Know Your Environment. Protect Your Health.

Perchlorate

San Martin County Water District

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.

 

209

Samples

0

Samples exceeding legal limit (MCL)

120

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.63 ppb3613ND - 5.80 ppb
20190.850 ppb367ND - 4.70 ppb
20201.38 ppb3611ND - 5.50 ppb
20212.64 ppb3221ND - 4.90 ppb
20223.13 ppb3332ND - 4.70 ppb
20232.69 ppb36361.70 ppb - 3.60 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
2018-01-08CA4300542_005_005-2018010811494.10 ppb
2018-01-08CA4300542_003_003-201801081147ND
2018-01-08CA4300542_004_004-201801081148ND
2018-02-13CA4300542_003_003-2018021314034.10 ppb
2018-02-13CA4300542_004_004-201802131404ND
2018-02-13CA4300542_005_005-2018021314054.30 ppb
2018-03-05CA4300542_003_003-2018030511094.10 ppb
2018-03-05CA4300542_005_005-2018030511115.00 ppb
2018-03-05CA4300542_004_004-201803051110ND
2018-04-09CA4300542_003_003-201804091200ND
2018-04-09CA4300542_004_004-201804091201ND
2018-04-09CA4300542_005_005-2018040912024.30 ppb
2018-05-08CA4300542_004_004-2018050817184.20 ppb
2018-05-08CA4300542_005_005-201805081719ND
2018-05-08CA4300542_003_003-201805081717ND
2018-06-11CA4300542_005_005-201806111129ND
2018-06-11CA4300542_003_003-2018061111275.60 ppb
2018-06-11CA4300542_004_004-201806111128ND
2018-07-16CA4300542_003_003-201807161327ND
2018-07-16CA4300542_004_004-201807161328ND
2018-07-16CA4300542_005_005-201807161329ND
2018-08-13CA4300542_005_005-201808131159ND
2018-08-13CA4300542_004_004-201808131158ND
2018-08-13CA4300542_003_003-201808131157ND
2018-09-11CA4300542_004_004-201809111309ND
2018-09-11CA4300542_005_005-2018091113105.80 ppb
2018-09-11CA4300542_003_003-201809111308ND
2018-10-09CA4300542_003_003-2018100914064.30 ppb
2018-10-09CA4300542_005_005-2018100914084.20 ppb
2018-10-09CA4300542_004_004-2018100914074.60 ppb
2018-11-06CA4300542_003_003-201811061236ND
2018-11-06CA4300542_004_004-201811061237ND
2018-11-06CA4300542_005_005-2018110612384.20 ppb
2018-12-11CA4300542_003_003-201812111323ND
2018-12-11CA4300542_004_004-201812111324ND
2018-12-11CA4300542_005_005-201812111325ND
2019-01-22CA4300542_004_004-201901221309ND
2019-01-22CA4300542_003_003-201901221308ND
2019-01-22CA4300542_005_005-2019012213104.20 ppb
2019-02-19CA4300542_003_003-201902191023ND
2019-02-19CA4300542_005_005-201902191025ND
2019-02-19CA4300542_004_004-2019021910244.30 ppb
2019-03-04CA4300542_003_003-201903041301ND
2019-03-04CA4300542_004_004-2019030413024.50 ppb
2019-03-04CA4300542_005_005-2019030413034.40 ppb
2019-04-10CA4300542_004_004-201904101332ND
2019-04-10CA4300542_005_005-201904101333ND
2019-04-10CA4300542_003_003-201904101331ND
2019-05-13CA4300542_003_003-201905131126ND
2019-05-13CA4300542_004_004-201905131127ND
2019-05-13CA4300542_005_005-2019051311284.70 ppb
2019-06-19CA4300542_003_003-201906191301ND
2019-06-19CA4300542_004_004-201906191302ND
2019-06-19CA4300542_005_005-201906191303ND
2019-07-22CA4300542_003_003-201907221320ND
2019-07-22CA4300542_004_004-201907221321ND
2019-07-22CA4300542_005_005-201907221322ND
2019-08-13CA4300542_004_004-2019081313054.20 ppb
2019-08-13CA4300542_003_003-201908131304ND
2019-08-13CA4300542_005_005-2019081313064.30 ppb
2019-09-23CA4300542_003_003-201909231257ND
2019-09-23CA4300542_005_005-201909231259ND
2019-09-23CA4300542_004_004-201909231258ND
2019-10-08CA4300542_005_005-201910081320ND
2019-10-08CA4300542_003_003-201910081318ND
