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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Carson City Public Works

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.

 

289

Samples

0

Samples exceeding legal limit (MCL)

184

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20127.37 ppb8535ND - 84.0 ppb
201320.7 ppb4033ND - 93.8 ppb
201417.0 ppb3630ND - 71.2 ppb
201510.3 ppb5830ND - 75.6 ppb
201619.6 ppb3327ND - 99.3 ppb
201712.9 ppb3729ND - 105.0 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
2012-02-222012022401671.04 ppb
2012-02-2220120224016815.8 ppb
2012-02-2320120224016963.6 ppb
2012-02-2320120224017061.4 ppb
2012-02-2320120224017141.5 ppb
2012-02-2320120224017243.4 ppb
2012-02-2320120224017330.6 ppb
2012-02-2320120224017424.3 ppb
2012-06-05201206080383ND
2012-06-05201206080384ND
2012-06-0520120608038511.2 ppb
2012-06-0520120608038615.8 ppb
2012-06-0520120608038717.5 ppb
2012-06-052012060803885.43 ppb
2012-06-052012060803896.84 ppb
2012-06-0520120608039010.8 ppb
2012-06-18201206210179-VND
2012-06-18201206210173-VND
2012-06-18201206210177-VND
2012-06-18201206210181-VND
2012-06-182012-6210175-VND
2012-06-18201206210171-VND
2012-06-19201206210314-V18.0 ppb
2012-06-19201206220025-VND
2012-06-19201206220012-VND
2012-06-19201206220010-VND
2012-06-21201206220323-VND
2012-06-21201206220321-VND
2012-06-25201206270438-VND
2012-06-25201206170436-VND
2012-06-25201206270510-VND
2012-06-25201206270244-VND
2012-06-25201206270216-V7.80 ppb
2012-06-25201206270434-VND
2012-06-25201206270444-VND
2012-07-11201207130064-V84.0 ppb
2012-07-12201207140141-VND
2012-07-12201207140139-VND
2012-08-07201208100589-VND
2012-08-07201208100440-VND
2012-08-08201208100442-VND
2012-08-08201208100396-VND
2012-08-15201208170343-VND
2012-08-15201208170411-VND
2012-08-15201208170498-V53.0 ppb
2012-08-202012082303850.580 ppb
2012-08-20201208230386ND
2012-08-2020120823038716.5 ppb
2012-08-212012082303880.810 ppb
2012-08-212012082303892.48 ppb
2012-08-212012082303902.02 ppb
2012-08-212012082303913.48 ppb
2012-08-212012082303920.670 ppb
2012-08-27201208300178-VND
2012-08-27201208300180-VND
2012-08-27201208300158-VND
2012-09-11201209130775-VND
2012-09-11201209130771-VND
2012-09-11201209130773-VND
2012-09-11201209130709-VND
2012-09-12201209130715-VND
2012-09-12201209140297-VND
2012-09-12201209150006-VND
2012-09-12201209150004-VND
2012-09-12201209150030-VND
2012-09-12201209150221-V3.10 ppb
2012-09-18201209200727-V17.0 ppb
2012-09-18201209200453-VND
2012-09-19201209200729-VND
2012-09-20201209220114-VND
2012-09-20201209220112-V43.0 ppb
2012-10-01201210020385-VND
2012-10-01201210020301-VND
2012-10-02201210040117-VND
2012-10-02201210030297-VND
2012-10-102012101301773.45 ppb
2012-10-102012101301781.58 ppb
2012-10-102012101301794.28 ppb
2012-10-102012101301803.46 ppb
2012-10-102012101301813.95 ppb
2012-10-102012101301823.81 ppb
2012-10-102012101301834.27 ppb
2012-10-10201210130184ND
2012-10-22201210230058-VND
2012-11-13201211150453-VND
2013-01-30201301310322-V31.2 ppb
2013-01-30201301310323-V53.0 ppb
