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EWG's Tap Water Database — 2019 UPDATE

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Nitrate

Contra Costa Water District

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.

 

55

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.0596 ppm111ND - 0.655 ppm
2013ND130ND
20140.0422 ppm151ND - 0.633 ppm
2015ND120ND
2016ND30ND
2017ND10ND

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

EPA Maximum Contaminant
Level (MCL) 10 ppm

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date Lab ID Result
2012-01-092473-003-08000.655 ppm
2012-04-192473-003-0830ND
2012-05-152473-003-1050ND
2012-06-122473-003-1030ND
2012-07-092473-003-0800ND
2012-07-172473-003-1215ND
2012-08-142473-003-1035ND
2012-09-112473-003-1155ND
2012-10-092473-003-1020ND
2012-11-132473-003-0815ND
2012-12-042473-003-1330ND
2013-03-202473-003-1250ND
2013-04-012473-003-0825ND
2013-04-092473-003-1035ND
2013-05-142473-003-1245ND
2013-06-112473-003-1400ND
2013-07-152473-003-1345ND
2013-07-162473-003-1000ND
2013-08-132473-003-1140ND
2013-09-102473-003-1254ND
2013-09-112473-019-1425ND
2013-10-152473-003-1300ND
2013-11-122473-003-0800ND
2013-12-109590-003-0800ND
2014-03-102473-003-11190.633 ppm
2014-04-072473-003-0740ND
2014-04-152473-003-0810ND
2014-05-132473-003-1255ND
2014-06-102473-003-0755ND
2014-07-072473-003-0755ND
2014-07-152473-003-1255ND
2014-07-212473-019-1330ND
2014-07-222473-003-1345ND
2014-08-122473-003-1454ND
2014-09-092473-003-1255ND
2014-10-062473-003-0758ND
2014-10-142473-003-0830ND
2014-11-182473-003-0830ND
2014-12-022473-003-1345ND
2015-03-182473-003-1427ND
2015-04-142473-003-1335ND
2015-05-122473-003-0821ND
2015-06-092473-003-1341ND
2015-07-062473-003-0815ND
2015-07-062473-003-0826ND
2015-07-142473-003-1400ND
2015-08-112473-003-0955ND
2015-09-152473-003-1200ND
2015-10-132473-003-0900ND
2015-11-102473-003-0945ND
2015-12-082473-003-0900ND
2016-04-042473-003-0900ND
2016-07-119590-003-1350ND
2016-07-112473-003-0900ND
2017-07-109590-003-1450ND