In California, a storm water permit is a crucial regulatory requirement designed to control and prevent the pollution of the state's water bodies from stormwater runoff generated by various activities. These permits are mandated under the federal Clean Water Act's National Pollutant Discharge Elimination System (NPDES) program and are administered by the California State Water Resources Control Board (SWRCB) and its nine Regional Water Quality Control Boards (RWQCBs).
Why Are Storm Water Permits Necessary?
Stormwater runoff, which is rainfall or snowmelt that flows over land or impervious surfaces like roads and parking lots, can pick up pollutants such as oil, grease, chemicals, metals, sediment, and other debris. Without proper controls, these contaminants are carried into storm sewer systems and discharged untreated into rivers, lakes, and oceans, harming aquatic ecosystems, contaminating drinking water sources, and impacting recreational activities. Storm water permits aim to minimize this pollution, protecting California's vital water resources.
Key Storm Water General Permits in California
California primarily issues three types of general NPDES storm water permits, each targeting specific sectors:
Industrial Stormwater General Permit (IGP)
The Industrial Stormwater General Permit (NPDES No. CAS000001) regulates stormwater discharges from specific industrial facilities that fall under certain Standard Industrial Classification (SIC) codes. These facilities include manufacturing plants, transportation facilities, recycling centers, and some waste disposal sites.
Operators of facilities subject to this permit are required to develop a Stormwater Pollution Prevention Plan (SWPPP). This essential document, developed by the facility's operators, serves to identify pollutants that are generated at a facility and outlines specific measures for controlling those pollutants.
Construction Stormwater General Permit (CGP)
The Construction Stormwater General Permit (NPDES No. CAS000002) applies to construction projects that disturb one acre or more of land, or smaller sites that are part of a larger common plan of development. The primary goal of this permit is to reduce pollutants, especially sediment, from construction sites that can be carried away by stormwater runoff. Permittees must also develop a SWPPP tailored to construction activities.
Municipal Separate Storm Sewer System (MS4) Permits
Municipal Separate Storm Sewer System (MS4) Permits are issued to cities, counties, and other public entities that operate municipal storm sewer systems. These permits require local governments to implement comprehensive stormwater management programs to reduce pollutants discharged from their systems. This includes public education, illicit discharge detection and elimination, construction site runoff control, post-construction stormwater management, and pollution prevention/good housekeeping for municipal operations.
The Role of the Stormwater Pollution Prevention Plan (SWPPP)
A cornerstone of compliance for many industrial and construction facilities is the Stormwater Pollution Prevention Plan (SWPPP). As previously mentioned, this document identifies potential sources of stormwater pollution at a site and describes Best Management Practices (BMPs) that will be implemented to reduce or prevent pollutants from being discharged.
Essential Components of a SWPPP
A well-developed SWPPP typically includes the following critical elements:
| Component | Description |
|---|---|
| Site Map | A detailed map showing property boundaries, drainage areas, stormwater discharge points, existing structural controls, pollutant sources, and locations of proposed BMPs. |
| Pollutant Source ID | An assessment of all potential sources of pollution at the facility, including industrial activities, material storage, waste handling, vehicle maintenance, and potential spill areas. |
| Best Management Practices (BMPs) | Specific structural and non-structural actions implemented to prevent or reduce pollution. Examples include sweeping, covering outdoor materials, erosion control, and spill prevention. |
| Monitoring Program | A plan for collecting stormwater samples, conducting visual observations, and analyzing the samples to evaluate the effectiveness of the BMPs and compliance with discharge limits. |
| Training Program | Procedures to ensure employees are properly trained on stormwater pollution prevention, their responsibilities, and the implementation of the SWPPP. |
| Record Keeping | Requirements for maintaining records of inspections, monitoring data, training, and any non-compliance events. |
Achieving and Maintaining Compliance
To ensure compliance with a storm water permit in California, permittees must:
- Develop and keep current their facility's or project's SWPPP.
- Implement and maintain appropriate Best Management Practices (BMPs) to control pollution.
- Conduct regular inspections and monitoring of stormwater discharges.
- Report monitoring data and compliance information to the SWRCB, often through the online Stormwater Multiple Application and Report Tracking System (SMARTS).
- Provide training to employees on stormwater pollution prevention practices.
- Respond promptly to any spills or unauthorized discharges.
By adhering to the requirements of their storm water permits, businesses and municipalities in California play a vital role in protecting the state's precious water resources for both environmental health and public use.
[[Stormwater Compliance]]
