National Drinking Water Database
Chloromethane in Massachusetts
Chloromethane is a naturally occuring chemical that forms during combustion of plant material; it may be released from the manufacture of silicone, rubber and pesticides, and also forms as a byproduct of water disinfection.
The Most Polluted Communities in Massachusetts
31 water utilities reported detecting Chloromethane in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Chloromethane level
| Rank | System | Population Served | Positive test results of total reported tests | Average Level (Range) |
|---|---|---|---|---|
| 1 | Trail Ridge Condominiums MA | 104 | 1 of 1 | 7.2 ppb (7.2 ppb) |
| 2 | East Chelmsford Water District Chelmsford, MA | 2,000 | 14 of 16 | 4.18 ppb (0 to 8.6 ppb) |
| 3 | Walpole Water Dept MA | 24,061 | 1 of 1 | 2 ppb (2 ppb) |
| 4 | Salisbury Water Supply Company Salisbury, MA | 20,000 | 1 of 1 | 0.7 ppb (0.7 ppb) |
| 5 | Worcester Dpw, Water Supply Division Worcester, MA | 172,648 | 1 of 1 | 0.69 ppb (0.69 ppb) |
| 6 | Clinton Water Dept Clinton, MA | 13,000 | 1 of 1 | 0.6 ppb (0.6 ppb) |
| 7 | Breton Estates MA | 48 | 1 of 1 | 0.6 ppb (0.6 ppb) |
| 8 | Spencer Water Department Spencer, MA | 6,675 | 1 of 4 | 0.53 ppb (0 to 2.1 ppb) |
| 9 | Norwell Water Department Norwell, MA | 10,031 | 1 of 1 | 0.5 ppb (0.5 ppb) |
| 10 | Shrewsbury Water Department Shrewsbury, MA | 31,640 | 3 of 12 | 0.45 ppb (0 to 3.5 ppb) |
Health Based Limits for Chloromethane
| Standard | Description | Level |
|---|---|---|
| Lifetime health-based limit, non-cancer risk | Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency. | 30 ppb |
| Health-Based Screening Level | A benchmark concentration of contaminants in water that may be of potential concern for human health, if exceeded. For noncarcinogens, the HBSL represents the contaminant concentration in drinking water that is not expected to cause any adverse effects over a lifetime of exposure. For carcinogens, the HBSL range represents the contaminant concentration in drinking water that corresponds to an excess estimated lifetime cancer risk of 1 chance in 1 million to 1 chance in 10 thousand. Source: U.S. Geological Survey. | 30 ppb |
| Drinking Water Equivalent Level | A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency. | 100 ppb |
| Children's health-based limit for 10-day exposure | Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency. | 400 ppb |
| Children's health-based limit for 1-day exposure | Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency. | 9000 ppb |
Violation Summary for Chloromethane in Massachusetts
There are no violations reported for this contaminant in Massachusetts