1104 Automotive Services and Repair
AUTOMOTIVE SERVICES AND cash and check advances REPAIR
This category includes automotive repair and service shops (SIC Nos.753x and 754x). Specific services of concern include Top, Body, and Upholstery Repair Shops and Paint Shops (SIC No. 7532); Automotive Exhaust System Repair Shops (SIC No. 7533); Automotive Transmission Repair Shops (SIC No. 7537); General Automotive Repair Shops (SIC No.7538); Automotive Repair Shops, Not Elsewhere Classified (SIC No.7539); and Carwashes (SIC No. 7542). Automotive Dealers and Gasoline Service Stations are classified separately in SIC major group 55; most of these facilities have repair operations and produce similar wastes.
Description of Operations
General Maintenance & Repair
Common types of vehicle maintenance operations include drainage and replacement of lubricants, coolants, and brake fluids; radiator and brake maintenance, and incidental mechanical repairs. Rapid lubrication and oil change services have become particularly popular automotive specialty services which handle large quantities of oils and other fluids.
Automotive repairs shops conduct a range of vehicular repair and maintenance services, which may include application of paints and coatings, as well as mechanical repairs. In addition to general repair shops, this group includes specialty muffler, brake, and transmission repair shops.
Parts cleaning and degreasing of automotive parts and steam cleaning of engines are regularly performed as part of maintenance and repair activities. The use of solvents and detergents has been the focus of environmental concerns.
Radiator repair shops clean, flush, and repair radiators. Radiators are drained of coolant and cleaned in tanks of highly alkaline solution (pH above 12), which may contain zinc chloride, and then rinsed with water either in a dip tank or by flushing with a hose. Radiators are pressure tested in a tank of water by plugging the inlet and outlet and blowing air into the radiator through an air hose. After testing and drying, radiators may be spray painted.
autobody Repair & Refinishing
Paint and body shops repair and paint vehicles. Old paint may be removed by stripping and sanding and new paints applied with hand-held sprayers. Body shops are frequently very small, two or three person operations.
Rustproofing shops may remove dirt from the undercarriage of vehicles using pressure hoses. Vehicles may also be pretreated with rust removers containing strong acids or alkalis prior to spraying on rustproofing solutions. Solvents such as kerosene or mineral spirits are used to clean spray equipment and to remove rustproofing compounds from painted surfaces of the vehicle, often using a hand-held solvent spray gun.
Automatic car washes are equipped with high-pressure spigots dispensing soap solutions, usually containing a degreasing agent such as methylene chloride or trichloroethylene (TCE), rinsewater, and waxes, and with rotating brushes and buffers. Self-service car washes may provide covered or outdoor paved areas with pressurized spray hoses dispensing soap solutions, rinsewater, and wax.
General Assessment and Recommendations for the Local Regulatory Official
A large number of surface-water and ground-water contamination incidents have been attributed to various types of operations associated with automotive service and repair. Vehicle service bay floor drains have been the principal route of contamination. Floor drains receive various wastes such as floor washdown containing detergents, sediments, and road salts; leaked or spilled fuels, oils, and solvents; drippage from vehicles; particulate paint wastes with heavy metals; and drips and spills from rustproofing operations. If these drains are connected to dry wells or septic systems, they provide a route of injection of these wastes to ground water; these injection wells may be difficult to find if they are located under buildings or paved surfaces. In some cases floor drains may discharge to storm sewers or directly to surface waters.
Wastewaters from floor washdown and car washes have been permitted to discharge to municipal sanitary sewer systems if they are pretreated for oil and grit removal. However, little is known about the impacts of these discharges to septic systems and ground water.
There is also a potential for ground-water and surface-water contamination through improper storage of solvents; spillage; improper disposal of concentrated liquid wastes by pouring on the ground or by burying wastes on-site; or through improper handling and disposal of solid wastes such as fuel and oil filters, used batteries, and engine parts. In addition, many of these shops have underground fuel storage tanks which have the potential to contaminate ground water through their failure.
DESIGN BMPs – GENERAL BEST MANAGEMENT PRACTICES
Floor drains in service bays and vehicle washing areas must either be connected either to a holding tank with a gravity discharge pipe, to sump which pumps to a holding tank, or to an appropriately designed oil/grit separator which discharges to a municipal sanitary sewer.
Oil/water separators must receive only floor washdown or vehicle washing wastewaters. They must not be used to collect spills or concentrated wastes.
