, the following storm water BMPs are required:

A. Outdoor work areas shall be provided with permanent overhead coverage, where feasible, and protected from run-on. Where permanent overhead coverage is not feasible, berms, dikes, curbs, or other containment structures shall be placed around the perimeter of the storage area to divert run-on around the work area and reduce the potential for runoff from the work area. In all cases, runoff from roofs and downspouts shall be directed away from work areas;

B. Impermeable surfaces shall be established for outdoor work areas to prevent contamination of soil or underlying groundwater, as applicable;

C. Outdoor work areas shall be located as far away from storm drains or discharge points as possible. Storm drains shall not be located within outdoor work areas; and

D. In cases where work performed in outdoor areas generates or uses water or other liquids, adequate controls to prevent illicit discharges shall be utilized. Plumbed connection of outdoor work areas to the sanitary sewer system may be required. All connections to the sanitary sewer system shall obtain appropriate permits.

(Ord. 5034 § 2, 2015)

All trash container storage areas shall meet the following requirements (limited exclusion: residential developments at which individual trash service and an individual trash storage container is proposed for each residence):

A. Paved with an impervious surface, designed not to allow run-on from adjoining areas and roofs, screened or walled to prevent off-site transport of trash;

B. Provide attached lids on all trash containers that exclude rain, and a permanent fire resistant roof or awning to minimize direct precipitation;

C. Locate storm drains away from the immediate vicinity of the trash storage area; and

D. Post signs on high density residential, commercial, and industrial trash enclosure areas informing users that hazardous materials are not to be disposed.

(Ord. 5034 § 2, 2015)

Development projects shall design landscaping and landscape irrigation systems to minimize pesticide and fertilizer use and to prevent the runoff of excess irrigation water into the storm water conveyance system. Irrigation runoff discharges to the storm water conveyance system are considered illicit discharges. The irrigation system shall be in compliance with the requirements of all City ordinances regulating the efficient irrigation of landscaping, including, but not limited to, El Cajon Municipal Code chapter 17.195. The following methods to eliminate irrigation runoff shall be considered, and incorporated and implemented where determined applicable and feasible by the City Engineer/Director of Public Works:

A. Employing rain shutoff devices to prevent irrigation after precipitation;

B. Designing irrigation systems to each landscape area's specific water requirements;

C. Using flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines;

D. Using drip irrigation systems where appropriate;

E. Using native, drought tolerant, or pest-resistant, plant species;

F. Sloping adjacent paved or other impervious areas to drain to landscaping or to infiltration, retention, or biofiltration BMPs; and

G. Employing other comparable, equally effective, methods to eliminate irrigation water runoff.

(Ord. 5034 § 2, 2015)

Each of the following requirements shall be incorporated into the design of development projects as applicable and feasible. Multiple requirements may apply at one project. Alternative features or design concepts that are comparable and equally effective to the listed requirements may be approved by the City Engineer/Director of Public Works.

A. Buildings design features that discourage entry of pests shall be noted in the project's SWMitP submittal.

B. Vehicle and Equipment Cleaning Areas. Development projects that include areas for washing, steam cleaning, or other cleaning of vehicles or equipment shall incorporate the following features into the design of such areas, as applicable:

1. Self-contained, and covered with a roof or overhang;

2. Have a grade or berm area to prevent run-on from surrounding areas;

3. Equipped with a clarifier, grease interceptor, or other pretreatment facility, as appropriate;

4. Properly connected to a sanitary sewer; and

5. No storm drains shall be located within wash areas.

C. Vehicle or Equipment Maintenance Bays. Maintenance bays shall include the following:

1. Repair/maintenance bays shall be indoors; or, designed to preclude urban run-on and runoff; and

2. Design a repair/maintenance bay drainage system to capture all wash water, leaks and spills. Connect drains to a sump for collection and disposal. Direct connection of the repair/maintenance bays to the storm drain system is prohibited. Applicable permits must be obtained for connections to the sanitary sewer system.

D. Fueling Areas. Retail and non-retail fuel dispensing areas shall contain the following:

1. Overhanging roof structure or canopy. The cover's minimum dimensions must be equal to or greater than the area within the grade break. The cover must not drain onto the fuel dispensing area and the downspouts must be routed to prevent drainage across the fueling area. The fueling area shall drain to the project's structural prior to discharging to the storm water conveyance system;

2. Paved with Portland cement concrete (or equivalent smooth impervious surface). The use of asphalt concrete is prohibited;

3. Have an appropriate slope to prevent ponding, and must be separated from the rest of the site by a grade break that prevents run-on of urban runoff; and

4. At a minimum, the concrete fuel dispensing area must extend 6.5 feet (2.0 meters) from the corner of each fuel dispenser, or the length at which the hose and nozzle assembly may be operated plus one foot (0.3 meter), whichever is less.

