This pollution prevention measure targets automobile maintenance businesses and other groups running fleets of vehicles such as schools and police departments. This measure's goal is to teach prevention methods that control pollutants and reduce stormwater effects. Automotive maintenance facilities are considered stormwater "hot spots," producing significant loads of hydrocarbons, trace metals, and other pollutants. Wastes generated in automobile maintenance facilities and by residents performing their own car maintenance include:
- Solvents (paints and paint thinners)
- Brake fluid and brake lining
- Motor oils
- Fuels (gasoline, diesel, kerosene)
- Lubricating grease.
An estimated 180 million gallons of used oil is improperly disposed of each year (Alameda CCWP, 1992). The used oil from one oil change can contaminate 1 million gallons of freshwater — a year's supply for 50 people. For this reason, automotive maintenance facilities' discharges to storm and sanitary sewer systems are highly regulated. Fluid spills and improper disposal of materials result in pollutants, heavy metals, and toxic materials entering ground and surface water supplies, creating public health and environmental risks. Altering practices involving the cleanup and storage of automotive fluids and the cleaning of vehicle parts can help reduce the influence of automotive maintenance practices on stormwater runoff and local water supplies.
The automotive repair industry is a leading producer of hazardous waste. Individually, the nation's many repair businesses generate small amounts of hazardous waste. Collectively, however, they represent a major source of stormwater pollution (USEPA, 1985). Maintenance shops generate waste when they clean auto parts, change vehicle fluids, and repair and replace equipment. Many car owners perform the same activities at home as part of normal vehicle care. Since automobile use is common in all climates and in all geographical locations, maintenance facilities exist nationwide, as do concerns about wastes created during vehicle repairs. In ultra-urban areas, the effects of automotive maintenance practices are more pronounced due to greater concentrations of vehicles and more impervious surfaces.
The most effective way to minimize the effects of wastes generated by vehicle maintenance is to prevent their production in the first place. To reduce liquid discharges to sewers and storm drains, pollution prevention programs should encourage facilities to run a dry operation. The following are suggestions to run a dry operation:
- Clean up spills immediately, whenever possible without using water.
- Seal off floor drains connected to sanitary sewers.
- Hire a solvent service to supply parts and cleaning materials, and to collect spent solvents.
Facilities unable to eliminate discharges to sanitary sewers may be required to treat their wastewater to prevent untreated wastewater from entering stormwater runoff. Some municipalities require structural treatment devices to pretreat wastes before discharge to sewage treatment plants. These devices prevent oil and grease from entering the sewer system, often by separating the oil and solids from water though settling or filtration.
Table 1. lists suggested practices to prevent or reduce discharges of pollutants from vehicle maintenance. Many of these practices apply to both business owners and to residents who maintain their own vehicles. The practices can also be used in the maintenance of municipal fleets, including school buses, public works, fire, police, parks and others.
The list is not comprehensive. Many other suggestions for reducing discharges are available to those managing stormwater runoff from maintenance facilities.
See the USEPA's Used Oil Management Program for more information, including materials that may be downloaded and distributed.
Table 1. Suggests practices to reduce stormwater impacts of vehicle maintenance
Pollution Prevention Method
- Minimize the number of solvents used to make recycling easier and to reduce hazardous waste management costs.
- Do all liquid cleaning at a centralized station to ensure that solvents and residues stay in one area.
- Locate drip pans and draining boards to direct solvents back into solvent sink or holding tank for reuse.
Using Safer Alternatives
- Use non-hazardous cleaners when possible.
- Replace chlorinated organic solvents with nonchlorinated ones like kerosene or mineral spirits.
- Purchase recycled products such as engine oil, transmission fluid, antifreeze, and hydraulic fluid to support the recycled products market.
Spill Clean Up
- Use as little water as possible to clean spills leaks, and drips.
- Use rags to clean small spills, dry absorbent material for larger spills, and a mop for general cleanup. Mop water can be disposed of via the sink or toilet to the sanitary sewer.
- Employee training and public outreach are necessary to reinforce proper disposal practices.
- Conduct maintenance work such as fluid changes indoors.
- Update facility schematics to accurately reflect all plumbing connections.
- Monitor parked vehicles for leaks, and place pans under leaks to collect the fluids for proper disposal or recycling.
- Promptly transfer used fluids to recycling drums or hazardous waste containers.
