Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

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.

MORE ABOUT THIS CONTAMINANT

 

254

Samples

0

Samples exceeding legal limit (MCL)

170

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201417.0 ppb3630ND - 71.2 ppb
201510.3 ppb5830ND - 75.6 ppb
201619.6 ppb3327ND - 99.3 ppb
201712.9 ppb3729ND - 105.0 ppb
20185.23 ppb5224ND - 41.3 ppb
201917.6 ppb3830ND - 80.0 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
2014-01-2820140130017432.7 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
2018-02-2720180228043210.6 ppb
2018-02-2720180228043525.7 ppb
2018-02-27201802280436ND
2018-02-2720180228043737.8 ppb
2018-02-2720180228043823.3 ppb
2018-02-2720180228043936.4 ppb
2018-02-2720180228044041.3 ppb
2018-02-272018022804410.930 ppb
2018-04-26201804300373ND
2018-05-102018051106395.45 ppb
2018-05-102018051106404.66 ppb
2018-05-10201805110641ND
2018-05-10201805110642ND
2018-05-102018051106431.27 ppb
2018-05-10201805110644ND
2018-05-102018051106450.770 ppb
2018-05-102018051106462.04 ppb
2018-05-15201805161020ND
2018-05-24201805250730ND
2018-05-30201805310575ND
2018-05-31201806010519ND
2018-07-23201807240376ND
2018-07-242018072604382.16 ppb
2018-07-2420180726043933.7 ppb
2018-07-2420180726044020.6 ppb
2018-07-242018072604412.28 ppb
2018-07-242018072604422.74 ppb
2018-07-24201807260443ND
2018-07-24201807260444ND
2018-07-24201807260445ND
2018-08-09201808110163ND
2018-08-14201808160451ND
2018-08-14201808160455ND
2018-09-13201809140770ND
2018-09-13201809140813-VOCND
2018-09-18201809190678ND
2018-09-19201809200852ND
2018-10-16201810170779ND
2018-10-16201810170780ND
2018-10-16201810180738AND
2018-10-16201810180748AND
2018-10-17201810190329AND
2018-10-18201810190370AND
2018-10-182018101906000.960 ppb
2018-10-18201810190601ND
2018-10-182018101906021.43 ppb
2018-10-1820181019060312.4 ppb
2018-10-182018101906041.54 ppb
2018-10-182018101906051.26 ppb
2018-10-182018101906061.57 ppb
2018-10-182018101906071.14 ppb
2018-11-26201811270444ND
2019-01-232019012404275.52 ppb
2019-01-2320190124042820.6 ppb
2019-01-232019012404293.78 ppb
2019-01-2320190124043018.4 ppb
2019-01-2320190124043121.8 ppb
2019-01-2320190124043227.2 ppb
2019-01-2320190124043324.7 ppb
2019-01-232019012404342.27 ppb
2019-04-23201904250221ND
2019-04-2320190425022255.1 ppb
2019-04-2320190425022330.4 ppb
2019-04-232019042502240.940 ppb
2019-04-2420190425022551.2 ppb
2019-04-2420190425022648.4 ppb
2019-04-2420190425022743.5 ppb
2019-04-2420190425022827.3 ppb
2019-06-24201906250202A17.0 ppb
2019-06-26201906270391ND
2019-07-232019072404740.780 ppb
2019-07-2320190724047580.0 ppb
2019-07-2320190724047671.1 ppb
2019-07-2320190724047741.8 ppb
2019-07-2320190724047832.1 ppb
2019-07-232019072404796.62 ppb
2019-07-232019072404802.15 ppb
2019-07-232019072404812.15 ppb
2019-08-21201908220455AND
2019-08-22201908230667AND
2019-09-24201909250291ND
2019-09-24201909250649AND
2019-10-222019102307171.51 ppb
2019-10-222019102307180.790 ppb
2019-10-2220191023071927.1 ppb
2019-10-222019102307200.960 ppb
2019-10-22201910230721ND
2019-10-222019102307221.40 ppb
2019-10-222019102307231.15 ppb
2019-10-22201910230724ND