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EWG's Tap Water Database — 2019 UPDATE

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Nitrate and nitrite

City of Redmond Water System

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.

 

25

Samples

0

Samples exceeding legal limit (MCL)

18

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.978 ppm54ND - 1.60 ppm
20130.950 ppm43ND - 1.40 ppm
20140.857 ppm32ND - 1.70 ppm
20150.918 ppm43ND - 1.60 ppm
20161.000 ppm43ND - 1.90 ppm
20170.796 ppm53ND - 1.70 ppm

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
2012-07-1310230ND
2012-07-13102311.000 ppm
2012-07-13102281.60 ppm
2012-07-13102291.30 ppm
2012-07-16270850.990 ppm
2013-07-11092181.000 ppm
2013-07-1109221ND
2013-07-11092201.40 ppm
2013-07-11092191.40 ppm
2014-07-09102980.870 ppm
2014-07-0910299ND
2014-07-09103001.70 ppm
2015-05-04062430.870 ppm
2015-05-04062441.60 ppm
2015-05-0406245ND
2015-07-22114841.20 ppm
2016-05-181.90 ppm
2016-05-181.10 ppm
2016-05-18ND
2016-05-181.000 ppm
2017-05-030.580 ppm
2017-05-03ND
2017-05-03ND
2017-05-031.70 ppm
2017-05-031.70 ppm