Nitrite

Keystone Water Supply

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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163

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.00500 ppm	24	1	ND - 0.120 ppm
2015	0.0677 ppm	22	4	ND - 0.610 ppm
2016	0.0500 ppm	24	5	ND - 0.340 ppm
2017	0.0679 ppm	24	6	ND - 0.560 ppm
2018	0.136 ppm	33	28	ND - 1.83 ppm
2019	0.0378 ppm	36	30	ND - 0.150 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	Lab ID	Result
2014-01-28	2029134	ND
2014-01-28	2029135	ND
2014-02-28	2035421	ND
2014-02-28	2035422	ND
2014-03-18	2039135	ND
2014-03-18	2039136	ND
2014-04-22	2045857	ND
2014-04-22	2045858	0.120 ppm
2014-05-27	2051576	ND
2014-05-27	2051577	ND
2014-06-24	2057162	ND
2014-06-24	2057163	ND
2014-07-22	2063592	ND
2014-07-22	2063593	ND
2014-08-26	2071603	ND
2014-08-27	2071602	ND
2014-09-23	2078654	ND
2014-09-23	2078655	ND
2014-10-28	2086750	ND
2014-10-28	2086751	ND
2014-11-18	2090661	ND
2014-11-18	2090662	ND
2014-12-17	2099187	ND
2014-12-17	2099188	ND
2015-01-27	2A50502-02	ND
2015-01-27	2A50502-03	ND
2015-02-25	2B50494-03	ND
2015-02-25	2B50494-02	ND
2015-03-25	2C50535-02	ND
2015-03-25	2C50535-03	ND
2015-04-27	1D51851-01	0.260 ppm
2015-04-27	1D51851-02	ND
2015-05-27	1E51805-01	ND
2015-05-27	1E51805-02	ND
2015-06-24	2F50689-03	ND
2015-06-24	2F50689-02	ND
2015-07-29	2G50745-02	ND
2015-07-29	2G50745-03	ND
2015-08-26	2H50632-02	0.610 ppm
2015-09-16	2I50482-03	ND
2015-09-16	2I50482-02	0.390 ppm
2015-10-28	2J50731-03	ND
2015-10-28	2J50731-02	0.230 ppm
2015-11-30	2K50604-02	ND
2015-12-21	2L50537-03	ND
2015-12-21	2L50537-02	ND
2016-01-26	2A60515-03	0.320 ppm
2016-01-26	2A60515-02	ND
2016-02-23	2B60475-03	ND
2016-02-23	2B60475-02	ND
2016-03-23	2C60501-02	ND
2016-03-23	2C60501-03	ND
2016-04-27	2D60744-02	ND
2016-04-27	2D60744-03	0.130 ppm
2016-05-24	2E60681-02	0.300 ppm
2016-05-24	2E60681-03	0.340 ppm
2016-06-27	2F60662-02	ND
2016-06-27	2F60662-03	ND
2016-07-27	2G60726-03	ND
2016-07-27	2G60726-02	ND
2016-08-24	2H60670-03	ND
2016-08-24	2H60670-02	ND
2016-09-27	2I60700-03	0.110 ppm
2016-09-27	2I60700-02	ND
2016-10-26	2J60836-02	ND
2016-10-26	2J60836-03	ND
2016-11-28	2K60654-02	ND
2016-11-28	2K60654-03	ND
2016-12-21	2L60461-03	ND
2016-12-21	2L60461-02	ND
2017-01-25	2A70513-02	ND
2017-01-25	2A70513-03	ND
2017-02-27	2B70514-03	0.470 ppm
2017-02-27	2B70514-02	0.150 ppm
2017-03-29	2C70591-03	ND
2017-03-29	2C70591-02	0.200 ppm
2017-04-26	2D70778-03	ND
2017-04-26	2D70778-02	ND
2017-05-31	2E70766-03	ND
2017-05-31	2E70766-02	ND
2017-06-28	2F70719-02	ND
