Mississippi
Underground Injection Control Program
The Underground Injection Control (UIC) Program of the Mississippi Department of Environmental Quality (MDEQ) is listed among the Waste Division's programs. MDEQ says EPA has delegated to it primary regulatory authority for Class I, III, IV and V injection wells, and has delegated the Class II injection well program to the Mississippi State Oil and Gas Board.
In a Phase I ESA
ASTM E1527-21 does not name injection well lists among its standard record sources. An injection well at or near a property still says something about how waste or fluids were handled there, and the first question is which agency has the record. MDEQ describes the classes this way:
- Class I. Wells used to inject liquid hazardous waste, industrial non-hazardous waste or municipal waste waters beneath the lowermost USDW, as MDEQ puts it. MDEQ says Mississippi currently has three facilities injecting industrial waste into seven Class I disposal wells, and no Class I municipal waste water injection wells.
- Class II. Wells used to inject fluids associated with the production of oil and natural gas, and for enhanced oil recovery. MDEQ says most enhanced oil recovery wells inject carbon dioxide, and that oversight of Class II wells is delegated by EPA to the Mississippi State Oil and Gas Board. MDEQ's page does not say where Class II well records are kept. This handbook has no page on the Board.
- Class III and IV. MDEQ says there are no Class III wells, used to inject fluids for the extraction of minerals, in the state. It says no Class IV wells, used to dispose of hazardous or radioactive waste into or above the USDW, currently exist in the state, and that federal regulations prohibit them.
- Class V. Wells not in the other classes that are used to inject non-hazardous fluids into or above a USDW. MDEQ says this class includes septic systems serving more than 20 persons and commercial and light industry facilities discharging waste into septic systems, and that Mississippi has over 7,500 identified Class V wells. For a commercial or light industrial property on a septic system, ask MDEQ whether the system is one of its identified Class V wells.
- Class VI. Wells used for the geologic sequestration of carbon dioxide. MDEQ's page describes them and does not name them among the classes delegated to it.
Where to look a site up
The UIC page links a Class I permit application and a staff contact. The pages read link no list of injection wells. The Waste Division's mailing address is P. O. Box 2261, Jackson, MS 39225, and its street address is 515 Amite St, Jackson, MS 39201.
Getting the file
MDEQ's route is a written public records request that names the facility, the city and county where it is located, and the type of information wanted; see Public records requests.
Sources
Mississippi Department of Environmental Quality pages, read October 12, 2026, no modified date shown: