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ECAR Fact Sheet for Hawaii
Wastewater Discharges

Self-Audit Checklist
Best Management Practices
Related ECAR Fact Sheets
Other Relevant Resources


The following fact sheet was prepared by the ECAR Center staff. Once prepared, each ECAR Center fact sheet undergoes a review process with the applicable state environmental agency(ies). You can check on the status of the review process here. Please read the disclaimer on the status page. While we have tried to present a summary of the essential information on this topic, you should be aware that other items, such as local regulations, may apply to you.

What You Need to Know

As an auto recycler, you almost certainly generate wastewater through operations such as rinsing parts and washing engines, cars and dirty tools. If water becomes mixed with oil, antifreeze, solvents, or other liquids, it is important that it be properly treated and contained prior to discharge. If your wastewater is currently just going down an unregulated drain, you're potentially causing significant problems for which you will be held responsible.  Even if your activities have gone unnoticed for years, there is an increasing chance that you will be inspected.  The federal EPA and the states are starting to look much more carefully at sources of water pollution that have so far remained unidentified, and they have decided to focus on auto recyclers in particular.

There are a few basic rules to keep in mind.  The first is that wastewater from ordinary lavatory use and hand washing ("domestic wastewater") can generally be discharged to a city sewer or a septic field only if it does not contain any waste from industrial sources. Wastewater from industrial discharges is usually handled by wastewater treatment plants, but you will probably be required to conduct "pretreatment" of the discharge. Most importantly, you should remember that the storm drains that carry rain and snow runoff from dismantling yards, roof downspouts, parking lots, and other surfaces typically go directly to open waterways, and must never be used illegally for disposal.  It is important that all the employees at your yard are aware of these rules, and that they respect them.

You will almost certainly need separate permits both for stormwater runoff (see the ECAR Stormwater fact sheet) and for any industrial wastewater that you generate.  This page will give you an overview of how to handle your industrial wastewater.


This fact sheet addresses wastewater discharges other than stormwater, which is covered by a different fact sheet. Wastewater from salvage yards can be subdivided into two main types:

  • "Domestic wastewater" includes the water coming from lavatories/washrooms, showers, drinking fountains, etc.
  • "Industrial wastewater" includes the water going into floor drains in areas such as dismantling, discharges from aqueous cleaning, water from steam cleaning or equipment wash down, water used for floor cleanup in dismantling areas (e.g., mop water), or water from any other sources where it comes into contact with dismantled parts, equipment, trucks, or machinery.

Domestic wastewater can be discharged to a city sewer system or an approved septic tank system. Most local governments require businesses to obtain a discharge permit. Domestic wastewater cannot be discharged to a stream, pond, or wetland without having a special permit.

Industrial wastewater is regulated differently than domestic wastewater. If you combine domestic and industrial wastewater, then the mixed wastewater is regulated like industrial wastewater. All industrial wastewater discharges are regulated by federal and state regulations and in most cases, also by local regulations established by the publicly owned treatment works or POTW.

Disposal Options. There are four primary options for disposing of industrial wastewater from auto recycling facilities:

  1. Discharge it to a POTW (Publicly Owned Treatment Works) or Sanitary Sewer System. If your facility discharges industrial wastewater into a municipal sewer that is connected to a POTW, you must meet the standards set by the receiving water treatment facility. Also, you may be required to treat your wastewater prior to discharging it to a sewer or POTW, and you will need a permit or written permission for all discharges. Contact your municipality to obtain a discharge permit and for applicable local requirements. You must also follow state and federal requirements, which are outlined under the Regulations section below.
  2. Haul it to an approved treatment facility. If your area is not served by a municipal sanitary sewer system, you may opt to transport your wastewater to an approved treatment facility. Before you haul wastewater you must perform a hazardous waste determination. This may involve getting it tested by a laboratory. If the wastewater is non-hazardous, then you should maintain test records that support your determination.
  3. Haul it to a Hazardous Waste Treatment Facility. If your industrial wastewater is considered "hazardous," you must manage it using special procedures. For more information, see the ECAR Hazardous Waste Fact Sheet. You will need to ensure that the tank storing this wastewater meets the requirements contained in the hazardous waste rules. In addition, you must ensure that you properly manage the wastewater upon removing it from the tank and that it is transported by certified hazardous waste transporters.
  4. Discharge it to the Surface Waters. If your facility discharges industrial wastewater via a "point source" (such as a pipe, etc.) directly to waters of the state, you will be required to obtain a National Pollutant Discharge Elimination System (NPDES) permit. Waters of the state include (but are not limited to) ground water, storm drains, rivers, ponds, streams, lakes and ditches. NPDES permits set limits on the quantity, discharge rate and concentrations of pollutants in the water that are discharged from a point source into waters of the state. If you obtain this type of permit, you will be required to frequently collect samples of your wastewater and have them analyzed at a laboratory. You will also have reporting and recordkeeping responsibilities.

