Nitrate
Connecticut Water Company - Northern Region-Western 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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 2.82 ppm | 30 | 30 | 0.1000 ppm - 6.13 ppm |
| 2015 | 3.41 ppm | 21 | 21 | 0.0900 ppm - 7.13 ppm |
| 2016 | 3.82 ppm | 20 | 19 | ND - 7.65 ppm |
| 2017 | 2.91 ppm | 13 | 13 | 0.1000 ppm - 7.46 ppm |
| 2018 | 2.29 ppm | 12 | 12 | 0.150 ppm - 4.38 ppm |
| 2019 | 2.53 ppm | 11 | 11 | 0.176 ppm - 4.42 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 |
|---|---|---|
| 2014-01-06 | BF95192NOX | 1.84 ppm |
| 2014-01-15 | BF99638NOX | 2.07 ppm |
| 2014-01-16 | BG00211NOX | 0.900 ppm |
| 2014-01-28 | BG04228IOC1 | 4.10 ppm |
| 2014-01-28 | BG04228NOX | 4.10 ppm |
| 2014-01-29 | BG04219NOX | 0.120 ppm |
| 2014-01-29 | BG04659IOC1 | 1.59 ppm |
| 2014-03-17 | GBG19879NOX | 2.97 ppm |
| 2014-04-03 | BG27981NOX | 3.78 ppm |
| 2014-04-03 | BG37981NOX | 3.78 ppm |
| 2014-04-09 | 4561IOC1 | 0.200 ppm |
| 2014-04-09 | 4561NOX | 0.200 ppm |
| 2014-04-22 | BG35279NOX | 0.170 ppm |
| 2014-04-25 | BG37305NOX | 4.61 ppm |
| 2014-05-07 | 6132NOX | 0.1000 ppm |
| 2014-05-21 | BG47680NOX | 2.87 ppm |
| 2014-06-04 | BG53346NOX | 2.08 ppm |
| 2014-06-05 | BG53878IOC1 | 1.95 ppm |
| 2014-06-05 | BG53878NOX | 1.95 ppm |
| 2014-06-06 | BG54002NOX | 5.95 ppm |
| 2014-06-17 | BG60666NOX | 5.34 ppm |
| 2014-06-19 | BG62968NOX | 2.67 ppm |
| 2014-06-30 | BG67304NOX | 4.74 ppm |
| 2014-07-01 | BG68349NOX | 6.13 ppm |
| 2014-07-01 | BG68352NOX | 4.08 ppm |
| 2014-07-02 | BG68647NOX | 4.56 ppm |
| 2014-07-30 | BG85048NOX | 4.40 ppm |
| 2014-10-30 | BH34534NOX | 4.63 ppm |
| 2014-11-21 | 141121-0002IOC1 | 1.37 ppm |
| 2014-11-21 | BH44966NOX | 1.37 ppm |
| 2015-01-09 | BH61610NOX | 2.15 ppm |
| 2015-01-16 | BH64370NOX | 5.53 ppm |
| 2015-01-20 | BH64902NOX | 0.0900 ppm |
| 2015-02-23 | BH76101NOX | 3.38 ppm |
| 2015-03-06 | BH80296NOX | 3.30 ppm |
| 2015-03-19 | BH86047NOX | 1.80 ppm |
| 2015-04-29 | BJ09906NOX | 2.06 ppm |
| 2015-04-29 | BJ09904NOX | 2.83 ppm |
| 2015-04-30 | BJ10452NOX | 1.74 ppm |
| 2015-04-30 | BJ10443NOX | 0.760 ppm |
| 2015-04-30 | BJ10445NOX | 3.66 ppm |
| 2015-05-20 | BJ19795NOX | 7.13 ppm |
| 2015-05-20 | BJ19799NOX | 4.82 ppm |
| 2015-07-07 | BJ42534NOX | 7.03 ppm |
| 2015-07-30 | BJ65815NOX | 3.25 ppm |
| 2015-07-30 | BJ65812NOX | 4.53 ppm |
| 2015-08-27 | BJ82984NOX | 4.16 ppm |
