The Power of Information

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

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Trail Ridge Condominiums
MA
1041 of 17.2 ppb
(7.2 ppb)
2East Chelmsford Water District
Chelmsford, MA
2,00014 of 164.18 ppb
(0 to 8.6 ppb)
3Walpole Water Dept
MA
24,0611 of 12 ppb
(2 ppb)
4Salisbury Water Supply Company
Salisbury, MA
20,0001 of 10.7 ppb
(0.7 ppb)
5Worcester Dpw, Water Supply Division
Worcester, MA
172,6481 of 10.69 ppb
(0.69 ppb)
6Clinton Water Dept
Clinton, MA
13,0001 of 10.6 ppb
(0.6 ppb)
7Breton Estates
MA
481 of 10.6 ppb
(0.6 ppb)
8Spencer Water Department
Spencer, MA
6,6751 of 40.53 ppb
(0 to 2.1 ppb)
9Norwell Water Department
Norwell, MA
10,0311 of 10.5 ppb
(0.5 ppb)
10Shrewsbury Water Department
Shrewsbury, MA
31,6403 of 120.45 ppb
(0 to 3.5 ppb)

Health Based Limits for Chloromethane

StandardDescriptionLevel
Lifetime health-based limit, non-cancer riskConcentration 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 LevelA 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 LevelA 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 exposureConcentration 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 exposureConcentration 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