Nitrite

Clearwater Water System

Nitrite, closely related to the fertilizer chemical nitrate, comes from urban runoff and from fertilizer applied to agricultural lands to pollute drinking water. Nitrite is significantly more toxic than nitrate. Excessive nitrite in water can cause oxygen deprivation in infants and increase the risk of cancer.

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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	ND	1	0	ND
2015	ND	3	0	ND
2016	ND	3	0	ND
2017	ND	3	0	ND
2018	ND	3	0	ND
2019	0.0926 ppm	36	20	ND - 0.350 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 1 ppm

The legal limit for nitrite, established in 1991, was based on the rate of conversion of ingested nitrate into nitrite in adults. This limit may not fully protect against the risk of cancer due to nitrite exposure.

ppm = parts per million

All test results

Date	Result
2014-02-13	ND
2015-01-13	ND
2015-01-13	ND
2015-05-07	ND
2016-01-25	ND
2016-01-25	ND
2016-01-25	ND
2017-05-11	ND
2017-05-16	ND
2017-05-16	ND
2018-02-26	ND
2018-02-26	ND
2018-02-26	ND
2019-02-05	ND
2019-02-05	ND
2019-02-05	ND
2019-08-07	0.150 ppm
2019-08-07	0.260 ppm
2019-08-07	0.0360 ppm
2019-08-07	0.0330 ppm
2019-08-07	0.0280 ppm
2019-08-07	0.0490 ppm
2019-08-07	0.200 ppm
2019-08-07	0.260 ppm
2019-08-07	ND
2019-08-07	0.340 ppm
2019-08-07	0.350 ppm
2019-08-07	0.210 ppm
2019-08-07	0.1000 ppm
2019-08-07	0.0360 ppm
2019-08-07	0.120 ppm
2019-08-07	0.130 ppm
2019-08-08	ND
2019-08-08	0.0510 ppm
2019-08-08	ND
2019-08-08	ND
2019-08-08	0.210 ppm
2019-08-08	0.180 ppm
2019-08-08	ND
2019-08-08	0.330 ppm
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	ND
2019-08-08	0.260 ppm