RAPID/Roadmap/14
Geothermal Water Quality Overview (14)
The Clean Water Act is the primary federal law in the United States governing water pollution. The goal of the act is to drastically reduce water pollution in water of the United States and to make surface waters suitable for human sports and recreation.
The CWA addresses point source water pollution, non-point source water pollution, and the dredge and fill of wetland. The primary agency responsible for the CWA is the United States Environmental Protection Agency (EPA). Although, other federal and state agencies have a role in administering the CWA as well. In particular, the US Army Corps of Engineers administer 404 dredge and fill permits for wetlands.
The Safe Drinking Water Act (SDWA) provides the framework for protection of drinking water. SDWA requires that states develop source water assessment programs (SWAPs) that must be approved by the EPA. SWAPs are used to analyze existing and potential threats to the quality of public drinking water. The EPA developed Underground Injection Control (UIC) rules to protect underground sources of drinking water. When there is potential for groundwater contamination by injection well, the developer must obtain an UIC permit. Typically, UIC permits are used for spent geothermal fluids. If there is potential groundwater contamination by surface discharge, the developer will be required to obtain a permit through the state. Most of these controls are implemented by state agencies.
NOTE: Readers should be aware of ongoing policy changes and the recent Supreme Court decision in Sackett v. EPA, related to threshold definitions pertaining to the Clean Water Act, discussed below in more depth.
Water Quality Overview Process
14.1 - Will the Project Affect Waters of the United States?
The Clean Water Act establishes the basic structure for regulating discharges of pollutants into the waters of the United States and establishes water quality standards for surface waters. The basis of the CWA was enacted in 1948 and was called the Federal Water Pollution Control Act. The Act was significantly reorganized and expanded in 1972. "Clean Water Act" became the Act's common name with amendments in 1972. Under the CWA, EPA has implemented pollution control programs such as setting waste water standards for industry. The CWA makes it unlawful to discharge any pollutant from a point source into waters of the United States, unless a permit is obtained under the EPA's National Pollutant Discharge Elimination System (NPDES). Point sources are discrete conveyances such as pipes or man-made ditches.
NOTE: Readers should be aware of the recent Supreme Court decision in Sackett v. EPA and proposed rules on this matter and continue to monitor the issue at the state and national level. On November 18, 2021, the U.S. Environmental Protection Agency (EPA) and the Department of the Army announced the signing of a proposed rule to revise the definition of “Waters of the United States,” effectively revoking the Navigable Waters Protection Rule. The final rule was published on January 25, 2023 and became effective March 25, 2023. On April 12, 2023, a district court judge in the federal district of North Dakota issued a preliminary injunction of the WOTUS rule in 24 states, preventing the administration of the rule in those states. An additional two states were affected by a previous injunction of the rule, bringing the total number of states in which the rule is stayed to 26. Concurrent to the development of the WOTUS rule, the Supreme Court of the United States granted Certiorari in Sackett v. EPA. In the case, a dispute over the fill of a wetland, the Ninth Circuit Court of Appeals applied the significant nexus test to find that the wetland was covered by the Clean Water Act. The test used by the Court of Appeals, based on Supreme Court precedent, is largely codified by the Final Rule. The sole issue on appeal in Sackett was whether this significant nexus test was the correct test to apply for determining jurisdiction over wetlands or whether some other test should be used. On May 25, 2023, the Supreme Court rejected the significant nexus test. The Court held that federal jurisdiction over wetlands applies only to those wetlands that have “a continuous surface connection to bodies that are ‘waters of the United States’ in their own right, so that there is demarcation between ‘waters’ and wetlands. In light of this decision the EPA and Department of the Army are developing a proposed rule to amend the rule for the “Waters of the United States” definition. The proposed rule is expected to be published in fall 2023. Readers should continue to monitor the issue at the state and national level.
Waters of the United States
In the states of Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, and Wisconsin, the new definition of "Waters of the United States" went into effect on March 25, 2023. Under the new rule,
“Waters of the United States” are defined as:
- The territorial seas, and waters which are currently used, were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
- Tributaries;
- Lakes and ponds, and impoundments of jurisdictional waters; and
- Adjacent wetlands. 33 C.F.R. § 328.3(a).
