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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

New York City System

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.

 

483

Samples

0

Samples exceeding legal limit (MCL)

467

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201232.8 ppb838316.0 ppb - 50.0 ppb
201335.2 ppb808013.0 ppb - 74.0 ppb
201432.1 ppb808013.0 ppb - 47.0 ppb
201530.9 ppb808011.0 ppb - 56.0 ppb
201637.5 ppb808016.0 ppb - 69.0 ppb
201722.6 ppb8064ND - 46.0 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
2012-02-07301236.0 ppb
2012-02-07301137.0 ppb
2012-02-07299916.0 ppb
2012-02-07300428.0 ppb
2012-02-07300131.0 ppb
2012-02-07301821.0 ppb
2012-02-07299537.0 ppb
2012-02-07301522.0 ppb
2012-02-07301336.0 ppb
2012-02-07300222.0 ppb
2012-02-07301732.0 ppb
2012-02-07301624.0 ppb
2012-02-07299638.0 ppb
2012-02-07299436.0 ppb
2012-02-07300325.0 ppb
2012-02-07300730.0 ppb
2012-02-07300539.0 ppb
2012-02-07300021.0 ppb
2012-02-07300831.0 ppb
2012-02-07301439.0 ppb
2012-02-07300935.0 ppb
2012-02-07299736.0 ppb
2012-02-07301039.0 ppb
2012-05-01986923.0 ppb
2012-05-01986740.0 ppb
2012-05-01985224.0 ppb
2012-05-01986432.0 ppb
2012-05-01986633.0 ppb
2012-05-01985024.0 ppb
2012-05-01986840.0 ppb
2012-05-01986031.0 ppb
2012-05-01985721.0 ppb
2012-05-01985328.0 ppb
2012-05-01985941.0 ppb
2012-05-01986537.0 ppb
2012-05-01986236.0 ppb
2012-05-01985541.0 ppb
2012-05-01985825.0 ppb
2012-05-01986143.0 ppb
2012-05-01985121.0 ppb
2012-05-01986327.0 ppb
2012-05-01985634.0 ppb
2012-05-01985433.0 ppb
2012-08-071838342.0 ppb
2012-08-071838132.0 ppb
2012-08-071839641.0 ppb
2012-08-071839234.0 ppb
2012-08-071838029.0 ppb
2012-08-071839045.0 ppb
2012-08-071839448.0 ppb
2012-08-071839339.0 ppb
2012-08-071838946.0 ppb
2012-08-071838639.0 ppb
2012-08-071839539.0 ppb
2012-08-071837935.0 ppb
2012-08-071838240.0 ppb
2012-08-071838450.0 ppb
2012-08-071838845.0 ppb
2012-08-071839122.0 ppb
2012-08-071838547.0 ppb
2012-08-071838741.0 ppb
2012-08-071839847.0 ppb
2012-08-071839749.0 ppb
2012-11-072641428.0 ppb
2012-11-072641127.0 ppb
2012-11-072642028.0 ppb
2012-11-072641026.0 ppb
2012-11-072641527.0 ppb
2012-11-072642624.0 ppb
2012-11-072642129.0 ppb
2012-11-072641825.0 ppb
2012-11-072641934.0 ppb
2012-11-072641731.0 ppb
2012-11-072642330.0 ppb
2012-11-072641226.0 ppb
2012-11-072642237.0 ppb
2012-11-072640824.0 ppb
2012-11-072640724.0 ppb
2012-11-072641625.0 ppb
2012-11-072642430.0 ppb
2012-11-072642539.0 ppb
2012-11-072641328.0 ppb
2012-11-072640925.0 ppb
2013-02-05296624.0 ppb
2013-02-05297121.0 ppb
2013-02-05295513.0 ppb
2013-02-05296820.0 ppb
2013-02-05296927.0 ppb
2013-02-05295716.0 ppb
2013-02-05296120.0 ppb
2013-02-05297315.0 ppb
2013-02-05296517.0 ppb
2013-02-05295417.0 ppb
2013-02-05295918.0 ppb
2013-02-05296017.0 ppb
2013-02-05295616.0 ppb
2013-02-05297020.0 ppb
2013-02-05297227.0 ppb
2013-02-05296219.0 ppb
2013-02-05296717.0 ppb
2013-02-05296317.0 ppb
2013-02-05295821.0 ppb
2013-02-05296422.0 ppb
2013-05-071052822.0 ppb
