THURSTON WOODS 2011

Thurston Woods           EPA # 1332050
Inorganic Contaminants Date(s) Collected Highest Detect Range Detected MCL or MRDL MCLG or MRDLG Violation Yes/No Typical Source of Contaminant
Arsenic (ppb) 1/14/10 4/26/10 7/15/10 11/3/10 12            4.75-RAA nd - 12 10 N/A No Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes.
Arsenic: While your drinking water meets EPA’s standard for arsenic, it does contain low levels of arsenic. EPA’s standard balances the current understanding of arsenic’s possible health effects against the cost of removing arsenic from drinking water. EPA continues to research the health effects of low levels of arsenic which is a mineral know to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.
Nitrate as Nitrogen (ppm 4/26/10 0.42 N/A 10 10 No Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits.
Sodium (ppm) 4/26/10 29.8 N/A Not Regulated N/A Natural sources; runoff from use as salt on roadways; by-product of treatment process
Volatile Organic Contaminants              
Chlorine (ppm) 2010 0.43 Avg 0.1 - 0.8 4 4 No Water additive used to control microbes
Total Trihalomethanes (ppb) 8/26/10 16 16 80 0 No By-product of drinking water chlorination
Haloacetic Acids (ppb) 8/26/10 6.5 N/A 60 0 No By-product of drinking water chlorination
Radiological Contaminants              
Radium 226 & 228 (pCi/L) 2006 2.1 nd - 2.1 5 0 No Erosion of natural deposits
Radon (pCi/L) 4/21/10 321 N/A Not Regulated N/A Erosion of natural deposits
  Date(s) Collected 90th Percentile Action Level MCLG # of Sites Sampled # Sites Above Action Level Violation Yes/No Typical Source of Contaminant
Lead (ppb) 11/20/08 < 5 15 0 5 0 No Corrosion of household plumbing system
Copper (ppm) 11/20/08 0.230 1.3 1.3 5 0 No Corrosion of household plumbing system
What is the source of my drinking water?
Thurston Woods obtains its water from two bedrock wells.  Bedrock Well # 1 is located 154 feet south of the pump house and is 760 feet deep and yields 10 gallons per minute.  Bedrock Well # 2 is located 174 feet south of the pump house and is 447 feet deep and yields 20 gallons per minute.  Current water treatment consists of chlorine for disinfection, aeration to remove radon, and an arsenic removal system.  
Source Water Assessment Summary
    Summary of Susceptibility Factors
Source Name Date Low Med High
Bedrock Well # 1 2/28/06 9 3 0
Bedrock Well # 2 2/28/06 9 3 0
The complete Assessment Report is available for review.  For more information call Gary Tetley at 800-553-5191 ext. 2378 or visit NH Department of Environmental Services Drinking Water and Groundwater Bureau web site at http://www.des.nh.gov/organization/divisions/water/dwgb/dwspp/reports/index.htm