Underground Injection Control (UIC)

Underground Injection Control (UIC)

Underground Injection Control are also known as “dry wells”.

The Underground Injection Control program was created by Congress to protect underground sources of drinking water from discharges of fluids to the ground. The UIC program in the state of Washington is administered by the Department of Ecology. In Washington State all ground water is protected equally under RCW 90.48 and Chapter 173-200 WAC Water Quality Standards for Ground Waters of the State of Washington.

The two basic requirements of the UIC Program are:

  • Register UIC wells with the Washington State Department of Ecology unless the wells are located on tribal land. Well on tribal land should be registered with the Environmental Protection Agency.
  • Make sure that current and future underground sources of ground water are not endangered by pollutants in the discharge non-endangerment standard.

Since stormwater picks up contaminants as it runs over the land surface, it can pollute ground water once infiltration occurs. Pollution of ground water from stormwater discharges can be prevented by careful design of the UIC well, strategic siting and effective operation and maintenance. Pollution can also be prevented by use of treatment before discharge to the sub-surface and by reducing the stormwater contact with potential sources of contamination.

UIC wells must be registered. For more information visit Ecology's website.