Nitrate
Pittsburgh Water & Sewer Authority
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 | 0.638 ppm | 4 | 4 | 0.500 ppm - 0.740 ppm |
| 2019 | 0.655 ppm | 4 | 4 | 0.530 ppm - 0.790 ppm |
| 2020 | 0.552 ppm | 5 | 5 | 0.340 ppm - 0.760 ppm |
| 2021 | 0.458 ppm | 8 | 8 | 0.320 ppm - 0.710 ppm |
| 2022 | 0.550 ppm | 9 | 9 | 0.380 ppm - 0.830 ppm |
| 2023 | 0.550 ppm | 5 | 5 | 0.380 ppm - 0.830 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 |
|---|---|---|
| 2018-03-01 | 18C0104-03 | 0.740 ppm |
| 2018-05-02 | 18E0265-01 | 0.500 ppm |
| 2018-08-10 | 18H1250-01 | 0.710 ppm |
| 2018-11-19 | 18K1736-01 | 0.600 ppm |
| 2019-02-06 | 19B0869-01 | 0.790 ppm |
| 2019-05-21 | 19E2495-01 | 0.570 ppm |
| 2019-08-07 | 19H1554-01 | 0.530 ppm |
| 2019-12-03 | 19L1205-01 | 0.730 ppm |
| 2020-02-05 | 21752603.00 | 0.760 ppm |
| 2020-05-05 | 22310190.00 | 0.490 ppm |
| 2020-08-04 | 22895328.00 | 0.490 ppm |
| 2020-09-30 | 23621148.00 | 0.340 ppm |
| 2020-12-14 | 23621146.00 | 0.680 ppm |
| 2021-02-02 | 23970337.00 | 0.710 ppm |
| 2021-05-25 | 24535207.00 | 0.460 ppm |
| 2021-05-25 | 24535208.00 | 0.460 ppm |
| 2021-09-22 | 25309599.00 | 0.360 ppm |
| 2021-09-27 | 25309693.00 | 0.320 ppm |
| 2021-10-27 | 25495133.00 | 0.400 ppm |
| 2021-11-02 | 25672560.00 | 0.470 ppm |
| 2021-11-02 | 25672561.00 | 0.480 ppm |
| 2022-02-03 | 26198692.00 | 0.830 ppm |
| 2022-02-03 | 26198691.00 | 0.820 ppm |
| 2022-05-18 | 26744064.00 | 0.630 ppm |
| 2022-05-18 | 26744065.00 | 0.640 ppm |
| 2022-08-01 | 27335522.00 | 0.390 ppm |
| 2022-08-22 | 27335645.00 | 0.440 ppm |
| 2022-08-22 | 27335644.00 | 0.440 ppm |
| 2022-11-02 | 27907716.00 | 0.380 ppm |
| 2022-11-02 | 27907717.00 | 0.380 ppm |
| 2023-02-06 | 28431336.00 | 0.830 ppm |
| 2023-05-18 | 29001686.00 | 0.380 ppm |
| 2023-08-22 | 29597696.00 | 0.510 ppm |
| 2023-08-22 | 29597694.00 | 0.510 ppm |
| 2023-11-15 | 30157326.00 | 0.520 ppm |