Know Your Environment. Protect Your Health.

Nitrate and nitrite

Annapolis 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)

5

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.220 ppm220.200 ppm - 0.240 ppm
20190.142 ppm220.0740 ppm - 0.210 ppm
20200.103 ppm220.102 ppm - 0.103 ppm
20210.210 ppm220.193 ppm - 0.226 ppm
20220.0525 ppm220.0470 ppm - 0.0580 ppm
20230.0930 ppm220.0890 ppm - 0.0970 ppm

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
2018-07-10AD293930.200 ppm
2018-07-10AD293940.240 ppm
2019-07-23AD520840.0740 ppm
2019-07-23AD520850.210 ppm
2020-07-2720116690.102 ppm
2020-07-2720116700.103 ppm
2021-07-1921136820.193 ppm
2021-07-1921136830.226 ppm
2022-07-1222147710.0470 ppm
2022-07-1222147720.0580 ppm
2023-07-1923116800.0890 ppm
2023-07-1923116790.0970 ppm