Ground Water

When rain falls to the ground, the water does not stop moving. Some of it flows along the land surface to streams or lakes, some is used by plants. Some evaporates and returns to the atmosphere. And some seeps underground, into pores between sand, clay and rock formations called aquifers. Water moves through aquifers much like a glass of water poured onto a pile of sand.

Many communities obtain their drinking water from aquifers. Water suppliers drill wells through soil and rock into aquifers to reach the ground and supply the public with drinking water. Many homes also have their own private wells drilled on their property to tap this supply. Unfortunately, the ground water can become contaminated by human activity. These chemicals can enter the soil and rock, polluting the aquifer and eventually the well.

This page includes links to the Office of Ground Water and Drinking Water’s activities to protect ground water.

• Underground Injection Control Program - The UIC Program is responsible for regulating the construction, operation, permitting, and closure of injection wells that place fluids underground for storage or disposal. This site provides information for owners and operators of injection wells and state regulators on how to safely operate injection wells to prevent contamination of underground drinking water resources.
• Ground Water Rule  - The Ground Water Rule provides for increased protection against microbial pathogens in public water systems that use ground water sources.
  
• Source Water Protection
  • Wellhead Protection Program - The Wellhead Protection Program (WHPP) is a pollution prevention and management program used to protect underground sources of drinking water.
  • Citizen's Guide to Ground Water Protection (PDF) (34 pp, 2MB, About PDF)
    
• Private Drinking Water Wells - Approximately 15 percent of Americans rely on their own private drinking water supplies, and these supplies are not subject to EPA standards. Some state and local governments do set rules to protect users of private wells. Households with private wells must take special precautions to ensure the protection and maintenance of their drinking water supplies.
• Ground Water Classroom Activities - Find lesson plans that illustrate how water is stored in an aquifer, how ground water can become contaminated, and how this contamination ends up in the drinking water well.

Other EPA Ground Water Links

• Aquatic Biodiversity: Groundwater
  Provides information about ground water, including definitions and a graphic of the hydrologic cycle.
  
• Ground Water and Ecosystems Restoration Research
  Provides information about the Office of Research and Development’s Ground Water and Ecosystems Restoration Research Division.
• Related Links - Many states, organizations, and university extension services offer information on ground water, particularly for private well owners.