Know Your Environment. Protect Your Health.

Nitrate

Williams Bay Waterworks

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.

 

24

Samples

0

Samples exceeding legal limit (MCL)

15

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.118 ppm440.0900 ppm - 0.150 ppm
20190.135 ppm440.0500 ppm - 0.200 ppm
20200.180 ppm330.1000 ppm - 0.240 ppm
20210.192 ppm550.130 ppm - 0.260 ppm
20220.168 ppm440.150 ppm - 0.200 ppm
20230.180 ppm440.140 ppm - 0.260 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

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date Lab ID Result
2018-02-141802-3080.0900 ppm
2018-06-261806-7610.150 ppm
2018-07-171807-5120.120 ppm
2018-12-031812-0100.110 ppm
2019-02-191902-4500.0500 ppm
2019-06-121906-3390.150 ppm
2019-07-2411366710.140 ppm
2019-12-181912-5090.200 ppm
2020-06-1511934950.240 ppm
2020-08-252008-7590.1000 ppm
2020-10-2812252940.200 ppm
2021-03-102103-3420.260 ppm
2021-03-102103-3420.260 ppm
2021-05-1812545740.130 ppm
2021-08-0912702480.180 ppm
2021-10-1112832330.130 ppm
2022-01-1812965130.200 ppm
2022-04-1313077790.160 ppm
2022-08-0813284520.150 ppm
2022-12-0713523860.160 ppm
2023-02-07WB00646-010.260 ppm
2023-06-14WB03531-010.140 ppm
2023-08-23WB05330-030.150 ppm
2023-11-30WB07639-010.170 ppm