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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Portsmouth Public Water System

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.

 

52

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND120ND
2015ND120ND
2016ND120ND
2017ND120ND
2018ND30ND
20190.00300 ppm110.00300 ppm

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
2014-01-02A140045500ND
2014-02-19A140078790ND
2014-03-06A140078791ND
2014-04-03A140061199ND
2014-05-01A140187057ND
2014-06-05A140201671ND
2014-07-03A140038418ND
2014-08-07A140218819ND
2014-09-04A140235702ND
2014-10-02A140201997ND
2014-11-06A140248628ND
2014-12-04A140248629ND
2015-01-08A150255059ND
2015-02-05A150257913ND
2015-03-12A150269992ND
2015-04-02A150038417ND
2015-05-07A150257740ND
2015-06-04A150049092ND
2015-07-02A150299378ND
2015-08-06A150257738ND
2015-09-03A150299379ND
2015-10-01A150318357ND
2015-11-05A150038416ND
2015-12-02A150342894ND
2016-01-07A160350279ND
2016-02-04A160353822ND
2016-03-03A160371483ND
2016-04-07A160376857ND
2016-05-05A160335300ND
2016-06-02A160269991ND
2016-07-06A160291787ND
2016-08-03A160418767ND
2016-09-07A160201995ND
2016-10-05A160409260ND
2016-11-02A160438516ND
2016-12-14A160448662ND
2017-01-04A170460639ND
2017-02-08A170462999ND
2017-03-01A170469763ND
2017-04-05A170021029ND
2017-05-03A170480561ND
2017-06-07A170444027ND
2017-07-05A170504142ND
2017-08-02A170503619ND
2017-09-06A170503620ND
2017-10-04A170430691ND
2017-11-01A170534704ND
2017-12-06A170533508ND
2018-01-03A180504190ND
2018-02-07A180503622ND
2018-03-07A180575590ND
2019-02-069B00491-010.00300 ppm