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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Louisa County Water Authority

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
20140.265 ppm220.1000 ppm - 0.430 ppm
20150.270 ppm220.110 ppm - 0.430 ppm
20160.285 ppm220.130 ppm - 0.440 ppm
20170.290 ppm21ND - 0.580 ppm
20180.230 ppm21ND - 0.460 ppm
20190.225 ppm21ND - 0.450 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
2014-03-12E1312015170.430 ppm
2014-03-12E1312015150.1000 ppm
2015-03-04VA010-DCLS0.430 ppm
2015-03-04VA010-DCLS0.110 ppm
2016-01-13E1512037950.440 ppm
2016-01-13E1512037960.130 ppm
2017-01-31E1611048930.580 ppm
2017-06-13E170203185ND
2018-03-07E1712021300.460 ppm
2018-06-19E180302695ND
2019-02-25E1811034400.450 ppm
2019-06-25E190305325ND