Underground Injection Control Program

The Mississippi Department of Environmental Quality is delegated by the U.S. Environmental Protection Agency as the primary regulatory authority for Class, I, III, IV, and V injection wells.   The Class II injection well program has been delegated to the Mississippi State Oil & Gas Board by the U.S. EPA.  The primary focus of the UIC programs are to protect the groundwater resources of the United States, through regulatory programs that establish minimum programs for various types of UIC wells in the state. These wells include the following types:

Class I injection wells used to inject liquid hazardous waste, industrial non-hazardous waste or municipal waste waters beneath the lowermost USDW.  Mississippi currently has three facilities injecting industrial waste into seven Class I disposal wells.  There are no Class I municipal waste water injection wells in the state.

Class II injection wells used to inject fluids associated with the production of oil and natural gas.  Class II well are also used for enhanced oil recovery.  Most enhanced oil recovery wells inject carbon dioxide. As previously acknowledged, the oversight of the class II injection wells in Mississippi is delegated by USEPA to the Mississippi State Oil and Gas Board.

Class III injection wells used to inject fluids for the extraction of mineral and there are none in the state.

Class IV wells used to dispose of hazardous or radioactive waste into or above the USDW.  No wells of this type currently exist in the state and federal regulations prohibit the operation of such wells.

Class V wells – wells not included in the other classes that are used to inject non-hazardous fluids into or above a USDW.  This class includes septic systems serving more than 20 persons and commercial and light industry facilities discharging waste into septic systems. Mississippi has over 7,500 identified Class V wells. TVA has 2 wells drilled and in-service.

Class VI wells that are not experimental in nature that are used for geologic sequestration of carbon dioxide beneath the lowermost formation containing a USDW; or, wells used for the geologic sequestration of carbon dioxide that have been granted a waiver of the injection dept requirements pursuant to requirements; or, wells used for geologic sequestration of carbon dioxide that have received an expansion to the areal extent of an existing Class II enhanced oil recovery or enhanced gas recovery aquifer exemption.

Contact Information

For more information on the UIC program, click here.

Mailing Address
Underground Injection Control Program
Waste Division
P. O. Box 2261
Jackson, MS 39225

Street Address
Underground Injection Control Program
Waste Division
515 Amite St
Jackson, MS 39201

Fax Number: 601-961-5785