Tributaries must be relatively permanent, standing or continuously flowing bodies of water; or, either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of downstream waters that are subject to the Clean Water Act. 33 C.F.R. § 328.3(a)(3).
Similarly, Wetlands must be relatively permanent, standing or continuously flowing bodies of water with a continuous surface connection to jurisdictional waters; or, either alone or in combination with similarly situated waters in the region, must significantly affect the chemical, physical, or biological integrity of waters subject to the Clean Water Act. 33 C.F.R. § 328.3(a)(4). “Wetlands” are defined as “those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.” 33 C.F.R. § 328.3(c)(1).
For both tributaries and wetlands, “Significantly affect” means “A material influence on the chemical, physical, or biological integrity of waters” subject to the Clean Water Act. To determine whether waters, either alone or in combination with similarly situated waters in the region, have a material influence on the chemical, physical, or biological integrity of waters, the following factors must be assessed:
- Contribution of flow;
- Trapping, transformation, filtering, and transport of materials (including nutrients, sediment, and other pollutants);
- Retention and attenuation of floodwaters and runoff;
- Modulation of temperature in waters identified in paragraph (a)(1) of this section; or
- Provision of habitat and food resources for aquatic species located in waters subject to the Clean Water Act.
In addition, the following factors must be considered:
- The distance from a water subject to the Clean Water Act;
- Hydrologic factors, such as the frequency, duration, magnitude, timing, and rate of hydrologic connections, including shallow subsurface flow;
- The size, density, or number of waters that have been determined to be similarly situated;
- Landscape position and geomorphology; and
- Climatological variables such as temperature, rainfall, and snowpack.
In the states of Alabama, Alaska, Arkansas, Florida, Georgia, Idaho, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Montana, Nebraska, New Hampshire, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia, and Wyoming, federal district courts have enjoined the EPA's new definition of Waters of the United States. Therefore, in these states, the old definition of "Waters of the United States" currently applies. This definition of "Waters of the United States" includes:
- The territorial seas, and waters which are currently used, were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
- Tributaries;
- Lakes and ponds, and impoundments of jurisdictional waters; and
- Adjacent wetlands. 33 C.F.R. § 328.3(a).
Tributaries must be perennial or intermittent within a typical year, which the rule defines as a year "when precipitation and other climatic variables are within the normal periodic range for the geographic area of the applicable aquatic resource based on a rolling thirty-year period." 33 C.F.R. § 328.3(c)(13).
"Waters of the United States" do not include:
- Waters or water features that are not identified in paragraph (a)(1), (2), (3), or (4) of this section;
- Groundwater, including groundwater drained through subsurface drainage systems;
- Ephemeral features, including ephemeral streams, swales, gullies, rills, and pools;
- Diffuse stormwater run-off and directional sheet flow over upland;
- Ditches that are not waters identified in paragraph (a)(1) or (2) of this section, and those portions of ditches constructed in waters identified in paragraph (a)(4) of this section that do not satisfy the conditions of paragraph (c)(1) of this section;
- Prior converted cropland;
- Artificially irrigated areas, including fields flooded for agricultural production, that would revert to upland should application of irrigation water to that area cease;
- Artificial lakes and ponds, including water storage reservoirs and farm, irrigation, stock watering, and log cleaning ponds, constructed or excavated in upland or in non-jurisdictional waters, so long as those artificial lakes and ponds are not impoundments of jurisdictional waters that meet the conditions of paragraph (c)(6) of this section;
- Water-filled depressions constructed or excavated in upland or in non-jurisdictional waters incidental to mining or construction activity, and pits excavated in upland or in non-jurisdictional waters for the purpose of obtaining fill, sand, or gravel;
- Stormwater control features constructed or excavated in upland or in non-jurisdictional waters to convey, treat, infiltrate, or store stormwater run-off;
- Groundwater recharge, water reuse, and wastewater recycling structures, including detention, retention, and infiltration basins and ponds, constructed or excavated in upland or in non-jurisdictional waters; and
- Waste treatment systems. 33 C.F.R. § 328.3(b).
14.2 - Will the Project Require a Point Source Discharge of a Pollutant?
