Source Water Assessment Program

Significant Potential Contaminant Sources

Potential contaminant sources (PCS) have been identified and mapped in all source water areas. These inventories were targeted at contaminants which are regulated under the Safe Drinking Water Act. PCSs were first identified when the state’s Vulnerability Assessment program was developed in 1992. This list of potential sources was revised to include sources suggested in U.S. Environmental Protection Agency’s Source Water Assessment Program Guidance and again as field experience was gained. The PCSs mapped for SWAP are listed in Public Water Supply Contaminant Use Inventory - Form 3300-215. The form includes an explanation sheet describing these potential sources and how they will be located on a map, and listing specific contaminants likely to be present.

For surface water systems PCS inventories have consisted of making use of available information (including the PCSs mapped for groundwater systems), identifying land uses, and locating a few key potential contaminant sources which were also targeted for groundwater systems’ assessments. This was done by working with other environmental management programs to collect data on potential contaminant sources of mutual interest. The Drinking Water and Groundwater program worked cooperatively with other DNR programs to collect the following statewide PCS layers.

Landfills - all licensed landfills and many that are not licensed,
Concentrated animal feeding operations with greater than 1000 animal units.
Large quantity hazardous waste generators
Superfund sites
Leaking Underground Storage Tank and other spills sites
Wisconsin Pollutant Discharge Elimination System permitted outfalls (groundwater and surface water)

Efforts needed to complete these layers generally consisted of preliminary data review and accurate site location using Global Positioning Systems technology or digitizing from 1:24,000 scale maps. These PCSs were chosen because of their potential to threaten public water supplies and the potential for cooperation with other programs to complete the work.

Back to Source Water Assessment Program

Last Revised: Monday March 26 2007