Know Your Environment. Protect Your Health.

Radium, combined (-226 and -228)

Hillview Water Company-oakhurst/sierra Lakes

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.

 

173

Samples

0

Samples exceeding legal limit (MCL)

41

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.07 pCi/L16160.38 pCi/L - 3.38 pCi/L
20190.54 pCi/L73ND - 1.57 pCi/L
20200.04 pCi/L92ND - 0.17 pCi/L
20210.06 pCi/L8115ND - 0.63 pCi/L
20220.13 pCi/L524ND - 2.97 pCi/L
20230.16 pCi/L81ND - 1.28 pCi/L

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
2018-03-06CA1510040_007_007-2018041709303.19 pCi/L
2018-03-06CA3610043_DST_604-2018030507381.11 pCi/L
2018-06-19CA1910048_007_007-2018052909400.85 pCi/L
2018-06-19CA4910013_DST_021-2018071009150.38 pCi/L
2018-06-20CA1510040_008_008-2018071708203.04 pCi/L
2018-06-20CA1510040_010_010-2018011611151.58 pCi/L
2018-06-20CA4900665_001_001-2018080810152.28 pCi/L
2018-07-25CA1510031_111_111-2018020611111.99 pCi/L
2018-07-25CA3310037_015_015-2018110812301.47 pCi/L
2018-08-28CA1910048_007_007-2018080609252.96 pCi/L
2018-08-28CA3610041_025_025-2018100907352.22 pCi/L
2018-08-28CA4900675_001_001-2018060508103.13 pCi/L
2018-10-03CA1510025_014_014-2018071209191.83 pCi/L
2018-10-03CA3310038_090_090-2018100411570.59 pCi/L
2018-10-03CA4910014_006_006-2018110609003.04 pCi/L
2018-10-09CA3610047_DST_601-2018052913163.38 pCi/L
2019-01-08CA1000199_001_001-2020090210201.57 pCi/L
2019-01-08CA1900130_001_001-2020090108101.21 pCi/L
2019-01-08CA3610120_005_005-201907031109ND
2019-07-31CA5410016_088_088-2021091009240.99 pCi/L
2019-07-31CA5410016_125_125-202001231040ND
2019-09-09CA1000200_003_003-202110041250ND
2019-12-16CA5410016_088_088-202010111402ND
2020-12-07CA1910009_102_090-202003090912ND
2020-12-07CA1910211_DST_800-201904091315ND
2020-12-07CA3710005_DST_906-202111021210ND
2020-12-07CA3710006_DST_900-2019111208300.17 pCi/L
2020-12-07CA3710020_DST_910-20190212NULND
2020-12-07CA5410016_088_088-2020051409410.17 pCi/L
2020-12-07CA5410016_092_092-201909061310ND
2020-12-07CA5410016_092_092-202005191311ND
2020-12-09CA1910211_DST_803-201907101015ND
2021-02-02CA1910009_102_090-201908140855ND
2021-02-02CA1910211_DST_802-202007151045ND
2021-02-03CA3710023_003_003-2022062210500.36 pCi/L
2021-02-08CA1000069_004_004-202010211240ND
2021-02-08CA1900100_001_001-2020031914000.63 pCi/L
2021-02-08CA1900100_002_002-201903061050ND
2021-02-08CA1910009_102_090-201907090836ND
2021-02-08CA1910009_102_093-202209120846ND
2021-02-08CA1910009_102_093-202210260940ND
2021-02-08CA3702236_001_001-2021091608000.17 pCi/L
2021-02-08CA3710005_DST_907-202208121342ND
2021-02-08CA4010018_019_019-202012091037ND
2021-02-08CA4010019_036_036-202006020830ND
2021-02-08CA5400670_008_008-2022032717200.44 pCi/L
2021-02-08CA5410016_088_088-202112010920ND
2021-02-08CA5410016_089_089-2021082410580.17 pCi/L
2021-02-17CA1900102_001_001-202006301227ND
2021-05-04CA1910211_DST_802-202010120802ND
2021-05-04CA4010017_DST_016-2020070610150.25 pCi/L
2021-05-10CA1000199_012_012-2022071310300.34 pCi/L
2021-05-10CA3610120_002_002-2020072908570.27 pCi/L
2021-05-10CA3710006_019_019-2021021007450.34 pCi/L
2021-05-10CA3710006_019_019-202105120751ND
2021-05-10CA3710006_DST_900-2021111608250.21 pCi/L
2021-05-10CA3710006_DST_901-202211140949ND
2021-05-10CA3710006_DST_904-202005110947ND
2021-05-10CA3710023_002_002-202103020800ND
2021-05-10CA4010018_020_020-2020021811500.25 pCi/L
2021-05-10CA4010019_036_036-2019070909250.23 pCi/L
2021-05-10CA4010022_003_003-202104050935ND
2021-05-10CA4010022_DST_006-202002031108ND
2021-05-10CA5400604_003_003-202108301400ND
2021-05-10CA5400670_009_009-201912111115ND
2021-05-10CA5410016_088_088-2021060409450.29 pCi/L
2021-05-10CA5410016_088_088-2022120311050.20 pCi/L
2021-05-10CA5410016_089_089-202108300815ND
2021-05-12CA1910211_DST_802-202104121050ND
2021-05-12CA3710006_018_018-2022101807450.38 pCi/L
2021-08-03CA3610039_120_120-202102101100ND
2021-08-03CA5410016_047_047-202110210845ND
2021-08-04CA2010007_030_030-202108040946ND
2021-08-04CA2010007_033_033-202108041042ND
2021-08-04CA2010007_031_031-202108041008ND
2021-08-04CA3610109_010_010-202210170920ND
2021-08-04CA3610118_010_010-201906140855ND