If vehicle washing is conducted regularly, floor drains in wash bays must be connected to a separate grit separator, which then discharges to the municipal sanitary sewer. Wastewaters from vehicle washing represent significant flows which can hydraulically overload an oil separator, and may contain detergents which can emulsify oils in an oil separator and impair treatment of oily wastewaters from service bay floor drains.
Service bay floor drains that discharge to dry wells must be cleaned out and eliminated. Liquid and sediment samples should be taken, and contaminated dry wells must be removed and contents disposed in accordance with regulatory requirements.
If no floor drains are installed, there should be no vehicle washing, and there should be no discharges to the environment of any kind.
Vehicle wash bays must be completely bermed.
Seal service bay concrete floors with an impervious material to facilitate cleanup without using solvents.
Floors should not be cleaned by flushing with water; use a wet-vacuum or mop and dispose of cleaning wastes properly.
Some facilities may use service “pits” which allow a vehicle to be serviced without using a hydraulic lift. These pits often have earthen floors, which are vulnerable to spills and contamination. Service pits must be checked for historical contamination, taking remedial action taken when necessary. Service pits should be completely surfaced with concrete and sealed with a suitable impermeable material. There must also be provisions for the collection of spills or accumulations of wastes, such as a sump that discharges to a holding tank. The construction of service pits must be avoided in any new facilities.
Areas where vehicles are stored or repaired must have an impermeable surface and have provisions for containment of vehicle leaks.
Hydraulic lifts should be checked for leaks and potential releases of fluid. Lift systems must be provided with a secondary containment system. Above-ground lift systems should be used wherever possible. A nonhazardous hydraulic fluid should be used.
Uncovered vehicle storage areas should have a separate stormwater collection system with an oil/grit separator which discharges to the municipal sanitary sewer or to a dead holding tank.
Dedicating service bays for a specific operation, such as parts cleaning & degreasing, engine steam cleaning, radiator repair, fluid changes and replacement, vehicle washing, rustproofing & undercoating, and body stripping & painting, can minimize cross-contamination, facilitate segregation of waste streams, and allow for more efficient handling of materials and wastes.
Each service bay should be provided with a waste collection station. Each station could have labeled containers or for each type of waste fluid, or labeled waste sinks which discharge to an appropriate waste-holding tank.
General Maintenance & Repair
In engine rebuilding, engine bakeout and ball peening may be a suitable substitute for engine boilout.
Use drip pans to minimize leaks and spills onto the floor.
High-performance, longer lasting oils can reduce the frequency of changes and the amount of waste produced.
Used engine oil should be recycled through a licensed recycling service.
Spent oil filters may be recycled for their scrap metal content. A drain rack over a waste oil sink might be used to drain and collect all residual oil prior to disposal.
Consider the use of propylene glycol-based antifreeze as an alternative to the more toxic ethylene glycol types.
Antifreeze can be recovered either on-site or off-site. Units are available which chemically restore ethylene glycol by removing impurities and neutralizing organic acids formed as breakdown products of the coolant. Other services are available which will regularly remove and process used antifreeze, selling the product back to the generator at reduced cost.
Parts Cleaning & Degreasing
Aqueous or alkaline cleaners may be substituted for solvent-based cleaners in some applications, particularly for non-aluminum parts.
High-pressure water washing may be an effective method of parts cleaning; wastewater can be treated with an oil/water separator and recycled.
Substitute nonchlorinated solvents for chlorinated compounds wherever possible.
Parts cleaning and degreasing area should be isolated from other operations, preferably located within a containment area with no direct access to outside the facility, and the floor must be sealed with a suitable impermeable material.
Precleaning parts with a squeegee, rag, or wire brush, followed by steam cleaning, high-pressure wash, or hot bath which recycles an aqueous solution using an oil separator, would be an efficient approach to minimizing or even eliminating the use of hazardous solvents and would prolong the life of any subsequent cleaning solution.
Where possible use only hot water for the precleaning and subsequent cleaning steps. With a recycling system, a detergent may be used and arrest inhibitor may be added if parts are sensitive to corrosion.
For non-aluminum parts an alkaline-based aqueous cleaner may be used.
If hot water, detergent, or alkaline baths are demonstrably inadequate, then a nonchlorinated organic solvent might be used, such as d-limeoline (a terpene), or a high flash (> 140 F) naphtha. Chlorinated solvents and other solvents which have a specific gravity greater than 1.0 (water) should be avoided.
Using one multi-purpose solvent rather than several would increase reuse and recycling potentials.
Parts cleaning and degreasing should be done in a self-contained, recirculating solvent sink.
Extend solvent life by using a two-stage rinsing process with “dirty” and “clean” solvent baths. Reduce the frequency of solvent bath replacement to reduce solvent use and handling.
