Class III

Class III wells are used to inject fluids to dissolve and extract minerals.  Production wells, which bring mining fluids to the surface, are not regulated under the UIC program. Companies mine uranium salt, copper and sulfur using Class III wells. In 2018 approximately 165 mining sites utilized 28,327 Class III wells in mining operations across the nation.1

2018 Injection Wells by Class

Injection Well ClassNumber of Injection WellsInjection Wells Inspected
Class I830453
Class II181,43184,317
Class III28,327406
Class IV12227
Class V531,1764,038
Class VI20

Source: EPA 816F19005 April 2020

Class IV EPA UIC Wells
Class III EPA UIC Wells

1. USEPA. (n.d.). Class III injection wells for solution mining. Retrieved 11/9/2020 from

Images: “Graphic” by Top Energy Training