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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Middlesex Water Company

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.

In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

235

Samples

0

Samples exceeding legal limit (MCL)

195

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
201416.4 ppb4136ND - 48.9 ppb
201516.6 ppb4135ND - 42.9 ppb
201616.8 ppb3730ND - 52.0 ppb
201723.6 ppb3730ND - 67.0 ppb
201819.6 ppb4033ND - 97.0 ppb
201918.6 ppb3931ND - 56.9 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

ppb = parts per billion

All test results

Date Lab ID Result
2014-02-04899ND
2014-02-069709.41 ppb
2014-02-069658.11 ppb
2014-02-069663.45 ppb
2014-02-069692.91 ppb
2014-02-069678.63 ppb
2014-02-07100511.6 ppb
2014-02-1111389.31 ppb
2014-02-24142402242014ND
2014-03-071713030720146.60 ppb
2014-04-142625041420145.20 ppb
2014-04-142631041420140.800 ppb
2014-05-05308221.0 ppb
2014-05-05308325.7 ppb
2014-05-0631231.80 ppb
2014-05-06312223.3 ppb
2014-05-07315136.0 ppb
2014-05-07314825.7 ppb
2014-05-0731476.12 ppb
2014-05-07315038.1 ppb
2014-06-09398906092014ND
2014-08-04031516-0020.740 ppb
2014-08-06031573-00242.4 ppb
2014-08-06031573-00148.1 ppb
2014-08-07540648.9 ppb
2014-08-07540834.9 ppb
2014-08-08544740.2 ppb
2014-08-08544613.6 ppb
2014-08-18568608182014ND
2014-09-026001090220147.70 ppb
2014-09-296688092920140.700 ppb
2014-11-03756011032014ND
2014-11-037562110320146.40 ppb
2014-11-04760226.2 ppb
2014-11-04760320.6 ppb
2014-11-04760424.7 ppb
2014-11-05762735.4 ppb
2014-11-05762433.6 ppb
2014-11-0576238.99 ppb
2014-11-05762636.0 ppb
2014-11-0776840.520 ppb
2015-02-0272211.7 ppb
2015-02-03763ND
2015-02-0478712.4 ppb
2015-02-047897.49 ppb
2015-02-047903.50 ppb
2015-02-0478612.6 ppb
2015-02-047919.73 ppb
2015-02-068618.99 ppb
2015-02-231243022020153.00 ppb
2015-02-23124502232015ND
2015-03-091573030920152.00 ppb
2015-05-04284329.2 ppb
2015-05-0428447.73 ppb
2015-05-04284524.8 ppb
2015-05-04284905042015ND
2015-05-042848050420155.50 ppb
2015-05-05288631.0 ppb
2015-05-06291025.3 ppb
2015-05-06290923.9 ppb
2015-05-07294927.3 ppb
2015-05-0829820.560 ppb
2015-08-0315080404-0226.0 ppb
2015-08-0315080404-0311.8 ppb
2015-08-0315080404-0420.3 ppb
2015-08-0415080704-0242.4 ppb
2015-08-0515080704-071.23 ppb
2015-08-0515080704-1031.4 ppb
2015-08-0515080704-0934.4 ppb
2015-08-0715080705-0233.1 ppb
2015-08-1015081208-02ND
2015-09-1615091802-024.82 ppb
2015-11-0215110408-02ND
2015-11-0315110408-0437.1 ppb
2015-11-0315110408-0516.4 ppb
2015-11-0315110408-0615.6 ppb
2015-11-0315110409-03ND
2015-11-0315110409-027.62 ppb
2015-11-0415110606-0538.7 ppb
2015-11-0415110606-0230.9 ppb
2015-11-0415110606-0442.9 ppb
2015-11-0515110607-0240.2 ppb
2016-02-02201602040291ND
2016-02-0320160204029417.0 ppb
2016-02-0320160204029317.0 ppb
2016-02-0320160204029614.0 ppb
2016-02-0520160209028717.0 ppb
2016-02-0520160209028413.0 ppb
2016-02-0520160209028516.0 ppb
2016-02-052016020902861.60 ppb
2016-02-082016020903128.50 ppb
2016-02-08201602090309ND
2016-05-02201600504058220.0 ppb
2016-05-0220160050405817.20 ppb
2016-05-032016005040584ND
2016-05-0420160506032519.0 ppb
2016-05-0420160506032118.0 ppb
2016-05-0420160506032215.0 ppb
2016-05-0420160506032414.0 ppb
2016-05-0520160506032716.0 ppb
2016-05-23201605240501ND
2016-08-0220160803076230.0 ppb
2016-08-0320160805051952.0 ppb
2016-08-0320160805051650.0 ppb
2016-08-0320160805051532.0 ppb
2016-08-0320160805051845.0 ppb
2016-08-0420160805052152.0 ppb
2016-08-0420160805052248.0 ppb
