Nitrate
Golden State Water Company - Tanglewood
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 | 0.508 ppm | 4 | 4 | 0.474 ppm - 0.542 ppm |
| 2015 | 0.527 ppm | 6 | 6 | 0.474 ppm - 0.587 ppm |
| 2016 | 0.546 ppm | 10 | 10 | 0.470 ppm - 0.700 ppm |
| 2017 | 0.698 ppm | 12 | 12 | 0.470 ppm - 2.80 ppm |
| 2018 | 0.513 ppm | 13 | 13 | 0.500 ppm - 0.530 ppm |
| 2019 | 0.513 ppm | 10 | 10 | 0.470 ppm - 0.540 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 | 2706-009-0915 | 0.542 ppm |
| 2014-04-02 | 2706-009-1015 | 0.474 ppm |
| 2014-04-02 | 2706-009-1000 | 0.497 ppm |
| 2014-10-08 | 2706-009-1105 | 0.520 ppm |
| 2015-01-07 | 2706-009-0800 | 0.520 ppm |
| 2015-01-21 | 2706-009-0800 | 0.474 ppm |
| 2015-04-01 | 2706-009-0800 | 0.497 ppm |
| 2015-07-22 | 2706-009-0805 | 0.520 ppm |
| 2015-10-07 | 2706-009-0936 | 0.565 ppm |
| 2015-11-10 | 2706-009-1030 | 0.587 ppm |
| 2016-02-03 | 2706-009-0850 | 0.490 ppm |
| 2016-03-09 | 2706-009-0850 | 0.700 ppm |
| 2016-05-11 | 2706-009-0755 | 0.620 ppm |
| 2016-06-01 | 2706-009-0745 | 0.520 ppm |
| 2016-07-06 | 2706-009-0745 | 0.680 ppm |
| 2016-08-03 | 2706-009-0755 | 0.500 ppm |
| 2016-09-07 | 2706-009-0800 | 0.490 ppm |
| 2016-10-05 | 2706-009-0825 | 0.470 ppm |
| 2016-11-02 | 2706-009-0810 | 0.470 ppm |
| 2016-12-07 | 2706-009-0753 | 0.520 ppm |
| 2017-01-10 | 9590-009-1105 | 2.80 ppm |
| 2017-01-17 | 9590-009-1130 | 0.490 ppm |
| 2017-02-14 | 9590-009-1100 | 0.490 ppm |
| 2017-03-07 | 9590-009-1115 | 0.510 ppm |
| 2017-04-25 | 9590-009-0810 | 0.510 ppm |
| 2017-05-02 | 9590-009-1010 | 0.470 ppm |
| 2017-07-05 | 9590-009-1140 | 0.520 ppm |
| 2017-08-01 | 9590-009-1135 | 0.500 ppm |
| 2017-09-05 | 9590-009-0910 | 0.520 ppm |
| 2017-10-03 | 9590-009-0945 | 0.510 ppm |
| 2017-11-07 | 9590-009-0925 | 0.530 ppm |
| 2017-12-19 | 9590-009-1245 | 0.520 ppm |
| 2018-01-09 | 9590-009-0900 | 0.510 ppm |
| 2018-01-30 | 9590-009-1200 | 0.520 ppm |
| 2018-02-06 | 9590-009-0800 | 0.520 ppm |
| 2018-03-06 | 9590-009-0845 | 0.510 ppm |
| 2018-04-03 | 9590-009-0835 | 0.510 ppm |
| 2018-05-01 | 2438-009-0927 | 0.510 ppm |
| 2018-06-05 | 2438-009-0825 | 0.510 ppm |
| 2018-07-02 | 2438-009-0953 | 0.520 ppm |
| 2018-08-07 | 9590-009-0743 | 0.500 ppm |
| 2018-09-04 | 9590-009-0930 | 0.510 ppm |
| 2018-10-09 | 9590-009-0905 | 0.530 ppm |
| 2018-11-06 | 9590-009-0830 | 0.500 ppm |
| 2018-12-04 | 9590-009-0855 | 0.520 ppm |
| 2019-01-08 | 9590-009-1245 | 0.520 ppm |
| 2019-02-05 | 9590-009-0819 | 0.500 ppm |
| 2019-03-05 | 9590-009-0836 | 0.540 ppm |
| 2019-04-03 | 9590-009-0851 | 0.540 ppm |
| 2019-05-07 | 9590-009-0945 | 0.500 ppm |
| 2019-06-04 | 9590-009-0905 | 0.490 ppm |
| 2019-07-09 | 9590-009-0950 | 0.520 ppm |
| 2019-08-06 | 9590-009-0849 | 0.470 ppm |
| 2019-09-03 | 9590-009-1145 | 0.520 ppm |
| 2019-10-01 | 9590-009-1025 | 0.530 ppm |