E. Dock Areas. Loading/unloading dock areas shall include the following:

1. Cover loading dock areas, or design drainage to preclude urban run-on and runoff;

2. Provide a roof overhang over the loading area or install door skirts (cowling) at each bay that enclose the end of the trailer; and

3. Direct connections to storm drains from depressed loading docks (truck wells) are prohibited.

F. Plazas, Sidewalks, and Parking Areas. To minimize the offsite transport of pollutants from parking areas, plazas, sidewalks, and parking areas shall regularly be swept or cleaned using an equally effective method. If pressure washing or other wet cleaning method is used, controls must be implemented to prevent illicit discharges to the storm water conveyance system.

1. Where landscaping is proposed in parking areas, incorporate landscape areas into the drainage design; and

2. Overflow parking (parking stalls provided in excess of the city's minimum parking requirements) should be constructed with permeable paving.

G. Hillside Landscaping. Hillside areas that are disturbed by project development shall be landscaped with deep-rooted, drought tolerant plant species selected for erosion control, satisfactory to the City Engineer/Director of Public Works.

(Ord. 5034 § 2, 2015)

All priority development projects must implement structural BMPs to control pollutants in stormwater that may be discharged from a project as listed below. All priority development projects shall design, construct and implement structural BMPs that meet the design standards of this section and the applicable portions of the El Cajon BMP Design Manual.

A. Each priority development project must implement structural BMPs that are designed to retain (intercept, store, infiltrate, evaporate, and/or evapotranspire) onsite the pollutants contained in the volume of storm water runoff produced from a 24-hour 85th percentile storm event (design capture volume).

1. If implementing BMPs to retain the full design capture volume onsite for a priority development project is not technically feasible, then the priority development project may utilize biofiltration BMPs. Biofiltration BMPs must be designed to have an appropriate hydraulic loading rate to maximize storm water retention and pollutant removal, as well as to prevent erosion, scour, and channeling within the BMP, and must be sized to:

a. Treat 1.5 times the design capture volume not reliably retained onsite; or

b. Treat the design capture volume not reliably retained onsite with a flow-thru design that has a total volume, including pore spaces and pre-filter detention volume, sized to hold at least 0.75 times the portion of the design capture volume not reliably retained onsite.

B. If the priority development project is a redevelopment project, the structural BMP performance requirements and hydromodification management requirements apply to redevelopment priority development projects as follows:

1. Where redevelopment results in the creation or replacement of impervious surface in an amount of less than fifty percent of the surface area of the previously existing development, then the structural BMP performance requirements for priority development projects apply only to the creation or replacement of impervious surface, and not the entire development; or

2. Where redevelopment results in the creation or replacement of impervious surface in an amount of more than fifty percent of the surface area of the previously existing development, then the structural BMP performance requirements for priority development projects apply to the entire development.

C. BMPs implemented to comply with this section shall treat runoff from the development project and shall be located onsite, except as otherwise allowed by section 16.60.250.

(Ord. 5034 § 2, 2015)

Priority development projects shall implement BMPs to manage hydromodification that may be caused by storm water runoff discharged from a project as follows:

A. Post-project flow rates and durations must meet the following criteria:

1. For flow rates ranging from 10 percent, 30 percent or 50 percent of the pre-development 2-year runoff event (0.1Q2, 0.3Q2, or 0.5Q2) to the pre-development 10-year runoff event (Q10), the post-project discharge rates and durations shall not deviate above the pre-development rates and durations by more than 10 percent over and more than 10 percent of the length of the flow duration curve. The specific lower flow threshold will depend on the erosion susceptibility of the receiving stream for the project site. Guidelines for selection of the appropriate lower flow threshold are provided in the San Diego Hydromodification Management Plan.

2. For flow rates ranging from the lower flow threshold to Q5, the post-project peak flows shall not exceed pre-development peak flows. For flow rates from Q5 to Q10, post-project peak flows may exceed pre-development flows by up to 10 percent for a 1-year frequency interval. For example, post-project flows could exceed pre-development flows by up to 10 percent for the interval from Q9 to Q10 or from Q5.5 to Q6.5, but not from Q8 to Q10.

B. BMPs implemented to comply with this section shall provide hydrologic control for runoff from the development project and shall be located onsite, except as otherwise allowed by section 16.60.250.

C. Each priority development project shall avoid critical coarse sediment yield areas identified in the Watershed Management Area Analysis or implement measures that allow critical coarse sediment to be discharged to receiving waters, such that there is no net impact to the receiving water.

