Nitrate
North Wales Water 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.
225
Samples
0
Samples exceeding legal limit (MCL)
203
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 1.47 ppm | 36 | 34 | ND - 4.07 ppm |
| 2015 | 1.31 ppm | 39 | 36 | ND - 3.96 ppm |
| 2016 | 1.27 ppm | 37 | 35 | ND - 3.91 ppm |
| 2017 | 1.36 ppm | 38 | 36 | ND - 3.99 ppm |
| 2018 | 1.48 ppm | 38 | 36 | ND - 4.01 ppm |
| 2019 | 1.39 ppm | 37 | 27 | ND - 4.36 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 |
|---|---|---|
| 2014-02-06 | 20140386 | 0.772 ppm |
| 2014-02-17 | 20140574 | 3.67 ppm |
| 2014-02-17 | 20140575 | 4.07 ppm |
| 2014-02-18 | 20140591 | 0.804 ppm |
| 2014-03-04 | 20140737 | 0.820 ppm |
| 2014-03-17 | 20140913 | 0.768 ppm |
| 2014-04-14 | 20141265 | 0.639 ppm |
| 2014-05-05 | 20141506 | 2.79 ppm |
| 2014-05-05 | 20141507 | 1.66 ppm |
| 2014-05-05 | 20141508 | ND |
| 2014-05-05 | 20141509 | 1.74 ppm |
| 2014-05-05 | 20141510 | 0.108 ppm |
| 2014-05-05 | 20141511 | 1.63 ppm |
| 2014-05-05 | 20141512 | 3.70 ppm |
| 2014-05-05 | 20141513 | 4.07 ppm |
| 2014-05-05 | 20141514 | 2.16 ppm |
| 2014-05-05 | 20141452 | 0.577 ppm |
| 2014-05-20 | 20141721 | 0.765 ppm |
| 2014-06-10 | 14060921-001 | 1.10 ppm |
| 2014-06-17 | 14061674-001 | ND |
| 2014-07-08 | 20142275 | 0.434 ppm |
| 2014-07-22 | 20142483 | 0.316 ppm |
| 2014-07-28 | 20142548 | 3.45 ppm |
| 2014-07-28 | 20142549 | 3.93 ppm |
| 2014-08-05 | 20142632 | 0.365 ppm |
| 2014-08-19 | 20142845 | 0.302 ppm |
| 2014-09-02 | 20142982 | 0.375 ppm |
| 2014-09-23 | 20143183 | 0.416 ppm |
| 2014-10-07 | 20143357 | 0.509 ppm |
| 2014-10-20 | 20143544 | 3.68 ppm |
| 2014-10-20 | 20143545 | 3.99 ppm |
| 2014-10-21 | 20143566 | 0.521 ppm |
| 2014-11-04 | 20143702 | 0.738 ppm |
| 2014-11-17 | 20143904 | 0.633 ppm |
| 2014-12-02 | 20144057 | 0.786 ppm |
| 2014-12-16 | 20144276 | 0.723 ppm |
| 2015-01-06 | 12288421 | 0.724 ppm |
| 2015-01-19 | 12288424 | 0.731 ppm |
| 2015-02-03 | 12403021 | 0.815 ppm |
| 2015-02-09 | 12403016 | 3.69 ppm |
| 2015-02-09 | 12403018 | 3.90 ppm |
| 2015-02-17 | 12403024 | 0.715 ppm |
| 2015-03-10 | 12516655 | 0.855 ppm |
| 2015-03-23 | 12516658 | 0.888 ppm |
| 2015-04-07 | 12634377 | 0.699 ppm |
| 2015-04-22 | 12634380 | 0.674 ppm |
| 2015-05-04 | 12634686 | 2.84 ppm |
| 2015-05-04 | 12634689 | 1.52 ppm |
| 2015-05-04 | 12634692 | ND |
| 2015-05-04 | 12634695 | 2.06 ppm |
| 2015-05-04 | 12634698 | 0.176 ppm |
| 2015-05-04 | 12634701 | 1.71 ppm |
| 2015-05-04 | 12634704 | 3.67 ppm |
| 2015-05-04 | 12634707 | 3.96 ppm |
| 2015-05-04 | 12634710 | 2.51 ppm |
| 2015-05-04 | 12634713 | 0.493 ppm |
| 2015-05-20 | 12750894 | 0.589 ppm |
| 2015-06-02 | 12751210 | 0.553 ppm |
| 2015-06-15 | 12883685 | 0.515 ppm |
| 2015-07-07 | 13014091 | 0.336 ppm |
| 2015-07-20 | 13014400 | 1.54 ppm |
| 2015-07-20 | 13014403 | 3.84 ppm |
| 2015-07-20 | 13014397 | 0.328 ppm |
| 2015-08-04 | 13136886 | 0.313 ppm |
| 2015-08-17 | 13136929 | 0.382 ppm |
