Source Water Assessment Program

The Source Water Assessment Program (SWAP) was required by the federal Safe Drinking Water Act Amendments of 1996, to determine the potential susceptibility of public water supply systems to contamination. The Louisiana Department of Health and Hospitals entered into an interagency agreement with the Louisiana Department of Environmental Quality (LDEQ) for LDEQ to develop and implement it. LDEQ says the work took place from 2000 to 2003, that the mandated completion date was May 6, 2003, and that assessments will continue for new or expanding water systems. LDEQ says its Drinking Water Protection Program is designed to follow the SWAP and includes elements of its Wellhead Protection Program, which it says was designed in 1989.

In a Phase I ESA

ASTM E1527-21 does not name source water assessments among its standard record sources. They can tell a consultant two things: whether a property lies inside an area drawn around a public water supply well or intake, and whether the inventory for that area recorded a potential source of contamination on or near it. That is advice for the search, not something LDEQ says. Four details shape it.

• Areas around wells are fixed circles. For ground water systems, LDEQ says it uses the Arbitrary Fixed Radius Method: a one-mile radius for wells screened above 1000 feet; a half-mile radius for wells screened below 1000 feet and completed before Louisiana Department of Transportation and Development regulations of November 1, 1985; a 1000-foot radius for wells screened below 1000 feet and completed after them; a half-mile radius for transient non-community wells in the Terrace Aquifer; and a 1000-foot radius for all other transient non-community wells.
• Areas around intakes follow the watershed. LDEQ says the area for a surface water intake takes in the entire watershed upstream of the intake, up to the state's borders, and that field assessment is conducted in the critical area, the upstream part of the watershed within 5 miles of the intake, and a database assessment over the rest.
• Each area has an inventory. LDEQ says the inventory holds regulated and unregulated potential sources of contamination in the area, with their contaminants of concern, and any known existing contamination. Its examples of significant potential sources include industrial facilities, underground storage tanks, auto repair shops, oil and gas activity, dry cleaners, abandoned water wells and agriculture, located by field surveys and available databases. LDEQ ranked the kinds of source into high, medium and low risk categories. It also says a release may never occur provided best management practices are used, so read a listing as a potential source, not as a release.
• The areas are marked and mapped. LDEQ's Drinking Water Protection Program page says signs reading "Drinking Water Protection Area" are placed on major highways at the boundary of the protection areas, and that LDEQ can provide maps to planning and zoning boards showing wells and intakes and the extent of each protection area. Note any such sign on the site visit.

Where to look a site up

The pages read link no search of protection areas or inventories. The program page links the Louisiana Source Water Assessment Program Document and an Appendices A-Z page, whose items include Significant Potential Sources of Contamination Affecting Ground Water, the same for surface water, and Surface Water Intakes by Parish. None of those files was opened for this handbook. For more information, LDEQ gives the Aquifer Evaluation and Protection Section at 225-219-3510, the same number its Drinking Water Protection Program page gives for that program's staff.

Getting the file

LDEQ's routes to a file are its Electronic Document Management System, an online public records request form, and visits to its Public Records Center or a regional office. They are described on the Public Records Requests page.

Sources

Louisiana Department of Environmental Quality pages, read October 16, 2026, no modified date shown:

• Source Water Assessment Program
• Drinking Water Protection Program
• Appendices A-Z
• Information & Records, read October 8, 2026