Groundwater as Drinking Water

The United States has one of the safest water supplies in the world. Yet, drinking water quality varies from place to place, depending on the condition of the source water from which it is drawn and the treatment it receives. The National Ground Water Association has determined that 49% of the U.S. population depends on ground water for its drinking water supply from either a public source or private well. Groundwater from a properly constructed and maintained well is usually high quality water and safe for drinking.

Drinking Water Standards

Based on the federal Safe Drinking Water Act, the US Environmental Protection Agency (EPA) has established drinking water standards for 20 health-related contaminants including arsenic, nitrate, bacteria, radioactivity, heavy metals such as lead and mercury, and several pesticides. The standards do not presently include many other contaminants sometimes found in drinking water. Drinking water standards and guidelines place a ceiling on contaminant levels in the drinking water supplied by the public water systems, regardless of whether the source is groundwater or surface water. When a standard or guideline is exceeded in a municipal or community water system, the state requires the operator of the system to take corrective steps. These steps can include treating the water through filtration or aeration, blending water from several sources to reduce contaminant levels in the system, or constructing a new well. There is no regulation for ensuring that private wells meet safe drinking water standards. However, private well owners can have their wells tested and use federal drinking water standards as a guide for assessing water quality.

Drinking Water from a Public Supplier

If your water comes from a public supplier, you have two ways to assess the quality of the water coming from your tap:

1.) Consumer Confidence Reports

Consumer Confidence Reports (CCRs) are annual reports provided by every community water supplier and provide information about the quality of drinking water from that particular supplier. The report includes the water's source, contaminants found in the water, and how consumers can get involved in protecting drinking water.

2.) Source Water Assessment Program

The Source Water Assessment Program (SWAP) has two components: assessment and protection. Source water assessment is mandatory and aims to gather valuable information about a community's source of drinking water. Assessment information should tell residents exactly where their water supply comes from and what conditions and/or practices may pose threats to its quality.

Source water protection is a voluntary program that aims to use assessment information to develop a plan or strategy to protect a water supply. Source water protection uses the assessment information to manage contaminants and do contingency planning.

Source Water Protection Sites

Drinking Water from a Private Well

Private well owners are responsible for the quality of their water, and no regulatory oversight exists to ensure water quality. However, there are numerous governmental and nonprofit resources for private well owners to assist them in maintaining high quality drinking water.