Know Your Environment. Protect Your Health.

Arsenic

Cws-split Mountain Water System

Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.

 

162

Samples

1

Samples exceeding legal limit (MCL)

111

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20184.02 ppb2619ND - 8.52 ppb
20194.13 ppb2724ND - 10.6 ppb
20202.95 ppb2714ND - 8.10 ppb
20213.94 ppb2919ND - 8.30 ppb
20223.55 ppb2618ND - 8.10 ppb
20233.36 ppb2717ND - 7.40 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.004 ppb

The EWG Health Guideline of 0.004 ppb for arsenic 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): 10 ppb

The legal limit for arsenic, established in 2001, was based on costs for arsenic removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to arsenic exposure.

ppb = parts per billion

All test results

Date Lab ID Result
2018-01-09CA1500407_005_005-201801091140ND
2018-01-09CA1500407_006_006-2018010912005.24 ppb
2018-01-23CA1500407_005_005-201801231010ND
2018-01-23CA1500407_006_006-2018012309505.20 ppb
2018-02-07CA1500407_006_006-2018020714305.40 ppb
2018-02-07CA1500407_005_005-201802071345ND
2018-03-14CA1500407_005_005-201803141110ND
2018-03-14CA1500407_006_006-2018031411306.93 ppb
2018-04-04CA1500407_006_006-2018040410306.88 ppb
2018-04-04CA1500407_005_005-2018040409452.00 ppb
2018-05-02CA1500407_006_006-2018050209356.91 ppb
2018-05-02CA1500407_005_005-201805020835ND
2018-06-12CA1500407_006_006-2018061209556.94 ppb
2018-06-12CA1500407_005_005-201806120935ND
2018-07-17CA1500407_006_006-2018071712206.22 ppb
2018-07-17CA1500407_005_005-2018071712142.37 ppb
2018-08-14CA1500407_006_006-2018081410157.96 ppb
2018-08-14CA1500407_005_005-2018081410003.08 ppb
2018-09-18CA1500407_006_006-2018091813356.87 ppb
2018-09-18CA1500407_005_005-201809181340ND
2018-10-03CA1500407_005_005-2018100314002.69 ppb
2018-10-03CA1500407_006_006-2018100313556.50 ppb
2018-11-13CA1500407_005_005-2018111310153.70 ppb
2018-11-13CA1500407_006_006-2018111310558.52 ppb
2018-12-10CA1500407_006_006-2018121010006.96 ppb
2018-12-10CA1500407_005_005-2018121009554.01 ppb
2019-01-15CA1500407_005_005-2019011511502.90 ppb
2019-01-15CA1500407_005_005-2019011511503.95 ppb
2019-01-15CA1500407_006_006-2019011511324.80 ppb
2019-01-15CA1500407_006_006-2019011511326.16 ppb
2019-02-06CA1500407_005_005-2019020612453.92 ppb
2019-02-06CA1500407_006_006-2019020612403.29 ppb
2019-03-12CA1500407_006_006-2019031211275.83 ppb
2019-03-12CA1500407_005_005-2019031211353.47 ppb
2019-04-10CA1500407_005_005-201904100850ND
2019-04-10CA1500407_006_006-2019041010505.58 ppb
2019-05-08CA1500407_005_005-201905081111ND
2019-05-08CA1500407_006_006-2019050811384.91 ppb
2019-05-13CA1500407_002_002-2019051309582.70 ppb
2019-06-05CA1500407_006_006-2019060511065.52 ppb
2019-06-05CA1500407_005_005-2019060511202.13 ppb
2019-07-22CA1500407_005_005-201907220910ND
2019-07-22CA1500407_006_006-20190722092010.6 ppb
2019-08-19CA1500407_005_005-2019081909542.33 ppb
2019-08-19CA1500407_006_006-2019081910007.30 ppb
2019-09-04CA1500407_005_005-2019090413302.65 ppb
2019-09-04CA1500407_006_006-2019090413405.30 ppb
2019-10-09CA1500407_006_006-2019100909326.13 ppb
2019-10-09CA1500407_005_005-2019100909402.59 ppb
2019-11-13CA1500407_005_005-2019111312563.35 ppb
2019-11-13CA1500407_006_006-2019111313026.36 ppb
2019-12-04CA1500407_005_005-2019120410153.49 ppb
2019-12-04CA1500407_006_006-2019120410406.20 ppb
2020-01-22CA1500407_005_005-202001221450ND
2020-01-22CA1500407_006_006-2020012214385.09 ppb
2020-01-22CA1500407_006_006-2020012214385.00 ppb
2020-01-22CA1500407_005_005-202001221450ND
2020-02-11CA1500407_007_007-2020021112472.90 ppb
2020-02-24CA1500407_005_005-202002241140ND
2020-02-24CA1500407_006_006-2020022411303.55 ppb
2020-03-17CA1500407_006_006-2020031710303.86 ppb
2020-03-17CA1500407_005_005-202003171035ND
2020-04-01CA1500407_005_005-202004011011ND
2020-04-01CA1500407_006_006-2020040110064.27 ppb
2020-05-06CA1500407_005_005-202005061335ND
2020-05-06CA1500407_006_006-2020050613294.44 ppb
2020-06-09CA1500407_006_006-2020060908346.93 ppb
2020-06-09CA1500407_005_005-202006090820ND
2020-07-06CA1500407_005_005-202007061039ND
2020-07-06CA1500407_006_006-2020070609457.40 ppb
2020-08-05CA1500407_005_005-202008051050ND
2020-08-05CA1500407_006_006-2020080510236.80 ppb
