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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Marion Waterworks

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

 

24

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND30ND
2015ND40ND
2016ND30ND
2017ND40ND
2018ND60ND
2019ND40ND

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.

EPA Maximum Contaminant
Level (MCL) 10 ppm

ppm = parts per million

All test results

Date Lab ID Result
2014-07-14Y141980024ND
2014-11-10Y143160007ND
2014-11-10Y143160006ND
2015-09-16Y152600001ND
2015-09-16Y152600003ND
2015-11-19Y153240001ND
2015-11-19Y153240004ND
2016-07-12Y161970002ND
2016-10-03Y162790018ND
2016-10-04Y162790019ND
2017-07-03Y171870046ND
2017-10-10Y172850019ND
2017-10-10Y172850018ND
2017-12-06Y173410001ND
2018-08-15Y182280007ND
2018-08-15Y182280001ND
2018-09-10Y182560022ND
2018-10-15Y182910016ND
2018-10-15Y182910015ND
2018-10-15Y182910002ND
2019-07-30Y192120120ND
2019-10-08Y192840012ND
2019-10-08Y192840030ND
2019-10-08Y192840013ND