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Groundwater is fresh water from rain or melting ice and snow that soaks into the soil and is stored underground. This valuable resource:
- Forms aquifers,
- Intersects with and fills other waterbodies (such as streams, rivers, lakes, ponds, and wetlands), and
- Can be pumped for drinking water, irrigation, industry, and other uses.
Half of the U.S. population relies on groundwater for domestic uses, including for drinking water. However, various activities pose a serious threat to the condition of groundwater, such as:
- Pesticides and fertilizers applied to the land;
- Waste from landfills, mining operations, livestock, and other industrial processes; and
- Unintentional chemical spills or leaks from aboveground (e.g., manufacturing facilities) and underground (e.g., septic tanks) sources.
These hazardous and toxic substances can soak through the soil and contaminate groundwater, potentially affecting drinking water sources and other waterbodies.
A group of federal laws enforced by the Environmental Protection Agency (EPA) work together to protect the quality of groundwater. Some rules directly regulate groundwater, such as requiring public water systems to treat groundwater to remove contaminants. Other rules indirectly regulate groundwater by controlling how hazardous and toxic substances are handled to prevent accidental contamination.
Scope
EPA protects groundwater through regulations across various federal acts, including the:
- Safe Drinking Water Act;
- Clean Water Act;
- Resource Conservation and Recovery Act;
- Comprehensive Environmental Response, Compensation, and Liability Act;
- Federal Insecticide, Fungicide, and Rodenticide Act; and
- Toxic Substances Control Act.
Most of the groundwater regulations directly impact public water systems and indirectly affect private industry.
Regulatory citations
- 40 CFR Part 141 — National Primary Drinking Water Regulations
- 40 CFR Part 142 — National Primary Drinking Water Regulations implementation
- 40 CFR Part 144 — Underground Injection Control Program
- 42 USC 300f et. seq. — Safety of public water systems
- 40 CFR Parts 300–399 Subchapter J — Superfund, emergency planning, and community right-to-know programs
- 42 USC 9601 et. seq. — Comprehensive environmental response, compensation, and liability
- 33 USC 1251 et. seq. — Water pollution prevention and control
- 40 CFR Parts 239–282 Subchapter I — Solid wastes
- 42 USC 6901 et. seq. — Solid waste disposal
- 40 CFR Parts 700–799 Subchapter R — Toxic Substances Control Act
- 15 USC 2601 et. seq. — Toxic substances control
- 40 CFR Parts 150–189 Subchapter E — Pesticide programs
- 7 USC 136 et. seq. — Environmental pesticide control
Key definitions
- Clean Water Act (CWA): The national law protecting the waters of the United States and regulating quality standards for surface waters.
- Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): Commonly known as Superfund, a federal law that created a tax on the chemical and petroleum industries and provides broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment.
- Contaminant: Any physical, chemical, biological, or radiological substance or matter in water.
- Emergency Planning and Community Right-to-Know Act (EPCRA): Authorized by Title III of the Superfund Amendments and Reauthorization Act, a federal law that helps communities plan for chemical emergencies and requires industry to report on the storage, use, and releases of certain chemicals to federal, state, tribal, territorial, and/or local governments.
- Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA): The federal statute that governs the registration, distribution, sale, and use of pesticides in the United States.
- Groundwater: Fresh water from rain or melting ice and snow that soaks into the soil and is stored in the tiny spaces (pores) between rocks and particles of soil.
- Public water system: A system that provides the public water for human consumption through pipes or other constructed conveyances and must: Have at least 15 service connections, or Regularly schedule an average of at least 25 individuals daily at least 60 days out of the year.
- Resource Conservation and Recovery Act (RCRA): The federal law that gives EPA the authority to control the generation, transportation, treatment, storage, and disposal of hazardous waste through regulations, guidance, and policies to ensure the safe management and cleanup of solid and hazardous waste.
