Uranium

Town of Poolesville

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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114

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	5.08 pCi/L	14	11	ND - 11.80 pCi/L
2015	4.72 pCi/L	14	9	ND - 14.67 pCi/L
2016	3.69 pCi/L	30	21	ND - 21.00 pCi/L
2017	4.17 pCi/L	33	26	ND - 20.40 pCi/L
2018	6.22 pCi/L	12	11	ND - 26.87 pCi/L
2019	7.34 pCi/L	11	11	0.01 pCi/L - 13.33 pCi/L

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
2014-03-13	140313_12_638914	8.54 pCi/L
2014-03-13	140313_13_638914	2.28 pCi/L
2014-06-10	140610_12_638915	9.40 pCi/L
2014-06-10	140610_13_638915	2.56 pCi/L
2014-09-18	140918_12_638917	11.34 pCi/L
2014-09-18	140918_13_638917	2.70 pCi/L
2014-11-06	141106_10_638918	ND
2014-11-06	141106_10_638918	ND
2014-12-04	141204_08_638918	2.78 pCi/L
2014-12-04	141204_07_638918	ND
2014-12-04	141204_12_638918	11.80 pCi/L
2014-12-04	141204_13_638918	2.69 pCi/L
2014-12-04	141204_13_638918	5.84 pCi/L
2014-12-18	6389-189-1-1	11.21 pCi/L
2015-03-05	150305_12_638920	11.39 pCi/L
2015-03-05	150305_13_638920	3.02 pCi/L
2015-06-04	004	ND
2015-06-04	002	ND
2015-06-04	007	10.85 pCi/L
2015-06-04	011	2.85 pCi/L
2015-09-03	6389-226-1-10	ND
2015-09-03	6389-226-1-2	13.94 pCi/L
2015-09-03	6389-226-1-6	3.51 pCi/L
2015-12-05	6389-242-1-20	3.06 pCi/L
2015-12-08	6389-242-1-8	2.73 pCi/L
2015-12-08	6389-242-1-16	14.67 pCi/L
2015-12-15	6389-244-1-1	ND
2015-12-15	6389-244-1-6	ND
2016-02-02	B160075-01	2.42 pCi/L
2016-02-02	B160075-05	ND
2016-02-02	B160075-02	ND
2016-02-02	B160075-03	8.38 pCi/L
2016-02-02	B160075-04	2.97 pCi/L
2016-04-12	B160170-03	2.21 pCi/L
2016-04-12	B160170-02	0.07 pCi/L
2016-04-12	B160170-05	3.48 pCi/L
2016-04-12	B160170-04	3.35 pCi/L
2016-04-12	B160170-01	ND
2016-04-14	6389_261_1_3	8.40 pCi/L
2016-04-14	6389_261_1_2	ND
2016-04-14	6389_261_1_1	ND
2016-04-14	6389_261_1_5	4.81 pCi/L
2016-04-14	6389_261_1_4	3.58 pCi/L
2016-07-12	B160315-01	3.15 pCi/L
2016-07-12	B160320-01	ND
2016-07-12	B160319-01	ND
2016-07-12	B160321-01	13.40 pCi/L
2016-07-12	B160316-01	3.42 pCi/L
2016-10-05	B160472-05	3.95 pCi/L
2016-10-05	B160472-01	0.00 pCi/L
2016-10-05	B160472-02	0.00 pCi/L
2016-10-05	B160472-03	21.00 pCi/L
2016-10-05	B160472-04	3.42 pCi/L
2016-10-11	16100627-001	2.64 pCi/L
2016-10-11	161000630-001	ND
2016-10-11	16100625-001	14.50 pCi/L
2016-10-11	16100626-001	5.58 pCi/L
2016-10-12	16100628-001	ND
2017-01-05	6389_304_1_5	2.71 pCi/L
2017-01-05	6389_304_1_2	5.12 pCi/L
2017-01-05	6389_304_1_4	9.37 pCi/L
2017-01-05	6389_304_1_7	0.84 pCi/L
2017-01-05	6389_304_1_6	ND
2017-01-05	6389_304_1_1	20.40 pCi/L
2017-01-05	6389_304_1_3	6.32 pCi/L
2017-01-11	B170022_05	0.70 pCi/L
2017-01-11	B170022-02A	3.33 pCi/L
2017-01-11	B170022_04	2.84 pCi/L
2017-01-11	B170022_07	0.00 pCi/L
2017-01-11	B170022_06	0.00 pCi/L
2017-01-11	B170022-01	13.00 pCi/L
2017-01-11	B170022_03	3.29 pCi/L
2017-04-11	B170086_03	2.74 pCi/L
2017-04-11	B170086_01	0.00 pCi/L
2017-04-11	B170086_02	0.00 pCi/L
2017-04-11	B170086_04	10.12 pCi/L
2017-04-11	B170086_05	2.48 pCi/L
2017-04-13	6389_317_1_4	ND
2017-04-13	6389_317_1_5	ND
2017-04-13	6389_317_1	13.20 pCi/L
2017-04-13	6389_317_1_2	4.03 pCi/L
2017-07-12	B170163_01	2.88 pCi/L
2017-07-12	B170163_04	12.60 pCi/L
2017-07-12	B170163_05	3.69 pCi/L
2017-07-12	B170163_03	ND
2017-07-12	B170163_02	ND
2017-10-11	B170229_05	2.93 pCi/L
2017-10-11	B170229_03	11.30 pCi/L
2017-10-11	B170229_04	3.62 pCi/L
2017-10-11	B170229_01	ND
2017-10-11	B170229_02	ND
2018-02-06	B180014_02	2.88 pCi/L
2018-02-06	6389_385_1_3	1.72 pCi/L
2018-02-06	B180014_01	26.87 pCi/L
2018-03-26	B180060_01	6.10 pCi/L
2018-05-01	B180091_01	ND
2018-05-01	6389_396_1_1	4.19 pCi/L
2018-08-07	6389_410_1_3	4.13 pCi/L
2018-08-14	B180197_01	2.32 pCi/L
2018-08-14	B180197_02	8.80 pCi/L
2018-11-06	B180283_01	2.81 pCi/L
2018-11-06	B180283_02	10.52 pCi/L
2018-11-06	6389_422_1_4	4.33 pCi/L
2019-02-07	63894361-4	11.19 pCi/L
2019-02-07	63894361-6	4.70 pCi/L
2019-05-06	2190	2.35 pCi/L
2019-05-06	2194	8.78 pCi/L
2019-05-14	63894461-4	0.01 pCi/L
2019-05-14	63894461-3	9.58 pCi/L
2019-08-08	63894591-1	11.06 pCi/L
2019-08-08	63894591-3	4.62 pCi/L
2019-10-03	714	10.79 pCi/L
2019-10-29	63894701-3	13.33 pCi/L
2019-10-29	63894701-4	4.36 pCi/L