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EWG's Tap Water Database — 2019 UPDATE

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Perchlorate

Los Angeles Department of Water and Power

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.

 

538

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND790ND
2013ND1130ND
2014ND1160ND
2015ND1120ND
2016ND640ND
2017ND540ND

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
2012-01-031200-133-0915ND
2012-01-031200-205-0650ND
2012-01-101200-133-1030ND
2012-01-101200-205-0650ND
2012-01-171200-133-0725ND
2012-01-171200-205-1005ND
2012-01-181200-205-1200ND
2012-01-241200-133-0625ND
2012-01-241200-205-1045ND
2012-01-311200-133-0955ND
2012-01-311200-205-0900ND
2012-02-021200-133-1000ND
2012-02-071200-133-0935ND
2012-02-071200-205-0810ND
2012-02-141200-011-1020ND
2012-02-141200-133-0630ND
2012-02-141200-205-0830ND
2012-02-211200-133-0805ND
2012-02-281200-133-1100ND
2012-03-061200-133-0725ND
2012-03-131200-133-1255ND
2012-03-201200-133-0720ND
2012-03-271200-133-1325ND
2012-04-031200-133-1205ND
2012-04-101200-133-1000ND
2012-04-171200-133-1255ND
2012-04-241200-133-1045ND
2012-05-011200-133-1015ND
2012-05-081200-133-1030ND
2012-05-151200-133-0925ND
2012-05-171200-011-0900ND
2012-05-221200-133-1045ND
2012-05-221200-133-1200ND
2012-05-291200-133-0945ND
2012-06-051200-133-0710ND
2012-06-121200-133-0650ND
2012-06-191200-133-1005ND
2012-06-261200-133-0650ND
2012-07-031200-133-1130ND
2012-07-101200-133-0740ND
2012-07-171200-133-1100ND
2012-07-241200-133-0700ND
2012-07-311200-133-1130ND
2012-08-071200-133-1200ND
2012-08-141200-011-1200ND
2012-08-141200-133-1030ND
2012-08-141200-133-1115ND
2012-08-211200-133-1115ND
2012-08-281200-133-1000ND
2012-09-041200-133-0630ND
2012-09-111200-133-1200ND
2012-09-181200-133-0615ND
2012-09-251200-133-0645ND
2012-10-021200-133-0625ND
2012-10-021200-205-0945ND
2012-10-091200-133-0640ND
2012-10-101200-205-0855ND
2012-10-161200-133-1245ND
2012-10-231200-133-1200ND
2012-10-231200-205-0845ND
2012-10-301200-133-1115ND
2012-10-301200-205-0945ND
2012-11-061200-133-1100ND
2012-11-061200-205-1005ND
2012-11-131200-011-1035ND
2012-11-131200-133-0830ND
2012-11-131200-133-0840ND
2012-11-131200-205-1010ND
2012-11-201200-133-0900ND
2012-11-201200-205-0835ND
2012-11-271200-133-0715ND
2012-11-271200-205-1050ND
2012-12-041200-133-0655ND
2012-12-041200-205-0905ND
2012-12-111200-205-1005ND
2012-12-181200-133-0710ND
2012-12-181200-205-1035ND
2012-12-251200-133-0810ND
2012-12-251200-205-1040ND
2013-01-011200-133-0655ND
2013-01-011200-205-1100ND
2013-01-081200-133-0700ND
2013-01-081200-205-1030ND
2013-01-151200-133-1305ND
2013-01-151200-205-1100ND
2013-01-221200-133-0655ND
2013-01-221200-205-1130ND
2013-01-299588-133-0645ND
2013-01-299588-205-0950ND
2013-02-051200-133-0650ND
2013-02-051200-205-1200ND
2013-02-121200-133-1230ND
2013-02-121200-205-0915ND
2013-02-191200-133-1300ND