D. At the discretion of the City Engineer/Director of Public Works, the City may exempt a priority development project from the hydromodification management BMP performance requirements described in this section where the project discharges storm water runoff to:

1. Existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean;

2. Conveyance channels whose bed and bank are concrete lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean; or

3. Forester Creek or conveyances that are concrete-lined from the point of discharge from the project area to the point of discharge to Forester Creek, and any other areas identified by the Copermittees as appropriate for an exemption by the optional Watershed Management Area Analysis and listed in a Water Quality Improvement Plan. No exemption listed in the Watershed Management Area Analysis may be granted until the Water Quality Improvement Plan containing the exemption has been accepted by the San Diego RWQCB.

(Ord. 5034 § 2, 2015)

The City may, at the discretion of the City Engineer/Director of Public Works, allow an applicant to implement an applicant-implemented alternative compliance project to meet the requirements of sections 16.60.230 and 16.60.240, as applicable, in lieu of complying solely using onsite BMPs that treat runoff generated by the development project.

A. Applicant-Implemented Alternative Compliance Projects: Applicant-implemented alternative compliance projects may propose using onsite BMPs to treat run-on from offsite using onsite BMPs or implementing offsite BMPs. For either type of applicant-implemented alternative compliance, the applicant is fully responsible for the alternative compliance project design, construction, and long-term operation and maintenance. BMPs proposed may be, but are not required to be, selected from candidate projects listed in the Watershed Management Area Analysis included in the Water Quality Improvement Plan. Applicant-implemented alternative compliance projects must also satisfy all of the following requirements:

1. The design shall be prepared in accordance with the Water Quality Equivalency (WQE) standards approved by the San Diego RWQCB.

2. The applicant shall provide evidence of an operation and maintenance mechanism that will ensure the operation and maintenance of the proposed BMPs in perpetuity.

3. All proposed BMPs included in the design, including offsite BMPs, if proposed, must be completed and operational before completion of the proposed development project.

B. Alternative compliance projects shall not be authorized by the City prior to acceptance of WQE standards by the San Diego RWQCB.

C. No regionally-accepted credit system has been established, alternative compliance via payments of inlieu fees or the equivalent is not a compliance option for projects in the City of El Cajon.

(Ord. 5034 § 2, 2015)

Infiltration devices shall comply with the criteria establish in the El Cajon BMP Design Manual, as amended, that is incorporated by reference as part of this chapter. These conditions do not apply to structural BMPs which allow incidental infiltration and are not designed to primarily function as infiltration devices (such as detention basins, bioretention areas, constructed wetlands, etc.). At a minimum, such infiltration BMPs must be in conformance with the design criteria listed below, unless the development project applicant demonstrates that one or more of the specific design criteria listed below are not necessary to protect groundwater quality. The design criteria listed below do not apply to small infiltration systems dispersed throughout a development project.

A. Runoff shall undergo pretreatment to remove both physical and chemical contaminants, such as sedimentation or filtration, prior to infiltration.

B. Pollution prevention and source control BMPs shall be implemented at a level appropriate to protect groundwater quality at sites where infiltration structural BMPs are to be used.

C. Infiltration BMPs must be adequately maintained to remove pollutants in storm water to the MEP.

D. The vertical distance from the base of any infiltration structural BMP to the seasonal high groundwater mark shall be at least ten feet or as determined on an individual, site-specific basis by the City Engineer/Director of Public Works. Where groundwater does not support beneficial uses, this vertical distance criterion may be reduced, provided groundwater quality is maintained.

E. The soil through which infiltration is to occur shall have physical and chemical characteristics (such as appropriate cation exchange capacity, organic, clay content, and infiltration rate) that are adequate for proper infiltration durations and treatment of urban runoff for the protection of groundwater beneficial uses.

F. Infiltration structural BMPs shall not be used for areas of industrial or light industrial activity and other high threat to water quality land uses and activities as designated by the City Engineer/Director of Public Works, unless source control BMPs are utilized to help prevent the exposure of high threat activities, or runoff from such activities is first treated or filtered to remove pollutants prior to infiltration.

G. The horizontal distance between the base of any infiltration structural BMP and any water supply wells shall be 100 feet or as determined on an individual, site-specific basis by the City Engineer/Director of Public Works.

(Ord. 5034 § 2, 2015)

The following requirements apply to shared and interim storm water BMPs:

A. Shared storm water BMPs shall be operational prior to the use of any dependent development or phase of development. The shared BMPs shall only be required to treat the dependent developments or phases of development that are in use;

B. Interim storm water BMPs that provide equivalent or greater treatment than is required for the permanent structural BMPs may be implemented by a dependent development until each shared BMP is operational. If interim BMPs are selected, the BMPs shall remain in use until permanent BMPs are operational.

