Nitrate
City of Cambridge
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 | 0.223 ppm | 12 | 8 | ND - 0.750 ppm |
| 2015 | 0.745 ppm | 12 | 12 | 0.180 ppm - 4.70 ppm |
| 2016 | 0.539 ppm | 12 | 12 | 0.280 ppm - 1.07 ppm |
| 2017 | 0.493 ppm | 12 | 12 | 0.150 ppm - 1.20 ppm |
| 2018 | 0.433 ppm | 11 | 10 | ND - 0.830 ppm |
| 2019 | 0.227 ppm | 10 | 7 | ND - 0.520 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 |
|---|---|---|
| 2014-01-08 | 901067 | ND |
| 2014-02-05 | 902068 | ND |
| 2014-03-05 | 903067 | 0.750 ppm |
| 2014-04-02 | 904043 | 0.409 ppm |
| 2014-05-07 | 905103 | ND |
| 2014-06-04 | 906036 | 0.160 ppm |
| 2014-07-16 | 907214 | 0.250 ppm |
| 2014-08-06 | 908047 | 0.140 ppm |
| 2014-09-17 | 909266 | 0.710 ppm |
| 2014-10-01 | 910008 | ND |
| 2014-11-05 | 911049 | 0.135 ppm |
| 2014-12-03 | 912044 | 0.119 ppm |
| 2015-01-07 | 101062 | 0.570 ppm |
| 2015-02-04 | 102048 | 0.180 ppm |
| 2015-03-04 | 103048 | 0.370 ppm |
| 2015-04-01 | 104010 | 0.430 ppm |
| 2015-05-06 | 105081 | 4.70 ppm |
| 2015-06-17 | 106255 | 0.480 ppm |
| 2015-07-09 | 107139 | 0.430 ppm |
| 2015-08-05 | 108072 | 0.240 ppm |
| 2015-09-02 | 109040 | 0.305 ppm |
| 2015-10-07 | 110099 | 0.450 ppm |
| 2015-11-04 | 111062 | 0.290 ppm |
| 2015-12-02 | 112039 | 0.500 ppm |
| 2016-01-06 | 201071 | 0.760 ppm |
| 2016-02-03 | 202067 | 0.590 ppm |
| 2016-03-02 | 203040 | 1.07 ppm |
| 2016-04-06 | 204073 | 0.280 ppm |
| 2016-05-04 | 205066 | 0.340 ppm |
| 2016-06-01 | 206010 | 0.542 ppm |
| 2016-07-20 | 207247 | 0.570 ppm |
| 2016-08-03 | 208091 | 0.315 ppm |
| 2016-09-07 | 209129 | 0.580 ppm |
| 2016-10-05 | 210072 | 0.438 ppm |
| 2016-11-02 | 211038 | 0.360 ppm |
| 2016-12-07 | 212080 | 0.620 ppm |
| 2017-01-04 | 301062 | 0.500 ppm |
| 2017-02-01 | 302007 | 0.600 ppm |
| 2017-03-01 | 303007 | 0.355 ppm |
| 2017-04-05 | 304053 | 0.530 ppm |
| 2017-05-03 | 305077 | 0.150 ppm |
| 2017-06-07 | 306108 | 0.523 ppm |
| 2017-07-05 | 307056 | 0.255 ppm |
| 2017-08-02 | 308061 | 0.480 ppm |
| 2017-09-06 | 309071 | 0.295 ppm |
| 2017-10-04 | 310069 | 1.20 ppm |
| 2017-11-01 | 311007 | 0.510 ppm |
| 2017-12-06 | 312079 | 0.522 ppm |
| 2018-01-03 | 401058 | 0.175 ppm |
| 2018-02-07 | 402084 | 0.570 ppm |
| 2018-03-07 | 403085 | 0.405 ppm |
| 2018-04-04 | 404062 | 0.380 ppm |
| 2018-05-02 | 405063 | 0.210 ppm |
| 2018-07-03 | 407029 | 0.510 ppm |
| 2018-08-01 | 408022 | 0.598 ppm |
| 2018-09-05 | 409073 | 0.490 ppm |
| 2018-10-03 | 410124 | 0.830 ppm |
| 2018-11-07 | 411151 | 0.590 ppm |
| 2018-12-05 | 412143 | ND |
| 2019-01-02 | 501044 | 0.495 ppm |
| 2019-02-06 | 502118 | 0.520 ppm |
| 2019-03-07 | 19031011 | 0.451 ppm |
| 2019-04-02 | 19040699 | 0.257 ppm |
| 2019-04-30 | 19050116 | ND |
| 2019-06-05 | 19060585 | ND |
| 2019-07-03 | 19070781 | ND |
| 2019-08-07 | 19080746 | 0.150 ppm |
| 2019-09-04 | 19090534 | 0.170 ppm |
| 2019-10-02 | 19100508 | 0.230 ppm |