2013-02-191200-205-0835ND
2013-02-201200-133-1200ND
2013-02-261200-133-1245ND
2013-02-261200-205-0825ND
2013-03-059588-133-1100ND
2013-03-059588-205-0735ND
2013-03-121200-133-1130ND
2013-03-121200-205-1155ND
2013-03-191200-133-0715ND
2013-03-191200-205-0825ND
2013-03-201200-011-1050ND
2013-03-261200-133-1100ND
2013-03-261200-205-0825ND
2013-04-021200-133-1145ND
2013-04-021200-205-0750ND
2013-04-091200-133-1340ND
2013-04-091200-205-0730ND
2013-04-161200-133-1230ND
2013-04-161200-205-1015ND
2013-04-231200-133-0630ND
2013-04-231200-205-0745ND
2013-04-301200-133-0635ND
2013-04-301200-205-0750ND
2013-05-071200-133-1320ND
2013-05-071200-205-0800ND
2013-05-091200-011-1025ND
2013-05-091200-133-0825ND
2013-05-141200-133-1255ND
2013-05-141200-205-0745ND
2013-05-211200-133-1215ND
2013-05-211200-205-1110ND
2013-05-281200-133-1045ND
2013-05-281200-205-1110ND
2013-06-041200-133-1030ND
2013-06-041200-205-1135ND
2013-06-111200-133-0815ND
2013-06-111200-205-1100ND
2013-06-181200-133-1100ND
2013-06-181200-205-0955ND
2013-06-251200-133-0620ND
2013-06-251200-205-1055ND
2013-07-021200-133-1625ND
2013-07-021200-205-0805ND
2013-07-091200-133-0615ND
2013-07-091200-205-0745ND
2013-07-161200-133-0635ND
2013-07-161200-205-0730ND
2013-07-231200-133-0635ND
2013-07-231200-205-0750ND
2013-07-301200-133-0635ND
2013-07-301200-205-0730ND
2013-08-061200-133-0710ND
2013-08-061200-205-0740ND
2013-08-131200-011-1235ND
2013-08-131200-133-1040ND
2013-08-131200-205-1300ND
2013-08-201200-133-0630ND
2013-08-201200-205-1300ND
2013-08-271200-133-0655ND
2013-08-271200-205-1030ND
2013-09-031200-133-0615ND
2013-09-031200-205-1300ND
2013-09-101200-133-1240ND
2013-09-101200-205-1215ND
2013-09-171200-133-1050ND
2013-09-171200-205-1130ND
2013-09-241200-133-0630ND
2013-09-241200-205-1005ND
2013-10-011200-133-1200ND
2013-10-011200-205-1030ND
2013-10-081200-133-1330ND
2013-10-081200-205-1145ND
2013-10-151200-133-1330ND
2013-10-151200-205-1030ND
2013-10-221200-133-0645ND
2013-10-221200-205-0830ND
2013-10-291200-133-1330ND
2013-10-291200-205-1100ND
2013-11-051200-133-1250ND
2013-11-051200-205-0935ND
2013-11-121200-133-1200ND
2013-11-121200-205-0645ND
2013-11-191200-011-1045ND
2013-11-191200-133-0630ND
2013-11-191200-133-0800ND
2013-11-191200-205-0745ND
2013-11-261200-133-1145ND
2013-11-261200-205-1120ND
2013-12-031200-133-1155ND
2013-12-031200-205-0925ND
2013-12-101200-133-1200ND
2013-12-101200-205-0805ND
2013-12-171200-133-0715ND
2013-12-171200-205-1125ND
2013-12-241200-133-0800ND
2013-12-241200-205-0820ND
2013-12-311200-133-0650ND
2013-12-311200-205-1105ND
2014-01-071200-133-0655ND
2014-01-071200-205-1110ND
2014-01-141200-133-1250ND
2014-01-141200-205-1055ND
2014-01-211200-133-0730ND
2014-01-211200-205-1105ND
2014-01-281200-133-1145ND
2014-01-281200-205-0805ND
2014-02-041200-133-1115ND
2014-02-041200-205-0730ND
2014-02-111200-133-1145ND
2014-02-111200-205-0900ND
2014-02-181200-133-1200ND
