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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

City of Norfolk

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

 

204

Samples

0

Samples exceeding legal limit (MCL)

204

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
201431.1 ppb343415.5 ppb - 40.4 ppb
201535.9 ppb323215.7 ppb - 47.0 ppb
201647.1 ppb424227.0 ppb - 63.4 ppb
201741.1 ppb323227.4 ppb - 55.3 ppb
201826.4 ppb323214.7 ppb - 36.3 ppb
201934.9 ppb323222.9 ppb - 46.1 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
2014-02-1114026205-THM16.4 ppb
2014-02-1114026206-THM16.4 ppb
2014-02-1114026203-THM16.1 ppb
2014-02-1114026204-THM16.0 ppb
2014-02-1114026202-THM15.8 ppb
2014-02-1114026209-THM15.8 ppb
2014-02-1114026207-THM15.8 ppb
2014-02-1114026208-THM15.5 ppb
2014-05-13201405190157-THM36.0 ppb
2014-05-13201405190154-THM34.0 ppb
2014-05-13201405190158-THM34.0 ppb
2014-05-13201405190160-THM34.0 ppb
2014-05-13201405190156-THM34.0 ppb
2014-05-13201405190159-THM34.0 ppb
2014-05-13201405190155-THM33.0 ppb
2014-05-13201405190152-THM32.0 ppb
2014-05-13201405190153-THM32.0 ppb
2014-05-13201405190151-THM31.0 ppb
2014-08-1214083442-THM40.4 ppb
2014-08-1214083439-THM40.2 ppb
2014-08-1214083441-THM40.0 ppb
2014-08-1214083444-THM39.7 ppb
2014-08-1214083440-THM39.5 ppb
2014-08-1214083443-THM38.9 ppb
2014-08-1214083445-THM37.3 ppb
2014-08-1214083438-THM36.5 ppb
2014-11-1214116652-THM38.2 ppb
2014-11-1214116651-THM37.5 ppb
2014-11-1214116649-THM37.3 ppb
2014-11-1214116653-THM37.3 ppb
2014-11-1214116650-THM37.2 ppb
2014-11-1214116654-THM34.7 ppb
2014-11-1214116655-THM30.5 ppb
2014-11-1214116648-THM29.2 ppb
2015-02-1000225-CITY OF NO33.5 ppb
2015-02-1000225-CITY OF NO33.3 ppb
2015-02-1000225-CITY OF NO33.2 ppb
2015-02-1000225-CITY OF NO32.7 ppb
2015-02-1000225-CITY OF NO32.5 ppb
2015-02-1000225-CITY OF NO19.9 ppb
2015-02-1000225-CITY OF NO16.2 ppb
2015-02-1000225-CITY OF NO15.7 ppb
2015-05-1200225-CITY OF NO37.6 ppb
2015-05-1200225-CITY OF NO37.5 ppb
2015-05-1200225-CITY OF NO37.5 ppb
2015-05-1200225-CITY OF NO37.5 ppb
2015-05-1200225-CITY OF NO37.4 ppb
2015-05-1200225-CITY OF NO37.3 ppb
2015-05-1200225-CITY OF NO37.2 ppb
2015-05-1200225-CITY OF NO36.9 ppb
2015-08-1100225-CITY OF NO47.0 ppb
2015-08-1100225-CITY OF NO46.9 ppb
2015-08-1100225-CITY OF NO46.9 ppb
2015-08-1100225-CITY OF NO45.7 ppb
2015-08-1100225-CITY OF NO45.4 ppb
2015-08-1100225-CITY OF NO45.2 ppb
2015-08-1100225-CITY OF NO44.6 ppb
2015-08-1100225-CITY OF NO42.8 ppb
2015-11-0900225-CITY OF NO38.1 ppb
2015-11-0900225-CITY OF NO38.1 ppb
2015-11-0900225-CITY OF NO37.3 ppb
2015-11-0900225-CITY OF NO37.3 ppb
2015-11-0900225-CITY OF NO36.9 ppb
2015-11-0900225-CITY OF NO30.2 ppb
2015-11-0900225-CITY OF NO26.1 ppb
2015-11-0900225-CITY OF NO25.5 ppb
2016-02-0916022769-THM37.1 ppb
2016-02-0916022767-THM36.7 ppb
2016-02-0916022770-THM36.6 ppb
2016-02-0916022771-THM35.8 ppb
2016-02-0916022768-THM35.1 ppb
2016-02-0916022766-THM27.6 ppb
2016-02-0916022773-THM27.1 ppb
2016-02-0916022772-THM27.0 ppb
2016-05-1016055867-THM39.6 ppb
2016-05-1016055874-THM39.4 ppb
2016-05-1016055873-THM38.4 ppb
2016-05-1016055869-THM35.6 ppb
2016-05-1016055870-THM35.2 ppb
2016-05-1016055871-THM34.9 ppb
2016-05-1016055868-THM34.0 ppb
2016-05-1016055872-THM33.9 ppb
2016-08-0916089119-THM54.7 ppb
2016-08-0916089118-THM53.5 ppb
2016-08-0916089116-THM53.2 ppb
2016-08-0916089117-THM52.6 ppb
2016-08-0916089120-THM50.2 ppb
2016-08-0916089121-THM49.0 ppb
2016-08-0916089122-THM47.0 ppb
2016-08-0916089115-THM46.7 ppb
