Uranium

City of Lake Charles Water System

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.

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Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	N/A	0	N/A
2015	ND	22	ND
2016	N/A	0	N/A
2017	ND	6	ND
2018	ND	26	ND
2019	ND	34	ND

pCi/L = picocuries per liter

State and national drinking water standards and health guidelines

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
2015-07-27	35199384005	ND
2015-07-27	35199384001	ND
2015-07-27	35199384002	ND
2015-07-27	35199384005	ND
2015-07-27	35199384004	ND
2015-07-27	35199384003	ND
2015-07-27	35199384002	ND
2015-07-27	35199384001	ND
2015-07-27	35199384003	ND
2015-07-27	35199384004	ND
2015-08-03	35200616005	ND
2015-08-03	35200616004	ND
2015-08-03	35200616003	ND
2015-08-03	35200616002	ND
2015-08-03	35200616001	ND
2015-08-03	35200616005	ND
2015-08-03	35200616004	ND
2015-08-03	35200616001	ND
2015-08-03	35200616002	ND
2015-08-03	35200616003	ND
2015-09-21	35208328005	ND
2015-09-21	35208328005	ND
2017-12-18	AE20279	ND
2017-12-18	AE20283	ND
2017-12-18	AE20287	ND
2017-12-18	AE20279	ND
2017-12-18	AE20287	ND
2017-12-18	AE20283	ND
2018-01-22	AE20433	ND
2018-01-22	AE20433	ND
2018-01-22	AE20441	ND
2018-01-22	AE20445	ND
2018-01-22	AE20441	ND
2018-01-22	AE20445	ND
2018-02-05	AE20558	ND
2018-02-05	AE20564	ND
2018-02-05	AE20561	ND
2018-02-05	AE20567	ND
2018-02-05	AE20555	ND
2018-02-05	AE20567	ND
2018-02-05	AE20555	ND
2018-02-05	AE20558	ND
2018-02-05	AE20561	ND
2018-02-05	AE20564	ND
2018-02-26	AE20783	ND
2018-02-26	AE20780	ND
2018-02-26	AE20786	ND
2018-02-26	AE20789	ND
2018-02-26	AE20780	ND
2018-02-26	AE20783	ND
2018-02-26	AE20786	ND
2018-02-26	AE20789	ND
2018-12-04	B1805821-001	ND
2018-12-04	B1805821-001	ND
2019-11-18	B1905174-005	ND
2019-11-18	B1905174-005	ND
2019-11-18	B1905174-004	ND
2019-11-18	B1905174-003	ND
2019-11-18	B1905174-002	ND
2019-11-18	B1905174-001	ND
2019-11-18	B1905174-004	ND
2019-11-18	B1905174-003	ND
2019-11-18	B1905174-002	ND
2019-11-18	B1905174-001	ND
2019-11-20	B1905305-002	ND
2019-11-20	B1905305-001	ND
2019-11-20	B1905305-003	ND
2019-11-20	B1905305-004	ND
2019-11-20	B1905305-005	ND
2019-11-20	B1905305-004	ND
2019-11-20	B1905305-003	ND
2019-11-20	B1905305-002	ND
2019-11-20	B1905305-001	ND
2019-11-20	B1905305-005	ND
2019-12-02	B1905454-001	ND
2019-12-02	B1905454-002	ND
2019-12-02	B1905454-006	ND
2019-12-02	B1905454-003	ND
2019-12-02	B1905454-001	ND
2019-12-02	B1905454-005	ND
2019-12-02	B1905454-004	ND
2019-12-02	B1905454-006	ND
2019-12-02	B1905454-005	ND
2019-12-02	B1905454-004	ND
2019-12-02	B1905454-003	ND
2019-12-02	B1905454-002	ND
2019-12-18	B1905687-001	ND
2019-12-18	B1905687-001	ND