What are the Requirements for Vehicle Washing?

The Office of Compliance Fact Sheet Series

What Operations Constitute Vehicle Washing?

Washing involves the cleaning of vehicle exterior surfaces through one or a combination of the approaches listed below:

• Mobile washing - vehicles are washed with portable equipment such as high pressure hot water (including steam) hoses or wands, brush cleaners, dry washing with aerosols, and self-propelled washing units.
• Permanent wash facilities - vehicles are washed at a fixed system in a building or outside. Permanent facilities include drive-through brush systems and multi-step pressure wash bays.
• Commercial washing - vehicles are taken to wash facilities operated by a commercial company other than the company that owns the vehicles being washed. The facilities operate similar to permanent wash facilities.

How Is the Wastewater from Vehicle Washing Managed?

Vehicle wash facilities create a great deal of wastewater that can be either discharged, recycled or a combination of the two. Discharges of wastewater from wash facilities usually contain pollutants and are either discharged through a sewer system (e.g., combined, storm or sanitary), discharged to surface waters, or percolated into the soil. Some of the pollutants in typical washing wastewater that must be addressed are:

Discharges to surface water.

• Drainage to a storm water ditch or sewer from washing activities on asphalt parking areas
• Oil-water separator flow to a stream or other waterway from permanent wash facilities or wash racks.

Persons responsible for new wastewater discharges requiring an NPDES permit for vehicle washing are required to apply for an individual permit or seek coverage under a general permit (if available) at least 180 days before discharge of vehicle wash wastewater is scheduled to begin. Some states do not allow this discharge into the environment.

Discharges to local publicly owned treatment works (POTW).

Discharges of wastewater that are treated in a POTW must meet pollutant limits assigned by the POTW. In order for these discharge limits to be met, the owner or operator of the facility performing the washing activity may have to pretreat the wastewater. A common pretreatment used to meet POTW acceptance criteria is separating the oil, water, and suspended solids. This pretreatment is typically performed in oil-water separators outfitted with a grit settling chamber. Other pretreatment may be required to meet the acceptance limits for the POTW. Owners and operators of facilities that perform vehicle washing need to contact their local POTW to learn its acceptance criteria and perform any additional pretreatment, other than separation of oil, water and solids, before discharging vehicle washing wastewater.

If I Have an Oil-water Separator, What Are My Requirements?

Oil-water separators require periodic servicing to maintain their performance. Accumulated solids must be removed regularly from the bottom of the separator, and oil floating at the top of the separator must also be removed regularly. The frequency for servicing is not mandated by regulation. It is based on the size of the separator and the volume and make-up of the wastewater flowing through it. Periodic inspections allow facility personnel to determine when the sludge must be pumped out and the oil removed.

The oily waste generated by the oil-water separator generally can be sent to a used oil recycler and managed as a "used oil". Separator sludge may be hazardous waste due to metals content. The sludge should be sampled to determine if it is a hazardous waste. If the sludge exhibits any characteristic of a hazardous waste, it must be handled as such.

How Do I Obtain More Information?

State environmental offices and EPA regional offices may have regulatory authority over various aspects of vehicle washing. State or Regional EPA offices should be contacted with specific questions.

Publications:

If you need more regulatory guidance as it relates to vehicle washing, please consult the following EPA publications:

• Storm Water Management for Industrial Activities, EPA 832-R-92-006
• Overview of the Storm Water Program, EPA 833-R-96-008
• Phase I NPDES Permit Renewal Fact Sheet
• Storm Water Phase II Program. Fact Sheet
• Do I Need a Storm Water Permit in the Trucking Industry? Fact Sheet

Contacts: Contact the American Trucking Association at 703-838-1700 or access EPA's home page at.