Know Your Environment. Protect Your Health.

Radium, combined (-226 and -228)

St Charles Water District 1 East Bank

Radium is a radioactive element that causes bone cancer and other cancers. It can occur naturally in groundwater, and oil and gas extraction activities such as hydraulic fracturing can elevate concentrations. Read More.

Radium releases radioactive particles that harm health in many ways, causing tumors in bone, lungs and other organs; leukemia; and skin and blood damage. Water utilities typically report radium amounts in picocuries per liter (pCi/L), which is a measure of radioactivity in water. The two most common forms of radium are radium-226 and radium-228. They may be reported separately or together.

Federal law allows up to 5 picocuries per liter of combined radium-226 and radium-228 in tap water. Research by the U.S. Geological Survey shows that in some regions of the country, such as the mid-continental region and North Atlantic coastal region, more than 20 percent of sampled wells have radium in levels exceeding the federal drinking water limit. And the legal limit does not equate safety: The EPA estimates that one in every 10,000 people drinking water containing radium at this level would develop cancer over a lifetime.

California set a public health goal much lower than the federal limit – 0.05 picocuries per liter of radium-226 and 0.019 picocuries per liter of radium-228, concentrations that are lower than the detection limit for most water tests.

Click here to read more on radiological contaminants.

 

36

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND40ND
20190.27 pCi/L83ND - 0.73 pCi/L
2020ND60ND
2021ND60ND
2022ND60ND
2023ND60ND

pCi/L = picocuries per liter

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.05 pCi/L

EWG applied the health guideline of 0.05 pCi/L, defined by the California Office of Environmental Health Hazard Assessment as a public health goal for radium-226, to radium-226 and radium-228 combined. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL): 5 pCi/L

The legal limit for combined radium-226 and radium-228, established in 1976, was based on costs for radium removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to radium exposure.

pCi/L = picocuries per liter

All test results

Date Lab ID Result
2018-01-2335370117001ND
2018-01-2335370117001ND
2018-01-232020518-FINISHED: WELL #3 - NEND
2018-01-232020428-GRASSY HOLE GP WELL -ND
2019-01-2235444038001ND
2019-01-222020624-RAW WATER: ANDREWS IIND
2019-01-22202047-DISTRIBUTING RESERVOIR:ND
2019-01-222020218-ANNURSNAC RESERVOIRND
2019-01-222020212-672 HARVARD ST - RESID0.73 pCi/L
2019-01-2235444038001ND
2019-01-22354440370010.73 pCi/L
2019-01-22354440370010.73 pCi/L
2020-03-05202164-RAW WATER: LANCASTER AVND
2020-03-05202146-RUN HILL ROAD GP WELL #ND
2020-03-0535535509002ND
2020-03-0535535509001ND
2020-03-052021413-GP WELL #4RND
2020-03-052021426-POND ST. WELL 1ND
2021-01-282021121-LAKE MIRIMICHI WELLS 1ND
2021-01-282021119-WWTPND
2021-01-2820211116-FINISHED: LELAND ROADND
2021-01-2820211026-TRINITY WELLFIELD WTPND
2021-01-2835608065001ND
2021-01-2835608065002ND
2022-02-02202277-FINISHED: WELL #3 VILLAND
2022-02-022022817-WELL #4 GREAT ROAD WTPND
2022-02-02202297-WATER TREATMENT PLANTND
2022-02-0235694868001ND
2022-02-02202275-MAPLE SPRINGS PLANTND
2022-02-0235694870001ND
2023-03-2035787604001ND
2023-03-2035787602001ND
2023-03-202023420-CYR STATION 1ND
2023-03-202023421-WELL 2 SOURCE WATER TAND
2023-03-202023511-LORING SCHOOLND
2023-03-20202355-SPRAGUE ROAD STATIONND