2014-02-181200-205-1000ND
2014-02-251200-133-1230ND
2014-02-251200-205-0745ND
2014-02-261200-011-1215ND
2014-02-261200-133-1215ND
2014-03-041200-133-1230ND
2014-03-041200-205-0815ND
2014-03-111200-133-0710ND
2014-03-111200-205-1000ND
2014-03-181200-133-0700ND
2014-03-181200-205-1115ND
2014-03-251200-133-0700ND
2014-03-251200-205-1045ND
2014-04-011200-133-0620ND
2014-04-011200-205-0945ND
2014-04-081200-133-0650ND
2014-04-081200-205-1130ND
2014-04-151200-133-0650ND
2014-04-151200-205-1115ND
2014-04-221200-133-1130ND
2014-04-221200-205-1105ND
2014-04-291200-133-0700ND
2014-04-291200-205-1015ND
2014-05-061200-133-1220ND
2014-05-061200-205-1100ND
2014-05-131200-133-1145ND
2014-05-131200-205-1100ND
2014-05-141200-011-1115ND
2014-05-141200-133-1105ND
2014-05-201200-133-0615ND
2014-05-201200-205-1110ND
2014-05-271200-133-0615ND
2014-05-271200-205-1105ND
2014-06-031200-133-1225ND
2014-06-031200-205-0720ND
2014-06-101200-133-0645ND
2014-06-101200-205-0650ND
2014-06-171200-133-1200ND
2014-06-171200-205-0725ND
2014-06-241200-133-0625ND
2014-06-241200-205-0655ND
2014-07-011200-133-1240ND
2014-07-011200-205-0720ND
2014-07-081200-133-1205ND
2014-07-081200-205-0700ND
2014-07-151200-133-1305ND
2014-07-151200-205-0700ND
2014-07-221200-133-0640ND
2014-07-221200-205-1055ND
2014-07-251200-159-1050ND
2014-07-291200-133-0715ND
2014-07-291200-205-1120ND
2014-08-051200-133-0700ND
2014-08-051200-205-1100ND
2014-08-121200-011-1030ND
2014-08-121200-133-0640ND
2014-08-121200-205-1055ND
2014-08-191200-133-0645ND
2014-08-191200-205-1015ND
2014-08-201200-133-0900ND
2014-08-261200-133-1145ND
2014-08-261200-159-0945ND
2014-08-261200-205-0625ND
2014-09-021200-133-1200ND
2014-09-021200-205-1010ND
2014-09-091200-133-1140ND
2014-09-091200-205-1105ND
2014-09-161200-133-1115ND
2014-09-161200-205-0650ND
2014-09-231200-133-1115ND
2014-09-231200-205-0720ND
2014-09-291200-159-1050ND
2014-09-301200-205-0650ND
2014-10-011200-133-0835ND
2014-10-071200-205-0915ND
2014-10-081200-133-0900ND
2014-10-141200-205-1045ND
2014-10-151200-133-1245ND
2014-10-211200-205-0945ND
2014-10-221200-133-0805ND
2014-10-281200-205-0930ND
2014-10-291200-133-1150ND
2014-11-041200-205-0900ND
2014-11-051200-133-0830ND
2014-11-111200-159-0905ND
2014-11-111200-205-0745ND
2014-11-121200-011-1240ND
2014-11-121200-133-0700ND
2014-11-181200-133-0935ND
2014-11-181200-205-1110ND
2014-11-191200-133-1130ND
2014-11-251200-205-1130ND
2014-11-261200-133-1100ND
2014-12-021200-205-1040ND
2014-12-031200-133-1020ND
2014-12-091200-205-1125ND
2014-12-101200-133-0640ND
2014-12-161200-205-0700ND
2014-12-171200-133-1115ND
2014-12-231200-205-0700ND
2014-12-241200-133-0715ND
2014-12-301200-205-0655ND
2014-12-311200-133-0800ND
2015-01-061200-205-0645ND
2015-01-071200-133-0750ND
2015-01-131200-205-0700ND
2015-01-141200-133-0735ND
2015-01-201200-205-0710ND
2015-01-211200-133-1115ND
2015-01-261200-159-0950ND
2015-01-271200-205-0655ND
