Contributors: J.A. Arnold, S.W. Coffey, D.E. Line, and J. Spooner, Extension Biological & Agricultural Engineering Specialists, and D.W. Moody, U.S. Geological Survey
Industries often contribute lubricating oils to runoff from their processes, raw material, and finished product stockpiles, and from truck traffic and maintenance. Warehousing and freight operations produce waste lubricants from truck maintenance and cleaning. Oil and grease enter stormwater as it flows over traffic aprons at these facilities and from illegal disposal of waste oil and cleaning solutions. Fuel spills and improper storage of fuel contribute to stormwater pollution.
Impacts. Much of the oil and grease binds to sediment, eventually settling to the bottom of water bodies. There the oil and grease concentrate and can adversely affect the organisms that live in the bottom sediments. Little is currently known about the toxicity of oil and grease in water bodies.
Indicator parameters. The multi-colored slicks on water and an odor of fuel, oil or solvents may indicate the presence of oils and grease.
Source reduction. Used motor oil should be taken to a recycling center or other proper disposal facility. Some service stations will accept used oil as a service to the community. Private citizens should repair oil leaks in their personal vehicles and should report any illegal disposal observed. Industries and commercial businesses should dispose of oil in an approved manner and vehicle washing areas should not discharge to storm drains. Floor drains in shops and repair areas should be connected to sanitary sewers, not storm drains, to keep oil and grease out of stormwater. Storage tanks should have appropriate containment measures in case of spills and leaks.
Removal. These pollutants can be removed using a variety of manufactured oil/ water separators and skimmers. The manufacturer's directions must be followed for proper operation and the waste oil and grease from the oil/water separator must be disposed of properly.
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