2016-08-052016080906730.550 ppb
2016-08-09201608100560ND
2016-11-01201611020680ND
2016-11-0220161103035418.0 ppb
2016-11-0220161103033317.0 ppb
2016-11-0220161103034912.0 ppb
2016-11-0220161103035214.0 ppb
2016-11-0420161108061516.0 ppb
2016-11-042016110806139.70 ppb
2016-11-0420161108061413.0 ppb
2016-11-14201611150663ND
2017-02-0617020705-0224.1 ppb
2017-02-0617020705-0321.6 ppb
2017-02-0617020706-038.37 ppb
2017-02-0617020706-02ND
2017-02-0717021003-0219.3 ppb
2017-02-0817021005-0419.8 ppb
2017-02-0817021005-028.50 ppb
2017-02-1017021405-05ND
2017-02-1017021405-038.79 ppb
2017-02-1017021405-028.38 ppb
2017-05-0117050504-0212.6 ppb
2017-05-0217050504-0423.7 ppb
2017-05-0317050504-06ND
2017-05-0317050504-0927.6 ppb
2017-05-0317050504-0825.5 ppb
2017-05-0417050505-0212.5 ppb
2017-05-0517050505-0439.0 ppb
2017-05-0517050505-0538.3 ppb
2017-05-2217052308-02ND
2017-08-02A245700.520 ppb
2017-08-02A2457556.0 ppb
2017-08-02A2457458.7 ppb
2017-08-03A2457667.0 ppb
2017-08-0417080807-0256.0 ppb
2017-08-0417080807-0334.3 ppb
2017-08-0417080807-0451.6 ppb
2017-08-0717080809-02ND
2017-08-1717082202-0212.6 ppb
2017-11-0717110920-0235.9 ppb
2017-11-0717110922-0233.1 ppb
2017-11-0717110922-0334.7 ppb
2017-11-0717110922-0435.4 ppb
2017-11-0817110920-04ND
2017-11-0817110921-0344.1 ppb
2017-11-0817110921-0247.3 ppb
2017-11-0917111407-027.99 ppb
2017-11-2717112806-02ND
2018-02-0538664278.20 ppb
2018-02-063866432ND
2018-02-0638664309.90 ppb
2018-02-0638664342.60 ppb
2018-02-07386876214.0 ppb
2018-02-07386876011.0 ppb
2018-02-08386876511.0 ppb
2018-02-0938704676.10 ppb
2018-02-20387595111.0 ppb
2018-02-203875950ND
2018-04-2539209484.30 ppb
2018-05-01392740513.0 ppb
2018-05-01392740815.0 ppb
2018-05-023927415ND
2018-05-02392741018.0 ppb
2018-05-02392742812.0 ppb
2018-05-02392741313.0 ppb
2018-05-0239274179.70 ppb
2018-05-04393035112.0 ppb
2018-05-143935709ND
2018-08-06401455949.0 ppb
2018-08-064014581ND
2018-08-06401458219.0 ppb
2018-08-08401642886.0 ppb
2018-08-08401642367.0 ppb
2018-08-08401642676.0 ppb
2018-08-0940179421.000 ppb
2018-08-09401794097.0 ppb
2018-08-09401794428.0 ppb
2018-08-10402110639.0 ppb
2018-11-054111576ND
2018-11-05411157415.0 ppb
2018-11-05411157813.0 ppb
2018-11-06411325418.0 ppb
2018-11-07411407531.0 ppb
2018-11-07411407724.0 ppb
2018-11-07411407329.0 ppb
2018-11-08411646216.0 ppb
2018-12-104145918ND
2018-12-1741521904.60 ppb
2019-02-0419020504-02ND
2019-02-0519020806-020.528 ppb
2019-02-0519020806-0312.8 ppb
2019-02-0619020804-0315.4 ppb
2019-02-0619020804-0212.4 ppb
2019-02-0719020806-056.15 ppb
2019-02-0819020806-0813.8 ppb
2019-02-0819020806-0710.4 ppb
2019-02-1119021205-024.39 ppb
2019-02-1119021205-03ND
2019-05-0619050706-0232.4 ppb
2019-05-0619050704-02ND
2019-05-0719050805-0424.1 ppb
2019-05-0719050805-0222.2 ppb
2019-05-0719050805-0320.2 ppb
2019-05-0819051005-02ND
2019-05-0819051005-0629.3 ppb
2019-05-0819051005-0321.7 ppb
2019-05-0819051005-0530.4 ppb
2019-06-2419062505-0216.3 ppb
2019-08-0519080605-0217.9 ppb
2019-08-0619080804-0437.9 ppb
2019-08-0619080804-0237.9 ppb
2019-08-0619080804-0324.5 ppb
2019-08-0719080806-05ND
2019-08-0719080806-0356.9 ppb
2019-08-0719080806-0252.0 ppb
2019-08-0919080910-0232.4 ppb
2019-08-1919082006-03ND
2019-08-1919082006-0216.4 ppb
2019-11-0419110606-0217.1 ppb
2019-11-0419110607-01ND
2019-11-0619110804-02ND
2019-11-0619110805-0329.7 ppb
2019-11-0619110805-0226.6 ppb
2019-11-0719110808-0435.1 ppb
2019-11-0719110808-0231.0 ppb
2019-11-0719110808-0336.7 ppb
2019-11-0819110808-060.626 ppb