| Williamsburg | EPA # 1851010 | ||||||||
| Inorganic Contaminants | Date(s) Collected | Highest Detect | Range Detected | MCL or MRDL | MCLG or MRDLG | Violation Yes/No | Typical Source of Contaminant | ||
| Barium (ppm) | 10/20/09 | 0.012 | N/A | 2 | 2 | No | Erosion of natural deposits | ||
| Nitrate as Nitrogen (ppm | 10/27/10 | 3.05 | N/A | 10 | 10 | No | Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits. | ||
| Sodium (ppm) | 10/20/09 | 22.3 | 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 | 0.3 - 0.7 | 4 | 4 | No | Water additive used to control microbes | ||
| Total Trihalomethanes (ppb) | 8/10/10 | 7.2 | N/A | 80 | 0 | No | By-product of drinking water chlorination | ||
| Haloacetic Acids (ppb) | 8/10/10 | 1.7 | N/A | 60 | 0 | No | By-product of drinking water chlorination | ||
| Radiological Contaminants | |||||||||
| Radium 226 & 228 (pCi/L) | 2/20/07 4/25/07 7/17/07 10/22/07 | 1.1 | nd - 1.1 | 5 | 0 | No | Erosion of natural deposits | ||
| Radon (pCi/L) | 4/27/10 | 698 | 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) | 11/3/09 | < 5 | 15 | 0 | 10 | 0 | No | Corrosion of household plumbing system | |
| Copper (ppm) | 11/3/09 | 0.313 | 1.3 | 1.3 | 10 | 0 | No | Corrosion of household plumbing system | |
| What is the source of my drinking water? | |||||||||
| The sources of the Williamsburg water supply are two gravel pack wells. The pump house is located near the intersection of Mount Vernon Drive and Valley Forge Drive in Pelham, NH. Treatment consists of chlorine addition to kill bacteria and sodium hydroxide to raise the pH to aid in corrosion control. | |||||||||
| Source Water Assessment Summary | |||||||||
| Summary of Susceptibility Factors | |||||||||
| Source Name | Date | Low | Med | High | |||||
| Gravel Pack Well 1 | 3/2/01 | 7 | 4 | 1 | |||||
| Gravel Pack Well 1A | 3/2/01 | 7 | 4 | 1 | |||||
| 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 | |||||||||