Know Your Environment. Protect Your Health.

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.

 

217

Samples

0

Samples exceeding legal limit (MCL)

204

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.48 ppm3836ND - 4.01 ppm
20191.39 ppm3727ND - 4.36 ppm
20201.31 ppm3736ND - 4.09 ppm
20211.45 ppm37370.300 ppm - 4.16 ppm
20221.23 ppm36360.300 ppm - 3.91 ppm
20231.22 ppm32320.340 ppm - 3.82 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.14 ppm

The EWG health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.

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
2018-01-09201800870.693 ppm
2018-01-22201803053.72 ppm
2018-01-22201803064.01 ppm
2018-01-23201803210.969 ppm
2018-02-06201804801.08 ppm
2018-02-20201806641.22 ppm
2018-03-13201809440.982 ppm
2018-03-26201811030.879 ppm
2018-04-03201812570.768 ppm
2018-04-17201814680.686 ppm
2018-04-23201816262.76 ppm
2018-04-23201816271.74 ppm
2018-04-23201816291.03 ppm
2018-04-2320181630ND
2018-04-23201816312.14 ppm
2018-04-23201816323.77 ppm
2018-04-23201816333.80 ppm
2018-04-23201816342.53 ppm
2018-05-01201816760.651 ppm
2018-05-038052006-01ND
2018-05-15201819130.640 ppm
2018-06-05201821360.772 ppm
2018-07-10201826000.359 ppm
2018-07-23201827992.90 ppm
2018-07-23201828003.96 ppm
2018-07-24201828170.497 ppm
2018-08-07201829850.436 ppm
2018-08-21201832350.415 ppm
2018-09-04201833610.474 ppm
2018-09-18201835540.698 ppm
2018-10-01201837163.12 ppm
2018-10-01201837173.74 ppm
2018-10-02201837390.536 ppm
2018-10-16201839560.715 ppm
2018-11-07201842040.794 ppm
2018-11-19201843850.898 ppm
2018-12-04201845610.888 ppm
2018-12-18201847670.911 ppm
2019-01-08201900730.792 ppm
2019-01-21201902273.66 ppm
2019-01-21201902283.91 ppm
2019-01-22201902310.852 ppm
2019-02-05201904330.795 ppm
2019-02-21201906870.862 ppm
2019-03-19201910410.769 ppm
2019-04-02201912200.631 ppm
2019-04-16201914510.662 ppm
2019-04-22201915342.89 ppm
2019-04-22201915351.63 ppm
2019-04-2220191536ND
2019-04-22201915371.04 ppm
2019-04-22201915380.201 ppm
2019-04-22201915392.30 ppm
2019-04-22201915403.71 ppm
2019-04-22201915414.12 ppm
2019-04-22201915422.44 ppm
2019-05-079052358-01ND
2019-05-219054390-01ND
2019-06-049061931-01ND
2019-06-189064070-01ND
2019-07-099073410-01ND
2019-07-239075912-01ND
2019-07-29201928933.27 ppm
2019-08-069083171-014.01 ppm
2019-08-19201932590.531 ppm
2019-09-03201934320.463 ppm
2019-09-179093731-01ND
2019-10-019101721-01ND
2019-10-159103854-01ND
2019-11-05201943030.804 ppm
2019-11-19201946264.01 ppm
2019-11-19201946274.36 ppm
2019-11-19201945720.780 ppm
2019-12-03201947370.857 ppm
2019-12-17201949370.982 ppm
2020-01-0721348975.000.750 ppm
2020-01-2021504756.002.91 ppm
2020-01-2021504758.004.03 ppm
2020-01-2121504760.000.700 ppm
2020-02-0421505233.000.810 ppm
2020-02-1821669097.000.790 ppm
2020-03-0321669703.000.690 ppm
2020-04-1322025457.002.85 ppm
2020-04-1322025459.000.630 ppm
2020-04-1322025461.00ND
2020-04-1322025463.001.07 ppm
2020-04-1322025465.000.330 ppm
2020-04-1322025467.002.17 ppm
