Know Your Environment. Protect Your Health.

Nitrate and nitrite

St. Martin Parish Water Works District 4 Catahoula

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)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND20ND
20190.640 ppm660.200 ppm - 0.900 ppm
20200.673 ppm440.590 ppm - 0.800 ppm
20210.500 ppm110.500 ppm
20220.800 ppm110.800 ppm
20230.700 ppm220.400 ppm - 1.000 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
2019-08-08354886010030.900 ppm
2019-08-08354886020010.820 ppm
2019-08-08354886010030.900 ppm
2019-08-08354886020010.820 ppm
2019-11-05355099670010.200 ppm
2019-11-05355099670010.200 ppm
2020-02-10355297590010.590 ppm
2020-06-22355581620010.610 ppm
2020-06-22355581620020.690 ppm
2020-08-20355724410010.800 ppm
2021-03-15B2101149-0010.500 ppm
2022-02-28B2200928-0010.800 ppm