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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Western MWD (Arlington)

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

 

77

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND100ND
2015ND140ND
2016ND120ND
2017ND130ND
2018ND100ND
2019ND180ND

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
2014-02-034790-009-0930ND
2014-02-034790-007-1115ND
2014-02-064790-001-1120ND
2014-02-064790-005-1300ND
2014-02-064790-004-1240ND
2014-02-064790-002-1145ND
2014-02-064790-003-1210ND
2014-05-054790-009-1345ND
2014-05-054790-007-1100ND
2014-08-054790-007-1400ND
2015-02-094790-007-0930ND
2015-02-094790-009-1130ND
2015-02-114790-003-1440ND
2015-02-114790-002-1415ND
2015-02-114790-004-1500ND
2015-02-114790-005-1520ND
2015-02-184790-009-1400ND
2015-02-244790-001-1045ND
2015-05-044790-007-1350ND
2015-05-054790-009-0905ND
2015-08-034790-009-1345ND
2015-08-044790-007-1310ND
2015-11-024790-009-1130ND
2015-11-024790-007-1250ND
2016-02-124790-009-1030ND
2016-02-134790-001-0930ND
2016-02-134790-003-0950ND
2016-02-134790-004-1010ND
2016-02-134790-005-1030ND
2016-03-294790-002-0705ND
2016-05-024790-007-1120ND
2016-05-024790-009-1015ND
2016-08-014790-007-0930ND
2016-08-014790-009-1030ND
2016-11-014790-007-0900ND
2016-11-014790-009-1120ND
2017-02-064790-009-1030ND
2017-02-074790-001-1330ND
2017-02-074790-002-1230ND
2017-02-074790-003-1245ND
2017-02-074790-004-1300ND
2017-02-074790-005-1315ND
2017-04-034790-009-1231ND
2017-05-014790-009-1240ND
2017-05-014790-007-1252ND
2017-08-014790-007-1005ND
2017-08-014790-009-1217ND
2017-11-064790-009-1100ND
2017-11-074790-007-0845ND
2018-02-214790-007-1100ND
2018-02-214790-009-0900ND
2018-02-264790-001-1340ND
2018-02-264790-002-1405ND
2018-05-144790-007-1010ND
2018-05-234790-009-1030ND
2018-08-284790-009-0940ND
2018-08-284790-007-0910ND
2018-11-054790-007-1000ND
2018-11-054790-009-1115ND
2019-02-044790-008-1330ND
2019-02-044790-009-1255ND
2019-02-044790-007-1400ND
2019-02-254790-004-1230ND
2019-02-254790-002-1250ND
2019-03-044790-009-1235ND
2019-03-124790-005-1345ND
2019-03-124790-003-0930ND
2019-05-064790-009-1130ND
2019-05-064790-007-1000ND
2019-05-074790-008-1030ND
2019-08-134790-007-1045ND
2019-08-134790-009-1115ND
2019-08-134790-008-1120ND
2019-08-204790-001-1025ND
2019-11-044790-008-1030ND
2019-11-044790-007-1210ND
2019-11-044790-009-1120ND