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What's in Your Water Groundwater Contamination of Private Wells

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What's in Your Water    Groundwater Contamination of Private Wells Powered By Docstoc
					      What's in Your Water?
Groundwater Contamination of Private
      Wells in North Carolina
 An integrative investigation of the sources and
 effects of groundwater contamination for local
     communities and homeowners in North
                    Carolina

• Avner Vengosh, Erika Weinthal, Lori Snyder Bennear, Emily
  Klein, and Marie Lynn Miranda: Nicholas School of
  Environment and Earth Sciences, Duke University
• Mark Wiesner: Pratt School of Engineering, Duke University
• Hope Taylor-Guevara: Clean Water for North Carolina
• Ted Campbell , Rick Bolich, North Carolina Dept. of
  Environment and Natural Resources, Division of Water
  Quality - Groundwater Section
     An integrative investigation of the sources and
     effects of groundwater contamination for local
    communities and homeowners in North Carolina

 Awareness, Willingness-                Mobilization
 to-pay (Socioeconomic)                 (geochemistry)

                           Occurrence
                           (GIS)
 Public policy,                           Remediation
 Legislation                              (technology)

                            Outreach

USDA project 2006-03956
        Statement of the Problem
• More than two million residents in North Carolina use
  groundwater as a sole source for drinking water. Increase
  in population is associated with drilling new wells (5,000
  to 6,000 per year).

• In several areas, the levels of natural contaminants,
  radon, arsenic, and radium exceed drinking water
  regulations.

• Wells of private homeowners are not regulated.
Major hydrogeological units of North Carolina




      Hot spots
     Typical private well and geology in the Piedmont, NC




Regolith    saprolite                 Casing

           Transition
           zone

                                       …igneous,
                                       metasedimentary,
                          Open hole    and metavolcanic
Fractured rock            hole
                                       rocks
(NCGS data)
                           2005, 103 private wells
Detailed above
  Radon
Formations
  20,000 pCi/L

(60X proposed MCL)

Radon: 300 to 4000 pCi/L
Radon: above 4000 pCi/L


                                                          granite
                                                          gneiss
                                                       Ordivician, 438 M , interlayered
                                                       w/ biotite augens



   granodiorite                                        Henderson
   Devonian, 390 M
                                                       Gneiss
                                                       Cambrian, 500 M




                                       Meta-igneous rock
                                       Metasedimentary rock
                           Ted Campbell, NC Division of Water Quality,
                           Aquifer Protection Section
                                  Slate Belt and Raleigh Belt


                                                             60 wells above
                                                              4,000 pCi/L

                                            Metamorphosed
            Guilford                        granitic rock
                                                                                     Franklin
            Felsic and
            mafic igneous                                                            27 wells above
            and meta-                        Orange                                   10,000 pCi/L
            igneous rock

                                                                    Wake
                                                                              Granitic
     Median = 735 pCi/L                                          Raleigh      plutons
                                  Median = 586 pCi/L             gneiss
     Max = 6,300 pCi/L
                                  Max = 4,229 pCi/L
         (70 private wells)
                                         (42 wells)
     (Spruill and others, 1997)                              Median = 2800 pCi/L
                                  (Orange Co. staff, 1997)
                                                             Max = 32,000 pCi/L
                                                             (305 private wells - Phase I & II)

              Meta-igneous rock                              (Cornell and others, 2005)
                                                             (Bolich and Stoddard, 2004)
Ted Campbell, NC Division of Water Quality,
Aquifer Protection Section
      Radium violations (>5 pCi/L) in public water systems




Modified after Menetrez and Watson, 1983. Natural radioactivity in North Carolina groundwater supplies. University of
North Carolina, Water Resources Research Institution, Report 208, 30p.
Distribution of radium in groundwater in Wake County
Distribution of Arsenic in Groundwater in North Carolina
High-arsenic Groundwater in the Slate Belt
Distribution of natural contaminants in
    groundwater of North Carolina
            Health effects of arsenic
              radium, and radon
• Epidemiological studies have shown that long-term utilization of
  drinking water with arsenic and radium levels exceeding the EPA
  MCL standards is associated with higher frequencies of lung and
  skin cancer (for arsenic) and leukemia and bone cancer (for radium).

• High radon in domestic waters could increase the exposure of users
  to airborne radon due to degassing of radon from showers and other
  water utilities in the house. High level of airborne radon is associated
  with higher frequency of lung cancer.
The Piedmont Geology
               (USGS data)
   How to protect North Carolina’s private wells

• House Bill 2873 Safe Drinking Water/Private Wells:
From 2008 all 100 counties establish permitting and inspection
programs for new wells. Newly constructed private drinking water
wells will be tested for inorganic contaminants (e.g.,arsenic,
barium, cadmium, lead, iron) and bacterial indicators.

• Emergency Drinking Water Fund as part House Bill 2884:
Providing funding to notify well users within 1,500 feet of known
contaminated sites and assistance with testing

• Outreach, education - is   that enough?

				
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