Performing Well Surveys

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Printed on Recycled Paper
Illinois Office of Community Relations May 2006
Environmental P.O. Box 19276
Protection Agency Springfield, Illinois 62794-9276
Fact Sheet
Performing Well Surveys
Background
Requirements exist in Illinois and federal regulations1 to identify potable water wells in relation to cleanup sites to ensure that water supply wells are protected by proposed cleanup remedies. Because of concerns about known inaccuracies in certain databases and instances with inadequate documentation, a more thorough approach is needed for surveys of potable water supply wells. The enhanced techniques described in this fact sheet will apply across all remedial programs and RCRA Permits in Illinois EPA’s Bureau of Land. While some additional research and reporting may be required, this approach should not prove overly burdensome to the regulated community, and it will provide the level of detail necessary to make informed decisions to protect well users. Much of the information for identifying wells can now be accessed through a Geographic Information System (GIS) database.
Why does the Illinois EPA require water well surveys?
When a site is being investigated for contamination, it is necessary to know whether site-related contaminants have affected the groundwater (or may affect it in the future) and, further, whether those contaminants affect any public or private drinking water supply before decisions can be made about how cleanup should proceed.
Do the enhanced techniques apply to clean up sites under review by different Illinois EPA cleanup programs?
Yes. While the search distances for specific potable wells (community wells or private wells, for example) from a given site may vary depending on program rules, the performance of surveys of potable water supply wells will now be consistent across all the cleanup programs.
What sources should be researched for location of potable wells?
To identify community water supply wells and other potable wells (private, semi-private and non-community water supply wells) within applicable distances2 as defined by the appropriate program regulations, the following sources should be contacted:
􀂾􋸠 Illinois EPA, Division of Public Water Supplies;
􀂾􋸠 Illinois State Geological Survey (ISGS);
􀂾􋸠 Illinois State Water Survey;
􀂾􋸠 Illinois Department of Public Health or delegated county/local health department; and
􀂾􋸠 The local water supply entity to determine what areas/ properties are served by the community water supply.
1 Leaking Underground Storage Tank regulations (35 Ill. Adm. Code 732); Leaking Underground Storage Tank regulations (35 Ill. Adm. Code 734); Site Remediation Program (35 Ill. Adm. Code 740.425(b)(2)(D)); RCRA Permit regulations (35 Ill. Adm. Code 703.183(s)(9); 703.184(a)(3)); and the National Contingency Plan (40 CFR 300.430(d)). 2 For example, if groundwater contamination has exceeded the Tier 1 remediation objectives of 35 Ill. Adm. Code 742 or is modeled to migrate off-site, the area of the survey of water supply wells is extended based on the actual and modeled groundwater plume.