2007

The source of the Avery  water supply consist of two wells and a pump house located off Rossini Road in Londonderry, NH.  Well #1 is 75' southeast of the pump house and well # 2 is 350' southeast of the PH.  Treatment consist of chlorine addition for disinfection, arsenic removal, softeners for hardness removal, aeration for radon removal, and bag filters for sediment removal.  
AVERY
EPA # 1392250
Inorganic Contaminants Units MCLG MCL Averge Level Detected  Ragne Date Violation Yes/No Typical Source of Contaminant
Arsenic ppb n/a 10 2.1 nd to 6 2006 NO Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes.
Fluoride ppm 4 4 0.3 n/a 2004 NO Erosion of natural deposits
Nitrate as Nitrogen ppm 10 10 0.26 n/a 2006 NO Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits.
Radiological Contaminants Units MCLG MCL Average Level Detected  Range Year Violation Yes/No Typical Source of Contaminant
Gross Alpha (Compliance) pCi/L 0 15 2.1 nd to 5 2006 NO Erosion of natural deposits
Combined Radium pCi/L 0 5 0.5 0.2 to 1.1 2006 NO Erosion of natural deposits
Uranium ppb 0 30 13.3 nd to 37 2006 NO Erosion of natural deposits
Volatile Organic Contaminants Units MCLG MCL Average Level Detected Range Year Violation Yes/No Typical Source of Contaminant
Total Trihalomethanes (TTHMs) ppb n /a 80 9 4.9 to 15 2006 NO By-product of drinking water chlorination.
Haloacetic Acids (HAA5) ppb n/a 60 1.3 n/a 2004 NO By-product of drinking water chlorination.
Ethylbenzene ppb 700 700 4.1 nd to 19 2006 NO Discharge from petroleum factories
Toluene ppb 1,000 1,000 0.6 nd to 1.5 2006 NO Discharge from petroleum factories
Total Xylenes ppb 10,000 10,000 30 0.6 to 120 2006 NO Discharge from petroleum factories; discharge from chemical factories.
Volatile Organic Contaminants Units MRDLG MRDL Yearly Average Range Year Violation Yes/No Typical Source of Contaminant
Chlorine ppm 4 4 0.4 0.2 to 0.9 2006 NO Water additive used to control microbes
Inorganic Contaminants Units MCLG AL 90th percentile sample value                      # sites above AL Year Violation Yes/No Typical Source of Contaminant
Copper ppm 1.3 1.3 0.176 0 2006 NO Corrosion of household plumbing system
Source Assessment Information
  Summary of Susceptibility Factors
Source Name Date Low Med High              
Bedrock Well # 1 /75' SE of Pump Station 9/20/01 9 2 1              
Bedrock Well # 2/350' SE Pump Station 3/12/02 8 3 1              
The complete Assessment Report is available for inspection.  For more information call Gary Tetley or visit NH DES's Drinking Water Source Assessment Program web site at www.des.state.nh.us/dwspp