Arsenic Testing of Private Residential Wells

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Arsenic Testing of Private Residential Wells

• Robert Miller, MPH, RS
• Director of Health
• Eastern Highlands Health District

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Arsenic Testing In Private Residential Wells -
Outline

• Background
• Implementation
• Results
• Discussion

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Arsenic Testing in Private Residential Wells
Background

• EPA lowered Arsenic MCL from 50 ppb to 10 ppb,
  effective January 2006
• At least one PWS in 42 of 169 Towns reports
  levels of arsenic ranging from 1 50 ppb (as of
  7/11/05)
• Three of those Towns are EHHD members
• DPH recommended testing of private wells in areas
  of concern in 7/11/05 memo

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Arsenic Testing of Private Residential Wells -
Implementation

• Instituted mandatory arsenic testing for all new
  residential wells within EHHD jurisdiction,
  effective January 2006
• Notified area laboratories, well drillers, home
  builders, real estate agents of local testing
  requirement with information to facilitate
  testing

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Arsenic Testing of Private Residential Wells -
Results

• Private wells permitted from 1/06 to 1/07, n284
• Detections at or above detectable limits, n19
  (detection limits varied by lab, lowest
  0.001mg/l)
• MCL exceedances, n3

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Geographic Distribution of Detections
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Arsenic Testing of Private Residential Wells
Discussion

• Detections occurred in four (4) additional Towns
  not identified in DPH list.
• 6.7 of wells permitted had detection.
• 1.1 of wells permitted had MCL exceedance.
• Are these observed frequencies consistent with
  other arsenic surveys?
• How many EHHD residents may be exposed to arsenic
  via private well water?
• How would this observed frequency of
  detections/exceedences compare with other
  contaminates?
• Should EHHD continue testing program?