2021-08-04CA3710006_DST_901-202005111026ND
2021-08-04CA4010019_003_003-201907091140ND
2021-08-04CA4010019_012_012-202009010900ND
2021-08-04CA5400670_011_011-202006291640ND
2021-08-04CA5410016_077_077-202106150945ND
2021-08-09CA1000200_003_003-201904011515ND
2021-08-09CA1910009_102_090-202005041128ND
2021-08-09CA3610039_119_119-202110130945ND
2021-08-09CA3702236_001_001-202109160800ND
2021-08-09CA4010022_DST_006-202105031110ND
2021-08-16CA3610093_DST_602-202107071102ND
2021-08-16CA3710006_018_018-202111080743ND
2021-08-16CA3710006_DST_905-201905131054ND
2021-08-16CA3710023_002_002-202006101400ND
2021-08-16CA5410016_093_093-201906100810ND
2021-08-16CA5410016_094_094-202103141110ND
2021-11-08CA1900055_001_001-202107130823ND
2021-11-08CA1900130_001_001-202012040840ND
2021-11-08CA1910009_102_093-202212140750ND
2021-11-08CA1910211_DST_802-202107121000ND
2021-11-08CA3610093_DST_601-202107070942ND
2021-11-08CA3610109_001_001-202208100940ND
2021-11-08CA3610118_005_005-202209010845ND
2021-11-08CA3710008_013_016-202210051205ND
2021-11-08CA4010019_015_015-202208021315ND
2021-11-08CA5410016_081_081-201912101100ND
2021-11-08CA5410016_087_087-202111200730ND
2021-11-08CA5410016_088_088-201911030938ND
2021-11-08CA5410016_091_091-201912211245ND
2021-11-08CA5410016_091_091-202103050950ND
2021-11-22CA1000069_004_004-202010211240ND
2021-11-22CA1900130_001_001-202201071025ND
2021-11-22CA3610109_008_008-202212051130ND
2021-11-22CA3710005_DST_906-202208121314ND
2021-11-22CA3710008_001_001-202010130705ND
2021-11-22CA3710020_DST_914-20200310NULND
2022-02-07CA1910009_102_090-201907090836ND
2022-02-07CA1910211_DST_802-202204110938ND
2022-02-07CA3710005_DST_906-202111021210ND
2022-02-07CA3710005_DST_907-202208121342ND
2022-02-07CA3710006_DST_900-201911121137ND
2022-02-07CA5400670_007_007-202212281115ND
2022-02-07CA5410016_087_087-202102181150ND
2022-02-07CA5410016_088_088-202112010920ND
2022-02-07CA5410016_088_088-202211021428ND
2022-02-07CA5410016_089_089-202108241058ND
2022-03-14CA3710020_DST_915-20190409NULND
2022-03-15CA3610093_DST_602-201904030809ND
2022-03-15CA3610093_DST_602-202004010954ND
2022-05-11CA3710005_DST_905-201902120904ND
2022-05-11CA5400567_002_002-202204271106ND
2022-05-16CA1000078_002_002-202002201313ND
2022-05-16CA3702236_001_001-202109160800ND
2022-05-16CA3710006_014_014-202205160759ND
2022-05-16CA3710006_DST_902-202211140932ND
2022-05-16CA3710021_DST_900-2019081309261.18 pCi/L
2022-05-16CA4010019_031_031-202008111310ND
2022-05-16CA5400604_003_003-202108301400ND
2022-05-16CA5400670_009_009-201912111115ND
2022-05-16CA5410016_077_077-202111150920ND
2022-06-13CA1000199_011_011-2020030510261.67 pCi/L
2022-06-13CA1910211_DST_804-201904091500ND
2022-06-13CA3610109_001_001-2021101810001.18 pCi/L
2022-06-13CA3610120_007_007-202007280912ND
2022-06-13CA5410016_088_088-202108020926ND
2022-06-13CA5410016_118_118-202102250831ND
2022-08-08CA3610109_009_009-202208160945ND
2022-08-16CA3610039_119_119-202010211130ND
2022-08-16CA3710006_018_018-202201040734ND
2022-08-16CA3710006_DST_901-202105121037ND
2022-08-16CA3710006_DST_903-202011100646ND
2022-08-16CA3710021_DST_902-2021020908132.97 pCi/L
2022-08-16CA5400670_008_008-201912111255ND
2022-08-16CA5410016_045_045-202211171030ND
2022-08-16CA5410016_080_080-202202181147ND
2022-08-16CA5410016_080_080-202208121125ND
2022-08-16CA5410016_081_081-202105100925ND
2022-11-02CA1000069_004_004-202010211240ND
2022-11-02CA3710006_DST_900-201911120830ND
2022-11-21CA1910211_DST_802-202107121000ND
2022-11-21CA3710006_015_015-202003240838ND
2022-11-21CA4010018_014_014-202003030835ND
2022-11-21CA4010018_DST_023-202107071130ND
2022-11-21CA5400616_001_001-202212161100ND
2022-11-21CA5400670_008_008-202212281100ND
2022-11-21CA5400670_011_011-202012201140ND
2022-11-21CA5410016_088_088-202006111005ND
2022-11-21CA5410016_088_088-202201061004ND
2023-02-01CA1010007_646_646-202310251355ND
2023-02-01CA1910060_021_013-202309251047ND
2023-02-01CA1910146_073_073-202312040901ND
2023-02-01CA3610039_001_001-2023071907551.28 pCi/L
2023-02-01CA3610039_062_062-202307251100ND
2023-02-01CA3610039_064_064-202301110805ND
2023-06-12CA3610034_DST_601-202308100912ND
2023-06-12CA5410048_002_002-202306211100ND