NPDES Stormwater
The goal of the Storm Water Program is to prevent or minimize the discharge of pollutants contained in storm water runoff to waters of the state. During rainfall events, water runs across surfaces which may be contaminated by pollutants (such as motor oil, litter, etc). The storm water runoff is often directed into storm drains which then discharge to nearby creeks and rivers. Common pollutants contained in storm water runoff include:
- Sediment - construction or other activities expose and loosen soils, while vehicles break-up pavement. Excessive sediment in water can effect the respiration, growth, and reproduction of aquatic organisms, cause aesthetic impacts to receiving streams and affect spawning habitat for salmonids.
- Nutrients - sources include fertilizer, lawn clippings, and car exhaust, which contain nutrients like phosphorous and nitrogen. An overabundance of nutrients can accelerate the growth of algae, which is a key factor in the decline of water clarity in Lake Tahoe and other water bodies.
- Heavy metals and toxic chemicals - sources include cars (brake pads, engine wear, etc), pesticides and herbicides. Maintaining and cleaning transportation vehicles can release solvents, paint, rust, and lead. These chemicals may poison organisms or cause serious birth defects.
- Bacteria- sources include failing septic tanks, sewer overflows, decaying organic material, and the improper disposal of household pet fecal material. Some bacteria found in storm water runoff can result in disease. Beach closures result from high bacteria levels.
Recent studies have shown that storm water runoff is a significant source of water pollution, causing declines in fisheries, restrictions on swimming, and limiting our ability to enjoy many of the other benefits that water provides (USEPA). The federal Storm Water Permit Program attempts to curtail storm water pollution by requiring some specific industries and municipalities to obtain a permit for storm water discharges. The permit regulates the permittees activities to ensure the proper management of pollution sources. There are three types of permits required under the federal program: Construction, Industrial, and Municipal permits.
Industrial Permits
Storm water discharges to surface waters from companies involved in manufacturing operations, transportation facilities where vehicles are maintained (maintenance includes fueling and washing), landfills, hazardous waste sites, and other similar operations must be covered by a storm water discharge permit. For coverage under the state's industrial storm water general permit, each facility must submit an application to the State, prepare and implement a Storm Water Pollution Prevention Plan, and monitor the flow of pollutants leaving the site. Although the plan does not have to be submitted to the Regional Board, the permittee must keep the plan available to onsite inspectors and submit an annual report to the Board. With State approval, the general permit allows group monitoring, where only selected facilities within a group are monitored in order to characterize the whole group. Also, a company may be exempt from all or part of the general permit if industrial materials (including wastes, products, machinery, roof exhausts, etc.) are not exposed to rain.
Construction Permits
The major pollutant expected from construction sites is erosion-related, where large amounts of sediment laden water flows into storm drains. Construction activities that involve more than five acres of land disturbance must obtain a permit for discharges of storm water. Construction on sites of less than five acres that are part of a larger project that covers more than five acres also must be permitted. However, construction activities that essentially maintain existing facilities, and do not involve a change in the slope of the land, are not required to be covered under a permit. The State's general permit for discharges of storm water from constuction activities requires the site owner to apply with the State, to prepare and implement a Storm Water Pollution Prevention Plan, and to monitor the effectiveness of the plan. The plan does not have to be submitted to the Regional Board, but must be on site and available to inspectors. The plan must also address post-construction control of pollutants in storm water. The size criteria for permit coverage will drop to 1 acre in March, 2003.
Municipal Permits
Large cities or other municipalities must obtain a storm water permit for discharges of urban runoff from municipal storm drain systems. The only municipality currently under a permit with this Regional Board is Santa Rosa, with the County of Sonoma and the Sonoma County Water Agency as copermittees. The permit for Santa Rosa requires specific practices associated with street cleaning, roadside maintenance, toxic/sewage spill responses, and public outreach, to name a few. Currently, the permit covers the City of Santa Rosa and the immediate area around it.
Phased Program
The Storm Water Program is a National Pollutant Discharge Elimination System (NPDES) Program, and is currently being implemented in two phases. The November 16, 1990 Federal Register describes the requirements of the Phase I Regulations and the December 8, 1999 Federal Register describes the Phase II regulations. The State of California carries out the Storm Water Regulations according to the California Water Code Section 13399.