Groundwater Info Center
GHEW Standards

DWR is updating the 1999 Draft Geothermal Heat Exchange Well Standards (GHEW Standards), pursuant to California Water Code (CWC) sections 231 and 13800, to provide minimum statewide standards for construction, maintenance, abandonment, and destruction of GHEWs.

DWR anticipates releasing a Public Draft in summer 2014 for public review and comment. During the public comment period, DWR plans to hold public workshops. DWR will consider comments received and revise the draft as necessary before finalizing and submitting to the State Water Resources Control Board for adoption into a Model Ordinance. Following adoption of the Model Ordinance, local jurisdictions with authority can either adopt a Local Ordinance that meets or exceeds the statewide Standards or allow the Model Ordinance to take effect.

Local enforcing agencies (LEAs), also referred to as well permitting agencies, are tasked with administering and enforcing the ordinance.

Scope of GHEW Standards

The Standards are applicable to all GHEWs that meet the definition of Geothermal Heat Exchange Well in Water Code section 13713:

"Geothermal heat exchange well," as used in this chapter, means any uncased artificial excavation, by any method, that uses the heat exchange capacity of the earth for heating and cooling, in which excavation the ambient ground temperature is 30 degrees Celsius (86 degrees Fahrenheit) or less, and which excavation uses a closed loop fluid system to prevent the discharge or escape of its fluid into surrounding aquifers or other geologic formations. Geothermal heat exchange wells include ground source heat pump wells.

Closed Loop System


Open Loop System


Based on the Water Code definition, GHEW Standards do not apply to the following:

  • "Hot" geothermal wells, where ground temperatures are in excess of 86 degrees Fahrenheit. Please refer to the Division of Oil, Gas, and Geothermal Resources (DOGGR) for regulation of "hot" geothermal wells.
  • "Open loop" systems, in which groundwater is extracted from a well, used for heating and cooling, then injected back into the same well, another well, or discharged to land or surface water (see schematic). These systems meet the definition of "water well" in the Water Code, so Water Well Standards apply.
  • "Surface water" systems, where heat is exchanged with surface water, in a pond or other surface water body.
  • "Groundwater source" systems, which exchange heat with groundwater using a closed loop of piping inserted into a water well, in which case, Water Well Standards apply.
Stakeholder Advisory Group (SAG)

In Fall/Winter 2013-14, DWR convened a Stakeholder Advisory Group (SAG) comprised of 18 members of industry, local and state agencies, and others, to review the SAG Review Draft of the GHEW Standards. The SAG discussed the draft at seven topic-specific meetings, the last of which was held on January 7, 2014. The SAG provided invaluable input to DWR. DWR is currently in the process of revising the SAG Review Draft Standards in consideration of the SAG's input.

SAG Membership
  • Ed Anderson, Baroid Industrial Drilling Products
  • David Bennett, HDD Consortium/Bennett Trenchless Engineers
  • Thomas Booze, Department of Toxic Substances Control (DTSC)
  • Robert Busby/Clay Rodgers, Water Boards (State Water Resources Control Board and Regional Water Quality Control Boards
  • George Chien, Department of Public Health (CDPH)
  • Thomas Elson, Groundwater Resources Association
  • Michael Golightly, ISCO Industries
  • Phil Henry, CaliforniaGeo – California Geothermal Heat Pump Association
  • Judith C. Ikle', California Public Utilities Commission
  • Douglas Jones, REHAU
  • Stewart Krause, Wyo-Ben, Inc.
  • Lisa Meline, CaliforniaGeo – California Geothermal Heat Pump Association
  • Mike Nichols, Wolseley Industrial Plastics
  • Bob Oliver, Cetco
  • John Townsend, Direct Exchange
  • Gary Williams, Baroid Industrial Drilling Products
  • Susan Williams, California Conference of Directors of Environmental Health, Water Well Technical Advisory Committee
  • Jeremy Wire, California Groundwater Association

Previous Announcements

Initial Stakeholder Meeting - Recorded Webcast (registration required)

Date and Time: November 30, 2012 9:30 – 11:30 AM

Location: Resources Building Auditorium, 1416 9th Street, Room 105, Sacramento, CA.

Purpose: This meeting is an opportunity for stakeholders to meet with DWR project staff, to learn more about the project, and to provide input.

Meeting Documents: Presentation (PDF: 2.49MB).