What is the Source Water Assessment Program?

City of Chubbuck Delineation MapThe sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

The 1996 Safe Drinking Water Act amendments created a new program of source water assessments. The purpose of this requirement is to identify, to the extent practicable, the origins of regulated and certain unregulated contaminants in the delineated area in order to determine the susceptibility of public water systems to these contaminants.

One of the ways in which information is being provided to the community is through the state of Idaho's Source Water Assessment program. This program is providing water managers and the public with an evaluation of where a public water supply well (in the example shown in the figure above, Chubbuck's Well #2) draws its water - a so-called capture zone, and where within that capture area, potential contaminant sources (land-use activities such as fuel storage tanks, industrial or commercial handlers of hazardous materials, agrichemical suppliers, etc.) are located.

The combination of how long it takes water within the capture zone to get to the well and how many and what kinds of potential contaminant sources occur within each time-of-travel zone, allows an assignment of the relative risk that that well water supply has of becoming contaminated.

Although neither the U.S. Environmental Protection Agency (EPA) or Idaho's Department of Environmental Quality (DEQ) requires water managers to take additional steps to protect a well if it is at risk, the intent of the Source Water Assessment program - and the hope - is that individual communities can determine what sort of management measures are required to protect their water supply. In other words, protection is a voluntary step, that is left to the community to decide.

GO VISIT Aquifer Protection for more information and a comprehensive presentation!

ALSO VISIT EPA's Source Water Assessment web site.