Know Your Environment. Protect Your Health.

Uranium

Tempe Water Supply Corporation 1

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.

 

43

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND80ND
2019ND80ND
2020ND80ND
2021ND90ND
2022ND70ND
2023ND30ND

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
2018-02-13AE13506ND
2018-02-13AE13504ND
2018-05-14AE26091ND
2018-05-14AE26090ND
2018-09-12AE39747ND
2018-09-12AE39748ND
2018-11-27AE46969ND
2018-11-27AE46970ND
2019-02-26AE55875ND
2019-02-26AE55876ND
2019-06-13AE70517ND
2019-06-13AE70516ND
2019-09-10AE82663ND
2019-09-10AE82665ND
2019-12-17AE92548ND
2019-12-17AE92549ND
2020-02-12AE98082ND
2020-02-12AE98084ND
2020-06-24AF16725ND
2020-06-24AF16726ND
2020-09-01AF26002ND
2020-09-01AF26000ND
2020-11-09AF33684ND
2020-11-09AF33686ND
2021-01-27AF41273ND
2021-01-27AF41274ND
2021-01-27AF41275ND
2021-05-11AF53456ND
2021-05-11AF53457ND
2021-08-25AF67882ND
2021-08-25AF67883ND
2021-11-02AF75539ND
2021-11-02AF75538ND
2022-02-09AF83930ND
2022-02-09AF83936ND
2022-02-09AF83937ND
2022-06-09AG00177ND
2022-06-09AG00178ND
2022-08-09AG08328ND
2022-12-20AG22325ND
2023-02-16AG29252ND
2023-05-30AG42264ND
2023-08-24AG53917ND