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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

North Penn Water Authority

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

 

369

Samples

0

Samples exceeding legal limit (MCL)

299

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201410.9 ppb4235ND - 43.7 ppb
201511.7 ppb4732ND - 44.6 ppb
201612.0 ppb7351ND - 36.8 ppb
201712.8 ppb6848ND - 53.7 ppb
201819.3 ppb7569ND - 55.5 ppb
201922.2 ppb64645.02 ppb - 47.0 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
2014-01-082014009714.1 ppb
2014-01-08201400988.31 ppb
2014-01-08201401048.15 ppb
2014-01-08201401029.45 ppb
2014-01-08201401010.992 ppb
2014-01-08201401039.17 ppb
2014-01-08201400999.41 ppb
2014-01-08201401004.76 ppb
2014-03-0520140816ND
2014-03-05201408170.782 ppb
2014-03-0520140818ND
2014-03-0520140819ND
2014-03-0520140820ND
2014-04-092014121916.8 ppb
2014-04-092014122017.9 ppb
2014-04-09201412268.80 ppb
2014-04-09201412248.85 ppb
2014-04-09201412230.808 ppb
2014-04-09201412258.23 ppb
2014-04-092014122111.5 ppb
2014-04-092014122213.7 ppb
2014-06-0420141932ND
2014-06-04201419332.83 ppb
2014-06-0420141935ND
2014-06-04201419360.809 ppb
2014-06-0420141934ND
2014-07-0914071329-0643.7 ppb
2014-07-0914071329-0133.0 ppb
2014-07-0914071329-0423.1 ppb
2014-07-0914071329-0333.7 ppb
2014-07-0914071329-071.20 ppb
2014-07-0914071329-0828.6 ppb
2014-07-0914071329-0529.2 ppb
2014-07-0914071329-0228.3 ppb
2014-10-0814101000-0622.8 ppb
2014-10-0814101000-0112.9 ppb
2014-10-0814101000-0410.1 ppb
2014-10-0814101000-0312.7 ppb
2014-10-0814101000-071.90 ppb
2014-10-0814101000-084.70 ppb
2014-10-0814101000-0512.0 ppb
2014-10-0814101000-026.00 ppb
2015-01-071228712020.3 ppb
2015-01-07122871007.97 ppb
2015-01-07122871108.03 ppb
2015-01-071228710510.8 ppb
2015-01-07122871251.85 ppb
2015-01-07122871304.29 ppb
2015-01-07122871159.73 ppb
2015-01-07122871357.17 ppb
2015-04-081263355619.7 ppb
2015-04-081263353615.8 ppb
2015-04-081263354610.1 ppb
2015-04-081263354113.2 ppb
2015-04-08126335611.000 ppb
2015-04-08126335665.80 ppb
2015-04-08126335518.50 ppb
2015-04-081263357114.8 ppb
2015-07-081301321236.5 ppb
2015-07-081301319240.5 ppb
2015-07-081301320231.4 ppb
2015-07-081301319744.6 ppb
2015-07-08130132172.20 ppb
2015-07-081301322216.2 ppb
2015-07-081301320719.5 ppb
2015-07-081301322736.6 ppb
2015-07-1313013082ND
2015-07-1313013108ND
2015-07-1313013134ND
2015-07-1313013160ND
2015-07-1313013186ND
2015-09-1413264725ND
2015-09-1413264751ND
2015-09-1413264777ND
2015-10-071338931439.1 ppb
2015-10-071338929423.2 ppb
2015-10-071338930415.5 ppb
2015-10-071338929926.3 ppb
2015-10-07133893191.95 ppb
2015-10-07133893246.83 ppb
2015-10-071338930916.5 ppb
2015-10-071338932932.6 ppb
2015-12-0213633361ND
2015-12-0213633387ND
2015-12-0213633413ND
2015-12-0213633439ND
2015-12-0213633465ND
2015-12-0213633491ND
2015-12-0913633517ND
2016-01-061375275128.8 ppb
2016-01-061375273123.2 ppb
2016-01-06137527419.18 ppb
2016-01-061375273612.9 ppb
2016-01-06137527568.46 ppb
2016-01-06137527615.93 ppb
2016-01-061375274611.9 ppb
2016-01-061375276610.00 ppb
2016-03-0213986070ND
2016-03-02139860962.74 ppb
2016-03-0213986122ND
2016-03-0213986148ND
2016-03-0213986174ND
2016-04-071410278223.1 ppb
2016-04-071410278323.1 ppb
2016-04-07141027587.63 ppb
2016-04-07141027597.63 ppb
2016-04-071410277010.6 ppb
2016-04-071410277110.6 ppb
2016-04-071410276412.5 ppb