Decanting solvent sludges from tanks can extend solvent bath life. Replace solvent only as needed or extend the replacement schedule.
The used solvent decanted from the separation of solvent sludges cane reused as a precleaning step for dirty parts or for less critical parts prior to a final cleaning.
Increase freeboard and place hoods or covers on all parts-cleaning tanks to minimize evaporation of solvent.
Solvent test kits may be used to check when solvent is too dirty for further use.
A drip rack placed over the cleaning tanks would allow for dragout to drain prior to any following cleaning step. Reduce dragout from parts cleaning by allowing longer drip time, or wipe parts with cloth or rags.
Spent aqueous and other nonhazardous solutions may become hazardous after use due to elevated concentration of heavy metals or toxic organic substances. They must be treated or disposed as a hazardous material.
A recommended procedure for parts cleaning is to employ a service which will maintain the parts-cleaning unit, and exchange spent solvents, recycle off-site, or dispose of them properly on a contractual basis. Some services recycle up to 70 – 80 % of the solvent and sell it back to the generator at reduced cost. This would reduce handling of solvents, and would ensure proper operation and maintenance of parts-cleaning equipment.
On-site recycling systems may be used which employ distillation and/or filtration. These systems should be maintained by trained staff or a contracted service agent. A reduced emission/closed loop type, which captures evaporative losses, is preferred.
Engine Steam Cleaning
Eliminate the use of solvents for steam cleaning engines and parts.
Steam cleaning should not be conducted outside, where wastewaters maybe discharge to the ground.
If no detergents or solvents are used, steam-cleaning wastewaters may discharge to the municipal sanitary sewer via an oil separator.
If detergents or solvents are employed, wastewaters must either be recycled and reused or discharged to a holding tank. If a grit separator has been installed for treating vehicle washing wastewater prior to discharging to the municipal sanitary sewer, and if no solvents are used for steam cleaning, then these wastewaters may discharge to the grit separator.
Autobody Refinishing & Painting
Consider the use of water-based paints to reduce the amount of hazardous waste generated. These types of paints are being developed for most automotive applications, and should become more widely available in the near future.
Paints with low volatility, lower metal concentrations, and higher solid content should be used when possible.
Autobody painting should be done in a separate, secure area with no floor drains.
Water curtains in paint booths must recirculate the water used. There should be no discharges.
Reusable metal or styrofoam paint booth filters should be used.
Use more efficient painting processes such as electrostatic painting or powder coating, which reduce the amounts of paint overspray and paint waste generated. The efficiency of paint-spraying equipment varies from about 30-60% for air-atomized sprayers and 65-80% for electrostatic sprayers, to as much as 90-99% for powder-coating equipment.
Use more efficient paint transfer equipment, such as high-volume low-pressure or low-volume low-pressure spray guns.
Paint transfer equipment should be regularly calibrated to maintain proper application rates and reduce waste.
Mix paint only as needed.
Heating paint mixtures may reduce the amount of thinner are required.
Reduce paint cup size on spray guns to reduce amount of wasted paint.
Waste paint can be reused as a rough coat for other applications, such as undercoating.
Use recycling spray-gun washers to reuse solvent and reduce amount of waste generated.
Recycling may consist of filtration and/or distillation.
Segregate waste paint and paint sludges from waste thinner.
Decant waste thinner for reuse as a precleaning solvent for spray guns and other equipment, then use a small amount of fresh solvent for final cleaning. Paint thinners may be prolonged by using multiple cleaning steps, which may reduce spoilage of “clean” thinner baths. Waste thinners may also be recycled for use as a precleaning step for parts cleaning.
Aromatic and chlorinated hydrocarbon solvents should be eliminated from vehicle-washing operations.
Vehicle-washing operations should recycle wastewaters by using rinsewaters as makeup for washwater and using appropriate treatment such as filtration and grit removal. Recycle systems are available which recycle up to 100 % of the wastewater generated.
Washwaters may discharge to a dedicated grit separator which discharges to the municipal sanitary sewer. Car-wash wastewaters are not recommended to combine with floor drain wastewaters. Detergents used in washing may emulsify oils captured in the separator, which may subsequently discharge to the sewer system.
Aromatic and chlorinated hydrocarbon solvents should not be used in radiator repair.
Eliminate the use of lead solder where possible, or use solder with the lowest lead content.
Radiator repair shops can use a three-step system; a boil-out tank (no discharge) for cleaning; a dragout (no discharge) from which rinsewater is decanted into the boil-out tank to make up for evaporative losses; and a recycling system for rinsing and pressure testing, from which water is treated to remove metals (copper, nickel, lead, zinc, tin, chromium) and then reused. With this procedure, most contamination remains in the boil-out or dragout tanks.