2013-05-071059330.0 ppb
2013-05-071053842.0 ppb
2013-05-071053934.0 ppb
2013-05-071052725.0 ppb
2013-05-071053138.0 ppb
2013-05-071052937.0 ppb
2013-05-071059429.0 ppb
2013-05-071054331.0 ppb
2013-05-071053430.0 ppb
2013-05-071053031.0 ppb
2013-05-071053245.0 ppb
2013-05-071054024.0 ppb
2013-05-071054627.0 ppb
2013-05-071054131.0 ppb
2013-05-071054540.0 ppb
2013-05-071053342.0 ppb
2013-05-071053531.0 ppb
2013-05-071053645.0 ppb
2013-05-071054238.0 ppb
2013-08-061893553.0 ppb
2013-08-061893049.0 ppb
2013-08-061894560.0 ppb
2013-08-061893244.0 ppb
2013-08-061893956.0 ppb
2013-08-061893348.0 ppb
2013-08-061893463.0 ppb
2013-08-061894942.0 ppb
2013-08-061893657.0 ppb
2013-08-061894856.0 ppb
2013-08-061894274.0 ppb
2013-08-061894344.0 ppb
2013-08-061894649.0 ppb
2013-08-061900453.0 ppb
2013-08-061894067.0 ppb
2013-08-061893134.0 ppb
2013-08-061894149.0 ppb
2013-08-061893859.0 ppb
2013-08-061893761.0 ppb
2013-08-061894449.0 ppb
2013-11-062710828.0 ppb
2013-11-062716139.0 ppb
2013-11-062710230.0 ppb
2013-11-062709738.0 ppb
2013-11-062710532.0 ppb
2013-11-062711049.0 ppb
2013-11-062710937.0 ppb
2013-11-062710036.0 ppb
2013-11-062711140.0 ppb
2013-11-062710441.0 ppb
2013-11-062710726.0 ppb
2013-11-062711428.0 ppb
2013-11-062710333.0 ppb
2013-11-062710638.0 ppb
2013-11-062709623.0 ppb
2013-11-062709529.0 ppb
2013-11-062709934.0 ppb
2013-11-062710139.0 ppb
2013-11-062711343.0 ppb
2013-11-062709833.0 ppb
2014-02-04271920.0 ppb
2014-02-04272518.0 ppb
2014-02-04272118.0 ppb
2014-02-04273227.0 ppb
2014-02-04277822.0 ppb
2014-02-04272718.0 ppb
2014-02-04273023.0 ppb
2014-02-04272322.0 ppb
2014-02-04271619.0 ppb
2014-02-04272020.0 ppb
2014-02-04271413.0 ppb
2014-02-04272620.0 ppb
2014-02-04272421.0 ppb
2014-02-04272218.0 ppb
2014-02-04271718.0 ppb
2014-02-04273317.0 ppb
2014-02-04271514.0 ppb
2014-02-04272929.0 ppb
2014-02-04271823.0 ppb
2014-02-04272822.0 ppb
2014-05-061022937.0 ppb
2014-05-061022738.0 ppb
2014-05-061024038.0 ppb
2014-05-061022237.0 ppb
2014-05-061023839.0 ppb
2014-05-061022438.0 ppb
2014-05-061023435.0 ppb
2014-05-061023531.0 ppb
2014-05-061023939.0 ppb
2014-05-061023741.0 ppb
2014-05-061023237.0 ppb
2014-05-061023339.0 ppb
2014-05-061023133.0 ppb
2014-05-061022532.0 ppb
2014-05-061022326.0 ppb
2014-05-061022645.0 ppb
2014-05-061023033.0 ppb
2014-05-061024128.0 ppb
2014-05-061022839.0 ppb
2014-05-061023636.0 ppb
2014-08-051839346.0 ppb
2014-08-051838742.0 ppb
2014-08-051838634.0 ppb
2014-08-051839245.0 ppb
2014-08-051839938.0 ppb
2014-08-051839444.0 ppb
2014-08-051839847.0 ppb
2014-08-051840040.0 ppb
2014-08-051838947.0 ppb
2014-08-051838841.0 ppb
2014-08-051839044.0 ppb
2014-08-051840236.0 ppb
2014-08-051838341.0 ppb
2014-08-051839738.0 ppb
2014-08-051840145.0 ppb
2014-08-051838540.0 ppb
2014-08-051839145.0 ppb
2014-08-051839539.0 ppb
2014-08-051839637.0 ppb
2014-08-051838429.0 ppb
2014-11-052622728.0 ppb
2014-11-052622534.0 ppb
2014-11-052623335.0 ppb
2014-11-052623434.0 ppb
2014-11-052622932.0 ppb
2014-11-052623126.0 ppb