(Ord. 5034 § 2, 2015)

Structural BMPs shall not be considered "effective," and shall not be accepted as meeting the MEP standard, unless a mechanism is in place that will ensure ongoing long-term maintenance of all structural BMPs. As part of project review, if a project proponent is required to include interim or permanent structural BMPs in project plans, and if the City Engineer/Director of Public Works does not provide a mechanism for BMP maintenance, the project proponent shall provide verification of maintenance requirements through such means as may be appropriate, at the discretion of the City Engineer/Director of Public Works, including, but not limited to covenants, legal agreements, maintenance agreements, and/or conditional use permits.

(Ord. 5034 § 2, 2015)

Public equity maintenance. The City Council may approve a public or acceptable quasi-public entity (e.g., the County Flood Control District, or annex to an existing assessment district, an existing utility district, a state or federal resource agency, or a conservation conservancy) to assume responsibility for maintenance, repair and replacement of the BMP. Unless acceptable to the City Council, public entity maintenance agreements shall ensure estimated costs are front-funded or reliably guaranteed (e.g., through a trust fund, cash deposit, assessment district fees, bond, letter of credit or similar means). In addition, the City Council may seek protection from liability by appropriate releases and indemnities. The City Council shall have the authority to approve storm water BMPs proposed for transfer to any other public entity within its jurisdiction before installation. The City Council shall be involved in the negotiation of maintenance requirements with any other public entities accepting maintenance responsibilities within their respective jurisdictions, and in negotiations with the resource agencies responsible for issuing permits for the construction and/or maintenance of the facilities. The City Council must be identified as a third party beneficiary empowered to enforce any such maintenance agreement within their respective jurisdictions.

A. Project proponent agreement to maintain storm water BMPs: The City Council may enter into a contract with the project proponent obliging the project proponent to maintain, repair and replace the storm water BMPs as necessary into perpetuity. Security may be required.

B. Assessment districts: The City Council may approve an Assessment District or other funding mechanism created by the project proponent to provide funds for storm water BMP maintenance, repair and replacement on an ongoing basis. Any agreement with such a District shall be subject to the Public Entity Maintenance Provisions above.

C. Lease provisions: In those cases where the City holds title to the land in question, and the land is being leased to another party for private or public use, the City Council may assure storm water BMP maintenance, repair and replacement through conditions in the lease.

D. Conditional use permits: For discretionary projects only, the City Council may assure maintenance of storm water BMPs through the inclusion of maintenance conditions in the conditional use permit. Security may be required.

E. Alternative mechanisms: The City Council may accept alternative maintenance mechanisms if such mechanisms are as protective as those listed above.

(Ord. 5034 § 2, 2015)

For discretionary projects, the City approved method of storm water BMP maintenance shall be incorporated into the project's permit, and shall be consistent with permits issued by resource agencies, before City approval of discretionary permits. For projects requiring only ministerial permits, the approved method of storm water BMP maintenance shall be incorporated into the permit conditions before the issuance of any ministerial permits. In all instances, the project proponent shall provide proof of execution of an approved method of maintenance repair and replacement before the issuance of construction approvals. Public projects that are not required to obtain permits shall be responsible for ensuring that an approved method of storm water BMP maintenance repair and replacement is executed prior to the commencement of construction. For all properties, the verification mechanism will include the project proponent's signed statement, as part of the project application, accepting responsibility for all structural treatment control BMP maintenance, repair and replacement, until a City-approved entity agrees to assume responsibility for structural treatment control BMP maintenance, repair and replacement.

(Ord. 5034 § 2, 2015)

A. Operation & Maintenance (O&M) Plan: An O&M plan, prepared by the project proponent shall be included in the SWMitP for all priority development projects. The O&M plan identifies the designated party(ies) responsible for maintaining storm water post-construction BMPs and describes typical maintenance activities and frequencies. Project proponents for all priority development projects shall also submit a completed Storm Water Facilities Maintenance Agreement to assure ongoing long-term maintenance of all proposed structural BMPs. The Storm Water Facilities Maintenance Agreement runs with the land. Parties responsible for the O&M plan shall retain records for at least five years. These documents shall be made available to the City for inspection upon request at any time.

B. Access Easement/Agreement: The City Engineer/Director of Public Works may require the project proponent to submit a copy of an executed access easement that shall be binding on the land throughout the life of the project, until such time that the storm water BMP requiring access is replaced, satisfactory to the City Engineer/Director of Public Works.

(Ord. 5034 § 2, 2015)