2015-01-281200-133-0945ND
2015-02-031200-205-0910ND
2015-02-041200-133-0755ND
2015-02-101200-205-0740ND
2015-02-111200-133-0810ND
2015-02-111200-133-0825ND
2015-02-171200-205-1135ND
2015-02-181200-133-0625ND
2015-02-191200-011-0845ND
2015-02-241200-159-0940ND
2015-02-241200-205-1200ND
2015-02-251200-133-1230ND
2015-03-031200-205-0915ND
2015-03-041200-133-0930ND
2015-03-101200-205-0750ND
2015-03-111200-133-0915ND
2015-03-171200-205-0735ND
2015-03-181200-133-1055ND
2015-03-241200-205-1300ND
2015-03-251200-133-1145ND
2015-03-311200-205-0715ND
2015-04-011200-133-0905ND
2015-04-071200-205-1050ND
2015-04-081200-133-0725ND
2015-04-141200-205-1125ND
2015-04-151200-133-1130ND
2015-04-211200-205-1040ND
2015-04-221200-133-0750ND
2015-04-281200-205-1120ND
2015-04-291200-133-1130ND
2015-05-051200-205-1200ND
2015-05-061200-133-0935ND
2015-05-071200-159-1105ND
2015-05-121200-205-1210ND
2015-05-131200-133-0840ND
2015-05-191200-011-0900ND
2015-05-191200-133-1100ND
2015-05-191200-205-1310ND
2015-05-201200-133-0905ND
2015-05-261200-205-1200ND
2015-05-271200-133-1255ND
2015-06-021200-205-1015ND
2015-06-031200-133-0715ND
2015-06-091200-205-0945ND
2015-06-101200-133-0930ND
2015-06-161200-205-1000ND
2015-06-171200-133-1140ND
2015-06-191200-159-0900ND
2015-06-231200-205-0930ND
2015-06-241200-133-1145ND
2015-06-301200-205-0900ND
2015-07-161200-159-0950ND
2015-08-041200-011-1040ND
2015-08-041200-133-0645ND
2015-08-041200-205-1200ND
2015-08-051200-133-0810ND
2015-08-111200-205-1115ND
2015-08-121200-133-1015ND
2015-08-181200-205-0835ND
2015-08-191200-133-0705ND
2015-08-201200-159-1000ND
2015-08-251200-205-1200ND
2015-08-261200-133-1115ND
2015-09-011200-205-1100ND
2015-09-021200-133-0950ND
2015-09-081200-205-0715ND
2015-09-091200-133-0945ND
2015-09-151200-205-1000ND
2015-09-161200-133-1115ND
2015-09-221200-205-1100ND
2015-09-231200-133-0800ND
2015-09-281200-159-1000ND
2015-09-291200-205-1240ND
2015-09-301200-133-1130ND
2015-10-061200-205-1030ND
2015-10-071200-133-1010ND
2015-10-131200-205-0915ND
2015-10-141200-133-1215ND
2015-10-201200-205-1155ND
2015-10-211200-133-0655ND
2015-10-271200-205-1040ND
2015-10-281200-133-1110ND
2015-10-301200-159-1050ND
2015-11-031200-205-1100ND
2015-11-041200-133-0725ND
2015-11-051200-011-1005ND
2015-11-051200-133-0755ND
2015-11-101200-205-1200ND
2015-11-111200-133-0845ND
2015-11-171200-205-0955ND
2015-11-181200-133-0625ND
2015-11-241200-205-1020ND
2015-11-251200-133-0720ND
2015-11-271200-159-0930ND
2015-12-011200-205-1200ND
2015-12-021200-133-0635ND
2015-12-081200-205-1030ND
2015-12-091200-133-0635ND
2015-12-151200-205-1010ND
2015-12-161200-133-0705ND
2015-12-221200-205-0730ND
2015-12-231200-133-0650ND
2015-12-291200-205-1050ND
2015-12-301200-133-1035ND
2016-01-051200-205-1030ND
2016-01-061200-133-0750ND
2016-01-121200-205-0655ND
2016-01-131200-133-0750ND
2016-01-131200-159-1040ND
2016-01-191200-205-1240ND
2016-01-201200-133-0800ND