2014-11-052621922.0 ppb
2014-11-052623636.0 ppb
2014-11-052622033.0 ppb
2014-11-052622630.0 ppb
2014-11-052622432.0 ppb
2014-11-052622127.0 ppb
2014-11-052623539.0 ppb
2014-11-052621824.0 ppb
2014-11-052622335.0 ppb
2014-11-052623229.0 ppb
2014-11-052623731.0 ppb
2014-11-052622830.0 ppb
2014-11-052622235.0 ppb
2014-11-052623033.0 ppb
2015-02-04274012.0 ppb
2015-02-04275114.0 ppb
2015-02-04274514.0 ppb
2015-02-04275013.0 ppb
2015-02-04275518.0 ppb
2015-02-04274212.0 ppb
2015-02-04274814.0 ppb
2015-02-04275820.0 ppb
2015-02-04275314.0 ppb
2015-02-04274314.0 ppb
2015-02-04274914.0 ppb
2015-02-04275716.0 ppb
2015-02-04275912.0 ppb
2015-02-04275213.0 ppb
2015-02-04274111.0 ppb
2015-02-04274417.0 ppb
2015-02-04275615.0 ppb
2015-02-04282213.0 ppb
2015-02-04274715.0 ppb
2015-02-04274614.0 ppb
2015-05-051023424.0 ppb
2015-05-051022924.0 ppb
2015-05-051022726.0 ppb
2015-05-051021936.0 ppb
2015-05-051022238.0 ppb
2015-05-051021635.0 ppb
2015-05-051022428.0 ppb
2015-05-051023128.0 ppb
2015-05-051022035.0 ppb
2015-05-051022139.0 ppb
2015-05-051021837.0 ppb
2015-05-051022826.0 ppb
2015-05-051022326.0 ppb
2015-05-051023331.0 ppb
2015-05-051022523.0 ppb
2015-05-051021327.0 ppb
2015-05-051023229.0 ppb
2015-05-051023034.0 ppb
2015-05-051021421.0 ppb
2015-05-051021732.0 ppb
2015-08-041887251.0 ppb
2015-08-041888050.0 ppb
2015-08-041888144.0 ppb
2015-08-041888237.0 ppb
2015-08-041886637.0 ppb
2015-08-041887344.0 ppb
2015-08-041887856.0 ppb
2015-08-041887647.0 ppb
2015-08-041886449.0 ppb
2015-08-041887948.0 ppb
2015-08-041886252.0 ppb
2015-08-041886755.0 ppb
2015-08-041887143.0 ppb
2015-08-041886848.0 ppb
2015-08-041886555.0 ppb
2015-08-041886925.0 ppb
2015-08-041887738.0 ppb
2015-08-041887527.0 ppb
2015-08-041887026.0 ppb
2015-08-041886331.0 ppb
2015-11-042776630.0 ppb
2015-11-042775943.0 ppb
2015-11-042770730.0 ppb
2015-11-042774834.0 ppb
2015-11-042779245.0 ppb
2015-11-042779344.0 ppb
2015-11-042776833.0 ppb
2015-11-042777342.0 ppb
2015-11-042775841.0 ppb
2015-11-042769734.0 ppb
2015-11-042775744.0 ppb
2015-11-042775034.0 ppb
2015-11-042778927.0 ppb
2015-11-042775636.0 ppb
2015-11-042777541.0 ppb
2015-11-042779125.0 ppb
2015-11-042777437.0 ppb
2015-11-042775140.0 ppb
2015-11-042779025.0 ppb
2015-11-042771139.0 ppb
2016-02-023594424.0 ppb
2016-02-023594832.0 ppb
2016-02-023594230.0 ppb
2016-02-023596221.0 ppb
2016-02-023594629.0 ppb
2016-02-023594917.0 ppb
2016-02-023595538.0 ppb
2016-02-023595235.0 ppb
2016-02-023595623.0 ppb
2016-02-023595016.0 ppb
2016-02-023595332.0 ppb
2016-02-023596130.0 ppb
2016-02-023594734.0 ppb
2016-02-023595136.0 ppb
2016-02-023595826.0 ppb
2016-02-023595925.0 ppb
2016-02-023594534.0 ppb
2016-02-023594318.0 ppb
2016-02-023596027.0 ppb
2016-02-023595723.0 ppb
2016-05-034512440.0 ppb
2016-05-034512236.0 ppb
2016-05-034513333.0 ppb
2016-05-034512345.0 ppb
2016-05-034512617.0 ppb
2016-05-034513739.0 ppb
2016-05-034512743.0 ppb
2016-05-034511842.0 ppb
2016-05-034512037.0 ppb
2016-05-034513142.0 ppb
2016-05-034511925.0 ppb
