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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Cal/Am Water Company - San Marino

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

 

72

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND120ND
2015ND120ND
2016ND240ND
2017ND10ND
2018ND10ND
2019ND220ND

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
2014-01-299590-007-1000ND
2014-04-141225-006-1050ND
2014-04-141225-044-0925ND
2014-04-141225-032-1015ND
2014-04-141225-029-0950ND
2014-04-141225-023-0935ND
2014-04-141225-020-1045ND
2014-04-141225-007-1110ND
2014-04-141225-011-0855ND
2014-05-121225-014-1300ND
2014-05-191225-010-0850ND
2014-06-231225-017-1045ND
2015-05-121225-017-1245ND
2015-05-121225-007-1200ND
2015-05-181225-032-1130ND
2015-05-181225-044-1110ND
2015-05-181225-011-1050ND
2015-05-181225-023-1110ND
2015-05-201225-029-1235ND
2015-05-201225-006-1255ND
2015-05-271225-010-0830ND
2015-05-271225-020-0855ND
2015-09-089588-010-0915ND
2015-09-089588-020-0935ND
2016-06-061225-032-1105ND
2016-06-061225-044-1000ND
2016-06-061225-029-1045ND
2016-06-061225-023-1135ND
2016-06-061225-006-1100ND
2016-06-061225-020-1040ND
2016-06-061225-007-1210ND
2016-06-061225-010-1000ND
2016-06-061225-017-1130ND
2016-06-099588-007-0915ND
2016-09-079588-011-1105ND
2016-09-079588-017-1020ND
2016-09-079588-023-1120ND
2016-09-079588-032-1140ND
2016-09-149590-006-0930ND
2016-09-149590-007-0835ND
2016-09-149590-010-0805ND
2016-09-149590-044-0945ND
2016-09-149590-032-1225ND
2016-09-149590-011-1130ND
2016-09-149590-029-0920ND
2016-09-149590-020-1145ND
2016-09-149590-017-0900ND
2016-09-149590-023-1200ND
2017-01-179590-020-1010ND
2018-09-209588-020-1040ND
2019-05-139588-017-1015ND
2019-05-139588-020-0930ND
2019-05-139588-032-0955ND
2019-05-139588-023-0945ND
2019-05-159590-006-1130ND
2019-05-159590-044-0925ND
2019-05-159590-029-0845ND
2019-06-189588-011-1005ND
2019-06-189588-007-1050ND
2019-06-189590-007-1155ND
2019-07-109590-017-1041ND
2019-07-109590-006-1009ND
2019-07-109590-011-0939ND
2019-07-109590-007-1104ND
2019-07-109590-044-1020ND
2019-07-109590-020-0921ND
2019-07-109590-032-0823ND
2019-07-109590-023-0833ND
2019-07-109590-029-1032ND
2019-07-179590-011-1050ND
2019-08-269588-010-0945ND
2019-08-269590-010-1001ND