Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

City of Tacoma

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

 

353

Samples

0

Samples exceeding legal limit (MCL)

332

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201414.4 ppb6460ND - 43.0 ppb
20156.81 ppb5546ND - 19.0 ppb
20167.27 ppb6159ND - 18.0 ppb
20179.55 ppb6360ND - 27.0 ppb
20187.28 ppb5958ND - 24.0 ppb
201910.5 ppb5149ND - 23.0 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
2014-01-07906364.20 ppb
2014-01-07906401.70 ppb
2014-01-07906263.60 ppb
2014-01-07906302.70 ppb
2014-01-07906336.20 ppb
2014-01-07906380.510 ppb
2014-01-07906272.40 ppb
2014-01-07906373.30 ppb
2014-01-07906345.60 ppb
2014-01-07906283.60 ppb
2014-01-07906313.60 ppb
2014-01-07906291.60 ppb
2014-01-07906324.30 ppb
2014-01-07906390.520 ppb
2014-01-07906354.40 ppb
2014-04-14704632.30 ppb
2014-04-14704683.90 ppb
2014-04-14704662.80 ppb
2014-04-14704710.670 ppb
2014-04-14704622.00 ppb
2014-04-14704704.90 ppb
2014-04-14704692.20 ppb
2014-04-14704613.00 ppb
2014-04-14704674.70 ppb
2014-04-15704751.10 ppb
2014-04-15704642.40 ppb
2014-04-1570473ND
2014-04-1570474ND
2014-04-15704651.90 ppb
2014-04-15704722.70 ppb
2014-07-147068322.0 ppb
2014-07-147068731.0 ppb
2014-07-147068415.0 ppb
2014-07-147068924.0 ppb
2014-07-147068126.0 ppb
2014-07-147069141.0 ppb
2014-07-147068519.0 ppb
2014-07-147068621.0 ppb
2014-07-147069030.0 ppb
2014-07-147068829.0 ppb
2014-07-147068221.0 ppb
2014-07-15706948.70 ppb
2014-07-15706936.80 ppb
2014-07-157069516.0 ppb
2014-07-157069225.0 ppb
2014-10-060026037.0 ppb
2014-10-060025943.0 ppb
2014-10-060026140.0 ppb
2014-10-060025841.0 ppb
2014-10-060025643.0 ppb
2014-10-060025232.0 ppb
2014-10-060025336.0 ppb
2014-10-060025440.0 ppb
2014-10-060025538.0 ppb
2014-10-060025731.0 ppb
2014-10-070026335.0 ppb
2014-10-070026623.0 ppb
2014-10-070026517.0 ppb
2014-10-070026412.0 ppb
2014-10-070026235.0 ppb
2014-11-13291910.750 ppb
2014-11-14291920.890 ppb
2014-11-1830352ND
2014-12-0234852ND
2015-01-13507397.90 ppb
2015-01-13507383.80 ppb
2015-01-13507373.00 ppb
2015-01-135073610.00 ppb
2015-01-13507358.60 ppb
2015-01-145073319.0 ppb
2015-01-145073215.0 ppb
2015-01-145073118.0 ppb
2015-01-145073011.0 ppb
2015-01-145072912.0 ppb
2015-01-14507287.60 ppb
2015-01-145072712.0 ppb
2015-01-14507269.60 ppb
2015-01-145073413.0 ppb
2015-01-145072512.0 ppb
2015-06-0827944ND
2015-07-07904217.30 ppb
2015-07-079042314.0 ppb
2015-07-08904202.50 ppb
2015-07-08904250.580 ppb
2015-07-08904273.30 ppb
2015-07-08904220.650 ppb
2015-07-08904246.40 ppb
2015-07-089042612.0 ppb
