For the first time in California’s long water-quality history, a new stormwater permit has been adopted that could significantly change the California waterscape. This new permit represents a major expansion of stormwater regulation beyond the traditional California Industrial General Permit (IGP). While the application is limited to two Los Angeles watersheds, the precedent is clear and could lead to increased stormwater regulations statewide.
Commercial, Industrial, and Institutional Facilities Impacted
The new Waste Discharge Requirements and General National Pollutant Discharge Elimination System (NPDES) Permit No. CAS004005 issued by the California Regional Water Quality Control Board, Los Angeles Region regulates stormwater discharges associated with commercial, industrial, and institutional (CII) facilities within the Dominguez Channel/Los Angeles and Long Beach Inner Harbor Watershed and the Los Cerritos Channel/Alamitos Bay Watershed.
Several hundred industrial and institutional facilities in the Dominguez Channel and Los Cerritos Channel watersheds are subject to permit compliance requirements. These facilities must manage stormwater runoff and authorized non-stormwater discharges because their discharges can contribute to water quality.
Most parcels are owned or leased by large businesses, which are expected to bear the majority of compliance costs. The permit’s requirements are estimated to represent a small percentage of average commercial or industrial rents. The permit also considers the economic benefits of improved water quality, including public health and tourism benefits.
General Permit Coverage and Applicability
The permit authorizes discharges of stormwater runoff and authorized non-stormwater discharges (NSWDs) from certain privately owned CII sites, excluding residential facilities.
Coverage includes sites with five or more acres of impervious surface that are not covered by other NPDES stormwater permits, or portions of sites not covered by other permits. Facilities with individual NPDES permits with at least as stringent requirements are exempt.
Dischargers must submit Permit Registration Documents via the Stormwater Multiple Application and Report Tracking System (SMARTS), including:
Compliance Options
Permittees and dischargers will have three primary compliance options for meeting water quality-based effluent limitations:
Option 1: Enter into a legally binding agreement with a local Watershed Management Group (WMG) to fund existing or planned downstream regional stormwater projects. Funding is proportional to the facility’s stormwater volume relative to the watershed’s total volume. This option is deemed compliant upon execution of the agreement and participation in it.
Option 2: Implement facility-specific design standards to capture and reduce stormwater runoff volume equivalent to the 85th percentile 24-hour storm event. This includes the use of structural and non-structural BMPs designed and certified by a California-licensed civil engineer. Infiltration BMPs must protect groundwater quality by meeting applicable Maximum Contaminant Levels (MCLs).
Option 3: Directly demonstrate compliance with numeric water quality-based effluent limitations through site-specific monitoring and reporting. This includes developing a Monitoring and Reporting Plan, conducting sampling during Qualifying Storm Events (QSEs), and submitting results via SMARTS.
Discharge Prohibitions and Authorized Non-Stormwater Discharges
The permit prohibits discharges inconsistent with eligibility, unauthorized non-stormwater discharges, trash discharges, and discharges of radiological, chemical, or biological warfare agents. Authorized NSWDs include fire hydrant flushing, potable water system discharges, uncontaminated groundwater, and incidental windblown mist, provided BMPs minimize pollutant contact and volume.
Stormwater Pollution Prevention Plan (SWPPP) Requirements
Dischargers must develop and implement a site-specific SWPPP including:
Effluent Limitations
The permit establishes both technology-based effluent limitations (TBELs) requiring implementation of BMPs reflecting Best Conventional Technology (BCT) and Best Available Technology economically achievable (BAT), and water quality-based effluent limitations (WQBELs) based on Total Maximum Daily Loads (TMDLs) and water quality objectives. Numeric effluent limits apply to specific pollutants including metals (copper, lead, zinc), indicator bacteria (Enterococcus, E. coli), toxicity, nutrients, legacy pesticides (DDT, chlordane, dieldrin), and PCBs in various receiving waters.
Sediment-associated effluent limitations are also established for certain pollutants in the Dominguez Channel Estuary and Los Angeles and Long Beach Inner Harbor Waters.
Monitoring and Reporting Requirements
All dischargers must conduct initial sampling within 18 months of the permit effective date to assess pollutant levels. Reporting includes annual visual observations of discharges, BMP implementation, and corrective actions. Specific monitoring requirements vary by compliance option:
Option 1: Annual reporting of funding agreements and visual observations during two Qualifying Storm Events (QSEs) per reporting period.
Option 2: Submission of design documentation, reporting of any bypass events, and annual inspection reports of BMPs.
Option 3: Detailed site-specific monitoring plans with sampling during four QSEs annually, analysis for all applicable pollutants, and submission of results and visual observations via SMARTS.
Provisions and Enforcement
Standard provisions consistent with federal regulations are included, such as a duty to comply, inspection rights, a prohibition on bypasses except under specific conditions, and requirements for proper operation and maintenance. Enforcement actions and penalties for violations are described, including mandatory minimum penalties for serious violations. Corrective actions must be taken for any exceedances of effluent limitations.
Special Provisions
The permit includes reopener provisions allowing modification or revocation for cause, including new information or changes in regulations. Electronic signature and certification requirements ensure compliance with electronic reporting rules. The permit continues in effect beyond its expiration date until a new order is adopted.
Watershed and Receiving Water Descriptions
The permit covers discharges to waters within the Dominguez Channel/Los Angeles and Long Beach Inner Harbor Watershed and the Los Cerritos Channel/Alamitos Bay Watershed, including Machado Lake sub-watershed. These watersheds are highly urbanized and include estuaries, harbors, lagoons, and coastal waters that support diverse aquatic life and endangered species. Many waterbodies are listed as impaired under the Clean Water Act and subject to TMDLs for various pollutants.
Prepare for the CII Permit
Screen your facility, using the >5-acre threshold and other NPDES parameters from the State Water Resources Control Board (SWRCB). Further consultation is likely needed as the CII Permit leaves the traditional SIC Code and Sector-based selection to geography and land use.
Start baseline copper/zinc source investigations before regulatory sampling drives stormwater management decisions. This has the potential to save considerable money later. The EPA expressly identifies copper and zinc impairment as a basis for the residual designation.
Sources that could cause or contribute stormwater pollutants of concern to this impairment include outdoor materials and activities, including galvanized roofing and fencing; metal roofs/downspouts; brake/tire wear; parking areas; HVAC equipment; dumpsters; outdoor metal storage; loading areas; vehicle traffic; wash areas; industrial fallout; and legacy site conditions.
SCS recommends seeking a Property and Applicability Screening as a first step. Some facilities may require Facility Compliance or Pollutant Source Assessments, and a Compliance Option Analysis to determine a roadmap to compliance.
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