2016-04-071410276512.5 ppb
2016-04-07141027880.997 ppb
2016-04-07141027890.997 ppb
2016-04-07141027947.32 ppb
2016-04-07141027957.32 ppb
2016-04-071410277611.7 ppb
2016-04-071410277711.7 ppb
2016-04-071410280011.2 ppb
2016-04-071410280111.2 ppb
2016-06-0614405907ND
2016-06-0614405908ND
2016-06-0614405934ND
2016-06-0614405935ND
2016-06-0614405988ND
2016-06-0614405989ND
2016-06-061440601517.0 ppb
2016-06-061440601617.0 ppb
2016-06-0614405961ND
2016-06-0614405962ND
2016-07-061456990930.5 ppb
2016-07-061456991030.5 ppb
2016-07-061456988532.8 ppb
2016-07-061456988632.8 ppb
2016-07-061456989721.6 ppb
2016-07-061456989821.6 ppb
2016-07-061456989133.7 ppb
2016-07-061456989233.7 ppb
2016-07-06145699151.35 ppb
2016-07-06145699161.35 ppb
2016-07-061456992112.2 ppb
2016-07-061456992212.2 ppb
2016-07-061456990329.4 ppb
2016-07-061456990429.4 ppb
2016-07-061456992736.8 ppb
2016-07-061456992836.8 ppb
2016-09-0714908096ND
2016-09-0714908097ND
2016-09-0714908123ND
2016-09-0714908124ND
2016-09-0714908150ND
2016-09-0714908151ND
2016-09-0714908177ND
2016-09-0714908178ND
2016-09-0714908204ND
2016-09-0714908205ND
2016-10-101507569932.0 ppb
2016-10-101507567525.3 ppb
2016-10-101507568721.4 ppb
2016-10-101507568130.5 ppb
2016-10-10150757051.20 ppb
2016-10-10150757118.80 ppb
2016-10-101507569313.9 ppb
2016-10-101507571730.9 ppb
2017-01-101551716020.8 ppb
2017-01-101551716120.8 ppb
2017-01-101551713617.6 ppb
2017-01-101551713717.6 ppb
2017-01-10155171487.04 ppb
2017-01-10155171497.04 ppb
2017-01-101551714211.7 ppb
2017-01-101551714311.7 ppb
2017-01-10155171661.81 ppb
2017-01-10155171671.81 ppb
2017-01-10155171725.49 ppb
2017-01-10155171735.49 ppb
2017-01-10155171549.91 ppb
2017-01-10155171559.91 ppb
2017-01-101551717814.9 ppb
2017-01-101551717914.9 ppb
2017-03-2215796101ND
2017-03-2215796102ND
2017-03-2215796128ND
2017-03-2215796129ND
2017-03-2215796155ND
2017-03-2215796156ND
2017-03-2215796182ND
2017-03-2215796183ND
2017-03-2215796209ND
2017-03-2215796210ND
2017-04-101593690018.0 ppb
2017-04-101593688017.1 ppb
2017-04-101593689012.3 ppb
2017-04-101593688512.1 ppb
2017-04-10159369050.800 ppb
2017-04-10159369107.90 ppb
2017-04-101593689518.0 ppb
2017-04-101593691514.2 ppb
2017-07-101641308645.8 ppb
2017-07-101641306641.1 ppb
2017-07-101641307630.0 ppb
2017-07-101641307153.7 ppb
2017-07-10164130911.40 ppb
2017-07-101641309618.9 ppb
2017-07-101641308136.4 ppb
2017-07-101641310123.0 ppb
2017-09-1116726766ND
2017-09-1116726767ND
2017-09-1116726793ND
2017-09-1116726794ND
2017-09-1116726820ND
2017-09-1116726821ND
2017-09-1116726847ND
2017-09-1116726848ND
2017-09-1116726874ND
2017-09-1116726875ND
2017-10-101688005239.9 ppb
2017-10-101688005339.9 ppb
2017-10-101688002827.8 ppb
2017-10-101688002927.8 ppb
2017-10-101688004018.0 ppb
2017-10-101688004118.0 ppb
2017-10-101688003427.8 ppb
2017-10-101688003527.8 ppb
2017-10-10168800582.47 ppb
2017-10-10168800592.47 ppb
2017-10-101688006411.0 ppb
2017-10-101688006511.0 ppb
2017-10-101688004618.2 ppb
2017-10-101688004718.2 ppb
2017-10-101688007025.0 ppb
2017-10-101688007125.0 ppb
2018-01-102018016419.0 ppb
2018-01-102018016419.0 ppb
2018-01-10201801607.71 ppb
2018-01-10201801607.71 ppb
2018-01-10201801626.72 ppb
2018-01-10201801626.72 ppb
2018-01-10201801619.26 ppb
2018-01-10201801619.26 ppb
2018-01-10201801656.22 ppb
2018-01-10201801656.22 ppb
2018-01-10201801662.92 ppb
2018-01-10201801662.92 ppb
2018-01-10201801637.06 ppb