2013-01-30201301310324-V49.5 ppb
2013-01-30201301310325-V93.8 ppb
2013-01-30201301310326-V92.9 ppb
2013-01-30201301310327-V76.9 ppb
2013-01-30201301310328-V37.7 ppb
2013-01-302013-1310321-V33.0 ppb
2013-04-292013043004124.30 ppb
2013-04-2920130430041339.3 ppb
2013-04-2920130430041423.0 ppb
2013-04-292013043004154.47 ppb
2013-04-292013043004164.60 ppb
2013-04-292013043004174.84 ppb
2013-04-292013043004184.72 ppb
2013-04-292013043004191.05 ppb
2013-05-13201305140672-VND
2013-06-18201306190582-V3.20 ppb
2013-06-26201306270194-V61.0 ppb
2013-07-162013071900201.28 ppb
2013-07-1620130719002148.3 ppb
2013-07-1620130719002237.4 ppb
2013-07-1620130719002319.2 ppb
2013-07-16201307190024ND
2013-07-172013071900258.00 ppb
2013-07-1720130719002614.0 ppb
2013-07-1720130719002714.9 ppb
2013-07-18201307200001-VND
2013-08-28201308290498-VND
2013-09-09201309100461-VND
2013-09-25201309260254-VND
2013-09-30201310010188-VND
2013-10-292013110100967.67 ppb
2013-10-292013110100972.73 ppb
2013-10-2920131101009814.1 ppb
2013-10-2920131101009928.5 ppb
2013-10-292013110101002.62 ppb
2013-10-292013110101013.29 ppb
2013-10-292013110101022.69 ppb
2013-10-292013110101033.09 ppb
2014-01-2820140130017432.7 ppb
2014-01-2820140130017534.2 ppb
2014-01-2820140130017627.1 ppb
2014-01-2820140130017739.5 ppb
2014-01-2820140130017858.7 ppb
2014-01-2820140130017971.2 ppb
2014-01-2820140130018060.2 ppb
2014-01-2820140130018122.7 ppb
2014-02-24201402260926-VND
2014-04-082014041202487.97 ppb
2014-04-082014041202490.780 ppb
2014-04-0820140412025034.3 ppb
2014-04-082014041202511.33 ppb
2014-04-08201404120252ND
2014-04-082014041202531.33 ppb
2014-04-082014041202546.68 ppb
2014-04-082014041202551.36 ppb
2014-05-27201405280593-V48.0 ppb
2014-07-01201407020370ND
2014-07-282014073002632.19 ppb
2014-07-2820140730026410.6 ppb
2014-07-2820140730026568.1 ppb
2014-07-282014073002663.65 ppb
2014-07-2820140730026716.6 ppb
2014-07-282014073002687.56 ppb
2014-07-2820140730026915.4 ppb
2014-07-28201407300270ND
2014-09-04201409050252ND
2014-10-272014102904400.830 ppb
2014-10-272014102904411.14 ppb
2014-10-2720141029044227.6 ppb
2014-10-272014102904432.17 ppb
2014-10-272014102904442.22 ppb
2014-10-272014102904453.16 ppb
2014-10-272014102904462.45 ppb
2014-10-27201410290447ND
2015-01-262015012807172.86 ppb
2015-01-2620150128071832.4 ppb
2015-01-2620150128071954.9 ppb
2015-01-26201501280720ND
2015-01-2620150128072158.6 ppb
2015-01-2620150128072275.6 ppb
2015-01-2620150128072370.9 ppb
2015-01-2620150128072475.0 ppb
2015-04-282015043001122.92 ppb
2015-04-282015043001131.11 ppb
2015-04-2820150430011436.6 ppb
2015-04-282015043001151.98 ppb
2015-04-28201504300116ND
2015-04-282015043001173.93 ppb
2015-04-282015043001183.52 ppb
2015-04-282015043001191.77 ppb
2015-05-19201505210392VND
2015-05-19201505210480V33.0 ppb
2015-05-19201505210341VND
2015-05-19201505210388VND
2015-05-20201505210403VND
2015-05-20201505210412VND
2015-05-20201505210405-VOCND
2015-05-21201505220242VND
2015-05-21201505220202V1.10 ppb
2015-05-21201505220247-VOCND
