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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

San Diego County Water Authority

Nitrite, closely related to the fertilizer chemical nitrate, comes from urban runoff and from fertilizer applied to agricultural lands to pollute drinking water. Nitrite is significantly more toxic than nitrate. Excessive nitrite in water can cause oxygen deprivation in infants and increase the risk of cancer.

MORE ABOUT THIS CONTAMINANT

 

78

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND130ND
2015ND120ND
2016ND130ND
2017ND140ND
2018ND150ND
2019ND110ND

ppm = parts per million

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 1 ppm

The legal limit for nitrite, established in 1991, was based on the rate of conversion of ingested nitrate into nitrite in adults. This limit may not fully protect against the risk of cancer due to nitrite exposure.

ppm = parts per million

All test results

Date Lab ID Result
2014-01-069590-003-0933ND
2014-02-059590-003-1250ND
2014-02-059590-003-1054ND
2014-04-079590-003-0923ND
2014-04-099590-003-1341ND
2014-06-039590-003-0706ND
2014-07-249590-003-1217ND
2014-08-049590-003-1302ND
2014-09-089590-003-0706ND
2014-10-069590-003-1226ND
2014-12-089590-003-1029ND
2014-12-169590-003-1151ND
2014-12-299590-001-1036ND
2015-02-039590-003-1148ND
2015-04-069590-003-1235ND
2015-04-089590-003-1416ND
2015-05-079590-003-1000ND
2015-07-099590-003-0741ND
2015-08-059590-003-1305ND
2015-08-259590-003-1402ND
2015-09-039590-003-1023ND
2015-10-059590-003-1323ND
2015-10-209590-003-1150ND
2015-11-039590-003-1223ND
2015-12-109590-003-0839ND
2016-01-149590-003-2107ND
2016-02-099590-003-1252ND
2016-02-109590-003-1325ND
2016-03-019590-003-1520ND
2016-04-059590-003-1120ND
2016-05-039590-003-0828ND
2016-06-169590-003-1414ND
2016-07-089590-003-0731ND
2016-08-029590-003-1116ND
2016-08-039590-003-1114ND
2016-10-039590-003-1311ND
2016-11-089590-003-1344ND
2016-11-299590-003-1333ND
2017-01-249590-003-1226ND
2017-03-149590-003-1418ND
2017-03-279590-003-1141ND
2017-04-039590-003-1305ND
2017-05-039590-003-1123ND
2017-06-149590-003-0928ND
2017-07-059590-003-1208ND
2017-07-069590-003-1205ND
2017-08-039590-003-0807ND
2017-09-079590-003-0952ND
2017-10-039590-003-1120ND
2017-10-169590-003-1255ND
2017-11-019590-003-1327ND
2017-12-079590-003-0739ND
2018-01-039590-003-1018ND
2018-01-039590-003-1209ND
2018-02-059590-003-1109ND
2018-03-219590-003-1013ND
2018-04-029590-003-1207ND
2018-04-109590-003-1207ND
2018-05-089590-003-1212ND
2018-06-049590-003-1208ND
2018-07-189590-003-1036ND
2018-08-069590-003-1234ND
2018-09-049590-003-1056ND
2018-09-179590-003-1314ND
2018-10-019590-003-1303ND
2018-10-039590-003-1014ND
2018-11-019590-003-1111ND
2019-04-239590-003-0929ND
2019-05-159590-003-0729ND
2019-06-139590-003-1020ND
2019-06-199590-003-0918ND
2019-07-109590-003-1104ND
2019-08-089590-003-0655ND
2019-09-049590-003-0738ND
2019-09-179590-003-1255ND
2019-10-039590-003-0410ND
2019-11-069590-003-0603ND
2019-12-119590-003-0631ND