2018-01-10201801637.06 ppb
2018-01-10201801498.40 ppb
2018-01-10201801498.40 ppb
2018-03-2020181073ND
2018-03-2020181073ND
2018-03-2020181074ND
2018-03-2020181074ND
2018-03-2020181075ND
2018-03-2020181075ND
2018-03-20201810760.545 ppb
2018-03-20201810760.545 ppb
2018-04-092018137224.6 ppb
2018-04-092018137224.6 ppb
2018-04-092018136815.2 ppb
2018-04-092018136815.2 ppb
2018-04-092018137012.3 ppb
2018-04-092018137012.3 ppb
2018-04-092018136922.4 ppb
2018-04-092018136922.4 ppb
2018-04-09201813739.77 ppb
2018-04-09201813739.77 ppb
2018-04-09201813747.32 ppb
2018-04-09201813747.32 ppb
2018-04-092018137110.7 ppb
2018-04-092018137110.7 ppb
2018-04-092018134610.2 ppb
2018-04-092018134610.2 ppb
2018-07-092018255750.0 ppb
2018-07-092018255750.0 ppb
2018-07-092018255342.0 ppb
2018-07-092018255342.0 ppb
2018-07-092018255533.9 ppb
2018-07-092018255533.9 ppb
2018-07-092018255443.6 ppb
2018-07-092018255443.6 ppb
2018-07-09201825582.10 ppb
2018-07-09201825582.10 ppb
2018-07-092018255917.2 ppb
2018-07-092018255917.2 ppb
2018-07-092018255626.0 ppb
2018-07-092018255626.0 ppb
2018-07-092018258323.7 ppb
2018-07-092018258323.7 ppb
2018-08-068082602-0139.9 ppb
2018-08-062018295828.6 ppb
2018-08-062018295828.6 ppb
2018-10-092018386155.5 ppb
2018-10-092018386155.5 ppb
2018-10-092018385738.9 ppb
2018-10-092018385738.9 ppb
2018-10-092018385929.2 ppb
2018-10-092018385929.2 ppb
2018-10-092018385834.5 ppb
2018-10-092018385834.5 ppb
2018-10-092018386230.1 ppb
2018-10-092018386230.1 ppb
2018-10-092018386319.1 ppb
2018-10-092018386319.1 ppb
2018-10-092018386035.1 ppb
2018-10-092018386035.1 ppb
2018-10-092018387313.1 ppb
2018-10-092018387313.1 ppb
2019-01-072019003931.9 ppb
2019-01-072019003931.9 ppb
2019-01-072019003525.2 ppb
2019-01-072019003525.2 ppb
2019-01-072019003718.8 ppb
2019-01-072019003718.8 ppb
2019-01-072019003618.6 ppb
2019-01-072019003618.6 ppb
2019-01-072019004014.2 ppb
2019-01-072019004014.2 ppb
2019-01-07201900419.26 ppb
2019-01-07201900419.26 ppb
2019-01-072019003819.0 ppb
2019-01-072019003819.0 ppb
2019-01-072019005615.0 ppb
2019-01-072019005615.0 ppb
2019-04-082019133320.6 ppb
2019-04-082019133320.6 ppb
2019-04-082019133713.8 ppb
2019-04-082019133713.8 ppb
2019-04-082019133419.2 ppb
2019-04-082019133419.2 ppb
2019-04-082019133523.1 ppb
2019-04-082019133523.1 ppb
2019-04-082019133110.2 ppb
2019-04-082019133110.2 ppb
2019-04-082019133013.6 ppb
2019-04-082019133013.6 ppb
2019-04-082019133216.7 ppb
2019-04-082019133216.7 ppb
2019-04-082019133612.2 ppb
2019-04-082019133612.2 ppb
2019-07-092019261347.0 ppb
2019-07-092019261347.0 ppb
2019-07-092019261745.2 ppb
2019-07-092019261745.2 ppb
2019-07-092019261439.9 ppb
2019-07-092019261439.9 ppb
2019-07-092019261536.2 ppb
2019-07-092019261536.2 ppb
2019-07-092019261110.4 ppb
2019-07-092019261110.4 ppb
2019-07-092019261024.1 ppb
2019-07-092019261024.1 ppb
2019-07-092019261229.5 ppb
2019-07-092019261229.5 ppb
2019-07-092019261627.1 ppb
2019-07-092019261627.1 ppb
2019-10-072019392633.5 ppb
2019-10-072019392633.5 ppb
2019-10-072019393023.8 ppb
2019-10-072019393023.8 ppb
2019-10-072019392719.3 ppb
2019-10-072019392719.3 ppb
2019-10-072019392828.5 ppb
2019-10-072019392828.5 ppb
2019-10-07201939245.02 ppb
2019-10-07201939245.02 ppb
2019-10-072019392311.0 ppb
2019-10-072019392311.0 ppb
2019-10-072019392524.1 ppb
2019-10-072019392524.1 ppb
2019-10-072019392923.2 ppb
2019-10-072019392923.2 ppb