Know Your Environment. Protect Your Health.

Nitrate and nitrite

City of Lewiston

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.

 

30

Samples

0

Samples exceeding legal limit (MCL)

15

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.171 ppm32ND - 0.413 ppm
20193.02 ppm85ND - 7.42 ppm
20201.77 ppm97ND - 7.09 ppm
20210.380 ppm61ND - 2.28 ppm
20222.10 ppm42ND - 5.71 ppm
2023N/A00N/A

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.14 ppm

The EWG 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
2018-02-21I180221045-0010.413 ppm
2018-02-22I180223004-0010.1000 ppm
2018-10-10N181010052-001ND
2019-01-24I190124017-001ND
2019-04-23I190423067-001ND
2019-04-23I190423067-0022.96 ppm
2019-05-15I190516039-0017.42 ppm
2019-07-17N190717057-0012.24 ppm
2019-08-14N190814075-001ND
2019-08-14N190814075-0024.34 ppm
2019-12-23N191224014-0017.19 ppm
2020-02-19I200219036-0011.38 ppm
2020-02-19I200219035-0011.37 ppm
2020-04-21NMAD0403-010.121 ppm
2020-07-28IMAG0811-050.670 ppm
2020-07-28IMAG0811-07ND
2020-07-28IMAG0811-012.51 ppm
2020-07-28IMAG0811-03ND
2020-09-22NMAI0615-012.75 ppm
2020-11-10IMAK0267-057.09 ppm
2021-06-08MBF0221-01ND
2021-06-29IMBF0852-01ND
2021-06-29IMBF0852-04ND
2021-06-29IMBF0852-07ND
2021-06-29IMBF0852-03ND
2021-06-29IMBF0852-062.28 ppm
2022-03-09NMCC0350-012.70 ppm
2022-03-09NMCC0354-01ND
2022-03-09NMCC0350-025.71 ppm
2022-03-09NMCC0350-03ND