2016-11-0816-2049363.4 ppb
2016-11-0816112206-THM62.5 ppb
2016-11-0816-2050262.5 ppb
2016-11-0816112205-THM60.2 ppb
2016-11-0816-2050160.2 ppb
2016-11-0816112199-THM59.6 ppb
2016-11-0816-2049559.6 ppb
2016-11-0816112200-THM56.7 ppb
2016-11-0816-2049656.7 ppb
2016-11-0816112202-THM55.4 ppb
2016-11-0816-2049855.4 ppb
2016-11-0816112203-THM55.1 ppb
2016-11-0816-2049955.1 ppb
2016-11-0816112201-THM53.8 ppb
2016-11-0816-2049753.8 ppb
2016-11-0816-2049453.2 ppb
2016-11-0816112204-THM47.8 ppb
2016-11-0816-2050047.8 ppb
2017-02-1417025512-THM55.3 ppb
2017-02-1417025511-THM54.2 ppb
2017-02-1417025513-THM54.2 ppb
2017-02-1417025510-THM54.1 ppb
2017-02-1417025509-THM51.0 ppb
2017-02-1417025514-THM41.3 ppb
2017-02-1417025515-THM41.3 ppb
2017-02-1417025508-THM38.8 ppb
2017-05-0917058265-THM48.2 ppb
2017-05-0917058272-THM47.6 ppb
2017-05-0917058271-THM43.9 ppb
2017-05-0917058266-THM43.7 ppb
2017-05-0917058269-THM43.4 ppb
2017-05-0917058268-THM43.0 ppb
2017-05-0917058270-THM41.1 ppb
2017-05-0917058267-THM40.3 ppb
2017-08-0817081393-THM45.6 ppb
2017-08-0817081392-THM44.5 ppb
2017-08-0817081390-THM44.0 ppb
2017-08-0817081387-THM43.1 ppb
2017-08-0817081388-THM42.9 ppb
2017-08-0817081389-THM42.8 ppb
2017-08-0817081391-THM40.7 ppb
2017-08-0817081386-THM39.8 ppb
2017-11-1417114473-THM31.9 ppb
2017-11-1417114480-THM31.4 ppb
2017-11-1417114479-THM29.5 ppb
2017-11-1417114477-THM28.3 ppb
2017-11-1417114474-THM27.9 ppb
2017-11-1417114476-THM27.5 ppb
2017-11-1417114478-THM27.5 ppb
2017-11-1417114475-THM27.4 ppb
2018-02-1318027197-THM14.7 ppb
2018-02-1318027198-THM22.2 ppb
2018-02-1318027199-THM22.3 ppb
2018-02-1318027200-THM23.4 ppb
2018-02-1318027201-THM23.1 ppb
2018-02-1318027202-THM23.1 ppb
2018-02-1318027203-THM16.9 ppb
2018-02-1318027204-THM15.4 ppb
2018-05-0818059809-THM32.2 ppb
2018-05-0818059810-THM26.0 ppb
2018-05-0818059811-THM25.3 ppb
2018-05-0818059812-THM26.8 ppb
2018-05-0818059813-THM26.5 ppb
2018-05-0818059814-THM24.4 ppb
2018-05-0818059815-THM28.1 ppb
2018-05-0818059816-THM32.0 ppb
2018-08-1418083091-THM36.3 ppb
2018-08-1418083092-THM27.0 ppb
2018-08-1418083093-THM24.9 ppb
2018-08-1418083094-THM23.8 ppb
2018-08-1418083095-THM27.2 ppb
2018-08-1418083096-THM25.1 ppb
2018-08-1418083097-THM29.0 ppb
2018-08-1418083098-THM34.2 ppb
2018-11-1318115959-THM26.8 ppb
2018-11-1318115960-THM30.6 ppb
2018-11-1318115961-THM29.4 ppb
2018-11-1318115962-THM30.0 ppb
2018-11-1318115963-THM31.3 ppb
2018-11-1318115964-THM30.5 ppb
2018-11-1318115965-THM29.4 ppb
2018-11-1318115966-THM28.1 ppb
2019-02-1219028718-THM29.3 ppb
2019-02-1219028719-THM30.9 ppb
2019-02-1219028720-THM30.2 ppb
2019-02-1219028721-THM30.6 ppb
2019-02-1219028722-THM31.7 ppb
2019-02-1219028723-THM30.5 ppb
2019-02-1219028724-THM30.3 ppb
2019-02-1219028725-THM30.4 ppb
2019-05-1419052465-THM42.8 ppb
2019-05-1419052466-THM41.9 ppb
2019-05-1419052467-THM41.0 ppb
2019-05-1419052468-THM41.4 ppb
2019-05-1419052469-THM43.5 ppb
2019-05-1419052470-THM40.8 ppb
2019-05-1419052471-THM43.9 ppb
2019-05-1419052472-THM43.0 ppb
2019-08-1319085333-THM41.8 ppb
2019-08-1319085334-THM41.5 ppb
2019-08-1319085335-THM38.7 ppb
2019-08-1319085336-THM46.1 ppb
2019-08-1319085337-THM40.1 ppb
2019-08-1319085338-THM44.4 ppb
2019-08-1319085339-THM40.7 ppb
2019-08-1319085364-THM40.6 ppb
2019-11-1219118047-THM26.4 ppb
2019-11-1219118048-THM24.1 ppb
2019-11-1219118049-THM22.9 ppb
2019-11-1219118050-THM25.7 ppb
2019-11-1219118051-THM24.2 ppb
2019-11-1219118052-THM25.1 ppb
2019-11-1219118053-THM26.1 ppb
2019-11-1219118054-THM27.0 ppb