Nitrate
Rra Arrowhead Lake Lots
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 | 0.206 ppm | 1 | 1 | 0.206 ppm |
| 2019 | 0.423 ppm | 1 | 1 | 0.423 ppm |
| 2020 | 0.344 ppm | 1 | 1 | 0.344 ppm |
| 2021 | 0.0756 ppm | 4 | 4 | 0.0354 ppm - 0.120 ppm |
| 2022 | 0.138 ppm | 4 | 4 | 0.0166 ppm - 0.244 ppm |
| 2023 | 0.215 ppm | 4 | 4 | 0.128 ppm - 0.307 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 |
|---|---|---|
| 2018-05-07 | Q1818316001 | 0.206 ppm |
| 2019-01-28 | Q1903918003 | 0.423 ppm |
| 2020-06-09 | Q2023221005 | 0.344 ppm |
| 2021-03-09 | Q2106052002 | 0.0354 ppm |
| 2021-06-08 | Q2114861003 | 0.0675 ppm |
| 2021-09-08 | Q2124630003 | 0.0793 ppm |
| 2021-12-06 | Q2133793003 | 0.120 ppm |
| 2022-03-23 | Q2209448001 | 0.0166 ppm |
| 2022-05-25 | Q2215153001 | 0.244 ppm |
| 2022-08-17 | Q2224342003 | 0.122 ppm |
| 2022-11-09 | Q2233923001 | 0.168 ppm |
| 2023-02-13 | Q2305501001 | 0.128 ppm |
| 2023-05-10 | Q2317966001 | 0.279 ppm |
| 2023-08-21 | Q2335128002 | 0.146 ppm |
| 2023-11-01 | Q2346861001 | 0.307 ppm |