Class V - Underground Injection Control Study

EPA/816-R-99-014, September, 1999

Fact Sheets ~ Study Volumes ~ Contact

Class V wells:

• are predominantly shallow injection wells
• according to the formal definition, are any injection wells which 
  • emplace fluids into the subsurface and 
  • do not meet the definitions of a Class I-IV well (40 CFR 146.5) 
• have a variety of uses including 
  • disposal
  • aquifer recharge, and 
  • mineral recovery
• range in complexity from
  • shallow storm water drainage wells to
  • large-capacity septic systems to 
  • sophisticated geothermal reinjection wells

Fact Sheets by Well Type (PDF)

Study Volumes

The study is divided into volumes addressing each particular well-type.  Each volume can be accessed below.   All files are in an Adobe PDF format (help with PDF).

Volume 1 provides a summary of the study. (155KB)

Volume 2: Agricultural Drainage Wells include all wells receiving agricultural runoff.  This includes improved sinkholes and abandoned drinking water wells receiving agricultural runoff, wells that recharge aquifers with agricultural tail waters, and wells used to drain flood irrigation. (511KB)

Volume 3:  Storm Water Drainage Wells are shallow injection wells designed for the disposal of rain water and melted snow.  These wells typically drain paved areas such as streets and parking lots, or roofs.  Improved sinkholes and abandoned drinking water wells receiving storm water runoff are considered to be storm water drainage wells. (500KB)

Volume 4:  Carwashes without undercarriage washing or engine cleaning. (140KB)

Volume 5:  Large-Capacity Septic Systems are used to dispose of sanitary waste through a septic tank, used by a multiple dwelling, business establishment, community, or regional business establishment for the injection of wastes.  Systems serving single families and non-residential systems serving less than 20 persons are not included. (1,164KB)

Volume 6:  Food processing disposal wells (1,272KB)

Volume 7: Sewage Treatment Effluent Wells are used by privately or publicly owned treatment works (POTW) to inject treated or untreated domestic sewage through a vertical well or a leachfield.  Aquifer Recharge wells, Aquifer Storage and Recovery Wells, Subsidence control wells, and Saline Intrusion Barrier wells injecting treated or untreated wastewater are considered Sewage Treatment Effluent wells for the purposes of this study. (425KB)

Volume 8:  Laundromats without dry cleaning facilities (73KB)

Volume 9:  Spent Brine Return Flow Wells are used to dispose of the spent brine which result from the extraction of minerals, halogens and other compounds from fluids.  These wells are commonly associated with manufacturing facilities that produce specialty chemicals such as boron, bromine, magnesia, or their derivatives. (227KB)

Volume 10:  Mine Backfill Wells are wells which inject water, sand, mill tailings, or other mining byproducts in order to control subsidence caused by mining, to dispose of mining byproducts, or to fill sections of a mine. (766K)

Volume 11: Aquaculture Wells dispose of water used for cultivation of marine and freshwater animals and plants. (123KB)

Volume 12: Solution Mining Wells inject leaching solutions (lixiviants) in order to remove an ore mineral from its original geological setting.  The saturated solution is then extracted by a production well, and the target mineral is harvested for processing.  Copper, gold, salt, silver, and uranium may all be mined by solution mining processes. (81KB)

Volume 13:  In-Situ Fossil Fuel Recovery Wells are used for in-situ recovery of lignite, coal, tar sands, and oil shale.  The wells inject water, air, oxygen, solvents, combustibles, or explosives into underground or oil shale beds to liberate fossil fuels, so they can be extracted for surface use.  Underground coal gasification (UCG) and in-situ oil shale retorting are two processes which use in-situ fossil fuel recovery injection wells. (592KB)

Volume 14:  Special Drainage Wells include a variety of wells such as potable water tank overflow, construction dewatering, swimming pool drainage, and mine dewatering wells.  These drainage wells receive fluids that cannot be classified as agricultural, industrial, or storm water. (198KB)

Volume 15:  Experimental Wells are used to test new technologies.  Wells will not be classified as experimental if the technology can be considered under an established well subclass.  For example, a well used for bioremediation will be classified as an aquifer remediation well. (232KB)

Volume 16:  Aquifer Remediation Wells are wells used to clean up, treat, or prevent contamination of underground sources of drinking water (USDWs).  Treated ground water (pump and treat), bioremediation agents, or other recovery enhancement materials may be injected into the subsurface via Class V wells.  These wells may be associated with Resource Conservation and Recovery Act (RCRA) or Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) projects. (298KB)

Volume 17:  Geothermal Electric Power Wells dispose of spent geothermal fluids following the extraction of heat for the production of electric power. (1,078KB)

Volume 18:  Geothermal Direct Heat Return Flow Wells dispose of spent geothermal fluids following the extraction of heat used directly (without conversion to electric power or passed through a heat exchanger) to heat homes, swimming pools, etc. (953KB)

Volume 19:  Heat Pump/Air Conditioning Return Flow Wells reinject ground water that has been passed through a heat exchanger in order to heat or cool buildings.  A heat pump takes thermal energy from the ground water and transfers it to the space being heated.  When cooling is required, the heat pump removes heat from a building and transfers it to the ground water.  For the purposes of the study, only open loop heat pump/AC return flow wells are considered. (975KB)

Volume 20:  Saline Intrusion Barrier Wells are used to inject fluids to prevent the intrusion of salt water into an aquifer.  These wells may have secondary purposes such as aquifer recharge. (711KB)

Volume 21:  Aquifer Recharge/Recovery Wells are used to inject fluids to recharge an aquifer.  These wells may have secondary purposes such as saline intrusion prevention, subsidence control, or aquifer storage and recovery (ASR). (334KB)

Volume 22:  Noncontact Cooling Water Wells (120KB)

Volume 23:  Subsidence Control Wells are used to control land subsidence caused by ground water withdrawal, or over pumping of oil and gas.  These wells may have secondary purposes such as aquifer recharge. (119KB)

Appendix A:  Information Collection Request for the Study (92KB)

Appendix B:  Questionnaires 

Appendix C:  Inventory Models (205KB)

Appendix D:  Maximum Contaminant Levels and Health Advisory Levels (126KB)

Appendix E:  Contaminant Persistence and Mobility Factors (55KB)

For general information, contact the Safe Drinking Water Hotline, toll-free 800-426-4791.  The Safe Drinking Water Hotline is open Monday through Friday, excluding federal holidays, from 9:00 a.m. to 5:30 p.m. Eastern Standard Time.  For technical inquiries, contact Lee Whitehurst, Underground Injection Control Program, Office of Ground Water and Drinking Water (mail code 4606), EPA, 401 M Street, SW, Washington, D.C., 20460.  Phone: 202-260-5532.  E-mail: whitehurst.lee@epa.gov.

Safewater Home | About Our Office | Publications | Calendar | Links | Office of Water | En Español

EPA Home | Privacy and Security Notice | Contact Us