TWIN RIDGE 2011

Twin Ridge           EPA #  1932050
Inorganic Contaminants Date(s) Collected Highest Detect Range Detected MCL or MRDL MCLG or MRDLG Violation Yes/No Typical Source of Contaminant
Barium (ppm) 8/25/09 4/8/10 0.011 0.011 - 0.048 2 2 No Erosion of natural deposits
Fluoride (ppm)  1/25/10 5/6/10 4/8/10 0.46 0.42 - 0.46 4 4 No Erosion of natural deposits
Sodium (ppm) 8/25/09 4/8/10 335 31.3 - 335 Not Regulated N/A Natural sources; runoff from use as salt on roadways; by-product of treatment process
Volatile Organic Contaminants              
Chlorine (ppm) 2010 0.45 Avg 0.3 - 0.7 4 4 No Water additive used to control microbes
Total Trihalomethanes (ppb) 7/13/10 8/10/10 12 8.1 - 12 80 0 No By-product of drinking water chlorination
Haloacetic Acids (ppb) 8/10/10 3.1 N/A 60 0 No By-product of drinking water chlorination
Methyl-Tertiary-Butyl Ether (MtBE) (ppb) 6/23/10 7/13/10 0.7 nd - 0.7 13 13 No Gasoline additive
Radiological Contaminants              
Compliance Gross Alpha (pCi/L) 5/3/10 4/8/10 18 2.9 - 18 15 0 No Erosion of natural deposits
Radium 226 & 228 (pCi/L) 5/3/10 4/8/10 9.8 0.5 - 9.8 5 0 No Erosion of natural deposits
Uranium (ppb) 5/3/10 4/8/10 6.7 4.0 - 6.7 30 0 No Erosion of natural deposits
Radon (pCi/L) 5/3/10 4/8/10 4,500 4,390 - 4,500 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) 8/13/09 9/15/09 9/17/09 15 15 0 10 1 No Corrosion of household plumbing system
Copper (ppm) 8/13/09 9/15/09 9/17/09 0.084 1.3 1.3 10 0 No Corrosion of household plumbing system
What is the source of my drinking water?
The source for the Twin Ridge water supply is four wells located off Culver Street in Plaistow, NH.  Well # 4 located 58 feet southeast of the pump house.  Well # 5 is located 104 feet southeast of the pump station.  Well # 6 is located 210 feet northeast of the pump house.  Well # 7 is located  600 feet southeast of the pump station.  Treatment consists of manganese green sand filtration to remove iron and manganese, ion exchange softeners to reduce water hardness, chlorine addition to kill bacteria, and sodium hydroxide to raise the pH to optimize iron and manganese removal and aid in corrosion control.
Text Box: On 12/3/10 approximately 8,400 gallons of drinking water was transferred from the Pennichuck Water Work's Treatment Plant in Nashua and 8,400 gallons of drinking water was transferred from the Whispering Winds community water system to the Twin Ridge storage tank.  This was necessary due to a main break in the distribution system.
Source Water Assessment Summary
    Summary of Susceptibility Factors
Source Name Date Low Med High
Bedrock Well # 4 3/11/05 8 3 1
Bedrock Well # 5 10/27/00 8 2 2
Bedrock Well # 6 10/22/04 7 2 3
Bedrock Well # 7 Assessment Summary not available at this time
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