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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Southwest City PWS

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.425 ppm21ND - 0.850 ppm
20151.23 ppm21ND - 2.46 ppm
20160.650 ppm21ND - 1.30 ppm
20170.419 ppm220.0270 ppm - 0.810 ppm
20181.000 ppm21ND - 2.00 ppm
20191.22 ppm220.110 ppm - 2.33 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
2014-08-27AC322190.850 ppm
2014-08-27AC32220ND
2015-04-17AC45377ND
2015-04-17AC453782.46 ppm
2016-04-12AC695811.30 ppm
2016-04-12AC69582ND
2017-04-11AC947910.0270 ppm
2017-04-11AC947900.810 ppm
2018-04-23AD18331ND
2018-04-23AD183322.00 ppm
2019-04-15AD463162.33 ppm
2019-04-15AD463170.110 ppm