2015-08-0585793ND
2015-10-13504097.10 ppb
2015-10-13504137.20 ppb
2015-10-13504124.10 ppb
2015-10-135040713.0 ppb
2015-10-135041012.0 ppb
2015-10-135039913.0 ppb
2015-10-13504049.60 ppb
2015-10-135040612.0 ppb
2015-10-135040116.0 ppb
2015-10-135040312.0 ppb
2015-10-135040011.0 ppb
2015-10-135040513.0 ppb
2015-10-135040816.0 ppb
2015-10-13504028.40 ppb
2015-10-14504116.00 ppb
2015-12-01386610.510 ppb
2015-12-01386610.510 ppb
2015-12-01386610.510 ppb
2015-12-01386610.510 ppb
2015-12-0238662ND
2015-12-0238662ND
2015-12-0238662ND
2015-12-0238662ND
2015-12-03386630.690 ppb
2015-12-03386630.690 ppb
2015-12-03386630.690 ppb
2015-12-03386630.690 ppb
2015-12-0741682ND
2015-12-0741681ND
2015-12-0841683ND
2016-01-042.80 ppb
2016-01-043.00 ppb
2016-01-043.80 ppb
2016-01-043.60 ppb
2016-01-052.60 ppb
2016-01-051.90 ppb
2016-01-051.80 ppb
2016-01-050.690 ppb
2016-01-050.510 ppb
2016-01-051.90 ppb
2016-01-067.20 ppb
2016-01-065.90 ppb
2016-01-063.40 ppb
2016-01-066.80 ppb
2016-01-066.00 ppb
2016-04-040.500 ppb
2016-04-040.830 ppb
2016-04-041.20 ppb
2016-04-046.60 ppb
2016-04-047.40 ppb
2016-04-042.50 ppb
2016-04-042.10 ppb
2016-04-049.00 ppb
2016-04-043.70 ppb
2016-04-044.10 ppb
2016-04-043.90 ppb
2016-04-043.70 ppb
2016-04-046.30 ppb
2016-04-052.70 ppb
2016-04-05ND
2016-04-06ND
2016-07-0614.0 ppb
2016-07-0611.0 ppb
2016-07-0613.0 ppb
2016-07-0611.0 ppb
2016-07-0616.0 ppb
2016-07-067.30 ppb
2016-07-0613.0 ppb
2016-07-064.10 ppb
2016-07-063.00 ppb
2016-07-0611.0 ppb
2016-07-0611.0 ppb
2016-07-067.10 ppb
2016-07-0612.0 ppb
2016-07-068.80 ppb
2016-07-069.90 ppb
2016-10-0314.0 ppb
2016-10-0316.0 ppb
2016-10-0318.0 ppb
2016-10-0313.0 ppb
2016-10-0318.0 ppb
2016-10-0318.0 ppb
2016-10-0312.0 ppb
2016-10-0310.00 ppb
2016-10-0313.0 ppb
2016-10-0313.0 ppb
2016-10-0413.0 ppb
2016-10-044.70 ppb
2016-10-049.10 ppb
2016-10-044.40 ppb
2016-10-048.80 ppb
2017-01-031.80 ppb
2017-01-036.00 ppb
2017-01-031.80 ppb
2017-01-033.40 ppb
2017-01-033.40 ppb
2017-01-039.30 ppb
2017-01-0315.0 ppb
2017-01-039.90 ppb
2017-01-0314.0 ppb
2017-01-034.40 ppb
2017-01-036.10 ppb
2017-01-036.10 ppb
2017-01-034.90 ppb
2017-01-035.70 ppb
2017-01-036.60 ppb
2017-04-0311.0 ppb
2017-04-039.70 ppb
2017-04-037.90 ppb
2017-04-0317.0 ppb
2017-04-039.70 ppb
2017-04-0311.0 ppb
2017-04-038.50 ppb
2017-04-0310.00 ppb
2017-04-0311.0 ppb
2017-04-0310.00 ppb
2017-04-039.00 ppb
2017-04-044.50 ppb
2017-04-047.20 ppb
2017-04-044.60 ppb
2017-04-0512.0 ppb
2017-05-10ND
2017-05-10ND
2017-07-054.90 ppb
2017-07-058.00 ppb
2017-07-0510.00 ppb
2017-07-059.80 ppb
2017-07-058.80 ppb