| 2015-09-01 | 13137221 | 0.411 ppm |
| 2015-09-14 | 13265877 | 0.482 ppm |
| 2015-10-06 | 13390436 | 0.613 ppm |
| 2015-10-07 | 13390439 | 3.26 ppm |
| 2015-10-07 | 13390442 | 3.82 ppm |
| 2015-10-20 | 13390446 | ND |
| 2015-11-03 | 13390483 | ND |
| 2015-11-16 | 13515328 | 0.551 ppm |
| 2015-12-01 | 13515333 | 0.436 ppm |
| 2015-12-14 | 13634639 | 0.424 ppm |
| 2016-01-05 | 13634731 | 0.652 ppm |
| 2016-01-18 | 13754087 | 0.527 ppm |
| 2016-02-01 | 13754091 | 2.82 ppm |
| 2016-02-01 | 13754093 | 3.15 ppm |
| 2016-02-02 | 13754409 | 0.640 ppm |
| 2016-02-16 | 13871456 | 0.760 ppm |
| 2016-03-07 | 13871773 | 0.518 ppm |
| 2016-03-21 | 13987513 | 0.556 ppm |
| 2016-04-05 | 13987802 | 0.474 ppm |
| 2016-04-19 | 14104377 | 0.372 ppm |
| 2016-05-02 | 14104468 | 2.60 ppm |
| 2016-05-02 | 14104470 | 1.96 ppm |
| 2016-05-02 | 14104472 | ND |
| 2016-05-02 | 14104474 | ND |
| 2016-05-02 | 14104476 | 1.56 ppm |
| 2016-05-02 | 14104478 | 2.79 ppm |
| 2016-05-02 | 14104480 | 2.78 ppm |
| 2016-05-02 | 14104482 | 2.50 ppm |
| 2016-05-16 | 14252327 | 1.16 ppm |
| 2016-05-17 | 14252329 | 0.374 ppm |
| 2016-06-07 | 14407007 | 0.442 ppm |
| 2016-07-05 | 14571702 | 0.289 ppm |
| 2016-07-19 | 14571704 | 0.259 ppm |
| 2016-08-01 | 14572076 | 3.50 ppm |
| 2016-08-01 | 14572078 | 3.91 ppm |
| 2016-08-02 | 14572080 | 0.438 ppm |
| 2016-08-16 | 14737304 | 0.483 ppm |
| 2016-09-06 | 14909756 | 0.423 ppm |
| 2016-09-20 | 14909754 | 0.345 ppm |
| 2016-10-03 | 14910179 | 3.58 ppm |
| 2016-10-03 | 14910181 | 3.85 ppm |
| 2016-10-04 | 14910183 | 0.555 ppm |
| 2016-10-18 | 15077233 | 0.465 ppm |
| 2016-11-01 | 15077605 | 0.461 ppm |
| 2016-11-15 | 15227765 | 0.515 ppm |
| 2016-12-06 | 15373637 | 0.574 ppm |
| 2016-12-20 | 15374067 | 0.611 ppm |
| 2017-01-10 | 15518965 | 0.629 ppm |
| 2017-01-24 | 15518967 | 0.879 ppm |
| 2017-01-30 | 15519054 | 3.56 ppm |
| 2017-01-30 | 15519056 | 3.76 ppm |
| 2017-02-07 | 15657237 | 0.691 ppm |
| 2017-02-21 | 15657239 | 0.659 ppm |
| 2017-03-28 | 15797413 | 0.669 ppm |
| 2017-04-04 | 15797851 | 0.777 ppm |
| 2017-04-18 | 15939264 | 0.541 ppm |
| 2017-04-24 | 15939246 | 2.72 ppm |
| 2017-04-24 | 15939248 | 1.62 ppm |
| 2017-04-24 | 15939250 | ND |
| 2017-04-24 | 15939252 | 1.15 ppm |
| 2017-04-24 | 15939254 | ND |
| 2017-04-24 | 15939256 | 1.73 ppm |
| 2017-04-24 | 15939258 | 3.99 ppm |
| 2017-04-24 | 15939260 | 3.81 ppm |
| 2017-04-24 | 15939262 | 1.66 ppm |
| 2017-05-02 | 15939464 | 0.529 ppm |
| 2017-05-16 | 16096514 | 0.574 ppm |
| 2017-06-06 | 16096973 | 0.536 ppm |
| 2017-06-27 | 16258961 | 0.500 ppm |
| 2017-07-06 | 16415500 | 0.435 ppm |
| 2017-07-25 | 16415629 | 0.318 ppm |
| 2017-07-31 | 16415648 | 3.56 ppm |
| 2017-07-31 | 16415650 | 3.81 ppm |
| 2017-08-01 | 16415652 | 0.490 ppm |
| 2017-08-15 | 16568065 | 0.503 ppm |
| 2017-09-05 | 16728637 | 0.416 ppm |
| 2017-09-19 | 16728644 | 0.480 ppm |
| 2017-10-03 | 16729093 | 0.529 ppm |
| 2017-10-16 | 16881904 | 3.47 ppm |
| 2017-10-16 | 16881906 | 3.76 ppm |
