Nitrate and nitrite
Cisco
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 | 1.37 ppm | 4 | 4 | 0.729 ppm - 1.79 ppm |
| 2019 | 1.20 ppm | 8 | 8 | 0.500 ppm - 2.01 ppm |
| 2020 | 1.05 ppm | 17 | 17 | 0.580 ppm - 2.14 ppm |
| 2021 | 0.904 ppm | 25 | 25 | 0.260 ppm - 1.78 ppm |
| 2022 | 1.23 ppm | 29 | 29 | 0.260 ppm - 2.24 ppm |
| 2023 | 1.66 ppm | 27 | 27 | 0.610 ppm - 2.39 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 |
|---|---|---|
| 2018-02-05 | 18B0142-01_01 | 0.729 ppm |
| 2018-05-22 | 18E0962-01 | 1.79 ppm |
| 2018-09-05 | 18I0108-01 | 1.77 ppm |
| 2018-11-14 | 18K0442-01_01 | 1.20 ppm |
| 2019-02-20 | 19B0402-01 | 1.56 ppm |
| 2019-05-20 | 19E0649-01 | 1.48 ppm |
| 2019-09-18 | 19I0761-01 | 2.01 ppm |
| 2019-10-28 | 19J0974-01 | 1.32 ppm |
| 2019-10-28 | 19J0974-02 | 1.20 ppm |
| 2019-11-20 | 19K0604-01 | 0.530 ppm |
| 2019-11-20 | 19K0604-02 | 0.970 ppm |
| 2019-12-18 | 19L0453-01 | 0.500 ppm |
| 2020-01-20 | 20A0413-01 | 0.580 ppm |
| 2020-01-20 | 20A0413-02 | 0.870 ppm |
| 2020-02-24 | 20B0563-01 | 0.610 ppm |
| 2020-02-24 | 20B0563-02 | 0.860 ppm |
| 2020-03-18 | 20C0500-02 | 0.880 ppm |
| 2020-04-14 | 20D0220-01 | 0.810 ppm |
| 2020-04-14 | 20D0220-02 | 1.18 ppm |
| 2020-05-20 | 20E0337-01 | 0.840 ppm |
| 2020-06-17 | 20F0344-01 | 1.04 ppm |
| 2020-06-17 | 20F0344-02 | 1.13 ppm |
| 2020-09-15 | 20I0619-01 | 1.09 ppm |
| 2020-10-27 | 20J0881-02 | 2.14 ppm |
| 2020-10-29 | 20J0937-01 | 1.27 ppm |
| 2020-11-17 | 20K0423-01 | 0.970 ppm |
| 2020-11-17 | 20K0423-02 | 1.56 ppm |
| 2020-12-08 | 20L0258-01 | 0.860 ppm |
| 2020-12-08 | 20L0258-02 | 1.24 ppm |
| 2021-01-19 | 21A0339-01 | 0.770 ppm |
| 2021-01-19 | 21A0339-02 | 1.56 ppm |
| 2021-02-08 | 21B0225-01 | 0.920 ppm |
| 2021-02-08 | 21B0225-02 | 1.17 ppm |
| 2021-03-10 | 21C0410-01 | 0.880 ppm |
| 2021-03-10 | 21C0410-02 | 1.18 ppm |
| 2021-03-10 | 21C0411-01 | 0.880 ppm |
| 2021-04-19 | 21D0512-01 | 0.820 ppm |
| 2021-04-19 | 21D0512-02 | 1.57 ppm |
| 2021-05-19 | 21E0549-01 | 0.370 ppm |
| 2021-05-19 | 21E0549-02 | 0.970 ppm |
| 2021-06-14 | 21F0506-01 | 0.260 ppm |
| 2021-06-14 | 21F0506-02 | 1.10 ppm |
| 2021-07-12 | 21G0389-01 | 1.22 ppm |
| 2021-07-12 | 21G0389-02 | 0.290 ppm |
| 2021-08-16 | 21H0841-01 | 0.310 ppm |
| 2021-08-16 | 21H0841-02 | 1.42 ppm |
| 2021-09-20 | 21I0778-01 | 0.290 ppm |
| 2021-09-20 | 21I0778-02 | 1.20 ppm |
| 2021-10-11 | 21J0318-01 | 1.58 ppm |
