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National Drinking Water Database


Chloroform in California


Chloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water. [read more]

The Most Polluted Communities in California

758 water utilities reported detecting Chloroform in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Chloroform level

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Snp-Wolverton
Three Rivers, CA
2,9001 of 1130 ppb
(130 ppb)
2Acwa Buckhorn Plant
Jackson, CA
9,0001 of 1100 ppb
(100 ppb)
3Riviera West Mutual Water Co.
Kelseyville, CA
50017 of 1795.85 ppb
(33.3 to 170 ppb)
4Mcclure Boat Club, Inc.
Snelling,, CA
2212 of 278 ppb
(56 to 100 ppb)
5Rabb Park Community Ser. Dist.
Pioneer, CA
1601 of 176 ppb
(76 ppb)
6Sonora Water Company Inc
Jamestown, CA
5002 of 274.9 ppb
(61.8 to 88 ppb)
7Ramona Municipal Wd
Ramona, CA
30,0003 of 371.33 ppb
(66 to 76 ppb)
8Sa#16 Sumner Hill
Madera, CA
1001 of 170 ppb
(70 ppb)
9Howell Mountain Mutual Water Company
Angwin, CA
1,50018 of 1869.76 ppb
(36 to 120 ppb)
10Plantation Mobile Home Park
Sacramento, CA
441 of 168 ppb
(68 ppb)

Health Based Limits for Chloroform

StandardDescriptionLevel
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.5.7 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.35 ppb
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.70 ppb
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.70 ppb
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.80 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.4000 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.4000 ppb

Violation Summary for Chloroform in California

There are no violations reported for this contaminant in California