Protecting Public Health and the Environment.

Idaho Environmental Guide for Local Governments: Ground Water

Ground water is water that is found underground in the cracks and spaces in sediments and rock. The layers that contain moving ground water are called aquifers. Aquifers typically consist of gravel, sand, sandstone, or fractured hard rock, like basalt.

Why Communities Should Care

Ground water is a key resource supporting many aspects of Idaho's way of life. It replenishes our streams and rivers and provides fresh water for irrigation, industry, and communities. Around nine billion gallons of ground water are withdrawn every day for various uses in the state. The water that flows from the tap likely comes from ground water, as it provides 90% of the state's drinking water.

Agriculture uses approximately 60% of the total ground water withdrawn in the state for dairy production, feedlots, and irrigation of such crops as potatoes, sugar beets, and barley. Aquaculture also relies on ground water, as do industrial processes that use ground water for food processing, fertilizer production, and high-tech manufacturing.

The Idaho Environmental Protection and Health Act (I.C. § 39-126) mandates that state and local governments incorporate policies from the Idaho Ground Water Quality Plan into their programs. The Environmental Protection Act also indicates that cities, counties, and other political subdivisions are authorized and encouraged to implement ground water quality protection policies within their jurisdictions.

The Idaho Local Land Use Planning Act (I.C. § 67-6537) requires local governing boards to consider the impact on ground water quality when amending, repealing, or adopting a comprehensive plan.

What Communities Can Do

  • Plan ahead. Local governments have authority to manage potential sources of ground water contamination within their jurisdictions. Protect ground water quality by including ground water protection as a component in comprehensive plans. Local governments can also implement ordinances and regulations such as wellhead protection overlay zones, riparian buffers, stormwater management ordinances, special use permits, and land-use controls to protect ground water quality.
  • Local governments have authority to implement ordinances that restrict ground water contamination beyond state and federal laws and regulations. Many land uses that pose a potential threat to ground water quality are managed at the local level. Therefore, local government can most efficiently administer and implement some provisions of the Environmental Protection and Health Act (I.C. § 39-126) Idaho and the Idaho Ground Water Quality Plan, particularly when implementation can be incorporated into existing programs. Determine what is best for the health and welfare of the community.
  • Implement ground water quality protection policies within a jurisdiction. The Idaho Ground Water Quality Plan provides guidance on ground water policies and implementation strategies for local government management efforts.
  • Consult plan to evaluate city or county use and management of pesticides, chemicals, and hazardous waste.
  • Consider implementing:
    • Land use regulations, zoning, or ordinances, especially for activities located near sensitive drinking water areas, such as protecting water supplies at the source using buffers or land use restrictions
    • Homeowner and business education programs to provide information on topics such as how to properly apply fertilizer
    • Water conservation standards
    • Collection sites for used oil, pharmaceuticals, or household hazardous waste
    • Community and business stewardship programs
    • Ground water protection policies and ordinances
    • Best management practices to mitigate the risk of potential contamination
  • Reference federal and state regulations that you may want to apply to unregulated tanks (for instance, heating oil tanks), such as the Idaho Underground Storage Tank Act or the Spill Prevention, Control, and Countermeasure (SPCC) Rule. Develop and use best management practices for facilities and persons that store and use materials that have potential to contaminate soil and ground water. This includes assistance with selecting, designing, installing, and maintaining secondary containment systems.
  • Consider a requirement that projects have pollution liability insurance.
  • Identify groups in the community working on water issues, such as utility companies, water quality agencies, or advocacy organizations, and explore ways to collaborate with them.
  • Contact DEQ for training and technical assistance in implementing ground water and drinking water protection.
  • Communities located within Nitrate Priority Areas can work with DEQ to form local ground water quality advisory committees to implement strategies and ground water quality improvement plans.
  • Research funding potential to replace septic systems with upgraded sewer systems.
  • Request CAFO siting evaluations.

Staff Contacts

Ground Water Bureau Chief
Ed Hagan
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0356

DEQ Resources

Idaho Ground Water Quality Plan

Let's Talk Ground Water

Related Pages

Ground Water in Idaho

Nitrate in Ground Water

Source Water in Idaho