Know Your Environment. Protect Your Health.

Uranium

Ward II Water District

Uranium is a known human carcinogen. The federal legal limit for uranium is set at 30 micrograms per liter (corresponding to parts per billion), but utilities can also report uranium in picocuries per liter (pCi/L), which is a measure of radioactivity in water. EWG translated all uranium results to pCi/L using a conversion factor developed by the EPA. With this conversion approach, the limit of 30 ppb corresponds to 20 pCi/L. Drinking water with this much uranium would cause more than 4.6 cancer cases in a population of 100,000. California set a public health goal for uranium of 0.43 pCi/L. Read More.

Multiple forms of uranium can be detected in water, including uranium-234, uranium-235 and uranium-238. Uranium-234 is the most toxic form of uranium for human health.

 

52

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.08 pCi/L262ND - 1.00 pCi/L
2019ND40ND
2020ND20ND
20210.06 pCi/L141ND - 0.87 pCi/L
2022ND10ND
2023ND50ND

pCi/L = picocuries per liter

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.43 pCi/L

The EWG Health Guideline of 0.43 pCi/L for uranium 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. Three most common uranium isotopes are U-234, U-235 and U-238. All isotopes of uranium are radioactive, and the total radioactivity depends on the ratio of isotopes. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL): 20 pCi/L

pCi/L = picocuries per liter

All test results

Date Lab ID Result
2018-05-02AE21727ND
2018-05-02AE21703ND
2018-05-02AE21703ND
2018-05-02AE21727ND
2018-06-06AE21821ND
2018-06-06AE21809ND
2018-06-06AE21812ND
2018-06-06AE21815ND
2018-06-06AE21818ND
2018-06-06AE21821ND
2018-06-06AE21818ND
2018-06-06AE21815ND
2018-06-06AE21812ND
2018-06-06AE21809ND
2018-06-25AE21988ND
2018-06-25AE21984ND
2018-06-25AE22000ND
2018-06-25AE21996ND
2018-06-25AE219921.00 pCi/L
2018-06-25AE21984ND
2018-06-25AE22000ND
2018-06-25AE21996ND
2018-06-25AE219921.00 pCi/L
2018-06-25AE21988ND
2018-09-10B1804157-001ND
2018-09-10B1804157-001ND
2019-07-2435485209001ND
2019-07-24B1903193-001ND
2019-07-2435485209001ND
2019-07-24B1903193-001ND
2020-06-23B2003030-001ND
2020-06-23B2003030-002ND
2021-03-29B2101469-003ND
2021-03-29B2101469-002ND
2021-03-29B2101469-001ND
2021-06-14B2102705-002ND
2021-06-14B2102705-005ND
2021-06-14B2102705-004ND
2021-06-14B2102705-003ND
2021-06-14B2102705-0010.87 pCi/L
2021-06-28B2103005-006ND
2021-06-28B2103005-005ND
2021-06-28B2103005-004ND
2021-06-28B2103003-003ND
2021-06-28B2103003-002ND
2021-06-28B2103003-001ND
2022-08-22B2203975-001ND
2023-05-08B2301971-001ND
2023-05-08B2301971-002ND
2023-05-08B2301971-003ND
2023-05-08B2301971-004ND
2023-05-08B2301971-005ND