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EWG's Tap Water Database — 2021 UPDATE

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Tetrachloroethylene (perchloroethylene)

Norwalk Water Department

Dry cleaning chemical tetrachloroethylene, or perc, can cause cancer. It pollutes soil and groundwater due to emissions from dry cleaning facilities, and automotive, metalworking and other industries. Read More.

The EPA considers tetrachloroethylene a likely human carcinogen. It has been linked with increased incidence of lung, breast and colon cancers. Tetrachloroethylene also damages the liver, kidneys and central nervous system. The California public health goal of 0.06 parts per billion, set to protect against cancer, is 80 times lower than the amount allowed by the federal government, which is a Maximum Contaminant Level of 5 parts per billion.

Click here to read more about carcinogenic VOCs.

MORE ABOUT THIS CONTAMINANT

 

67

Samples

0

Samples exceeding legal limit (MCL)

37

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.546 ppb124ND - 2.20 ppb
20150.313 ppb125ND - 1.10 ppb
20160.382 ppb125ND - 1.40 ppb
20171.18 ppb127ND - 3.30 ppb
20182.58 ppb881.60 ppb - 3.40 ppb
20191.56 ppb118ND - 3.80 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.06 ppb

The EWG Health Guideline of 0.06 ppb for tetrachloroethylene was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL) 5 ppb

The legal limit for tetrachloroethylene, established in 1991, was based on analytical detection limits at the time that the standard was set. This limit does not fully protect against the risk of cancer due to tetrachloroethylene exposure.

ppb = parts per billion

All test results

Date Lab ID Result
2014-02-199588-012-0930ND
2014-02-199588-003-10001.80 ppb
2014-02-199588-002-1030ND
2014-04-299588-012-0950ND
2014-04-299588-003-10182.20 ppb
2014-04-299588-002-1029ND
2014-07-239588-012-0945ND
2014-07-239588-003-10101.90 ppb
2014-07-239588-002-1025ND
2014-12-109588-012-0924ND
2014-12-109588-003-0945ND
2014-12-109588-002-10200.650 ppb
2015-03-259588-003-09400.750 ppb
2015-03-259588-012-0926ND
2015-03-259588-002-0953ND
2015-04-239588-012-0947ND
2015-04-239588-003-10240.590 ppb
2015-04-239588-002-1041ND
2015-07-309588-012-0928ND
2015-07-309588-002-1044ND
2015-07-309588-003-10150.780 ppb
2015-10-289588-003-09451.10 ppb
2015-10-289588-002-10000.530 ppb
2015-10-289588-012-0915ND
2016-03-249588-003-10100.710 ppb
2016-03-249588-002-1024ND
2016-03-249588-012-0940ND
2016-06-099588-003-09230.810 ppb
2016-06-099588-002-0945ND
2016-06-099588-012-0909ND
2016-07-209588-002-10150.560 ppb
2016-07-209588-003-09451.10 ppb
2016-07-209588-012-0915ND
2016-10-129588-003-09281.40 ppb
2016-10-129588-002-0957ND
2016-10-129588-012-0914ND
2017-01-189588-012-0900ND
2017-01-189588-003-09201.30 ppb
2017-01-189588-002-0935ND
2017-04-179588-002-09301.70 ppb
2017-04-179588-012-0910ND
2017-04-179588-003-09521.90 ppb
2017-07-249588-003-09552.00 ppb
2017-07-249588-012-0923ND
2017-07-249588-002-10282.80 ppb
2017-10-189588-002-09503.30 ppb
2017-10-189588-003-09401.20 ppb
2017-10-189588-012-0914ND
2018-01-249588-002-09403.40 ppb
2018-01-249588-003-09202.30 ppb
2018-04-119588-002-09533.10 ppb
2018-04-119588-003-09302.50 ppb
2018-07-259588-002-10002.10 ppb
2018-07-259588-003-09352.70 ppb
2018-10-269588-002-09401.60 ppb
2018-10-269588-003-09202.90 ppb
2019-01-239588-003-09203.80 ppb
2019-01-239588-002-09502.40 ppb
2019-04-259588-002-10301.20 ppb
2019-04-259588-003-10053.80 ppb
2019-05-249588-012-0920ND
2019-07-259588-012-0930ND
2019-07-259588-002-10352.10 ppb
2019-07-259588-003-10101.80 ppb
2019-10-259588-012-0930ND
2019-10-259588-003-10401.50 ppb
2019-10-259588-002-10000.560 ppb