2017-07-0510.00 ppb
2017-07-0514.0 ppb
2017-07-058.90 ppb
2017-07-053.30 ppb
2017-07-0612.0 ppb
2017-07-0612.0 ppb
2017-07-068.10 ppb
2017-07-068.40 ppb
2017-07-0615.0 ppb
2017-07-068.60 ppb
2017-10-0218.0 ppb
2017-10-0227.0 ppb
2017-10-0210.00 ppb
2017-10-0212.0 ppb
2017-10-0214.0 ppb
2017-10-0214.0 ppb
2017-10-0224.0 ppb
2017-10-0217.0 ppb
2017-10-0218.0 ppb
2017-10-024.60 ppb
2017-10-0210.00 ppb
2017-10-0215.0 ppb
2017-10-0218.0 ppb
2017-10-034.90 ppb
2017-10-0312.0 ppb
2017-10-10ND
2018-01-027.10 ppb
2018-01-027.20 ppb
2018-01-0210.00 ppb
2018-01-026.00 ppb
2018-01-025.30 ppb
2018-01-025.70 ppb
2018-01-029.00 ppb
2018-01-026.00 ppb
2018-01-027.90 ppb
2018-01-027.90 ppb
2018-01-024.40 ppb
2018-01-035.30 ppb
2018-01-032.00 ppb
2018-01-032.30 ppb
2018-01-034.00 ppb
2018-02-07ND
2018-03-120.830 ppb
2018-03-190.540 ppb
2018-04-025.20 ppb
2018-04-027.80 ppb
2018-04-028.80 ppb
2018-04-026.60 ppb
2018-04-026.70 ppb
2018-04-028.60 ppb
2018-04-026.50 ppb
2018-04-028.70 ppb
2018-04-026.60 ppb
2018-04-027.80 ppb
2018-04-023.00 ppb
2018-04-024.70 ppb
2018-04-032.60 ppb
2018-04-034.90 ppb
2018-07-025.90 ppb
2018-07-027.80 ppb
2018-07-027.70 ppb
2018-07-022.50 ppb
2018-07-023.00 ppb
2018-07-025.70 ppb
2018-07-026.20 ppb
2018-07-037.00 ppb
2018-07-039.50 ppb
2018-07-036.50 ppb
2018-07-037.60 ppb
2018-07-039.80 ppb
2018-07-037.80 ppb
2018-07-0313.0 ppb
2018-07-037.10 ppb
2018-10-3010.00 ppb
2018-10-3012.0 ppb
2018-10-3012.0 ppb
2018-10-309.80 ppb
2018-10-3011.0 ppb
2018-10-319.80 ppb
2018-10-3111.0 ppb
2018-10-3124.0 ppb
2018-10-3111.0 ppb
2018-10-3111.0 ppb
2018-10-3111.0 ppb
2018-10-3110.00 ppb
2019-01-02ND
2019-01-148.00 ppb
2019-01-1413.0 ppb
2019-01-147.50 ppb
2019-01-1420.0 ppb
2019-01-146.90 ppb
2019-01-1412.0 ppb
2019-01-147.30 ppb
2019-01-147.30 ppb
2019-01-147.10 ppb
2019-01-149.40 ppb
2019-01-146.20 ppb
2019-01-156.30 ppb
2019-04-019.70 ppb
2019-04-019.40 ppb
2019-04-0112.0 ppb
2019-04-019.40 ppb
2019-04-018.70 ppb
2019-04-018.50 ppb
2019-04-0112.0 ppb
2019-04-018.40 ppb
2019-04-018.90 ppb
2019-04-0112.0 ppb
2019-04-018.80 ppb
2019-04-037.30 ppb
2019-07-087.20 ppb
2019-07-088.20 ppb
2019-07-0811.0 ppb
2019-07-088.30 ppb
2019-07-088.20 ppb
2019-07-088.30 ppb
2019-07-0812.0 ppb
2019-07-088.40 ppb
2019-07-0812.0 ppb
2019-07-0811.0 ppb
2019-07-088.60 ppb
2019-07-087.80 ppb
2019-07-240.770 ppb
2019-10-0116.0 ppb
2019-10-0117.0 ppb
2019-10-0116.0 ppb
2019-10-0115.0 ppb
2019-10-0211.0 ppb
2019-10-0217.0 ppb
2019-10-0223.0 ppb
2019-10-0216.0 ppb
2019-10-0219.0 ppb
2019-10-0222.0 ppb
2019-10-0213.0 ppb
2019-10-0215.0 ppb
2019-12-03ND