| 2021-10-11 | 21J0318-02 | 0.330 ppm |
| 2021-11-08 | 21K0336-01 | 1.78 ppm |
| 2021-11-08 | 21K0336-02 | 0.350 ppm |
| 2021-12-13 | 21L0413-01 | 1.04 ppm |
| 2021-12-13 | 21L0413-02 | 0.340 ppm |
| 2022-01-11 | 22A0260-01 | 1.47 ppm |
| 2022-01-11 | 22A0260-02 | 0.260 ppm |
| 2022-02-21 | 22B0508-01 | 0.970 ppm |
| 2022-02-21 | 22B0508-02 | 0.300 ppm |
| 2022-03-09 | 22C0238-01 | 1.06 ppm |
| 2022-03-09 | 22C0238-02 | 0.280 ppm |
| 2022-03-09 | 22C0238-03 | 0.270 ppm |
| 2022-04-20 | 22D0524-01 | 1.22 ppm |
| 2022-04-20 | 22D0524-02 | 0.390 ppm |
| 2022-05-10 | 22E0263-01 | 1.21 ppm |
| 2022-05-10 | 22E0263-02 | 0.390 ppm |
| 2022-06-22 | 22F1206-01 | 1.05 ppm |
| 2022-06-22 | 22F1206-02 | 0.850 ppm |
| 2022-07-20 | 22G0783-01 | 2.12 ppm |
| 2022-07-20 | 22G0783-02 | 0.960 ppm |
| 2022-07-22 | 22G0875-01 | 1.72 ppm |
| 2022-08-17 | 22H0923-01 | 1.56 ppm |
| 2022-08-17 | 22H0923-02 | 1.24 ppm |
| 2022-08-23 | 22H1105-01 | 1.80 ppm |
| 2022-08-23 | 22H1105-02 | 1.36 ppm |
| 2022-09-21 | 22I0909-01 | 1.92 ppm |
| 2022-09-21 | 22I0909-02 | 1.73 ppm |
| 2022-09-26 | 22I1015-01 | 1.63 ppm |
| 2022-10-19 | 22J0941-01 | 2.00 ppm |
| 2022-10-19 | 22J0941-02 | 1.64 ppm |
| 2022-11-21 | 22K0607-01 | 1.26 ppm |
| 2022-11-21 | 22K0607-02 | 2.24 ppm |
| 2022-12-07 | 22L0191-01 | 1.83 ppm |
| 2022-12-07 | 22L0191-02 | 0.860 ppm |
| 2023-01-17 | 23A0275-01 | 2.09 ppm |
| 2023-01-17 | 23A0275-02 | 0.780 ppm |
| 2023-02-15 | 23B0512-01 | 1.56 ppm |
| 2023-02-15 | 23B0512-02 | 0.670 ppm |
| 2023-02-15 | 23B0512-03 | 0.680 ppm |
| 2023-03-15 | 23C0399-01 | 1.88 ppm |
| 2023-03-15 | 23C0399-02 | 0.610 ppm |
| 2023-04-19 | 23D0461-01 | 2.08 ppm |
| 2023-04-19 | 23D0461-02 | 0.880 ppm |
| 2023-05-22 | 23E0923-01 | 1.80 ppm |
| 2023-05-22 | 23E0923-02 | 1.25 ppm |
| 2023-06-19 | 23F0762-01 | 2.39 ppm |
| 2023-06-19 | 23F0762-02 | 1.58 ppm |
| 2023-06-22 | 23F0891-01 | 1.79 ppm |
| 2023-06-22 | 23F0891-02 | 1.70 ppm |
| 2023-07-20 | 23G0862-01 | 1.78 ppm |
| 2023-07-20 | 23G0862-02 | 1.94 ppm |
| 2023-08-22 | 23H1190-01 | 1.98 ppm |
| 2023-08-22 | 23H1190-02 | 1.79 ppm |
| 2023-09-25 | 23I0989-01 | 2.15 ppm |
| 2023-09-25 | 23I0989-02 | 1.97 ppm |
| 2023-10-24 | 23J0869-01 | 2.05 ppm |
| 2023-10-24 | 23J0869-02 | 1.67 ppm |
| 2023-11-15 | 23K0423-01 | 2.32 ppm |
| 2023-11-15 | 23K0423-02 | 1.79 ppm |
| 2023-12-13 | 23L0296-01 | 2.02 ppm |
| 2023-12-13 | 23L0296-02 | 1.53 ppm |