2019-10-08CA4300542_004_004-201910081319ND
2019-11-12CA4300542_004_004-201911121230ND
2019-11-12CA4300542_003_003-201911121229ND
2019-11-12CA4300542_005_005-201911121231ND
2019-12-10CA4300542_004_004-201912101308ND
2019-12-10CA4300542_005_005-201912101309ND
2019-12-10CA4300542_003_003-201912101307ND
2020-01-07CA4300542_004_004-202001071222ND
2020-01-07CA4300542_005_005-202001071223ND
2020-01-07CA4300542_003_003-202001071221ND
2020-02-04CA4300542_005_005-2020020411314.10 ppb
2020-02-04CA4300542_004_004-202002041130ND
2020-02-04CA4300542_003_003-202002041129ND
2020-03-10CA4300542_003_003-202003101330ND
2020-03-10CA4300542_005_005-2020031013324.00 ppb
2020-03-10CA4300542_004_004-202003101331ND
2020-04-21CA4300542_003_003-202004211320ND
2020-04-21CA4300542_004_004-202004211321ND
2020-04-21CA4300542_005_005-202004211322ND
2020-05-05CA4300542_004_004-202005051334ND
2020-05-05CA4300542_003_003-202005051333ND
2020-05-05CA4300542_005_005-202005051335ND
2020-06-08CA4300542_004_004-202006081149ND
2020-06-08CA4300542_005_005-202006081150ND
2020-06-08CA4300542_003_003-202006081148ND
2020-07-14CA4300542_004_004-202007141244ND
2020-07-14CA4300542_005_005-2020071412454.00 ppb
2020-07-14CA4300542_003_003-202007141243ND
2020-08-11CA4300542_004_004-2020081112484.70 ppb
2020-08-11CA4300542_005_005-2020081112494.80 ppb
2020-08-11CA4300542_003_003-2020081112474.30 ppb
2020-09-08CA4300542_005_005-2020090812094.80 ppb
2020-09-08CA4300542_003_003-2020090812074.40 ppb
2020-09-08CA4300542_004_004-2020090812085.50 ppb
2020-10-21CA4300542_005_005-2020102112245.00 ppb
2020-10-21CA4300542_003_003-202010211222ND
2020-10-21CA4300542_004_004-202010211223ND
2020-11-17CA4300542_005_005-2020111712354.10 ppb
2020-11-17CA4300542_003_003-202011171233ND
2020-11-17CA4300542_004_004-202011171234ND
2020-12-08CA4300542_003_003-202012081244ND
2020-12-08CA4300542_004_004-202012081245ND
2020-12-08CA4300542_005_005-202012081246ND
2021-01-19CA4300542_003_003-202101191153ND
2021-01-19CA4300542_004_004-202101191154ND
2021-01-19CA4300542_005_005-202101191155ND
2021-02-09CA4300542_003_003-2021020912394.70 ppb
2021-02-09CA4300542_005_005-2021020912414.90 ppb
2021-02-09CA4300542_004_004-2021020912404.60 ppb
2021-03-16CA4300542_003_003-202103161345ND
2021-03-16CA4300542_004_004-202103161346ND
2021-03-16CA4300542_005_005-202103161347ND
2021-04-06CA4300542_005_005-202104061342ND
2021-04-06CA4300542_003_003-202104061340ND
2021-04-06CA4300542_004_004-202104061341ND
2021-05-11CA4300542_004_004-202105111129ND
2021-05-11CA4300542_003_003-202105111128ND
2021-05-11CA4300542_005_005-2021051111304.10 ppb
2021-06-07CA4300542_003_003-2021060711394.20 ppb
2021-06-07CA4300542_005_005-2021060711414.40 ppb
2021-06-07CA4300542_004_004-2021060711404.70 ppb
2021-07-13CA4300542_005_005-2021071313323.90 ppb
2021-07-13CA4300542_003_003-2021071313303.20 ppb
2021-07-13CA4300542_004_004-2021071313313.70 ppb
2021-08-17CA4300542_005_005-2021081712384.00 ppb
2021-08-17CA4300542_004_004-2021081712373.80 ppb
2021-08-17CA4300542_003_003-2021081712362.90 ppb
2021-09-14CA4300542_003_003-2021091412203.20 ppb
2021-09-14CA4300542_004_004-2021091412213.90 ppb
2021-09-14CA4300542_005_005-2021091412224.10 ppb
2021-11-09CA4300542_003_003-2021110913143.60 ppb
2021-11-09CA4300542_005_005-2021110913164.40 ppb
2021-12-07CA4300542_004_004-2021120713054.60 ppb
2021-12-07CA4300542_005_005-2021120713064.40 ppb