| 2017-10-17 | 16881908 | 0.491 ppm |
| 2017-11-07 | 16882352 | 0.716 ppm |
| 2017-11-14 | 17025019 | 0.712 ppm |
| 2017-12-05 | 17025454 | 0.608 ppm |
| 2017-12-19 | 17163806 | 0.545 ppm |
| 2018-01-09 | 20180087 | 0.693 ppm |
| 2018-01-22 | 20180305 | 3.72 ppm |
| 2018-01-22 | 20180306 | 4.01 ppm |
| 2018-01-23 | 20180321 | 0.969 ppm |
| 2018-02-06 | 20180480 | 1.08 ppm |
| 2018-02-20 | 20180664 | 1.22 ppm |
| 2018-03-13 | 20180944 | 0.982 ppm |
| 2018-03-26 | 20181103 | 0.879 ppm |
| 2018-04-03 | 20181257 | 0.768 ppm |
| 2018-04-17 | 20181468 | 0.686 ppm |
| 2018-04-23 | 20181626 | 2.76 ppm |
| 2018-04-23 | 20181627 | 1.74 ppm |
| 2018-04-23 | 20181629 | 1.03 ppm |
| 2018-04-23 | 20181630 | ND |
| 2018-04-23 | 20181631 | 2.14 ppm |
| 2018-04-23 | 20181632 | 3.77 ppm |
| 2018-04-23 | 20181633 | 3.80 ppm |
| 2018-04-23 | 20181634 | 2.53 ppm |
| 2018-05-01 | 20181676 | 0.651 ppm |
| 2018-05-03 | 8052006-01 | ND |
| 2018-05-15 | 20181913 | 0.640 ppm |
| 2018-06-05 | 20182136 | 0.772 ppm |
| 2018-07-10 | 20182600 | 0.359 ppm |
| 2018-07-23 | 20182799 | 2.90 ppm |
| 2018-07-23 | 20182800 | 3.96 ppm |
| 2018-07-24 | 20182817 | 0.497 ppm |
| 2018-08-07 | 20182985 | 0.436 ppm |
| 2018-08-21 | 20183235 | 0.415 ppm |
| 2018-09-04 | 20183361 | 0.474 ppm |
| 2018-09-18 | 20183554 | 0.698 ppm |
| 2018-10-01 | 20183716 | 3.12 ppm |
| 2018-10-01 | 20183717 | 3.74 ppm |
| 2018-10-02 | 20183739 | 0.536 ppm |
| 2018-10-16 | 20183956 | 0.715 ppm |
| 2018-11-07 | 20184204 | 0.794 ppm |
| 2018-11-19 | 20184385 | 0.898 ppm |
| 2018-12-04 | 20184561 | 0.888 ppm |
| 2018-12-18 | 20184767 | 0.911 ppm |
| 2019-01-08 | 20190073 | 0.792 ppm |
| 2019-01-21 | 20190227 | 3.66 ppm |
| 2019-01-21 | 20190228 | 3.91 ppm |
| 2019-01-22 | 20190231 | 0.852 ppm |
| 2019-02-05 | 20190433 | 0.795 ppm |
| 2019-02-21 | 20190687 | 0.862 ppm |
| 2019-03-19 | 20191041 | 0.769 ppm |
| 2019-04-02 | 20191220 | 0.631 ppm |
| 2019-04-16 | 20191451 | 0.662 ppm |
| 2019-04-22 | 20191534 | 2.89 ppm |
| 2019-04-22 | 20191535 | 1.63 ppm |
| 2019-04-22 | 20191536 | ND |
| 2019-04-22 | 20191537 | 1.04 ppm |
| 2019-04-22 | 20191538 | 0.201 ppm |
| 2019-04-22 | 20191539 | 2.30 ppm |
| 2019-04-22 | 20191540 | 3.71 ppm |
| 2019-04-22 | 20191541 | 4.12 ppm |
| 2019-04-22 | 20191542 | 2.44 ppm |
| 2019-05-07 | 9052358-01 | ND |
| 2019-05-21 | 9054390-01 | ND |
| 2019-06-04 | 9061931-01 | ND |
| 2019-06-18 | 9064070-01 | ND |
| 2019-07-09 | 9073410-01 | ND |
| 2019-07-23 | 9075912-01 | ND |
| 2019-07-29 | 20192893 | 3.27 ppm |
| 2019-08-06 | 9083171-01 | 4.01 ppm |
| 2019-08-19 | 20193259 | 0.531 ppm |
| 2019-09-03 | 20193432 | 0.463 ppm |
| 2019-09-17 | 9093731-01 | ND |
| 2019-10-01 | 9101721-01 | ND |
| 2019-10-15 | 9103854-01 | ND |
| 2019-11-05 | 20194303 | 0.804 ppm |
| 2019-11-19 | 20194626 | 4.01 ppm |
| 2019-11-19 | 20194627 | 4.36 ppm |
| 2019-11-19 | 20194572 | 0.780 ppm |
| 2019-12-03 | 20194737 | 0.857 ppm |
| 2019-12-17 | 20194937 | 0.982 ppm |