Domestic Well photo grid

Groundwater is one of Missouri’s most vital natural resources. Wells are used to access groundwater for drinking and irrigation, to monitoring aquifer health, to provide geothermal energy for heating and cooling, and to collect geologic information. Well construction is regulated in Missouri to protect our groundwater resources. Well and pump installation contractors must be permitted by the department in order to do business in Missouri. Well construction requirements are determined by geologic, hydrologic and environmental factors. 

Nearly 3 million Missourians depend on water wells for their drinking water. Over the years, construction methods for water wells have evolved from being dug by hand, bored with augers, and hammered by cable tool rigs to drilling with air rotary or sonic drill rigs. Over time, thousands of water wells were abandoned without being properly plugged. A well is considered abandoned when it can no longer produce water, transport water to its point of use, or causes a contamination risk to groundwater and has not been used for two or more years. Please report abandoned wells to us.  

Water Wells

Water wells are used for consumption and irrigation. They can be private domestic wells, multiple family wells, non-community public water supply wells, community public water supply wells, or high yield wells. The type of well needed is based on the number of service connections, the number of people served, and the amount of water needed. 

Monitoring Wells

Monitoring wells are used to collect information on groundwater. Valuable geologic information like the depth to groundwater, direction of groundwater movement, and the presence of contaminants are collected from these small diameter wells and used to determine aquifer characteristics. 

Heat Pumps Geothermal

Geothermal heat pump wells collect or disperse heat underground to provide energy efficient heating and air conditioning for homes and commercial buildings.

Mineral Test Holes

A test hole is a type of well drilled to collect geologic information. They are used for the exploration of minerals such as lead, coal, limestone or fireclay. Test holes also are used to gather stratigraphic or structural data that is not associated with an environmental characterization or remediation. Therefore, test holes do not include monitoring wells.

Test Holes Wells - PUB2946

Injection Wells

Originally regulated under the Safe Drinking Water Act, an injection well is used to place fluids underground into porous geologic formations as regulated under the federal Clean Water Act 40 CFR 144. A well is a bored, drilled or driven shaft whose depth is greater than the largest surface dimension, a dug hole whose depth is greater than the largest surface dimension, an improved sinkhole or a subsurface fluid distribution system. 

Class II – Oil and Gas Injection Wells. These wells are regulated by the department’s Missouri Geological Survey through the State Oil and Gas Council per Chapter 259, RSMo.

Class VUnderground Injection Control Wells. These wells are regulated by the department’s Water Protection Program. In general, Class V wells inject non-hazardous fluids into or above underground sources of drinking water and are typically shallow, onsite disposal systems. All Class V wells must be registered with the department's Missouri Geological Survey. Use the Class V Well Inventory MO 780-1774 form for all new UIC Class V wells or for existing Class V wells not previously inventoried.

Oil and Gas Resources – Learn more about oil and gas resources in Missouri.