2016-01-261200-205-1230ND
2016-01-271200-133-0825ND
2016-02-021200-205-1210ND
2016-02-031200-133-0820ND
2016-02-091200-133-0930ND
2016-02-091200-205-0735ND
2016-02-101200-133-0835ND
2016-02-161200-205-0920ND
2016-02-171200-133-1045ND
2016-02-241200-011-1215ND
2016-02-271200-159-0840ND
2016-03-291200-159-1000ND
2016-04-191200-159-0945ND
2016-05-051200-205-0845ND
2016-05-121200-205-0840ND
2016-05-171200-205-1300ND
2016-05-249588-205-1320ND
2016-05-251200-011-1135ND
2016-05-251200-133-1210ND
2016-05-261200-159-1015ND
2016-05-311200-205-1205ND
2016-06-071200-205-1330ND
2016-06-141200-205-1300ND
2016-06-211200-205-1310ND
2016-06-281200-205-1140ND
2016-07-051200-205-1240ND
2016-07-121200-205-0705ND
2016-07-191200-205-0855ND
2016-07-211200-205-1225ND
2016-07-261200-205-0835ND
2016-08-021200-205-0735ND
2016-08-091200-205-0840ND
2016-08-161200-205-0705ND
2016-08-171200-011-1010ND
2016-08-231200-133-1005ND
2016-08-231200-205-1100ND
2016-08-301200-205-0710ND
2016-09-061200-205-0725ND
2016-09-131200-205-1045ND
2016-09-201200-205-0930ND
2016-09-271200-205-1220ND
2016-10-041200-205-0945ND
2016-10-111200-205-1020ND
2016-10-181200-205-0640ND
2016-10-251200-205-1015ND
2016-11-011200-205-0730ND
2016-11-081200-205-0740ND
2016-11-151200-205-0830ND
2016-11-211200-133-1115ND
2016-11-221200-205-1050ND
2016-11-291200-011-0845ND
2016-11-291200-159-1005ND
2016-11-291200-205-1100ND
2016-12-061200-205-1115ND
2016-12-131200-205-0825ND
2016-12-201200-205-1100ND
2016-12-271200-205-1130ND
2017-01-031200-205-1040ND
2017-01-101200-205-1005ND
2017-01-171200-205-1325ND
2017-01-241200-205-1205ND
2017-01-301200-159-1015ND
2017-01-311200-205-1100ND
2017-02-071200-205-1150ND
2017-02-141200-205-1230ND
2017-02-161200-159-0940ND
2017-02-211200-011-1140ND
2017-02-211200-133-1210ND
2017-02-211200-205-1235ND
2017-02-281200-205-1310ND
2017-03-071200-205-1315ND
2017-03-101200-159-0920ND
2017-03-141200-205-1226ND
2017-03-211200-205-1237ND
2017-03-281200-205-1205ND
2017-04-041200-205-1219ND
2017-04-111200-205-1125ND
2017-04-181200-205-0810ND
2017-04-261200-205-1330ND
2017-05-031200-133-1035ND
2017-05-031200-205-1015ND
2017-05-091200-011-0940ND
2017-05-101200-205-0839ND
2017-05-171200-133-0941ND
2017-05-171200-205-0912ND
2017-05-241200-205-0852ND
2017-05-311200-205-0828ND
2017-06-071200-133-1115ND
2017-06-071200-205-0725ND
2017-06-141200-205-0737ND
2017-06-211200-205-0725ND
2017-06-221200-159-0830ND
2017-06-281200-205-1235ND
2017-07-051200-133-0814ND
2017-07-051200-205-1224ND
2017-07-101200-159-1135ND
2017-07-121200-205-1000ND
2017-07-121200-205-1034ND
2017-08-011200-133-0940ND
2017-08-091200-133-0840ND
2017-08-211200-011-1010ND
2017-08-291200-159-1215ND
2017-09-061200-133-0826ND
2017-09-271200-159-1030ND
2017-10-041200-133-1110ND
2017-10-201200-159-1000ND
2017-11-031200-159-1050ND
2017-11-081200-133-1005ND
2017-11-201200-011-1000ND
2017-11-201200-133-1040ND
2017-12-061200-133-0921ND