| 2015-10-15 | BK08820NOX | 4.09 ppm |
| 2015-11-30 | BK29149NOX | 3.59 ppm |
| 2015-12-23 | BK43694NOX | 1.11 ppm |
| 2015-12-28 | BK44425NOX | 4.60 ppm |
| 2016-01-15 | BK53768NOX | 0.760 ppm |
| 2016-01-27 | BK58483NOX | 1.86 ppm |
| 2016-01-27 | BK58485NOX | 3.30 ppm |
| 2016-01-27 | BK58484NOX | 3.20 ppm |
| 2016-03-18 | BK81669NOX | 7.65 ppm |
| 2016-04-21 | BN17626NOX | 4.87 ppm |
| 2016-05-12 | BN31364NOX | 1.93 ppm |
| 2016-05-19 | BN35998NOX | 5.85 ppm |
| 2016-05-24 | BN39642NOX | 2.78 ppm |
| 2016-05-25 | BN40000NOX | 3.46 ppm |
| 2016-06-22 | BN61158NOX | 7.60 ppm |
| 2016-06-24 | BN62539NOX | 3.61 ppm |
| 2016-07-01 | BN66356NOX | 5.03 ppm |
| 2016-07-01 | BN66354NOX | 6.53 ppm |
| 2016-07-22 | BN79282NOX | 5.66 ppm |
| 2016-09-15 | BV16051NOX | 4.58 ppm |
| 2016-09-29 | BV31669NOX | 2.12 ppm |
| 2016-10-06 | BV40210NOX | 4.35 ppm |
| 2016-10-11 | BV44061NOX | ND |
| 2016-10-18 | BV56707NOX | 1.23 ppm |
| 2017-01-06 | BX17339NOX | 7.46 ppm |
| 2017-02-08 | BX57436NOX | 0.1000 ppm |
| 2017-03-03 | BX79851NOX | 1.59 ppm |
| 2017-04-06 | BY00572NOX | 3.86 ppm |
| 2017-04-20 | BY07159NOX | 3.80 ppm |
| 2017-04-21 | BY07962NOX | 2.93 ppm |
| 2017-05-30 | BY30818NOX | 3.39 ppm |
| 2017-06-14 | BY39226NOX | 2.12 ppm |
| 2017-06-23 | BY45937NOX | 2.08 ppm |
| 2017-07-07 | BY54440NOX | 3.76 ppm |
| 2017-07-07 | BY54441NOX | 0.660 ppm |
| 2017-09-22 | BZ07174NOX | 2.03 ppm |
| 2017-11-10 | BZ39757NOX | 4.04 ppm |
| 2018-01-12 | BZ72529NOX | 1.66 ppm |
| 2018-01-12 | BZ72527NOX | 4.38 ppm |
| 2018-01-12 | BZ72528NOX | 0.740 ppm |
| 2018-01-23 | BZ78886NOX | 0.150 ppm |
| 2018-01-23 | BZ78887NOX | 0.150 ppm |
| 2018-01-31 | BZ82949NOX | 3.55 ppm |
| 2018-03-02 | BZ97488NOX | 1.54 ppm |
| 2018-04-19 | CA23517NOX | 3.22 ppm |
| 2018-07-12 | CA89150 | 2.19 ppm |
| 2018-07-13 | CA89903 | 2.82 ppm |
| 2018-07-20 | CA94720 | 4.25 ppm |
| 2018-12-10 | NOX 200515418 | 2.84 ppm |
| 2019-01-02 | NOX 200517305 | 0.176 ppm |
| 2019-01-15 | NOX 200518779 | 0.224 ppm |
| 2019-03-15 | NOX 200524883 | 0.439 ppm |
| 2019-03-22 | NOX 200525613 | 2.16 ppm |
| 2019-03-22 | NOX 200525612 | 3.92 ppm |
| 2019-05-30 | NOX 200534244 | 4.42 ppm |
| 2019-05-30 | NOX 200534243 | 3.10 ppm |
| 2019-07-02 | NOX 200538782 | 4.34 ppm |
| 2019-07-02 | NOX 200538771 | 2.72 ppm |
| 2019-07-18 | NOX 200541147 | 2.27 ppm |
| 2019-10-03 | NOX 200551371 | 4.02 ppm |