2015-06-01201506030407-VOCND
2015-06-01201506030355-VOCND
2015-06-012015506030247-VOND
2015-06-01201506030333-VOCND
2015-06-09201506120280-VOCND
2015-06-09201506120278-VOCND
2015-06-11201506120209-VOCND
2015-06-11201506120140-VOCND
2015-06-29201506300124-VOCND
2015-06-29201506300177-VOCND
2015-06-30201507010430-VOCND
2015-06-30201507160442-VOCND
2015-07-282015073002290.910 ppb
2015-07-2820150730023010.9 ppb
2015-07-2820150730023154.9 ppb
2015-07-282015073002322.01 ppb
2015-07-28201507300233ND
2015-07-282015073002343.50 ppb
2015-07-282015073002350.850 ppb
2015-07-282015073002362.35 ppb
2015-08-03201508040410-VOC0.860 ppb
2015-08-04201508050421-VOCND
2015-08-10201508110263-VOCND
2015-09-15201509020134-VOCND
2015-10-12201510140539ND
2015-10-122015101405401.16 ppb
2015-10-1220151014054157.2 ppb
2015-10-122015101405421.88 ppb
2015-10-122015101405432.04 ppb
2015-10-122015101405441.87 ppb
2015-10-122015101405453.04 ppb
2015-10-12201510140546ND
2016-01-202016012202256.48 ppb
2016-01-2020160122022682.8 ppb
2016-01-2020160122022764.8 ppb
2016-01-202016012202281.25 ppb
2016-01-2020160122022980.3 ppb
2016-01-2020160122023099.3 ppb
2016-01-2020160122023191.8 ppb
2016-01-2020160122023299.2 ppb
2016-04-262016042803783.24 ppb
2016-04-262016042803790.810 ppb
2016-04-2620160428038058.2 ppb
2016-04-26201604280381ND
2016-04-262016042803822.49 ppb
2016-04-26201604280383ND
2016-04-272016042803842.35 ppb
2016-04-272016042803853.47 ppb
2016-06-22201606230265-VOC27.0 ppb
2016-07-27201602804200.960 ppb
2016-07-272016072804211.10 ppb
2016-07-27201607280422ND
2016-07-272016072804232.41 ppb
2016-07-272016072804242.61 ppb
2016-07-272016072804252.61 ppb
2016-07-272016072804261.86 ppb
2016-07-27201607280430ND
2016-10-122016101305122.40 ppb
2016-10-122016101305131.11 ppb
2016-10-12201610130514ND
2016-10-122016101305151.86 ppb
2016-10-122016101305162.54 ppb
2016-10-122016101305172.61 ppb
2016-10-122016101305182.60 ppb
2016-10-12201610130519ND
2017-01-2520170127042817.9 ppb
2017-01-252017012704295.84 ppb
2017-01-2520170127043028.3 ppb
2017-01-2520170127043113.1 ppb
2017-01-2520170127043323.8 ppb
2017-01-2520170127043473.3 ppb
2017-01-2520170127043538.9 ppb
2017-01-252017127043216.6 ppb
2017-02-212017022209281.88 ppb
2017-04-2420170426076395.1 ppb
2017-04-242017042607641.35 ppb
2017-04-24201704260765ND
2017-04-242017042607661.07 ppb
2017-04-242017042607676.10 ppb
2017-04-242017042607684.52 ppb
2017-04-242017042607691.21 ppb
2017-04-242017042607700.950 ppb
2017-05-1520170516057118.0 ppb
2017-05-16201705170782-VOCND
2017-05-23201705240769ND
2017-06-21201706220614ND
2017-07-18201707190690105.0 ppb
2017-07-182017071906911.53 ppb
2017-07-182017071906925.97 ppb
2017-07-182017071906931.89 ppb
2017-07-182017071906942.14 ppb
2017-07-182017071906952.39 ppb
2017-07-182017071906962.50 ppb
2017-07-18201707190697ND
2017-10-052017100601502.55 ppb
2017-10-05201710060152ND
2017-10-052017100601531.15 ppb
2017-10-052017100601540.770 ppb
2017-10-052017100601551.01 ppb
2017-10-052017100601561.52 ppb
2017-10-05201710060157ND
2017-10-16201710170612ND