Nitrate
Portsmouth Public Water System
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 |
|---|---|---|---|---|
| 2014 | 0.937 ppm | 12 | 12 | 0.590 ppm - 1.60 ppm |
| 2015 | 0.704 ppm | 12 | 11 | ND - 1.04 ppm |
| 2016 | 0.726 ppm | 12 | 12 | 0.500 ppm - 1.10 ppm |
| 2017 | 0.838 ppm | 12 | 12 | 0.570 ppm - 1.04 ppm |
| 2018 | 0.764 ppm | 10 | 10 | 0.600 ppm - 0.990 ppm |
| 2019 | 0.862 ppm | 10 | 10 | 0.658 ppm - 1.05 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EWG Health Guideline 0.14 ppm
The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.
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 |
|---|---|---|
| 2014-01-02 | A140045500 | 1.000 ppm |
| 2014-02-19 | A140078790 | 1.16 ppm |
| 2014-03-06 | A140078791 | 1.60 ppm |
| 2014-04-03 | A140061199 | 0.880 ppm |
| 2014-05-01 | A140187057 | 0.720 ppm |
| 2014-06-05 | A140201671 | 0.640 ppm |
| 2014-07-03 | A140038418 | 1.45 ppm |
| 2014-08-07 | A140218819 | 0.820 ppm |
| 2014-09-04 | A140235702 | 0.900 ppm |
| 2014-10-02 | A140201997 | 0.660 ppm |
| 2014-11-06 | A140248628 | 0.820 ppm |
| 2014-12-04 | A140248629 | 0.590 ppm |
| 2015-01-08 | A150255059 | 0.900 ppm |
| 2015-02-05 | A150257913 | 0.960 ppm |
| 2015-03-12 | A150269992 | 0.840 ppm |
| 2015-04-02 | A150038417 | 0.980 ppm |
| 2015-05-07 | A150257740 | ND |
| 2015-06-04 | A150049092 | 0.550 ppm |
| 2015-07-02 | A150299378 | 0.820 ppm |
| 2015-08-06 | A150257738 | 0.610 ppm |
| 2015-09-03 | A150299379 | 0.460 ppm |
| 2015-10-01 | A150318357 | 0.530 ppm |
| 2015-11-05 | A150038416 | 1.04 ppm |
| 2015-12-02 | A150342894 | 0.760 ppm |
| 2016-01-07 | A160350279 | 0.900 ppm |
| 2016-02-04 | A160353822 | 0.880 ppm |
| 2016-03-03 | A160371483 | 0.950 ppm |
| 2016-04-07 | A160376857 | 0.760 ppm |
| 2016-05-05 | A160335300 | 0.500 ppm |
| 2016-06-02 | A160269991 | 0.560 ppm |
| 2016-07-06 | A160291787 | 0.570 ppm |
| 2016-08-03 | A160418767 | 0.640 ppm |
| 2016-09-07 | A160201995 | 0.530 ppm |
| 2016-10-05 | A160409260 | 0.580 ppm |
| 2016-11-02 | A160438516 | 1.10 ppm |
| 2016-12-14 | A160448662 | 0.740 ppm |
| 2017-01-04 | A170460639 | 1.02 ppm |
| 2017-02-08 | A170462999 | 1.04 ppm |
| 2017-03-01 | A170469763 | 0.910 ppm |
| 2017-04-05 | A170021029 | 0.860 ppm |
| 2017-05-03 | A170480561 | 0.580 ppm |
| 2017-06-07 | A170444027 | 0.800 ppm |
| 2017-07-05 | A170504142 | 1.04 ppm |
| 2017-08-02 | A170503619 | 0.860 ppm |
| 2017-09-06 | A170503620 | 0.570 ppm |
| 2017-10-04 | A170430691 | 0.680 ppm |
| 2017-11-01 | A170534704 | 0.750 ppm |
| 2017-12-06 | A170533508 | 0.940 ppm |
| 2018-01-03 | A180504190 | 0.890 ppm |
| 2018-02-07 | A180503622 | 0.990 ppm |
| 2018-03-07 | A180575590 | 0.810 ppm |
| 2018-04-04 | A180503624 | 0.650 ppm |
| 2018-05-02 | A180589604 | 0.650 ppm |
| 2018-06-06 | A180604785 | 0.600 ppm |
| 2018-07-11 | A180619917 | 0.960 ppm |
| 2018-08-01 | A180622613 | 0.650 ppm |
| 2018-09-05 | A180569757 | 0.650 ppm |
| 2018-12-05 | 8L00463-01 | 0.793 ppm |
| 2019-01-02 | 9A00143-01 | 0.741 ppm |
| 2019-02-06 | 9B00491-01 | 0.997 ppm |
| 2019-03-06 | 9C00517-01 | 0.863 ppm |
| 2019-04-02 | 9D00397-01 | 0.741 ppm |
| 2019-05-01 | 9E00087-01 | 0.658 ppm |
| 2019-06-05 | 9F00425-02 | 0.818 ppm |
| 2019-07-02 | 9G00410-01 | 0.986 ppm |
| 2019-08-06 | 9H00844-02 | 0.853 ppm |
| 2019-09-04 | 9I00271-01 | 0.910 ppm |
| 2019-10-01 | 9J00239-02 | 1.05 ppm |