- Safe Drinking Water Act (SDWA): The federal law established to protect the quality of drinking water in the United States.
- Surface water: All water that’s open to the atmosphere and subject to runoff.
- Toxic Substances Control Act (TSCA): A federal law that provides EPA with authority to require reporting, recordkeeping, testing, and restrictions related to chemical substances and/or mixtures. TSCA addresses the production, importation, use, and disposal of specific chemicals.
- Underground injection: A “well injection,” which refers to the subsurface emplacement of fluids through a well.
Summary of requirements
- Determine whether the facility is subject to any of the above regulations.
- Ensure compliance at the facility with any applicable regulations.
Safe Drinking Water Act (SDWA)
The SDWA has two control programs: one for enforcing contaminant level restrictions for drinking water provided by public water systems and the other for controlling discharges to groundwater.
The National Primary Drinking Water Regulations apply to public water systems. This set of regulations includes the Ground Water Rule, which applies to:
- Public water systems that use groundwater as a source of drinking water, and
- Any system that delivers surface and groundwater to consumers where groundwater is added to the distribution system without treatment.
To comply with the GWR:
- Conduct routine sanitary surveys of systems,
- Comply with triggered source water monitoring for systems that identify a positive sample,
- Take corrective action for systems with significant deficiencies or fecal contamination, and
- Conduct compliance monitoring to ensure treatment technology inactivates or removes 99.99 percent of viruses.
The Underground Injection Control Program (UIC) establishes controls to protect sources of drinking water obtained from groundwater. The UIC Program applies to those engaged in underground injection activities regulated by the SDWA.
Clean Water Act (CWA)
The CWA regulates groundwater that connects with surface water. Comply with the allowable amounts of pollutant discharges to surface water.
Resource Conservation and Recovery Act (RCRA)
RCRA regulates hazardous waste treatment, storage, and disposal facilities (TSDFs) and underground storage tanks (USTs).
TSDFs
The TSDFs covered under RCRA include those that manage hazardous waste in:
- Landfills,
- Surface impoundments,
- Land treatment units, and
- Some waste piles (referred to as “regulated units” in the regulations).
If applicable, implement a groundwater monitoring program to detect the release of hazardous constituents to the underlying groundwater.
Note that the requirements for RCRA-permitted TSDFs (regulated under 40 CFR Part 264 Subpart F) differ significantly from the requirements for interim-status TSDFs (regulated under Part 265 Subpart F).
UST program
UST systems storing either petroleum or certain hazardous substances are also regulated under RCRA through the UST program.
Ensure compliance with the regulations, which focus on preventing releases from USTs and detecting releases from USTs to stop contamination.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) release reporting
If a CERCLA-covered substance has been released into the environment (including groundwater) in an amount equal to or greater than the reportable quantity within a 24-hour period, immediately report the release to the National Response Center.
Additionally, as required under the Emergency Planning and Community Right-to-Know Act, notify applicable local/tribal emergency planning committees and state emergency response commissions of any releases of extremely hazardous substances or CERCLA hazardous substances.
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)
Under the SDWA, public water systems are required to treat drinking water for bacteria, among other contaminants. Any product intended to kill or otherwise control pests (including microorganisms like bacteria) must be registered under FIFRA to be sold or distributed. If applicable, use only registered pesticides to treat for bacteria and other microorganisms.
Note that while it’s the responsibility of the chemical manufacturer or distributor to obtain FIFRA registration, each public water system must ensure all pesticidal products used to treat drinking water are registered — and therefore regulated — by EPA under FIFRA.
Toxic Substances Control Act (TSCA)
Through TSCA, EPA develops information on specific toxic substances and regulates those found to present an unreasonable risk of injury to human health and/or the environment, which includes water (15 U.S.C. 53.2602(6)).
If applicable, ensure the facility meets all TSCA regulations that control the manufacture, use, storage, distribution, and disposal of toxic chemicals that have the potential to leach into groundwater.