2016-05-034513833.0 ppb
2016-05-034512140.0 ppb
2016-05-034512516.0 ppb
2016-05-034512940.0 ppb
2016-05-034513438.0 ppb
2016-05-034513538.0 ppb
2016-05-034513634.0 ppb
2016-05-034512845.0 ppb
2016-05-184661537.0 ppb
2016-08-095568062.0 ppb
2016-08-095567057.0 ppb
2016-08-095567759.0 ppb
2016-08-095567856.0 ppb
2016-08-095567145.0 ppb
2016-08-095568453.0 ppb
2016-08-095566833.0 ppb
2016-08-095568669.0 ppb
2016-08-095568854.0 ppb
2016-08-095568744.0 ppb
2016-08-095568353.0 ppb
2016-08-095580252.0 ppb
2016-08-095566954.0 ppb
2016-08-095568148.0 ppb
2016-08-095567428.0 ppb
2016-08-095567249.0 ppb
2016-08-095567529.0 ppb
2016-08-095567651.0 ppb
2016-08-095568245.0 ppb
2016-08-095567346.0 ppb
2016-11-016447829.0 ppb
2016-11-016447539.0 ppb
2016-11-016446351.0 ppb
2016-11-016447637.0 ppb
2016-11-016446437.0 ppb
2016-11-016446618.0 ppb
2016-11-016446939.0 ppb
2016-11-016447447.0 ppb
2016-11-016446840.0 ppb
2016-11-016445925.0 ppb
2016-11-016446517.0 ppb
2016-11-016447142.0 ppb
2016-11-016445834.0 ppb
2016-11-016446039.0 ppb
2016-11-016447238.0 ppb
2016-11-016446138.0 ppb
2016-11-016446238.0 ppb
2016-11-016447749.0 ppb
2016-11-016447337.0 ppb
2016-11-016446747.0 ppb
2017-02-07371324.0 ppb
2017-02-07371823.0 ppb
2017-02-07372022.0 ppb
2017-02-07371921.0 ppb
2017-02-07371523.0 ppb
2017-02-07371220.0 ppb
2017-02-07371718.0 ppb
2017-02-07372415.0 ppb
2017-02-07372318.0 ppb
2017-02-07372718.0 ppb
2017-02-07370917.0 ppb
2017-02-07371420.0 ppb
2017-02-07371618.0 ppb
2017-02-07371116.0 ppb
2017-02-07372821.0 ppb
2017-02-07372916.0 ppb
2017-02-07371018.0 ppb
2017-02-07372523.0 ppb
2017-02-07372226.0 ppb
2017-02-07372616.0 ppb
2017-05-021174626.0 ppb
2017-05-021175621.0 ppb
2017-05-021174535.0 ppb
2017-05-021174428.0 ppb
2017-05-021175024.0 ppb
2017-05-021174926.0 ppb
2017-05-021174231.0 ppb
2017-05-021173830.0 ppb
2017-05-021175326.0 ppb
2017-05-021175224.0 ppb
2017-05-021175119.0 ppb
2017-05-021175419.0 ppb
2017-05-021174032.0 ppb
2017-05-021173940.0 ppb
2017-05-021173732.0 ppb
2017-05-021173630.0 ppb
2017-05-021175521.0 ppb
2017-05-021174335.0 ppb
2017-05-021174719.0 ppb
2017-05-021174125.0 ppb
2017-08-0121319ND
2017-08-0121312ND
2017-08-0121298ND
2017-08-012132136.0 ppb
2017-08-0121286ND
2017-08-012132742.0 ppb
2017-08-0121346ND
2017-08-0121349ND
2017-08-0121290ND
2017-08-0121347ND
2017-08-0121311ND
2017-08-0121348ND
2017-08-0121276ND
2017-08-0121310ND
2017-08-0121326ND
2017-08-0121296ND
2017-08-0121340ND
2017-08-0121309ND
2017-08-012132841.0 ppb
2017-08-012139938.0 ppb
2017-11-083184832.0 ppb
2017-11-083184531.0 ppb
2017-11-083183241.0 ppb
2017-11-083182927.0 ppb
2017-11-083183440.0 ppb
2017-11-083184445.0 ppb
2017-11-083184635.0 ppb
2017-11-083183034.0 ppb
2017-11-083182828.0 ppb
2017-11-083183743.0 ppb
2017-11-083183640.0 ppb
2017-11-083183927.0 ppb
2017-11-083184746.0 ppb
2017-11-083183833.0 ppb
2017-11-083183339.0 ppb
2017-11-083184144.0 ppb
2017-11-083183133.0 ppb
2017-11-083184329.0 ppb
2017-11-083184228.0 ppb
2017-11-083183537.0 ppb