Source Water Assessments in Idaho
In 1996, Congress amended the Safe Drinking Water Act to emphasize the protection of surface and ground water sources used for public drinking water. The amendments require that each state possessing primacy over its drinking water develop a source water assessment plan for public drinking water sources, conduct assessments on all public water systems, and make the assessments available to the public.
With input from a diverse group of stakeholders and Idaho's Source Water Assessment Advisory Committee, DEQ completed the Idaho Source Water Assessment Plan in October 1999, and it was approved EPA in November 1999. DEQ was successful in completing assessments on all recognized public water sources by May 2003, in accordance with the timetable set forth by the state and EPA.
The completed source water assessments summarize the likelihood of individual drinking water sources becoming contaminated (usually a short-term "contamination event") and serve as a foundation for public water systems to prepare source water (drinking water) protection plans and implement protection measures. Each source water assessment report:
- Defines the zone of contribution, which is that portion of the watershed or subsurface area contributing water to the well or surface water intake (source water area delineation)
- Identifies the significant potential sources of drinking water contamination in those areas (potential contaminant source inventory)
- Determines the likelihood that the water supply will become contaminated (susceptibility analysis)
Existing public water systems are constantly changing: a new well is added, another is removed, a surface water intake is added, etc. Assessments are updated as soon as new information is added to the databases used to generate the assessments. The assessments shown on the website are then updated to reflect these changes.
Source water assessments are the cornerstone for source water protection. Local communities can use the information gathered through the assessment process to create a broader source water protection program to address current problems and prevent future threats to the quality of their drinking water supplies. The information acquired from assessments also assists DEQ in overseeing public water systems.
Source Water Assessment Reports Database
Use this database to find the source water assessment report for your water system. Each report provides information on the source of the water, potential sources of contamination, susceptibility to contamination, and maps of the location of the public water system.
You may search by the identification number of the public water system, the name of the public water system, the county in which the water system is located, or any combination of these criteria. Partial names and identification numbers are acceptable.