Underground Injection Control Program

The Underground Injection Control (UIC) Program is a federal program established under the provision of the Safe Drinking Water Act (SDWA) of 1974. Since groundwater is a major source of drinking water in the United States, the UIC Program requirements were designed to prevent contamination of groundwater resulting from the operation of injection wells.

Injection wells are used for disposal of fluids by "injection" into the subsurface. The construction of injection wells range from very technical designs with twenty-four hour monitoring to simply a hole dug in the ground to control runoff. As a result of this diversity, the UIC Program divides injection wells into five different classes.

Class IWells injecting hazardous or non-hazardous waste below the lowest Underground Source of Drinking Water (USDW). Class I wells are commonly referred to as the deep wells. Presently there are four Class I wells operating in Illinois.
Class IIWells injecting fluids associated with production, storage and recovery of oil and natural gas. In Illinois the Class II Program is administered by the Illinois Department of Natural Resources, Office of Mines and Minerals.
Class IIIWells used to extract minerals following the injection of fluids into an ore bed such as uranium. No Class III wells exist in Illinois.
Class IVWells used to inject hazardous waste into or above a USDW. Class IV wells are banned by regulation.
Class VWells used to inject non-hazardous waste into or above a USDW. Class V wells are commonly referred to as the shallow wells. This is the largest class of injection wells with over 6000 Class V wells in Illinois alone.

The owner of a Class V well is not required to obtain a permit prior to beginning injection. Class V wells are Rule Authorized and must submit the Inventory Information prior to beginning injection. The Inventory Information identifies the type of Class V well and the nature of the injection activity. Following review of this information the well owner may be required to provide additional information to demonstrate operation of the well will not result in contamination of a USDW. In rare cases, a Class V well owner may be required to obtain a true permit prior to beginning operation.