Most auto recyclers use option 1 or 2. Option 1 is viable when the facility is located in an area served by a sanitary sewer system, while Option 2 is the economical choice when the volume is small. Before you begin to discharge industrial wastewater using option 1, you must acquire a permit or written approval from your local sewer district or POTW. You also will have to meet certain rules found in federal and state regulations, including:

  • You are prohibited from discharging any pollutant, including oil, that may upset or interfere with the sewage treatment processes or pass through the system untreated;
  • The pH of your wastewater often must be between 6.0 and 9.0;
  • You cannot discharge pollutants (e.g., solvents) that may cause a fire in the sewer system; and
  • You cannot discharge pollutants such as sludge (e.g., grease, dirt) that may clog the sewer system.

Pretreatment. To meet the rules listed above, you may need to install treatment equipment such as an oil/water separator to prevent oil and sludge from being discharged to the sewer. This is referred to as "pretreatment." The oil and sludge collected by pretreatment equipment will have to be periodically removed and disposed of, possibly as a hazardous waste (you must make a hazardous waste determination).

*It is important to note that discharging industrial wastewater to a septic tank is not a viable option. Septic tank systems, wells, drain fields, cesspools and similar disposal sites are regulated by federal and state Underground Injection Control (UIC) program rules that are designed to prevent the contamination of underground drinking water supplies. For more information see the Septic Tanks and Disposal Wells Fact Sheet.

Links to the Regulations and Forms. Use the following links to view the regulations and permit forms pertaining to wastewater.

Hawaii Wastewater Regulations - Chapter 11-62 HAR

NPDES Permits

UIC Application for Backfilling an Injection-Well Cesspool Instructions

Self-Audit Checklist

When an inspector comes to your facility, there are certain things he or she checks to see if you are in compliance with environmental regulations. It makes good sense for you to perform a "self-audit" and catch and correct problems before they result in penalties. Also, there are some compliance incentives associated with self-audits (see Audit Policy Page).

Use the following list to audit your wastewater management activities.

  1. Does your facility discharge process wastewater? Are the discharges authorized by a permit? Check all uses of water and steam within the industrial areas of your facility. Determine where wastewater is generated and discharged. You must have a NPDES permit to discharge to surface waters and you will likely need a permit to discharge to your local sewer authority. Check with your local POTW and the Tennessee Department of Environment and Conservation (TDEC) to ensure you have the proper permits.
  2. Have you performed the necessary pretreatment? If you are discharging to a sewer system/treatment plant, you may have to perform pretreatment of your waste. Check with your local sewer authority.
  3. Is oil or solvent discharged to the sewer? Federal and state laws prohibit the discharge of oil or flammable solvents to the sewer system. These are regulated wastes that must be properly disposed of.

Best Management Practices (BMPs)

Most regulations tell you what you have to do to be in compliance, but they don't explain how to do it. That's where "best management practices" come into play. BMPs are proven methods that help you to get into compliance and stay there. The following BMPs are recommended for wastewater management.

  • Limit water use and the volume of water discharged through conservation methods and by reusing water whenever possible.
  • Train employees to use water efficiently.
  • Don't use water for cleaning floors and equipment unless absolutely necessary. Use dry cleanup methods for spills.
  • Post signs at all floor drains and sinks in industrial areas of your facility to discourage employees from using the drains to dispose of oil, other vehicle fluids, solvent, paint or similar liquids. Review these rules with your employees.
  • Use only non-toxic soaps to clean floors and vehicles instead of hazardous materials.
  • If you have floor drains at your facility that are not in use, consider having them capped or plugged to prevent misuse or accidental discharges.
  • Prevent drips and spills from reaching the floor.
  • Check your floor drains and make certain you know where they discharge.
  • Setup and use a maintenance schedule for inspection and cleaning of floor drains, oil/water separators, traps, etc.
  • Never have floor drains where hazardous materials are stored.
  • If your wastewater is nonhazardous, you may want to purchase evaporating equipment to evaporate your wastewater. It should be noted that evaporators may require an air permit or registration, and evaporator bottoms may be considered a hazardous waste.
  • Don't use degreaser solvents to clean engines. Most engine degreasers are hazardous and should not be discharged to a POTW. Even if you use nonhazardous degreasers, the oil and grease concentration in the spent degreaser may exceed the limit allowed by your sewer authority.


  1. For more information, contact the Hawaii Department of Health (DOH), Solid and Hazardous Waste Branch, Hazardous Waste Section at (808) 586-4226.
  2. To report a spill or leak, or to report an environmental incident or complaint, call the Hawaii Department of Health Office of Hazard Evaluation and Emergency Response 24-hour hotline at 808-247-2191, or 808-586-4249 during regular office hours.

Related ECAR Fact Sheets

  1. Stormwater
  2. Septic Tanks and Disposal Wells

Other Relevant Resources

  1. Directory of Environmental Businesses in Hawaii, 2000
  2. Hawaii Recycling Industry Guide


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