A point source is a single identifiable source of water pollution. Under CWA § 502, the term "pollutant" means dredged spoil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and agricultural waste discharged into waters of the United States. Generally, point source discharges are surface-based discharges; the effect of which will flow into waters of the United States. This term does not mean (A) "sewage from vessels"; or (B) water, gas, or other material which is injected into a well to facilitate production of oil or gas, or water derived in association with oil or gas production and disposed of in a well, if the well used either to facilitate production or for disposal purposes is approved by authority of the State in which the well is located, and if such State determines that such injection or disposal will not result in the degradation of ground or surface water resources.
To discharge a pollutant into "waters of the United States" and EPA NPDES permit or state equivalent is required. What constitutes "waters of the United States" has been continually litigated and may at times be uncertain. Developers should contact the U.S. Army Corps of Engineers for guidance in cases where it is unclear.
On certain federal and state lands the EPA controls NPDES permitting. For other lands, in most states, the EPA has delegated NPDES permitting to a state environmental agency.
See EPA's NPDES Program webpage.
14.3 - NPDES Permit
In most states, under most circumstances, the EPA has delegated NPDES permitting to a state environmental organization.
Alaska
In Alaska, developers may need a General Discharge Permit for geothermal project construction. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-AK-b
Arizona
In Arizona, developers must obtain an Arizona Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-AZ-b
California
In California, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
NationalPollutant Discharge Elimination System Permit:
14-CA-b
Colorado
In Colorado, the Colorado Department of Public Health and Environment requires a discharge permit to discharge any pollutant into any state water from a point source. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-CO-b
Hawaii
In Hawaii, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-HI-b
Idaho
In Idaho, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-ID-b
Montana
In Montana, developers must obtain a Montana Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-MT-b
New Mexico
In New Mexico, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-NM-b
Nevada
In Nevada, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-NV-b
Oregon
In Oregon, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-OR-b
Texas
In Texas, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-TX-b
Utah
In Utah, developers must obtain a Utah Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-UT-b
Washington
In Washington, developers must obtain a National Pollutant Discharge Elimination System Permit for all facilities which discharge pollutants into navigable waters. For more information, see:
National Pollutant Discharge Elimination System Permit:
14-WA-b
West Virginia
In West Virginia, a developer may need a WV/NPDES Permit from the West Virginia Department of Environmental Protection if the project may result in point source discharges. For more information, see:
State Pollutant Discharge Elimination System Permit:
14-WV-b
If a state environmental agency in not authorized to issue a NPDES permit than the EPA will handle the NPDES process.
EPA NPDES Permitting Process:
14-FD-b
14.4 - Nonpoint Source Pollution
The 1987 amendments to the Clean Water Act established the Section 319 Nonpoint Source Management Program. Section 319 addresses the need for greater federal leadership to help focus state and local nonpoint source efforts. Under Section 319, states, territories and tribes receive grant money that supports a wide variety of activities including technical assistance, financial assistance, education, training, technology transfer, demonstration projects and monitoring to assess the success of specific nonpoint source implementation projects.
Alaska
In Alaska, geothermal developers may need to comply with the Alaska Department of Environmental Conservation’s regulations regarding non-point pollution. For more information, see:
Nonpoint Source Pollution Program Overview:
14-AK-a
Arizona
In Arizona, a geothermal developer must comply with the Arizona Department of Water Resources's regulations regarding non-point source pollution. For more information, see:
California
In California, geothermal developers should consult with the California State Water Resources Control Board or the Regional Water Quality Control Boards to determine whether the proposed project fall within any of the non-point solution pollution control programs. For more information, see:
Nonpoint Source Pollution:
14-CA-a
Colorado
In Colorado, geothermal developers should consult with the Colorado Department of Public Health and Environment regarding the State’s voluntary non-point source program. For more information, see:
Nonpoint Source Pollution Program:
14-CO-a
Hawaii
In Hawaii, geothermal developers should consult with the Hawaii Department of Health regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-HI-a
Idaho
In Idaho, geothermal developers should consult with the Idaho Department of Environmental Quality regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-ID-a
Montana
In Montana, geothermal developers should consult with the Montana Department of Environmental Quality regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-MT-a
Nevada
In Nevada, geothermal developers should consult with the Nevada Division of Environmental Protection regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-NV-a
New Mexico
In New Mexico, geothermal developers should consult with the New Mexico Environment Department regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-NM-a
Oregon
In Oregon, geothermal developers should consult with the Oregon Department of Environmental Quality regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-OR-a
Texas
In Texas, geothermal developers should consult with the Texas Commission on Environmental Quality regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-TX-a
Utah
In Utah, geothermal developers should consult with the Utah Department of Environmental Quality regarding the State’s non-point source program. For more information, see:
Nonpoint Source Pollution:
14-UT-a
14.5 - Will the Project Require the Dredge or Fill of Waters of the United States?
