Know Your Environment. Protect Your Health.

Nitrate

Sammamish Plateau Water and Sewer

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.

 

43

Samples

0

Samples exceeding legal limit (MCL)

24

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.634 ppm86ND - 2.09 ppm
20190.499 ppm83ND - 2.23 ppm
2020N/A00N/A
20210.543 ppm95ND - 2.21 ppm
20220.815 ppm106ND - 2.11 ppm
20230.568 ppm84ND - 2.35 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
2018-08-152.09 ppm
2018-08-150.430 ppm
2018-08-15ND
2018-08-151.41 ppm
2018-08-15ND
2018-08-150.390 ppm
2018-08-150.350 ppm
2018-08-150.400 ppm
2019-08-14ND
2019-08-14ND
2019-08-14ND
2019-08-14ND
2019-08-141.37 ppm
2019-08-142.23 ppm
2019-08-14ND
2019-09-180.390 ppm
2021-04-074102144ND
2021-06-3041370460.590 ppm
2021-08-044147922ND
2021-08-0441479200.230 ppm
2021-08-0441479212.21 ppm
2021-08-044147968ND
2021-08-0441593610.560 ppm
2021-09-294183214ND
2021-09-2941832081.30 ppm
2022-05-1142869112.11 ppm
2022-05-114281374ND
2022-07-064333080ND
2022-07-0643385170.270 ppm
2022-07-2743642011.81 ppm
2022-07-2743320320.580 ppm
2022-08-1043315361.87 ppm
2022-08-104331537ND
2022-08-1043315351.51 ppm
2022-08-104331540ND
2023-07-264497677ND
2023-07-264497679ND
2023-07-2644976810.560 ppm
2023-07-264497676ND
2023-07-2644976752.35 ppm
2023-07-2644976801.41 ppm
2023-07-2644976780.220 ppm
2023-07-264497780ND