Nitrate and nitrite
City of Flagstaff
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.
32
Samples
0
Samples exceeding legal limit (MCL)
25
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 | 0.365 ppm | 2 | 1 | ND - 0.730 ppm |
| 2015 | 0.593 ppm | 7 | 7 | 0.150 ppm - 1.40 ppm |
| 2016 | 0.460 ppm | 10 | 9 | ND - 1.40 ppm |
| 2017 | 0.373 ppm | 3 | 2 | ND - 0.980 ppm |
| 2018 | 0.508 ppm | 10 | 9 | ND - 1.50 ppm |
| 2019 | N/A | 0 | 0 | N/A |
ppm = parts per million
State and national drinking water standards and health guidelines
EWG Health Guideline 0.14 ppm
The 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
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-05-29 | 201405300314I | 0.730 ppm |
| 2014-09-04 | 2014095050485I | ND |
| 2015-03-10 | 201503050252I | 0.180 ppm |
| 2015-04-14 | 201503050251I | 0.150 ppm |
| 2015-07-09 | 201507100072I | 0.570 ppm |
| 2015-07-28 | 201507210370I | 0.580 ppm |
| 2015-07-30 | 201507310184I | 0.980 ppm |
| 2015-08-27 | 201508280194I | 1.40 ppm |
| 2015-09-10 | 201509120269I | 0.290 ppm |
| 2016-02-17 | 201602180314I | 0.750 ppm |
| 2016-02-17 | 201602180313I | 0.150 ppm |
| 2016-07-11 | 201607120771I | 0.290 ppm |
| 2016-07-11 | 201607120775I | 0.160 ppm |
| 2016-07-11 | 201607120774I | 0.130 ppm |
| 2016-07-11 | 201607120773I | 0.990 ppm |
| 2016-07-11 | 201607120772I | 1.40 ppm |
| 2016-07-25 | 201607260445I | 0.580 ppm |
| 2016-07-25 | 201607260412I | ND |
| 2016-08-17 | 201608180220I | 0.150 ppm |
| 2017-07-05 | 201707061058I | ND |
| 2017-08-28 | 201708290222I | 0.980 ppm |
| 2017-08-28 | 201708290221I | 0.140 ppm |
| 2018-05-15 | 201805160793 I | 0.360 ppm |
| 2018-05-15 | 201805160792 I | 1.50 ppm |
| 2018-05-15 | 201805160791 I | 0.630 ppm |
| 2018-06-11 | 201806120451 I | ND |
| 2018-06-13 | 201806140903I | 0.150 ppm |
| 2018-06-13 | 201806140902I | 0.980 ppm |
| 2018-08-27 | 201808280602I | 0.160 ppm |
| 2018-08-27 | 201808281003I | 1.000 ppm |
| 2018-08-27 | 201808281002I | 0.170 ppm |
| 2018-08-27 | 201808281001I | 0.130 ppm |