Nitrate
City of Richland
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 | 0.670 ppm | 8 | 8 | 0.0873 ppm - 1.70 ppm |
| 2019 | 1.16 ppm | 8 | 8 | 0.121 ppm - 3.26 ppm |
| 2020 | 0.494 ppm | 8 | 8 | 0.155 ppm - 0.993 ppm |
| 2021 | 0.504 ppm | 8 | 8 | 0.207 ppm - 0.732 ppm |
| 2022 | 0.455 ppm | 8 | 8 | 0.119 ppm - 0.886 ppm |
| 2023 | 0.395 ppm | 8 | 8 | 0.0537 ppm - 0.855 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 |
|---|---|---|
| 2018-02-01 | Q1804162004 | 0.427 ppm |
| 2018-02-01 | Q1804162001 | 0.0873 ppm |
| 2018-04-18 | Q1815929002 | 0.609 ppm |
| 2018-04-18 | Q1815929001 | 1.70 ppm |
| 2018-07-18 | Q1828596001 | 0.341 ppm |
| 2018-07-18 | Q1828596002 | 0.757 ppm |
| 2018-10-26 | Q1843297001 | 0.482 ppm |
| 2018-10-26 | Q1843297004 | 0.953 ppm |
| 2019-02-07 | Q1905809001 | 0.728 ppm |
| 2019-02-07 | Q1905809003 | 1.41 ppm |
| 2019-04-30 | Q1917509002 | 2.55 ppm |
| 2019-04-30 | Q1917509003 | 3.26 ppm |
| 2019-09-24 | Q1968206002 | 0.167 ppm |
| 2019-09-24 | Q1968206001 | 0.278 ppm |
| 2019-11-20 | Q1977645001 | 0.121 ppm |
| 2019-11-20 | Q1977645002 | 0.773 ppm |
| 2020-02-11 | Q2005441001 | 0.155 ppm |
| 2020-02-11 | Q2005441002 | 0.487 ppm |
| 2020-06-18 | Q2024812001 | 0.993 ppm |
| 2020-06-18 | Q2024812002 | 0.265 ppm |
| 2020-09-24 | Q2037865001 | 0.385 ppm |
| 2020-09-24 | Q2037865002 | 0.735 ppm |
| 2020-10-20 | Q2041062001 | 0.172 ppm |
| 2020-10-20 | Q2041062002 | 0.760 ppm |
| 2021-01-14 | Q2101050001 | 0.566 ppm |
| 2021-01-14 | Q2101050002 | 0.356 ppm |
| 2021-04-05 | Q2108456001 | 0.470 ppm |
| 2021-04-05 | Q2108456002 | 0.732 ppm |
| 2021-07-27 | Q2119608001 | 0.708 ppm |
| 2021-07-27 | Q2119608004 | 0.316 ppm |
| 2021-10-14 | Q2128818001 | 0.207 ppm |
| 2021-10-14 | Q2128818002 | 0.680 ppm |
| 2022-03-15 | Q2208888001 | 0.202 ppm |
| 2022-03-15 | Q2208888002 | 0.119 ppm |
| 2022-05-04 | Q2213445001 | 0.376 ppm |
| 2022-05-04 | Q2213445002 | 0.411 ppm |
| 2022-08-17 | Q2224343001 | 0.194 ppm |
| 2022-08-17 | Q2224343002 | 0.592 ppm |
| 2022-11-09 | Q2233875001 | 0.886 ppm |
| 2022-11-09 | Q2233875002 | 0.856 ppm |
| 2023-02-09 | Q2305192001 | 0.0537 ppm |
| 2023-02-09 | Q2305192002 | 0.141 ppm |
| 2023-05-02 | Q2316479001 | 0.803 ppm |
| 2023-05-02 | Q2316479002 | 0.855 ppm |
| 2023-08-22 | Q2335421001 | 0.176 ppm |
| 2023-08-22 | Q2335421002 | 0.608 ppm |
| 2023-11-02 | Q2347074003 | 0.462 ppm |
| 2023-11-02 | Q2347074004 | 0.0624 ppm |