Boil tanks should be placed in a secure area with secondary containment. The solutions from these boil tanks should be used for as long as possible.
Drainage from boil tanks should be collected in holding tanks or drums and may have to be disposed of as a hazardous waste.
Sludges from the treatment of the recycled rinsewaters must be collected and disposed as a hazardous waste.
Discharges from flushing rinsewater may be treated for metals removal and discharged to a municipal sanitary sewer system in accordance with federal, state, and local discharge regulations.
Spray painting of radiators should follow BMPs for autobody painting.
Eliminate the use of solvents in rustproofing operations where possible.
Use high pressure washing as an alternative to using solvents.
This operation may use equipment similar to that used in autobody painting. Follow BMP’s for autobody refinishing and repainting.
Solvent drippage from cleaning automobile surfaces prior to rustproofing or undercoating must be collected in a holding tank and disposed of properly. There must be no discharges from these operations.
If a pressure washing is done without using solvents, the wastewater may discharge to a grit separator connected to a municipal sanitary sewer. All federal, state, and local discharge regulations must be met.
Do not undercoat vehicles with used solvent or solvent sludge. Solvents and solvent sludges can drip from the vehicle undercarriage enter the ground.
Acid spills must be neutralized and discharged to R holding tank.
Rain and snowmelt can be cleaned with a wet-dry vacuum, or mopped. Collected material may be discharged to a waste-holding tank, or an oil/water separator connected to a municipal sanitary sewer.
Materials & Waste Management
Segregate wastes that are generated, such as chlorinated from nonchlorinated solvents, oils from solvents, and antifreeze from both oils and solvents in order to minimize disposal costs and facilitate recycling and reuse.
Use high-performance, longer lasting oils.
Do not use waste oil as a dust suppressant.
Do not use antifreeze as a de-icing agent.
Waste-oil tanks should be used to collect and store petroleum-based fluids drained from vehicle, including used oil, transmission fluid, and brake fluid; they should not be used for collecting cleaning solvents or antifreeze. Tanks should be pumped out by a waste hauler licensed in accordance with federal, state, and local regulations.
Spent oil filters should be recycled for their scrap metal content. A drain rack over a waste oil sink might be used to drain and collect all residual oil prior to disposal.
Antifreeze should be recycled on site or be taken to a recycler. Service contractors may be available to maintain equipment on site and to recycle antifreeze.
Some facilities accept household disposal of antifreeze and waste oil. These must be segregated from business-derived wastes. Household wastes are exempt from RCRA requirements. Segregation will also eliminate the possibility of cross-contamination from the introduction of contaminants in the household wastes.
Lead-acid batteries should be recycled. Store small quantities of lead-acid batteries in acid-resistant tubs. Inspect batteries for cracks or leaks, especially if exposed to freezing temperatures, and store in a container that will hold released material. Large quantities of batteries should be stored in an isolated area with no floor drains, or floor directed to sumps connected to a dedicated holding tank. Storage areas should be sealed with an acid-resistant material and have a containment berm. Batteries stored on pallets must not be stacked higher than 3 to 5 feet, and should be covered and stored within an enclosed area and protected from freezing temperatures.
Inspect damaged vehicles to be serviced for leaks; use drip pans, isolated from floor drains or other possible pathways to the environment.
Have oil/grit separators cleaned every 6 – 12 months by a waste hauler licensed in accordance with federal, state, and local regulations. Maintain proper water level in separator to prevent pass-through of oils and other floatables.
Send waste solvent to a waste exchange for further reuse and recycling.
Wring out solvent rags and soaked adsorbent pads and booms for reuse, being careful to minimize human contact.
Waste paints, thinners, paint sludges and solids should be collected and drummed and disposed of according to federal and state regulations.
Scrap metal parts, or other parts which were in contact with lubricant, must be stored in enclosed containers indoors or in areas secured from stormwater accumulation. Dumpsters containing scrap metal should have drain plug in place and be covered. Preferably, they should be located on a concrete pad with a separate collection catch basin, which is pumped out periodically.
Trial-.test recycling equipment to ensure compatibility with materials used and usable recycled product.
Regular inspection and maintenance schedules should address oil and grit separators, catch basins, and vehicle storage areas.
Clean hands with waterless cleaners and dispose of waste properly with hazardous waste, then wash hands.
Store wastes indoors in covered areas to prevent moisture from seeping in.
Source: US EPA
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