Nitrate and nitrite
Metropolitan District Commission
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.
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 | 0.0186 ppm | 7 | 2 | ND - 0.0700 ppm |
| 2019 | 0.0429 ppm | 7 | 5 | ND - 0.130 ppm |
| 2020 | 0.157 ppm | 11 | 11 | 0.00500 ppm - 0.430 ppm |
| 2021 | 0.0343 ppm | 7 | 6 | ND - 0.0800 ppm |
| 2022 | 0.0343 ppm | 7 | 6 | ND - 0.0710 ppm |
| 2023 | 0.0410 ppm | 9 | 9 | 0.0110 ppm - 0.0800 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
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-07-18 | AE01630GE | ND |
| 2018-07-18 | AE01632GE | 0.0600 ppm |
| 2018-07-18 | AE01640GE | ND |
| 2018-07-18 | AE01641GE | ND |
| 2018-07-18 | AE01637GE | ND |
| 2018-07-18 | AE01636GE | ND |
| 2018-07-18 | AE01631GE | 0.0700 ppm |
| 2019-12-03 | CE70734 | 0.130 ppm |
| 2019-12-03 | CE70735 | ND |
| 2019-12-03 | CE70736 | ND |
| 2019-12-03 | CE70733 | 0.0200 ppm |
| 2019-12-03 | CE70741 | 0.0700 ppm |
| 2019-12-03 | CE70739 | 0.0200 ppm |
| 2019-12-03 | CE70740 | 0.0600 ppm |
| 2020-06-16 | AE60680GE | 0.430 ppm |
| 2020-06-16 | AE60679GE | 0.0600 ppm |
| 2020-06-16 | AE60681GE | 0.340 ppm |
| 2020-06-16 | AE60689GE | 0.140 ppm |
| 2020-06-16 | AE60690GE | 0.120 ppm |
| 2020-06-16 | AE60686GE | 0.410 ppm |
| 2020-06-16 | AE60685GE | 0.120 ppm |
| 2020-12-08 | IOCR 200600617 | 0.00500 ppm |
| 2020-12-08 | IOCR 200600616 | 0.0360 ppm |
| 2020-12-08 | IOCR 200600614 | 0.00800 ppm |
| 2020-12-08 | IOCR 200600615 | 0.0580 ppm |
| 2021-11-23 | N300107450 300107453 | 0.0480 ppm |
| 2021-11-23 | N300107451 300107459 | 0.0800 ppm |
| 2021-11-23 | I300107476 300107478 | ND |
| 2021-11-29 | N300109635 300109639 | 0.0170 ppm |
| 2021-11-29 | I300109610 300109612 | 0.0120 ppm |
| 2021-11-30 | I300109649 300109652 | 0.0270 ppm |
| 2021-11-30 | I300109650 300109658 | 0.0560 ppm |
| 2022-12-08 | I300283837 300283841 | 0.0470 ppm |
| 2022-12-08 | 300283822 300283826B | 0.0250 ppm |
| 2022-12-15 | N300287072 300287075 | 0.0250 ppm |
| 2022-12-15 | I300287081 300287085 | ND |
| 2022-12-15 | I300287109 300287111 | 0.0120 ppm |
| 2022-12-15 | N300287100 300287103 | 0.0710 ppm |
| 2022-12-15 | N300287053 300287056 | 0.0600 ppm |
| 2023-12-06 | N300456222 300456224 | 0.0720 ppm |
| 2023-12-06 | N300456228 300456230 | 0.0770 ppm |
| 2023-12-06 | I300456234 300456236 | 0.0110 ppm |
| 2023-12-06 | N300456234 300456236 | 0.0110 ppm |
| 2023-12-12 | N300459242 300459243 | 0.0710 ppm |
| 2023-12-12 | N300459261 300459262 | 0.0150 ppm |
| 2023-12-12 | N300459237 300459239 | 0.0200 ppm |
| 2023-12-12 | N300459258 300459260 | 0.0800 ppm |
| 2023-12-12 | N300459231 300459233 | 0.0120 ppm |