We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Underground Injection Control (UIC)

Class V Wells for Injection of Non-Hazardous Fluids into or Above Underground Sources of Drinking Water

On this page:


Use of Class V wells

Class V wells are used to inject non-hazardous fluids underground. Most Class V wells are used to dispose of wastes into or above underground sources of drinking water. This disposal can pose a threat to ground water quality if not managed properly.

The different types of Class V wells pose various threats. Most Class V wells are shallow disposal systems that depend on gravity to drain fluids directly in the ground. Over 20 well subtypes fall into the Class V category. 

EPA estimates that there are more than 650,000 Class V wells in operation nationwide. Most of these Class V wells are unsophisticated shallow disposal systems.  Examples include:

  • Stormwater drainage wells
  • Septic system leach fields
  • Agricultural drainage wells

Top of Page


Complex Class V wells 

""Your community may have industrial waste disposal wells, stormwater drainage wells, large-capacity septic systems, and other Class V wells. They are regulated and are not allowed to endanger underground sources of drinking water.

EPA's regulations define Class V wells as injection wells not included in other well classes.  As a result, in addition to shallow wells, the Class V well category includes deep complex wells used at commercial and industrial facilities. Complex Class V well types may include:

  • Aquifer storage and recovery wells
  • Geothermal electric power wells
  • Experimental wells used for pilot geologic sequestration

Regardless of the use of Class V wells, owners and operators are responsible for protecting underlying ground water from contamination. 

Top of Page