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Water: Source Water Protection

Frequent Questions about Source Water Assessments

What is a source water assessment?
An assessment is a study and report, unique to each water system, that provides basic information about

  • Where the drinking water comes from: an assessment provides a map and information about the area that most directly provides the raw water used by a public water system to supply potable water.

  • What could pose a threat to drinking water quality: an assessment identifies the major potential sources of contamination to the drinking water supply. This information is used to determine how susceptible the water system is to contamination.

How much assessment work has been done?
Before 1996 some localities, states and individuals had been doing assessment work, usually in the context of wellhead protection programs or watershed protection programs. Approximately 6,000 public water systems had completed assessment work by 1996.

Today more than 140,000 public water systems have a source water assessment. In 1996 section 1453 of the Safe Drinking Water Act amendments required all states to get EPA approval for a source water assessment program (SWAP) and use that plan to conduct assessment for all public water system supplies within 3 years. Most states have completed these section 1453 assessments.

Who paid for these assessments?
Source water assessments are eligible uses of the Drinking Water State Revolving Fund (DWSRF) Set-Asides. States may use the funds for a mixture of source water-related local assistance activities. For example, funds are available for land acquisition and conservation easements.

Is more assessment work needed?
The section 1453 assessments are a snapshot in time. States completed them under a very tight time frame using the readily available data. At the local level, they can be used to prioritize needed protection measures, but they may or may not be adequate. These assessments will need to be updated, enhanced, and refined at the local level.

Does my state have a source water assessment program?
All states have EPA-approved SWAPs. The states had a great deal of flexibility in how they designed their programs. Individual assessment reports vary widely from state to state and even among different kinds of water systems within a state. However, each assessment report contains the following information for a water system:

  • a delineated protection area;
  • an inventory of potential sources of contamination; and
  • an evaluation of the likelihood of the water system being contaminated.

For example, a small public rest area might have a very simple assessment, whereas a large residential community would have a more detailed one. Some states chose to do more detailed assessment work in areas that were already known to be vulnerable to contamination.

Is my assessment information publicly available?
The results of completed assessments are provided to the public to help communities plan for protection activities. Information about the assessment are included in the yearly consumer confidence report that you receive from your water utility. Information is also available from your state source water protection program.

Is source water protection required?
The assessments are intended to be used for protection, but such use is not required under the Safe Drinking Water Act. Assessments are a state and local responsibility. Some states simply make the assessment results available to the public water systems. Others offer grants or technical assistance programs. Other states have mandatory requirements for wellhead protection at the local level.

More Frequent Questions about source water protection are available.

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