New York Sea Grant's
Marina Pollution Prevention Web Site

Section 5: Facility Management - Compressor Blowdowns

Potential Environmental Impacts

Air compressor blowdown water commonly contains lubricating oil or other potential pollutants. These hydrocarbons can contaminate surface and groundwater when improperly managed.

Best Management Practices

Evaluate the need for installing a dehumidifying system in the air compressor which would reduce the moisture content of the compressed air and therefore the volume of wastewater generated. This practice may also prolong the life of the compressor by reducing loss of lubrication and rusting.

Visually inspect the exterior of air compressor equipment for the presence of oil leaks on a regular basis.

Establish a preventative maintenance program which includes, but is not limited to, a schedule for cleaning parts, replacing oil, and replacing filters for the air compressor equipment as recommended in the manufacturer's specifications.

Remove or retain any floating layer of oil prior to discharge.

Investigate purchase of oil-free air compressor that would eliminate oil from the blowdown water.

Regulatory Issues

Compressor blowdown water may not be discharged into the ground or
surface water without a permit.

Either discharge air compressor blowdown water to sanitary sewer, or contain it in a holding tank. This wastewater should not be discharged into a septic system. Follow the BMPs listed above to ensure that the lubricating oil is removed from the water before discharge to the sewer. If you send more than 500 gallons per day to a municipal sewer, you may need a permit. Contact the water division at your state environmental department for more information on the requirements for your state.

Waste compressor oil, filters and oil/water separator waste must be managed as used oil in accordance with the federal [40 CFR 279, click here] and state requirements (For New York State requirements, click here).