A source water assessment is the state produced report that maps where your drinking water comes from and what can contaminate it before it reaches treatment. It is the document your wellhead protection plan is supposed to build on, yet most small systems treat it as a filing they have not opened in years. If your system draws from groundwater, start by checking your EPA public record free at orevant.com, then pull your assessment and compare it to what is actually happening around your wells today. This article is compliance information, not legal advice. Your state primacy agency sets the controlling requirements.
Where the assessment came from
The Source Water Assessment Program comes from the Safe Drinking Water Act Amendments of 1996, which directed every state to assess the source water for every public water system and share the results with the public. Each assessment has four parts: delineate the source water area that feeds the well or intake, inventory the potential contaminant sources inside that area, judge how susceptible the source is to those contaminants, and make a summary available to the public.
See exactly what your system is up against
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What yours should contain
For a groundwater system the assessment area is usually a wellhead protection area the state defines, often with a time of travel calculation or a fixed radius around the well. The contaminant inventory lists the land uses and facilities inside that area: underground storage tanks, septic systems, agricultural chemical handling, fuel stations, dry cleaners, and anything else that could release contaminants to the aquifer. The susceptibility finding then rates how likely a listed source is to reach your well.
Why an old assessment is not a pass
Most assessments were completed in the early 2000s and have not been updated since. A facility that did not exist twenty years ago can sit inside your wellhead protection area today and the assessment will never mention it. The assessment is a starting snapshot, not a live monitor. That is why the wellhead protection plan exists: it takes the assessment map and turns it into a maintained risk inventory with controls and records. See how to build the wellhead protection plan around it.
How it connects to your sanitary survey
The sanitary survey asks about source water and the area around your wells, and the source water assessment is the document the inspector expects to see when those questions come up. A system that can show an assessment, a current protection area map, and a risk inventory with controls answers the source water section without scrambling. A system that cannot is handing the inspector a finding.
What to do with yours this month
- Locate your state source water assessment for each source and confirm the assessment area it drew.
- Walk the protection area and list what has changed since the assessment was written: new tanks, new land uses, new businesses.
- Keep the assessment, the map, and the updated inventory in one place the operator and the board can both reach.
- If the assessment is missing or badly out of date, ask your state primacy agency for the current version.
A checklist helps you get organized. It does not tell you what is already open on your public record, which violations your state is tracking, or what your next deadline is. That is the gap the scan closes.
Prefer to see the public record first? Check your water system free at orevant.com.