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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Grafton Waterworks

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

 

157

Samples

0

Samples exceeding legal limit (MCL)

53

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.543 ppb269ND - 5.20 ppb
20150.917 ppb2612ND - 12.0 ppb
20160.991 ppb2615ND - 7.10 ppb
20171.18 ppb2411ND - 11.0 ppb
20180.976 ppb2513ND - 9.00 ppb
20190.789 ppb3012ND - 11.0 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
2014-03-10773674ND
2014-03-10773667ND
2014-03-10773656ND
2014-03-107736590.200 ppb
2014-03-107736680.430 ppb
2014-03-107736711.000 ppb
2014-04-07778332ND
2014-04-07778330ND
2014-04-07778325ND
2014-04-07778326ND
2014-04-077783290.290 ppb
2014-04-077783310.620 ppb
2014-07-29806739ND
2014-07-29806744ND
2014-07-29806738ND
2014-07-29806742ND
2014-07-29806743ND
2014-07-29806745ND
2014-07-298067474.30 ppb
2014-07-298067465.20 ppb
2014-12-15835979ND
2014-12-15835978ND
2014-12-15835983ND
2014-12-15835985ND
2014-12-158359820.480 ppb
2014-12-158359841.60 ppb
2015-03-04846466ND
2015-03-04846463ND
2015-03-04846449ND
2015-03-04846464ND
2015-03-04846451ND
2015-03-048464610.300 ppb
2015-05-26861799ND
2015-05-26861796ND
2015-05-26861792ND
2015-05-26861798ND
2015-05-26861793ND
2015-05-268617970.510 ppb
2015-09-08881969ND
2015-09-08881968ND
2015-09-088819620.210 ppb
2015-09-088819630.470 ppb
2015-09-09881966ND
2015-09-098819670.520 ppb
2015-09-098819712.40 ppb
2015-09-098819703.00 ppb
2015-12-28899817ND
2015-12-288998200.290 ppb
2015-12-288998180.500 ppb
2015-12-288998190.530 ppb
2015-12-288998143.10 ppb
2015-12-2889981312.0 ppb
2016-03-16910611ND
2016-03-16910606ND
2016-03-16910601ND
2016-03-169105990.300 ppb
2016-03-169106090.330 ppb
2016-03-169106070.620 ppb
2016-05-16921438ND
2016-05-16921435ND
2016-05-16921431ND
2016-05-169214370.420 ppb
2016-05-169214360.950 ppb
2016-05-169214320.950 ppb
2016-08-31942867ND
2016-08-31942864ND
2016-08-319428600.230 ppb
2016-08-319428650.880 ppb
2016-08-319428614.40 ppb
2016-09-019428660.590 ppb
2016-09-019428705.50 ppb
2016-09-019428697.10 ppb
2016-11-17960029ND
2016-11-17960026ND
2016-11-17960022ND
2016-11-179600280.330 ppb
2016-11-179600270.760 ppb
2016-11-179600232.40 ppb
2017-03-15978080ND
2017-03-15978083ND
2017-03-159780860.380 ppb
2017-03-16978076ND
2017-03-169780770.710 ppb
2017-03-169780732.10 ppb
2017-06-281001051ND
2017-06-281001047ND
2017-06-281001043ND
2017-06-2810010481.40 ppb
2017-06-28100105011.0 ppb
2017-09-201019870ND
2017-09-201019867ND
2017-09-201019869ND
2017-09-2010198680.740 ppb
2017-09-2010198631.90 ppb
2017-09-2010198723.90 ppb
2017-09-2010198714.80 ppb
2017-12-191034429ND
2017-12-191034426ND
2017-12-191034422ND
2017-12-191034423ND
2017-12-1910344270.360 ppb
2017-12-1910344281.000 ppb
2018-03-141045110ND
2018-03-141045107ND
2018-03-141045103ND
2018-03-1410451090.300 ppb
2018-03-1410451040.460 ppb
2018-03-1410451081.000 ppb
2018-06-191062396ND
2018-06-191062395ND
2018-06-191062390ND
2018-06-1910623890.310 ppb
2018-06-1910623940.470 ppb
2018-09-171080756ND
2018-09-171080752ND
2018-09-1710807530.310 ppb
2018-09-1710807581.80 ppb
2018-09-1710807574.10 ppb
2018-09-2610836080.260 ppb
2018-09-2610836090.690 ppb
2018-09-2610836103.70 ppb
2018-11-261094376ND
2018-11-261094369ND
2018-11-2610943709.00 ppb
2018-11-271094374ND
2018-11-271094373ND
2018-11-2710943752.00 ppb
2019-03-181110136ND
2019-03-181110131ND
2019-03-181110134ND
2019-03-181110130ND
2019-03-1811101280.210 ppb
2019-03-1811101320.550 ppb
2019-04-1711163880.580 ppb
2019-06-171128507ND
2019-06-171128504ND
2019-06-171128501ND
2019-06-171128502ND
2019-06-171128503ND
2019-06-1711285050.520 ppb
2019-06-1711285061.10 ppb
2019-09-241151017ND
2019-09-241151014ND
2019-09-241151016ND
2019-09-241151012ND
2019-09-2411510130.240 ppb
2019-09-2411510150.450 ppb
2019-09-2411510183.40 ppb
2019-09-2411510195.00 ppb
2019-09-24115101111.0 ppb
2019-12-101164883ND
2019-12-101164880ND
2019-12-101164882ND
2019-12-101164879ND
2019-12-101164878ND
2019-12-1011648770.270 ppb
2019-12-1011648810.360 ppb