CWA Section 404 establishes a program to regulate the discharge of dredged and fill material into waters of the United States, including wetlands. "Waters of the United States" is defined above in 14.1. Responsibility for administering and enforcing Section 404 is shared by the US Army Corps of Engineers and EPA. The Army Corps of Engineers administers the day-to-day program, including individual permit decisions and jurisdictional determinations; develops policy and guidance; and enforces Section 404 provisions. EPA develops and interprets environmental criteria used in evaluating permit applications, identifies activities that are exempt from permitting, reviews/comments on individual permit applications, enforces Section 404 provisions, and has authority to veto Army Corps of Engineers permit decisions.
The basic premise of the program is that no discharge of dredged or fill material may be permitted if:
(1) a practicable alternative exists that is less damaging to the aquatic environment or
(2) the nation’s waters would be significantly degraded.
See EPA's Dredge and Fill webpage.
14.6 - Dredge and Fill of Wetlands
"404" dredge and fill permits are administered by the US Army Corps of Engineers.
14.7 - Will the Project Impact a Source Water Protection Zone?
The Safe Drinking Water Act (SDWA) Amendments of 1996 required states to develop and implement source water assessment programs (SWAPs) to analyze existing and potential threats to the quality of the public drinking water throughout the state. Using these programs, most states have completed source water assessments for every public water system. The EPA works with state agencies, and local municipalities to create EPA-approved state Source Water Assessment Programs.
See EPA's Source Water Protection webpage.
The developer should contact the local environmental agency or water agency to determine if the project is in a source water protection zone.
14.8 - Local Source Water Protection Plan Evaluation Process
If the project will impact a source water protection zone then the developer should contact the local environmental or water agency to see if any permits are required or if there are special procedures to follow.
14.9 - Will Project Discharge to the Groundwater?
Water pollution can affect groundwater in two ways. Groundwater can be directly polluted though injection wells, or indirectly polluted by surface discharges that seep into the water table.
The Safe Drinking Water Act of 1974 established the basic framework for protecting the drinking water of the United States. The act instructs the United States Environmental Protection Agency (EPA) to establish a national program to prevent underground injection activities that endanger drinking water sources. The EPA has promulgated a series of Underground Injection Control (UIC) regulations to protect underground sources of drinking water. Injection wells are not allowed to discharge fluids or waste fluids containing any contaminant that may cause a violation of any National Primary Drinking Water Quality Standard or that may otherwise adversely affect human health.
In most cases EPA UIC controls have been delegated to a state environmental agency.
See EPA Groundwater Discharge webpage.
Additionally, state programs may regulate the discharge of wastewater and wastes to the surface, which have the potential to contaminate groundwater through seepage. States will issue groundwater discharge permits based on compliance with required state effluent limitations and technology control devices. States may require groundwater discharge permits for a number of activities including, but not limited to:
- Discharges of waste to land;
- Use of waste storage pits or landfills;
- Use of oil and gas or geothermal drilling pits;
- Waste water pits, ponds, and lagoons; and
- Process water ponds or impounds.
14.10 - Is the Discharge Regulated under the State Groundwater Protection Program or the Underground Injection Program?
Most applicable to geothermal development, If the potential groundwater contamination is by injection well then the developer must obtain a UIC permit from the proper state agency.
If the potential groundwater contamination is by surface discharge and seepage the developer must obtain a groundwater discharge permit from the proper state agency.
