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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Golden State Water Company - Cordova

Perchlorate, a component of rocket fuel, occurs both naturally and as a synthetic chemical. Ingested perchlorate interferes with thyroid function. Exposure to perchlorate during pregnancy and childhood can impair cognitive development. Read More.

According to the EPA, perchlorate likely contaminates the water of more than 16 million Americans. Perchlorate interferes with iodine uptake in the thyroid, which can result in reduced thyroid hormones and an impact on metabolism, physical development and cognitive development. Children and developing fetuses are the most at risk from perchlorate contamination.

Perchlorate is the only unregulated contaminant for which the EPA has attempted to set a federal drinking water standard since 1996. However, the agency has yet to propose a draft limit for this contaminant. Perchlorate in drinking water is regulated in Arizona, California, Massachusetts, New Jersey, New York and Texas. California set a public health goal of 1 part per billion for perchlorate in 2015.

Click here to read more about perchlorate.

MORE ABOUT THIS CONTAMINANT

 

212

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND450ND
2015ND230ND
2016ND250ND
2017ND220ND
2018ND350ND
2019ND620ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppb

The EWG Health Guideline of 1 ppb for perchlorate 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. This health guideline protects against hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-072706-029-0958ND
2014-01-142706-010-1140ND
2014-01-142706-019-1020ND
2014-01-142706-022-0845ND
2014-01-142706-028-0920ND
2014-01-142706-029-1305ND
2014-01-142706-030-0945ND
2014-01-142706-051-1210ND
2014-01-212706-029-1215ND
2014-01-282706-029-1035ND
2014-02-042706-029-1010ND
2014-02-112706-029-1127ND
2014-02-182706-029-1150ND
2014-02-252706-029-1031ND
2014-03-042706-029-1210ND
2014-03-112706-029-1145ND
2014-03-182706-029-1246ND
2014-04-022706-019-1238ND
2014-04-022706-022-1240ND
2014-04-022706-028-1012ND
2014-04-022706-030-1307ND
2014-04-082706-010-1325ND
2014-04-082706-051-1350ND
2014-07-012706-029-1029ND
2014-07-082706-029-1016ND
2014-07-152706-010-1314ND
2014-07-152706-019-1154ND
2014-07-152706-022-1105ND
2014-07-152706-028-1128ND
2014-07-152706-029-1410ND
2014-07-152706-030-1100ND
2014-07-152706-051-1328ND
2014-07-252706-029-1154ND
2014-07-292706-029-1109ND
2014-08-052706-029-1059ND
2014-08-122706-029-1159ND
2014-08-192706-029-1210ND
2014-08-262706-029-1336ND
2014-09-022706-029-1240ND
2014-10-142706-019-1203ND
2014-10-142706-022-1100ND
2014-10-142706-028-1114ND
2014-10-142706-030-1135ND
2014-10-212706-010-1055ND
2014-10-212706-051-1116ND
2015-01-132706-010-1157ND
2015-01-132706-019-1023ND
2015-01-132706-022-0930ND
2015-01-132706-028-0940ND
2015-01-132706-030-0910ND
2015-01-132706-051-1233ND
2015-04-082706-022-1110ND
2015-04-142706-010-1220ND
2015-04-142706-028-1300ND
2015-04-142706-030-1330ND
2015-04-142706-051-1135ND
2015-07-072706-022-0900ND
2015-07-072706-051-1205ND
2015-07-142706-010-1355ND
2015-07-142706-019-1143ND
2015-07-142706-028-0957ND
2015-07-142706-030-1112ND
2015-10-062706-010-1235ND
2015-10-062706-022-0915ND
2015-10-062706-051-1155ND
2015-10-202706-019-1120ND
2015-10-202706-028-1005ND
2015-10-202706-030-1040ND
2016-01-122706-010-1345ND
2016-01-122706-019-1005ND
2016-01-122706-028-0935ND
2016-01-122706-030-0920ND
2016-01-202706-051-1150ND
2016-01-262706-022-1011ND
2016-04-052706-022-0900ND
