Nitrate
Tryon Road Special Utility District
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.265 ppm | 5 | 5 | 0.146 ppm - 0.460 ppm |
| 2019 | 0.204 ppm | 5 | 5 | 0.0862 ppm - 0.281 ppm |
| 2020 | 0.144 ppm | 3 | 3 | 0.129 ppm - 0.154 ppm |
| 2021 | 0.188 ppm | 3 | 3 | 0.180 ppm - 0.201 ppm |
| 2022 | 0.184 ppm | 3 | 3 | 0.158 ppm - 0.198 ppm |
| 2023 | 0.199 ppm | 3 | 3 | 0.160 ppm - 0.241 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 |
|---|---|---|
| 2018-11-28 | Q1848464011 | 0.460 ppm |
| 2018-11-28 | Q1848464012 | 0.218 ppm |
| 2018-11-28 | Q1848464013 | 0.250 ppm |
| 2018-11-28 | Q1848464014 | 0.146 ppm |
| 2018-11-28 | Q1848464010 | 0.250 ppm |
| 2019-03-21 | Q1911930001 | 0.281 ppm |
| 2019-03-21 | Q1911930007 | 0.234 ppm |
| 2019-03-21 | Q1911930008 | 0.173 ppm |
| 2019-03-21 | Q1911930011 | 0.247 ppm |
| 2019-03-21 | Q1911930014 | 0.0862 ppm |
| 2020-05-26 | Q2020608023 | 0.129 ppm |
| 2020-05-26 | Q2020608029 | 0.149 ppm |
| 2020-05-26 | Q2020608015 | 0.154 ppm |
| 2021-02-26 | Q2105165007 | 0.183 ppm |
| 2021-02-26 | Q2105165008 | 0.180 ppm |
| 2021-11-18 | Q2132391004 | 0.201 ppm |
| 2022-10-24 | Q2231972001 | 0.158 ppm |
| 2022-10-24 | Q2231972009 | 0.198 ppm |
| 2022-10-24 | Q2231972010 | 0.196 ppm |
| 2023-07-19 | Q2328456005 | 0.197 ppm |
| 2023-08-10 | Q2333267008 | 0.241 ppm |
| 2023-08-10 | Q2333267017 | 0.160 ppm |