Nitrate and nitrite
Calico Rock
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.
68
Samples
0
Samples exceeding legal limit (MCL)
56
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.779 ppm | 10 | 8 | ND - 1.27 ppm |
| 2015 | 0.800 ppm | 12 | 10 | ND - 1.32 ppm |
| 2016 | 0.831 ppm | 12 | 11 | ND - 1.30 ppm |
| 2017 | 0.780 ppm | 10 | 8 | ND - 1.25 ppm |
| 2018 | 0.822 ppm | 13 | 12 | ND - 1.28 ppm |
| 2019 | 0.536 ppm | 11 | 9 | ND - 0.940 ppm |
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 |
|---|---|---|
| 2014-01-27 | 140300038 | 0.940 ppm |
| 2014-01-27 | 140300039 | 1.24 ppm |
| 2014-05-27 | 141490010 | 0.910 ppm |
| 2014-05-27 | 141490009 | 0.880 ppm |
| 2014-08-25 | Y142390011 | 1.27 ppm |
| 2014-08-25 | Y142390010 | 0.970 ppm |
| 2014-08-25 | Y142400016 | ND |
| 2014-08-25 | 142390016 | ND |
| 2014-10-14 | Y142880004 | 0.800 ppm |
| 2014-10-14 | Y142880003 | 0.780 ppm |
| 2015-01-13 | Y150150004 | 0.970 ppm |
| 2015-01-13 | Y150150003 | 0.890 ppm |
| 2015-04-14 | Y151060009 | 0.900 ppm |
| 2015-04-14 | Y151060008 | 0.820 ppm |
| 2015-06-08 | Y151610035 | 0.790 ppm |
| 2015-06-08 | Y151610036 | 1.02 ppm |
| 2015-08-19 | Y152320003 | ND |
| 2015-08-19 | Y152320002 | 1.32 ppm |
| 2015-08-19 | Y152320001 | 0.880 ppm |
| 2015-08-19 | Y152320004 | ND |
| 2015-10-14 | Y152890006 | 1.23 ppm |
| 2015-10-14 | Y152890005 | 0.780 ppm |
| 2016-01-13 | Y160150046 | 1.24 ppm |
| 2016-01-13 | Y160150034 | 0.920 ppm |
| 2016-04-12 | Y161050011 | 0.650 ppm |
| 2016-04-12 | Y161060004 | 1.09 ppm |
| 2016-07-12 | Y161960016 | ND |
| 2016-07-12 | Y161970006 | 0.780 ppm |
| 2016-07-12 | Y161970005 | 0.1000 ppm |
| 2016-07-12 | Y161970004 | 1.07 ppm |
| 2016-08-30 | Y162450007 | 0.780 ppm |
| 2016-09-26 | Y162730003 | 1.28 ppm |
| 2016-10-11 | Y162870010 | 0.760 ppm |
| 2016-10-11 | Y162870014 | 1.30 ppm |
| 2017-01-10 | Y170130010 | 0.850 ppm |
| 2017-01-10 | Y170130011 | 1.25 ppm |
| 2017-04-11 | Y171030020 | 0.790 ppm |
| 2017-04-11 | Y171030023 | 1.06 ppm |
| 2017-07-11 | Y171950123 | ND |
| 2017-07-11 | Y171950130 | ND |
| 2017-08-15 | Y172290006 | 1.18 ppm |
| 2017-08-15 | Y172290007 | 0.790 ppm |
| 2017-10-10 | Y172850031 | 0.790 ppm |
| 2017-10-10 | Y172850023 | 1.09 ppm |
| 2018-01-30 | Y180330005 | 1.28 ppm |
| 2018-01-30 | Y180320037 | 0.790 ppm |
| 2018-04-11 | Y181020013 | 0.750 ppm |
| 2018-04-11 | Y181020014 | 1.12 ppm |
| 2018-09-12 | Y182560025 | 0.760 ppm |
| 2018-09-12 | Y182560028 | 0.120 ppm |
| 2018-09-12 | Y182560027 | ND |
| 2018-09-12 | Y182560026 | 1.18 ppm |
| 2018-09-18 | Y182620011 | 0.810 ppm |
| 2018-09-18 | Y182620012 | 1.14 ppm |
| 2018-10-09 | Y182840035 | 1.24 ppm |
| 2018-10-09 | Y182840034 | 0.810 ppm |
| 2018-12-04 | Y183390013 | 0.690 ppm |
| 2019-01-15 | Y190180011 | 0.800 ppm |
| 2019-01-15 | Y190170023 | 0.790 ppm |
| 2019-03-19 | Y190790047 | 0.700 ppm |
| 2019-04-09 | Y191010015 | 0.490 ppm |
| 2019-04-09 | Y191010041 | 0.940 ppm |
| 2019-08-26 | Y192410023 | ND |
| 2019-08-26 | Y192410001 | 0.430 ppm |
| 2019-08-26 | Y192410002 | 0.670 ppm |
| 2019-08-26 | Y192410026 | ND |
| 2019-10-08 | Y192840024 | 0.600 ppm |
| 2019-10-08 | Y192840004 | 0.480 ppm |