14.11 - State Underground Injection Control (UIC) Permit
EPA regulations and state law dictate UIC permits. In most states UIC permits are administered by the state's environmental agency.
Alaska
Alaska does not have primacy to implement the UIC Program within the state. Instead, the EPA regulates UICs in Alaska:
Arizona
Arizona does not have primacy to implement the UIC Program for Class V wells within the state. Instead, the EPA regulates Class V UICs in Arizona:
California
California does not have primacy to implement the UIC Program for Class V wells within the state. Instead, the EPA regulates Class V UICs in California:
Colorado
Colorado does not have primacy to implement the UIC Program for Class V wells within the state. Instead, the EPA regulates Class V UICs in Colorado:
Hawaii
In Hawaii, geothermal developers should consult with the Hawaii Department of Health Safe Drinking Water Branch about the State’s Underground Injection Control program. For more information, see:
Underground Injection Control Permit:
14-HI-c
Idaho
In Idaho, geothermal developers should consult with the Idaho Department of Water Resources about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-ID-c
Montana
Montana does not have primacy to implement the UIC Program within the state. Instead, the EPA regulates UICs in Montana:
New Mexico
In New Mexico, geothermal developers should consult with the New Mexico Energy, Minerals and Natural Resources Department about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-NM-c
Nevada
In Nevada, geothermal developers should consult with the Nevada Division of Environmental Protection about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-NV-c
Oregon
In Oregon, geothermal developers should consult with the Oregon Department of Environmental Quality about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-OR-c
Texas
In Texas, geothermal developers should consult with the Texas Commission on Environmental Quality about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-TX-c
Utah
In Utah, geothermal developers should consult with the Utah Department of Environmental Quality about the State’s Underground Injection Control program. For more information, see
Washington
In Washington, geothermal developers should consult with the Washington State Department of Ecology about the State’s Underground Injection Control program. For more information, see
Underground Injection Control Permit:
14-WA-c
West Virginia
In West Virginia, a developer may need an injection control permit from the West Virginia Department of Environmental Protection (WVDEP) in order to develop a geothermal project. For more information, see;
14.12 - State Groundwater Discharge Permit
In most, states Groundwater Discharge Permits are administered by the state's environmental agency.
Arizona
In Arizona, a geothermal developer must comply with the State's underground discharge requirements. For more information, see:
Aquifer Protection Permit:
14-AZ-e
California
In California, geothermal developers may need to comply with the State’s waste discharge requirements. For more information, see:
Waste Discharge Requirements:
14-CA-e
Colorado
In Colorado, developers may need to obtain a Groundwater Discharge Permit from the Colorado Department of Public Health and Environment for a geothermal project. For more information, see:
Groundwater Discharge Permit:
14-CO-e
Montana
In Montana, developers may need to obtain a Groundwater Discharge Pollution System Permit from the Montana Department of Environmental Quality for a geothermal project. For more information, see:
Groundwater Pollution Control System:
14-MT-e
New Mexico
In New Mexico, developers may need to obtain a Groundwater Discharge Pollution System Permit from the New Mexico Environment Department for a geothermal project. For more information, see:
Groundwater Discharge Permit:
14-NM-e
Nevada
In Nevada, developers may need to obtain a Groundwater Discharge Permit from the Nevada Division of Environmental Protection for a geothermal project. For more information, see:
Groundwater Discharge Permit:
14-NV-e
Oregon
In Oregon, developers may need to obtain a Water Pollution Control Facility Permit from the Oregon Department of Environmental Quality for a geothermal project. For more information, see:
Water Pollution Control Facility Permit:
14-OR-e
Texas
In Texas, developers may need to obtain Groundwater Discharge Permit from the Railroad Commission of Texas for a geothermal project. For more information, see:
Utah
In Utah, developers may need to obtain Groundwater Discharge Permit from the Utah Department of Environmental Quality for a geothermal project. For more information, see:
Groundwater Quality Protection Permit:
14-UT-e
Washington
In Washington, developers may need to obtain State Wastewater Discharge Permit from the Washington State Department of Ecology for a geothermal project. For more information, see:
State Wastewater Discharge Permit:
14-WA-e
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