2021-12-07CA4300542_003_003-2021120713043.30 ppb
2022-01-25CA4300542_003_003-2022012513344.10 ppb
2022-01-25CA4300542_004_004-2022012513353.50 ppb
2022-01-25CA4300542_005_005-2022012513363.50 ppb
2022-02-15CA4300542_003_003-2022021513132.00 ppb
2022-02-15CA4300542_004_004-2022021513142.60 ppb
2022-02-15CA4300542_005_005-2022021513153.00 ppb
2022-03-07CA4300542_004_004-2022030711103.40 ppb
2022-03-07CA4300542_005_005-2022030711113.60 ppb
2022-03-07CA4300542_003_003-2022030711093.00 ppb
2022-04-13CA4300542_003_003-2022041312272.60 ppb
2022-04-13CA4300542_004_004-2022041312283.40 ppb
2022-04-13CA4300542_005_005-2022041312293.70 ppb
2022-05-16CA4300542_004_004-2022051612193.70 ppb
2022-05-16CA4300542_005_005-2022051612203.80 ppb
2022-05-16CA4300542_003_003-2022051612182.50 ppb
2022-06-20CA4300542_003_003-2022062013443.90 ppb
2022-06-20CA4300542_004_004-2022062013454.20 ppb
2022-06-20CA4300542_005_005-2022062013464.70 ppb
2022-07-11CA4300542_003_003-2022071113053.20 ppb
2022-07-11CA4300542_005_005-2022071113074.30 ppb
2022-07-11CA4300542_004_004-2022071113064.40 ppb
2022-09-13CA4300542_004_004-2022091312283.00 ppb
2022-09-13CA4300542_003_003-2022091312272.20 ppb
2022-09-13CA4300542_005_005-2022091312292.80 ppb
2022-10-24CA4300542_004_004-2022102413113.20 ppb
2022-10-24CA4300542_005_005-2022102413123.50 ppb
2022-10-24CA4300542_003_003-2022102413102.30 ppb
2022-11-14CA4300542_004_004-2022111412373.00 ppb
2022-11-14CA4300542_003_003-202211141236ND
2022-11-14CA4300542_005_005-2022111412383.20 ppb
2022-12-07CA4300542_003_003-2022120713192.30 ppb
2022-12-07CA4300542_004_004-2022120713202.40 ppb
2022-12-07CA4300542_005_005-2022120713212.30 ppb
2023-01-18CA4300542_004_004-2023011813383.00 ppb
2023-01-18CA4300542_003_003-2023011813372.20 ppb
2023-01-18CA4300542_005_005-2023011813393.20 ppb
2023-02-21CA4300542_004_004-2023022113282.70 ppb
2023-02-21CA4300542_005_005-2023022113292.80 ppb
2023-02-21CA4300542_003_003-2023022113272.00 ppb
2023-03-22CA4300542_005_005-2023032211272.50 ppb
2023-03-22CA4300542_003_003-2023032211252.20 ppb
2023-03-22CA4300542_004_004-2023032211262.80 ppb
2023-04-12CA4300542_004_004-2023041212012.80 ppb
2023-04-12CA4300542_003_003-2023041212002.20 ppb
2023-04-12CA4300542_005_005-2023041212023.60 ppb
2023-05-23CA4300542_004_004-2023052312201.80 ppb
2023-05-23CA4300542_005_005-2023052312212.60 ppb
2023-05-23CA4300542_003_003-2023052312192.90 ppb
2023-06-12CA4300542_005_005-2023061213272.90 ppb
2023-06-12CA4300542_003_003-2023061213252.00 ppb
2023-06-12CA4300542_004_004-2023061213263.10 ppb
2023-07-19CA4300542_003_003-2023071912552.00 ppb
2023-07-19CA4300542_004_004-2023071912563.40 ppb
2023-07-19CA4300542_005_005-2023071912573.30 ppb
2023-08-21CA4300542_003_003-2023082112501.70 ppb
2023-08-21CA4300542_004_004-2023082112513.10 ppb
2023-08-21CA4300542_005_005-2023082112522.80 ppb
2023-09-19CA4300542_004_004-2023091912523.20 ppb
2023-09-19CA4300542_003_003-2023091912512.00 ppb
2023-09-19CA4300542_005_005-2023091912533.10 ppb
2023-10-18CA4300542_004_004-2023101812262.80 ppb
2023-10-18CA4300542_003_003-2023101812251.70 ppb
2023-10-18CA4300542_005_005-2023101812272.90 ppb
2023-11-13CA4300542_005_005-2023111313053.40 ppb
2023-11-13CA4300542_003_003-2023111313032.20 ppb
2023-11-13CA4300542_004_004-2023111313043.20 ppb
2023-12-11CA4300542_003_003-2023121114062.20 ppb
2023-12-11CA4300542_004_004-2023121114073.50 ppb
2023-12-11CA4300542_005_005-2023121114083.00 ppb