N. C. Department of Environment and Natural Resources

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N. C. Department of Environment and Natural
Resources Division of Waste Management
Stony Hill Road Contamination Wake County
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DENR Organization(Background)

• Division of Water Quality (DWQ)
• Division of Waste Management (DWM)

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Site Discovery

• Resident at 7305 Stony Hill Road reported odor in
  their well water.
• Wake County Health Department sample showed TCE
  and PCE in that well.
• DWQ sampled 6 additional wells at nearby
  residences that granted access permission,
  finding all 6 to be clean.
• Resident at 7305 shut down their well and was
  connected to their neighbors well.

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2005 NC DWQ Potable Well Sampling
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Initial Response Actions

• Based on soil contamination and historic uses,
  7303 Stony Hill Road (circuit board assembly
  operations) confirmed likely source of well
  contamination.
• DWQ  sent the current owner notice of
  requirements to determine the extent of
  contamination through testing and to clean up the
  contamination.
• The current owner conducted a limited
  environmental assessment in 2006 that confirmed
  soil and groundwater contamination on the
  property.

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Responsible Parties Must Pay for Response Costs

• Responsible parties are required to conduct and
  pay for any testing and cleanup of contaminated
  sites and for providing alternate water supplies
  to affected properties.
• DWM must first request cooperation of responsible
  party prior to issuing orders.

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Responsible Parties Must Pay for Response Costs

• Proving who caused the contamination is most
  often difficult when multiple parties operated at
  a property, there were no requirements for record
  keeping and the potential responsible party has
  no incentive to be forthcoming with data that
  will show they caused the problem.
• Water line installation and connections at
  multiple homes can easily cost a few million
  dollars.
• Cleanup of groundwater contamination can run into
  the millions of dollars.
• Cleanup of groundwater is very difficult with
  todays technologies.

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Potential Responsible Party Investigation and
Actions

• DWM sent requests to various potential
  responsible parties associated the site to
  conduct testing to determine extent of
  contamination.
• DWM requested information regarding chemical
  usage and operational activities from various
  potential responsible parties.
• DWM attempted to contact 40-50 former employees
  (interviewed about 20) with C-Tron and CBA
• DWQ issues order to Flextronics requiring
  delineation of contamination

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New Adjoining Landowner Notified

• In 2008, 2009, and 2010, DWM sent letters to
  developers of a planned subdivision adjacent to
  the site due to potential for installation of a
  community well.

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Response Based on Known Risk

• DWM-IHSB is aware of 2600 contaminated sites that
  still require cleanup.
• On average, about 55 new contaminated sites
  discovered each year.
• DWM-IHSB required to work on the highest risk
  sites first.

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Response Based on Known Risk

• There are hundreds of sites in the state with
  contaminated wells or where water supply wells
  are near a source of contamination.
• Initial response at Stony Hill based on known
  risk at the time.

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2012 Well Testing

• In June 2012, DWM contacted 10 well owners within
  1000 feet of the 7305 well to request access for
  new sampling to support enforcement action and
  to get an update on site conditions.
• DWM sampled wells on June 20, 2012 at the three
  properties that granted access.

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June 2012 DWM-IHSB Sampling and Request for US
EPA Removal Action

• Laboratory results showed TCE and PCE in one new
  well at 7333 Stony Hill Road. This home was
  built since 2005 sampling took place.
• Contaminant levels are high enough to warrant US
  EPA Removal Action.
• DWM contacts US EPA same day to request action.

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June 2012 DWM Potable Well Sampling
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More Information

• DENR has set up a place on its web page where you
  can get more information
• Contacts
• Maps
• Fact Sheet
• More coming