2020-09-15CA1500407_005_005-202009150927ND
2020-09-15CA1500407_006_006-2020091510165.60 ppb
2020-10-21CA1500407_005_005-202010211339ND
2020-10-21CA1500407_006_006-2020102113458.10 ppb
2020-11-19CA1500407_006_006-2020111912138.00 ppb
2020-11-19CA1500407_005_005-202011191234ND
2020-12-16CA1500407_005_005-202012160929ND
2020-12-17CA1500407_006_006-2020121712407.80 ppb
2021-01-12CA1500407_005_005-202101121032ND
2021-01-12CA1500407_006_006-2021011210417.50 ppb
2021-01-26CA1500407_005_005-202101261344ND
2021-01-26CA1500407_006_006-2021012613366.30 ppb
2021-01-26CA1500407_006_006-2021012613366.30 ppb
2021-02-04CA1500407_005_005-2021020413202.40 ppb
2021-02-04CA1500407_006_006-2021020413116.00 ppb
2021-03-09CA1500407_005_005-202103090910ND
2021-03-09CA1500407_006_006-2021030909106.50 ppb
2021-04-06CA1500407_005_005-202104060946ND
2021-04-06CA1500407_006_006-2021040609105.10 ppb
2021-05-06CA1500407_005_005-202105061247ND
2021-05-06CA1500407_006_006-2021050612504.70 ppb
2021-05-25CA1500407_005_005-202105251320ND
2021-05-25CA1500407_006_006-2021052513155.00 ppb
2021-06-24CA1500407_006_006-2021062413387.10 ppb
2021-06-24CA1500407_005_005-2021062413324.20 ppb
2021-07-27CA1500407_006_006-2021072709306.60 ppb
2021-07-27CA1500407_005_005-202107270925ND
2021-08-31CA1500407_005_005-2021083109003.40 ppb
2021-08-31CA1500407_006_006-2021083109108.30 ppb
2021-09-09CA1500407_005_005-2021090909206.80 ppb
2021-09-09CA1500407_006_006-2021090909057.50 ppb
2021-10-28CA1500407_005_005-202110281024ND
2021-10-28CA1500407_006_006-2021102810297.50 ppb
2021-11-03CA1500407_005_005-202111030945ND
2021-11-03CA1500407_006_006-2021110309376.70 ppb
2021-12-15CA1500407_005_005-202112151125ND
2021-12-15CA1500407_006_006-2021121511156.30 ppb
2022-01-18CA1500407_005_005-202201181056ND
2022-01-18CA1500407_005_005-202201181056ND
2022-01-18CA1500407_006_006-2022011811116.70 ppb
2022-01-18CA1500407_006_006-2022011811116.20 ppb
2022-02-10CA1500407_005_005-202202101435ND
2022-02-10CA1500407_006_006-2022021014445.60 ppb
2022-03-15CA1500407_005_005-202203151142ND
2022-03-15CA1500407_006_006-2022031511475.30 ppb
2022-04-07CA1500407_005_005-202204071013ND
2022-04-07CA1500407_006_006-2022040710056.60 ppb
2022-05-03CA1500407_005_005-202205031106ND
2022-05-03CA1500407_006_006-2022050311105.80 ppb
2022-06-15CA1500407_006_006-2022061514168.10 ppb
2022-06-15CA1500407_005_005-2022061514121.20 ppb
2022-07-13CA1500407_006_006-2022071309256.40 ppb
2022-07-13CA1500407_005_005-2022071309161.10 ppb
2022-08-11CA1500407_005_005-202208110938ND
2022-08-11CA1500407_006_006-2022081109337.20 ppb
2022-09-14CA1500407_006_006-2022091412567.10 ppb
2022-09-14CA1500407_005_005-202209141247ND
2022-10-06CA1500407_006_006-2022100608255.90 ppb
2022-10-06CA1500407_005_005-2022100608151.10 ppb
2022-11-15CA1500407_006_006-2022111511328.10 ppb
2022-11-15CA1500407_005_005-2022111511231.000 ppb
2022-12-15CA1500407_006_006-2022121511037.60 ppb
2022-12-15CA1500407_005_005-2022121510571.40 ppb
2023-01-12CA1500407_006_006-2023011211107.40 ppb
2023-01-12CA1500407_005_005-2023011211131.90 ppb
2023-01-26CA1500407_005_005-202301260926ND
2023-01-26CA1500407_006_006-2023012609347.00 ppb
2023-02-07CA1500407_005_005-2023020714171.40 ppb
2023-02-07CA1500407_006_006-2023020714326.00 ppb
2023-02-23CA1500407_007_007-2023022313002.70 ppb
2023-03-13CA1500407_005_005-2023031310051.30 ppb
2023-03-13CA1500407_006_006-2023031309555.70 ppb
2023-04-12CA1500407_006_006-2023041213445.80 ppb
2023-04-12CA1500407_005_005-202304121340ND
2023-05-18CA1500407_006_006-2023051809146.00 ppb
2023-05-18CA1500407_005_005-202305180908ND
2023-06-08CA1500407_006_006-2023060811356.50 ppb
2023-06-08CA1500407_005_005-202306081113ND
2023-07-12CA1500407_006_006-2023071209206.10 ppb
2023-07-12CA1500407_005_005-202307120930ND
2023-08-15CA1500407_005_005-202308151425ND
2023-08-15CA1500407_006_006-2023081514205.40 ppb
2023-09-06CA1500407_005_005-202309060905ND
2023-09-06CA1500407_006_006-2023090608556.50 ppb
2023-10-10CA1500407_005_005-202310101147ND
2023-10-10CA1500407_006_006-2023101011437.40 ppb
2023-11-15CA1500407_005_005-202311150924ND
2023-11-15CA1500407_006_006-2023111509156.80 ppb
2023-12-14CA1500407_005_005-202312140831ND
2023-12-14CA1500407_006_006-2023121408206.70 ppb