Assessing Idahos Drinking Water Sources

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Assessing Idahos Drinking Water Sources

• Amy Williams
• Source Water Program Coordinator
• Idaho Department of Environmental Quality

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• There shall be no man or women dare to wash any
  unclean linen, wash clothes, nor rinse or make
  clean any kettle, pot or pan, or any suchlike
  vessel within twenty feet of the old well or new
  pump. Nor shall anyone aforesaid within less
  than a quarter mile of the fort, dare to do the
  necessities of nature, since by these unmanly,
  slothful, and loathsome immodesties, the whole
  fort may be chocked and poisoned
• Lord Delaware
• 1610

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Protection A Three Step Process

• Step 1 Assessment
• Step 2 Planning
• Step 3 Implementation

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Safe Drinking Water Act Amendments

• 1986 Wellhead Protection Program

• 1996 Source Water Protection Program

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What is a Source Water Assessment?

• The State is required to conduct assessments on
  all public water systems, to evaluate its
  susceptibility to potential contaminants and make
  the assessments available to the public

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Purpose of the Source Water Assessment

• Identify potential threats to public drinking
  water sources so that protective measures can be
  taken to protect the communitys drinking water
  supply from contamination now, and in the future.

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What does a Source Water Assessment Include?
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Component 1Source Water Area Delineation

• Identification of the areas that contribute water
  to a particular water source used as a public
  water supply (zone of contribution!).
• DEQ uses computer-generated ground water models
  using local drillers well logs, hydrogeologic and
  geologic data to identify the area.

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3, 6, 10 Year Time of Travel
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Component 2Contaminant Source Identification

• Identify past practices and discharges
• Look for the major sources of potential
  contaminants
• Primary and Enhanced Inventories

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Potential Sources of Contamination
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Component 3Perform a Susceptibility Analysis

• Evaluate the conditions in the delineated area to
  determine the potential for contaminants to
  impact water quality at the wellhead.
• Examples Hydrologic Sensitivity, Well
  Construction, Land Use, Potential Contaminant
  Source Characteristics, etc.

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Component 4Source Water Assessment Report

• Provides the public with the current status of
  their drinking water system
• Summarizes potential threats to the communities
  public water supply
• A starting point for drinking (source) water
  protection efforts

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Source Water Assessment Reports

• Online
• GIS information available through Public
  Information Request

www.deq.idaho.gov
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Questions?
Amy Williams Idaho Department of Environmental
Quality [phone] Amy.williams_at_deq.idaho.gov