2017-06-28	2F70719-03	ND
2017-07-27	2G70683-03	ND
2017-07-27	2G70683-02	ND
2017-08-29	2H70737-03	0.110 ppm
2017-08-29	2H70737-02	ND
2017-09-28	2I70661-02	0.560 ppm
2017-09-28	2I70661-03	0.140 ppm
2017-10-30	2J70785-03	ND
2017-10-30	2J70785-02	ND
2017-11-29	2K70693-02	ND
2017-11-29	2K70693-03	ND
2017-12-27	2L70545-02	ND
2017-12-27	2L70545-03	ND
2018-01-29	2A80547-02	ND
2018-01-29	2A80547-03	0.00143 ppm
2018-02-27	2B80503-02	ND
2018-02-27	2B80503-03	ND
2018-03-29	2C80559-02	ND
2018-03-29	2C80559-03	0.200 ppm
2018-04-30	2D80761-02	0.0428 ppm
2018-04-30	2D80761-03	0.0147 ppm
2018-05-30	2E80786-02	ND
2018-05-30	2E80786-03	0.400 ppm
2018-05-30	2E80786-05	0.430 ppm
2018-06-28	2F80749-02	0.0144 ppm
2018-06-28	2F80749-03	0.0112 ppm
2018-06-28	2F80749-04	0.0115 ppm
2018-07-27	2G80698-02	0.257 ppm
2018-07-27	2G80698-03	0.1000 ppm
2018-07-27	2G80698-04	0.1000 ppm
2018-08-27	2H80586-02	0.140 ppm
2018-08-27	2H80586-03	0.0765 ppm
2018-08-27	2H80586-04	0.0803 ppm
2018-09-26	2I80720-02	1.83 ppm
2018-09-26	2I80720-03	0.0889 ppm
2018-09-26	2I80720-04	0.0870 ppm
2018-10-25	1J82373-02	0.210 ppm
2018-10-25	2J80818-02	0.0415 ppm
2018-10-25	2J80818-03	0.0476 ppm
2018-10-25	2J80818-04	0.0447 ppm
2018-11-28	2K80554-02	0.0434 ppm
2018-11-28	2K80554-03	0.0466 ppm
2018-11-28	2K80554-04	0.0441 ppm
2018-12-26	2L80478-02	0.0425 ppm
2018-12-26	2L80478-03	0.0418 ppm
2018-12-26	2L80478-04	0.0368 ppm
2019-01-29	2A90534-02	0.0377 ppm
2019-01-29	2A90534-03	0.0368 ppm
2019-01-29	2A90534-04	0.0396 ppm
2019-02-19	2B90293-02	0.0434 ppm
2019-02-19	2B90293-03	0.0434 ppm
2019-02-19	2B90293-04	0.0469 ppm
2019-03-27	2C90522-02	0.0403 ppm
2019-03-27	2C90522-03	0.0507 ppm
2019-03-27	2C90522-04	0.0476 ppm
2019-04-25	2D90841-02	0.0190 ppm
2019-04-25	2D90841-03	0.0186 ppm
2019-04-25	2D90841-04	0.0193 ppm
2019-05-29	2E90675-02	0.0190 ppm
2019-05-29	2E90675-03	0.0158 ppm
2019-05-29	2E90675-04	0.00529 ppm
2019-06-18	2F90532-02	0.0705 ppm
2019-06-19	2F90532-03	0.0711 ppm
2019-06-19	2F90532-04	0.0685 ppm
2019-07-25	2G90696-02	0.150 ppm
2019-07-25	2G90696-03	0.150 ppm
2019-07-25	2G90696-04	0.150 ppm
2019-08-28	2H90650-02	0.000164 ppm
2019-08-28	2H90650-03	0.00453 ppm
2019-08-28	2H90650-04	0.00252 ppm
2019-09-25	2I90692-02	ND
2019-09-25	2I90692-03	ND
2019-09-25	2I90692-04	ND
2019-10-30	2J90885-02	0.0371 ppm
2019-10-30	2J90885-03	0.0378 ppm
2019-10-30	2J90885-04	0.0385 ppm
2019-11-20	2K90451-02	0.0321 ppm
2019-11-20	2K90451-03	0.0324 ppm
2019-11-20	2K90451-04	0.0338 ppm
2019-12-23	2L90595-02	ND
2019-12-23	2L90595-03	ND
2019-12-23	2L90595-04	ND