Missouri Public Drinking Water Website

Project Background & Details

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The Federal Safe Drinking Water Act requires that each public water supply routinely monitor for specific chemicals. The Public Drinking Water Program in the Missouri Department of Natural Resources (MoDNR) has the responsibility for testing each public water supply. However, if MoDNR can prove, with a reasonable degree of certainty, that a chemical is not present in an area which would affect a water source, then the test for that chemical at that water source can be waived. Issuance of testing waivers can result in considerable cost savings.

Objectives

  • Determine the locations of public drinking water supplies and potential sources of chemical contamination.
  • Spatially compare the locations of water supplies and contamination sources to determine whether a test waiver is justified.

Methods

  • Methods are based on guidelines developed by the U. S. Environmental Protection Agency (USEPA) and reviewed and approved by MoDNR and USEPA.
  • Two major geographic data layers are developed: one containing all public water sources in the state and another containing the potential sources of chemical contamination in the state.
  • Locations of contamination sources are determined based on existing state and federal data bases.
  • Where locational information is insufficient, additional information is obtained from the MoDNR regional office staff and the Missouri Department of Agriculture.
  • Water source information is obtained from the MoDNR regional office staff.
  • All geographic information are placed on 1:24,000 scale U. S. Geological Survey topographic quadrangles and incorporated into a geographic information system (GIS).
  • The GIS is used to determined whether issuing a testing waiver for each public water supply in Missouri is justified.
Waivers are issued based on the following guidelines:

Wellheads:

  • Each chemical within a one-mile radius is reported.
  • Each highway and railroad within 500 feet is reported to determine the threat posed by the transport of a chemical.
  • The percentage of the county planted in seven major crops is reported to determine he threat posed by agricultural chemical use.
  • The characteristics of soils and geology within a one-mile radius are reported.

Impoundment intakes:

  • Each chemical within the drainage area is reported.
  • The length of each highway and railroad within the watershed is reported to determine the threat posed by the transport of a chemical.
  • The percentage of the county planted in seven major crops is reported to determine the threat posed by agricultural chemical use.
  • The characteristics of soils within the drainage basin are reported.

River intakes:

  • Waivers are not issued for river intakes because the chemicals present in extremely large drainage areas cannot be accurately assessed.

Major Findings

  • The testing costs for monitoring the public water supplies in Missouri can be reduced from an estimated cost of $16 million to $1.8 million for the 1994-1995 testing period. The testing costs for the 1996-1998 testing period, which includes additional chemicals and classes of public drinking water supplies, can be reduced from $24.1 million to $2.9 million.
  • The majority of public drinking supplies are not threatened by potential sources of contamination from the evaluated chemicals.
  • Surface water supplies are more likely to be affected by chemical contamination than groundwater supplies.
  • The data bases used to determine the contamination source locations often contain poor locational information. Assistance of people with local area knowledge is required to map the sites.

Major Products

  • A report listing which water supplies should be tested for which chemicals.
  • A report detailing the susceptibility determination for each active wellhead
  • Geographic Information System (GIS) data layers. Click here for more information. Notice: Due to security concerns, the GIS datasets have moved to a password protected website.  For further information or to request access, please contact David Erickson, Missouri Department of Natural Resources, Water Resources Center, (573) 368-2332.
  • A variety of maps:
Funding amounts and project staff can be found on the project page at the CARES Website.

For more information contact David Erickson

Website funded by Missouri Department of Natural Resources, and administered by the Public Drinking Water Branch
of the Water Protection Program
http://drinkingwater.missouri.edu/va/details.html
- 04/23/2008
Site maintained by CARES,
University of Missouri - Columbia
(573) 882-7458
130 Mumford Hall,
Columbia, MO 65211