2016-04-122706-010-1155ND
2016-04-122706-019-1035ND
2016-04-122706-028-0915ND
2016-04-122706-030-0950ND
2016-04-122706-051-1225ND
2016-07-052706-010-1055ND
2016-07-052706-022-0920ND
2016-07-122710-019-1300ND
2016-07-122710-028-1220ND
2016-07-122710-030-1245ND
2016-07-122710-051-0943ND
2016-09-202706-029-1305ND
2016-10-042706-022-0920ND
2016-10-112706-010-1250ND
2016-10-112706-019-1140ND
2016-10-112706-028-0940ND
2016-10-112706-030-1015ND
2016-10-182706-051-1200ND
2017-02-149590-028-1313ND
2017-02-149590-030-1342ND
2017-02-239590-019-1040ND
2017-03-079590-051-1140ND
2017-04-259590-019-1030ND
2017-04-259590-051-1150ND
2017-05-029590-028-1112ND
2017-05-059590-010-1405ND
2017-05-099590-030-1258ND
2017-05-259590-022-1010ND
2017-07-089590-022-1325ND
2017-07-189590-010-1307ND
2017-07-189590-019-0729ND
2017-07-189590-028-0828ND
2017-07-189590-030-0750ND
2017-07-189590-051-1335ND
2017-10-039590-022-0934ND
2017-10-109590-010-1009ND
2017-10-109590-051-1044ND
2017-10-179590-019-1122ND
2017-10-179590-028-0950ND
2017-10-179590-030-0938ND
2018-01-109590-010-1416ND
2018-01-109590-019-1215ND
2018-01-109590-028-1136ND
2018-01-109590-030-1107ND
2018-01-109590-051-1438ND
2018-05-019590-022-0906ND
2018-07-109590-010-0958ND
2018-07-109590-019-1057ND
2018-07-109590-022-0846ND
2018-07-109590-028-1134ND
2018-07-109590-030-1155ND
2018-07-109590-051-1020ND
2018-08-219590-029-1044ND
2018-09-049590-029-0937ND
2018-09-119590-029-1512ND
2018-09-199590-029-1058ND
2018-09-279590-029-1058ND
2018-10-029590-029-1043ND
2018-10-099590-010-1111ND
2018-10-099590-019-1421ND
2018-10-099590-028-1321ND
2018-10-099590-030-1346ND
2018-10-099590-051-1036ND
2018-10-169590-029-1249ND
2018-10-239590-029-1007ND
2018-10-309590-029-1455ND
2018-11-069590-022-0905ND
2018-11-069590-029-1040ND
2018-11-139590-029-1354ND
2018-11-209590-029-1133ND
2018-11-279590-029-0822ND
2018-12-049590-029-1222ND
2018-12-119590-029-1001ND
2018-12-189590-029-1912ND
2018-12-269590-029-1253ND
2019-01-029590-029-1122ND
2019-01-089590-019-1430ND
2019-01-089590-029-1048ND
2019-01-089590-029-1049ND
2019-01-109590-029-1010ND
2019-01-159590-010-1254ND
2019-01-159590-022-0836ND
2019-01-159590-028-1047ND
2019-01-159590-029-0927ND
2019-01-159590-030-1018ND
2019-01-159590-051-1325ND
2019-01-299590-029-0900ND
2019-01-299590-029-0925ND
2019-02-059590-029-1010ND
2019-02-129590-029-0848ND
2019-02-269590-029-1312ND
2019-03-059590-029-1318ND
2019-03-129590-029-1102ND
2019-03-199590-029-1114ND
2019-03-269590-029-1113ND
2019-04-029590-029-0916ND
2019-04-099590-010-1230ND
2019-04-099590-022-0918ND
2019-04-099590-028-0757ND
2019-04-099590-029-1046ND
2019-04-099590-030-0825ND
2019-04-099590-051-1151ND
2019-04-169590-019-1026ND
2019-04-169590-029-0830ND
2019-04-239590-029-1047ND
2019-04-309590-029-1053ND
2019-05-079590-029-1040ND
2019-05-149590-029-0920ND
2019-05-219590-029-1017ND
2019-05-289590-029-1330ND
2019-06-049590-029-1327ND
2019-06-119590-029-0951ND
2019-06-189590-029-0948ND
2019-06-259590-029-1047ND
2019-07-029590-029-1050ND
2019-07-099590-010-1445ND
2019-07-099590-019-1025ND
2019-07-099590-028-0935ND
2019-07-099590-029-1241ND
2019-07-099590-029-1245ND
2019-07-099590-030-0902ND
2019-07-099590-051-1358ND
2019-07-169590-029-1302ND
2019-07-239590-022-0800ND
2019-07-239590-029-1017ND
2019-07-309590-029-1018ND
2019-08-069590-029-1310ND
2019-08-139590-029-0852ND
2019-08-209590-029-1152ND
2019-08-279590-029-1440ND
2019-10-019590-022-0906ND
2019-10-089590-010-1031ND
2019-10-089590-019-1311ND
2019-10-089590-022-0810ND
2019-10-089590-028-1211ND
2019-10-089590-030-1236ND
2019-10-089590-051-1105ND