- Do not pour liquid waste down floor drains, sinks, or outdoor storm drain inlets.
- Obtain and use drain mats to cover drains in the event of a spill.
- Store cracked batteries in leakproof secondary containers.
- Use detergent-based or water-based cleaning systems instead of organic solvent degreasers.
- Use steam cleaning and pressure washing instead of cleaning parts with solvent. The wastewater generated from steam cleaning can be discharged to the on-site oil/water separator.
Automotive maintenance facilities fail to apply pollutant-reducing recommendations for several reasons. Space and time constraints may make indoor work impractical. Containing spills from vehicles brought onsite after hours may be impossible. Educating employees in proper disposal techniques must be continually updated. Installing structural BMPs for pretreatment of wastewater discharges can be expensive. Recycled materials and fluids may cost more than non-recycled materials. A lack of businesses that provide recycled materials, hazardous waste removal, structural BMP maintenance, or solvent recycling equipment can also impede maintenance facilities.
Facilities responsible for pretreating wastewater prior to discharge have to undertake important maintenance activities to ensure that structural BMPs function properly. To maintain their effectiveness, devices must be routinely cleaned of oil and grease, usually at least monthly. Cleanouts are required more frequently during periods of heavy rainfall to ensure pollutant capture. Sediment removal is also required regularly to keep the device working efficiently.
Pollutant Removal:It is difficult to measure the pollutant-removal-effectiveness of automotive maintenance BMPs. However, several studies have demonstrated that pollution prevention practices can successfully reduce spillage of automotive fluids. A 1994 study of auto recycling facilities found that BMPs reduced stormwater toxicity and pollutant loads. The study facility used structural and nonstructural BMPs to reduce lead, oil, and grease concentrations to levels approaching USEPA benchmarks.
Increased Business Participation:Palo Alto, California's Clean Bay Business Program has successfully controlled contaminated flows from vehicle maintenance facilities. Facilities that allow yearly inspections and enact management practices recommended by inspectors earn the distinction of being a "Clean Bay Business." The designation entitles a facility to twice yearly full-page newspaper promotional ads, decals for shop windows, prize drawings, and discount coupon giveaways that help generate business for other facilities in the program. The program's success at changing behaviors is evident in the rise in the number of facilities receiving the Clean Bay Business designation. When the program began in 1992, only 4 percent of businesses used all of the recommended management practices. By 1998, 94 percent of businesses were instituting the suggested practices (NRDC, 1999).
The combined effect of the changes made by program participants resulted in the following:
- The elimination of 78 direct discharges to stormdrains by ceasing or modifying practices used in parking lot cleaning, vehicle washing, and wet sanding.
- A 90 percent drop in violations for storm drain protection requirements from 1992 through 1995.
- The number of shops conducting outdoor removal of vehicle fluids without secondary containment fell from 43 to 4.
The program's initial per-facility cost was approximately $300, with a cost of $150 for each subsequent year. This cost includes inspector visits and follow-up work, outreach materials, mailing lists, and database management. The program has been expanded to include auto parts stores, and outreach to local high schools and adult education repair classes.
Alameda Countywide Clean Water Program. 1992. Keeping it all in tune: Car repair and pollution prevention. Alameda Countywide Clean Water Program, Hayward, CA.
Camp Dresser & McKee et al. 1993. California Stormwater Industrial/Commercial Best Management Practice Handbook. Stormwater Quality Task Force, Sacramento, CA.
Center for Watershed Protection. 1995. Auto Recyclers-Onsite BMPs Mitigate Urban Runoff Hotspots. Watershed Protection Techniques, Vol 1, No. 4.
Santa Clara Valley Nonpoint Source Pollution Control Program. 1992. Best Management Practices for Automotive-Related Industries: Practices for Sanitary Sewer Discharges and Stormwater Pollution Control. Santa Clara Valley Nonpoint Source Pollution Control Program, San Jose, CA.
USEPA. 1991. Guides to Pollution Prevention: The Automotive Repair Industry. U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH.
USEPA. July 1992. Stormwater Management for Industrial Activities: Developing Pollution Prevention Plans and Best Management Practices. United States Environmental Protection Agency, Office of Wastewater Compliance, Washington, DC.
USEPA. No date. Used Oil Management Plan. [www.epa.gov/osw/conserve/materials/usedoil//]. Environmental Protection Agency, Office of Solid Waste, Washington, DC. Accessed September 15, 2005.