Know Your Environment. Protect Your Health.

Nitrate

Redmond Water Department

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.

 

45

Samples

0

Samples exceeding legal limit (MCL)

45

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.25 ppm770.180 ppm - 4.43 ppm
20190.534 ppm770.180 ppm - 1.73 ppm
20201.07 ppm770.190 ppm - 4.32 ppm
20210.568 ppm880.180 ppm - 1.61 ppm
20220.675 ppm880.200 ppm - 2.42 ppm
20230.684 ppm880.200 ppm - 2.64 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
2018-06-191845000-I0.490 ppm
2018-06-191845023-I0.210 ppm
2018-06-191845041-I0.500 ppm
2018-06-191844961-I0.300 ppm
2018-07-1718-52530-I0.180 ppm
2018-10-251881935-I4.43 ppm
2018-10-251881936-I2.64 ppm
2019-07-301954940-I0.320 ppm
2019-07-301954941-I0.270 ppm
2019-07-301954942-I0.580 ppm
2019-07-301954943-I0.190 ppm
2019-07-301954944-I0.180 ppm
2019-07-301954945-I0.470 ppm
2019-10-151976815-I1.73 ppm
2020-07-222046682-I0.290 ppm
2020-07-222046681-I1.56 ppm
2020-07-222046680-I4.32 ppm
2020-07-222046684-I0.190 ppm
2020-07-222046683-I0.500 ppm
2020-07-222046685-I0.190 ppm
2020-07-222046686-I0.470 ppm
2021-05-112132295-I0.290 ppm
2021-05-112132299-I0.490 ppm
2021-05-1121322640.540 ppm
2021-05-182133712-I0.180 ppm
2021-05-182133726-I0.460 ppm
2021-05-182133715-I0.190 ppm
2021-06-022137359-I1.61 ppm
2021-06-022137357-I0.780 ppm
2022-08-1022-514720.200 ppm
2022-08-1022-51436-I0.530 ppm
2022-08-1022-514750.530 ppm
2022-08-1022-51468-I0.530 ppm
2022-08-1022-51469-I0.210 ppm
2022-08-1722-532280.680 ppm
2022-08-1722-53230-I0.300 ppm
2022-08-1722-532262.42 ppm
2023-07-1323-408870.480 ppm
2023-07-1323-40885-I0.200 ppm
2023-07-1323-40863-I2.64 ppm
2023-07-1323-408820.310 ppm
2023-07-1323-40883-I0.500 ppm
2023-07-1323-40886-I0.510 ppm
2023-07-1323-40884-I0.200 ppm
2023-07-1723-41527-I0.630 ppm