Nitrate and nitrite

Louisville Water Company

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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2013	N/A	0	0	N/A
2014	0.763 ppm	8	8	0.1000 ppm - 1.60 ppm
2015	N/A	0	0	N/A
2016	N/A	0	0	N/A
2017	N/A	0	0	N/A
2018	0.717 ppm	6	6	0.300 ppm - 1.20 ppm
2019	0.663 ppm	8	8	0.200 ppm - 1.10 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
2014-01-27	2964016	0.200 ppm
2014-02-05	2968067	1.20 ppm
2014-04-22	3012691R1	1.30 ppm
2014-04-22	3013560R1	0.400 ppm
2014-07-14	3062424	1.60 ppm
2014-07-14	3062429	0.200 ppm
2014-10-13	3121540R1	1.10 ppm
2014-10-13	3121552R1	0.1000 ppm
2018-01-16	3853405	1.20 ppm
2018-01-16	3853396	0.300 ppm
2018-07-09	3982197	1.20 ppm
2018-07-09	3982202	0.300 ppm
2018-10-09	4083138R1	0.300 ppm
2018-10-09	4083147R1	1.000 ppm
2019-01-07	4165995	0.900 ppm
2019-01-07	4166287	0.300 ppm
2019-04-08	4252594R1	1.10 ppm
2019-04-08	4252603R1	0.500 ppm
2019-08-15	4388594	0.200 ppm
2019-08-15	4388599	1.000 ppm
2019-10-14	4454967R1	1.10 ppm
2019-10-14	4454957R1	0.200 ppm