Know Your Environment. Protect Your Health.

Arsenic

El Oso Water Supply Corporation

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.

 

31

Samples

0

Samples exceeding legal limit (MCL)

25

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20185.94 ppb54ND - 8.50 ppb
20196.68 ppb54ND - 9.90 ppb
20207.26 ppb552.10 ppb - 9.10 ppb
20216.26 ppb54ND - 8.80 ppb
20224.86 ppb54ND - 6.60 ppb
20236.03 ppb64ND - 9.97 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
2018-01-24AE101005.40 ppb
2018-01-24AE10099ND
2018-04-17AE229288.50 ppb
2018-07-27AE348257.40 ppb
2018-10-22AE440628.40 ppb
2019-02-19AE54807ND
2019-02-19AE548087.30 ppb
2019-04-01AE606206.90 ppb
2019-07-11AE740399.30 ppb
2019-11-15AE894569.90 ppb
2020-03-19AF037428.40 ppb
2020-03-19AF037432.10 ppb
2020-06-09AF146179.10 ppb
2020-09-11AF273018.20 ppb
2020-11-13AF345408.50 ppb
2021-01-26AF409868.10 ppb
2021-01-26AF40987ND
2021-06-15AF580198.80 ppb
2021-09-08AF690727.50 ppb
2021-12-10AF786226.90 ppb
2022-03-10AF88609ND
2022-03-10AF886105.90 ppb
2022-06-24AG023176.60 ppb
2022-09-08AG120085.90 ppb
2022-12-30AG232155.90 ppb
2023-02-16AG29241ND
2023-02-16AG292449.97 ppb
2023-03-29AG34744ND
2023-06-01AG427209.00 ppb
2023-09-27AG577328.10 ppb
2023-12-22AG673439.10 ppb