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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Cambridge Water Department (MWRA)

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.

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158

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
20150.0119 ppm3012ND - 0.0830 ppm
20160.00448 ppm4224ND - 0.0160 ppm
20170.0129 ppm4218ND - 0.130 ppm
20180.00233 ppm429ND - 0.0182 ppm
2019N/A00N/A

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 Result
2014-08-04ND
2014-08-18ND
2015-07-010.00500 ppm
2015-07-010.00700 ppm
2015-07-01ND
2015-07-01ND
2015-07-010.00500 ppm
2015-07-01ND
2015-08-10ND
2015-08-100.0550 ppm
2015-08-10ND
2015-08-10ND
2015-08-10ND
2015-08-10ND
2015-08-240.00800 ppm
2015-08-240.0830 ppm
2015-08-24ND
2015-08-24ND
2015-08-240.00700 ppm
2015-08-24ND
2015-09-090.00700 ppm
2015-09-090.0330 ppm
2015-09-09ND
2015-09-09ND
2015-09-09ND
2015-09-09ND
2015-09-210.0630 ppm
2015-09-210.00800 ppm
2015-09-210.0770 ppm
2015-09-21ND
2015-09-21ND
2015-09-21ND
2016-07-06ND
2016-07-060.0130 ppm
2016-07-06ND
2016-07-060.00600 ppm
2016-07-060.00600 ppm
2016-07-060.01000 ppm
2016-07-06ND
2016-07-200.00800 ppm
2016-07-200.00700 ppm
2016-07-20ND
2016-07-200.00700 ppm
2016-07-200.00600 ppm
2016-07-200.0160 ppm
2016-07-20ND
2016-08-010.00600 ppm
2016-08-010.00900 ppm
2016-08-01ND
2016-08-01ND
2016-08-01ND
2016-08-010.00700 ppm
2016-08-01ND
2016-08-170.00900 ppm
2016-08-170.00700 ppm
2016-08-17ND
2016-08-17ND
2016-08-17ND
2016-08-170.00600 ppm
2016-08-17ND
2016-09-140.00800 ppm
2016-09-140.00800 ppm
2016-09-14ND
2016-09-14ND
2016-09-14ND
2016-09-140.00800 ppm
2016-09-14ND
2016-09-210.00700 ppm
2016-09-210.00800 ppm
2016-09-210.00600 ppm
2016-09-210.00600 ppm
2016-09-210.00600 ppm
2016-09-210.00800 ppm
2016-09-21ND
2017-07-10ND
2017-07-100.0150 ppm
2017-07-10ND
2017-07-10ND
2017-07-10ND
2017-07-100.00600 ppm
2017-07-10ND
2017-07-240.00800 ppm
2017-07-240.0950 ppm
2017-07-24ND
2017-07-24ND
2017-07-24ND
2017-07-240.01000 ppm
2017-07-24ND
2017-08-090.01000 ppm
2017-08-090.130 ppm
2017-08-09ND
2017-08-09ND
2017-08-09ND
2017-08-090.0200 ppm
2017-08-09ND
2017-08-230.0140 ppm
2017-08-230.0330 ppm
2017-08-23ND
2017-08-23ND
2017-08-23ND
2017-08-230.01000 ppm
2017-08-23ND
2017-09-060.0180 ppm
2017-09-060.0620 ppm
2017-09-060.00700 ppm
2017-09-06ND
2017-09-06ND
2017-09-060.0130 ppm
2017-09-06ND
2017-09-200.0160 ppm
2017-09-200.0550 ppm
2017-09-20ND
2017-09-20ND
2017-09-20ND
2017-09-200.0210 ppm
2017-09-20ND
2018-07-09ND
2018-07-090.00800 ppm
2018-07-09ND
2018-07-09ND
2018-07-09ND
2018-07-09ND
2018-07-09ND
2018-07-18ND
2018-07-180.0160 ppm
2018-07-18ND
2018-07-18ND
2018-07-18ND
2018-07-18ND
2018-07-18ND
2018-08-08ND
2018-08-080.00700 ppm
2018-08-08ND
2018-08-08ND
2018-08-08ND
2018-08-08ND
2018-08-08ND
2018-08-22ND
2018-08-220.00900 ppm
2018-08-22ND
2018-08-22ND
2018-08-22ND
2018-08-22ND
2018-08-22ND
2018-09-050.00800 ppm
2018-09-050.00600 ppm
2018-09-05ND
2018-09-05ND
2018-09-05ND
2018-09-05ND
2018-09-05ND
2018-09-190.0102 ppm
2018-09-190.0155 ppm
2018-09-190.0182 ppm
2018-09-19ND
2018-09-19ND
2018-09-19ND
2018-09-19ND