2020-04-1322025469.002.57 ppm
2020-04-1322025471.004.09 ppm
2020-04-2122025503.000.530 ppm
2020-05-0522026076.000.550 ppm
2020-05-1922217420.000.470 ppm
2020-06-0222217700.002.33 ppm
2020-06-0222217698.000.460 ppm
2020-06-1622418619.000.410 ppm
2020-07-0722419200.000.350 ppm
2020-07-2022609691.002.51 ppm
2020-07-2022609693.003.99 ppm
2020-07-2122609689.000.370 ppm
2020-08-1122801267.000.450 ppm
2020-08-1822801269.000.470 ppm
2020-09-0122801796.000.400 ppm
2020-09-1523001413.000.420 ppm
2020-10-0623184724.000.560 ppm
2020-10-1923184744.002.43 ppm
2020-10-1923184746.003.93 ppm
2020-10-2023184748.000.590 ppm
2020-11-0423185225.000.800 ppm
2020-11-1823364204.000.730 ppm
2020-12-0123364574.000.710 ppm
2020-12-1523539427.000.630 ppm
2021-01-0523714638.000.780 ppm
2021-01-1923714642.000.650 ppm
2021-02-0323715176.003.43 ppm
2021-02-0323715178.003.98 ppm
2021-02-0423715173.000.600 ppm
2021-02-1623890528.000.670 ppm
2021-03-0223890821.000.810 ppm
2021-03-1624062510.000.630 ppm
2021-04-0624062975.000.570 ppm
2021-04-1924249698.000.500 ppm
2021-04-2124249701.002.87 ppm
2021-04-2124249704.001.61 ppm
2021-04-2124249708.002.12 ppm
2021-04-2124249711.003.79 ppm
2021-04-2124249714.004.00 ppm
2021-04-2124249717.002.77 ppm
2021-05-0424440668.001.90 ppm
2021-05-0424250232.000.410 ppm
2021-05-1824440710.000.300 ppm
2021-06-0124441279.000.480 ppm
2021-06-1524640246.000.620 ppm
2021-07-0624640809.000.460 ppm
2021-07-1924831098.002.95 ppm
2021-07-1924831100.004.16 ppm
2021-07-2024831096.000.620 ppm
2021-08-0324831530.000.440 ppm
2021-08-1725024924.000.380 ppm
2021-09-0725025508.000.550 ppm
2021-09-2125222360.000.520 ppm
2021-10-0525222801.000.430 ppm
2021-10-1825406993.003.16 ppm
2021-10-1825406995.003.86 ppm
2021-10-1825406991.000.550 ppm
2021-11-0225407188.000.650 ppm
2021-11-1625589843.000.500 ppm
2021-12-0125589948.000.480 ppm
2021-12-2825766344.000.530 ppm
2022-01-0425766346.000.650 ppm
2022-02-0926119369.000.750 ppm
2022-02-2226119414.003.82 ppm
2022-02-2226119416.003.90 ppm
2022-02-2226119412.000.610 ppm
2022-03-0126289349.000.640 ppm
2022-03-1526289351.000.620 ppm
2022-04-0426289652.002.89 ppm
2022-04-0426289654.001.59 ppm
2022-04-0426289656.001.29 ppm
2022-04-0426289658.001.94 ppm
2022-04-0426289664.003.67 ppm
2022-04-0426289660.003.91 ppm
2022-04-0426289662.002.04 ppm
2022-04-0526289666.000.530 ppm
2022-04-1926466012.000.470 ppm
2022-05-0326466488.000.460 ppm
2022-05-1726650609.000.580 ppm
2022-06-0726651188.000.500 ppm
2022-06-2126844650.000.300 ppm
2022-07-0526845190.000.410 ppm
2022-07-0626845192.002.44 ppm
2022-07-0626845194.003.89 ppm
2022-07-1927039241.000.390 ppm
2022-08-0227039491.000.420 ppm
2022-08-1627235827.000.470 ppm
2022-09-0627236532.000.400 ppm
2022-09-2027442927.000.410 ppm
2022-10-0327443440.000.500 ppm
2022-10-0327443442.000.500 ppm
2022-10-0427443438.000.630 ppm
2022-10-1727643299.000.520 ppm
2022-11-0127643780.000.550 ppm
2022-11-1527824537.000.510 ppm
2022-12-0627825007.000.500 ppm
2022-12-1928000380.000.640 ppm
2023-01-0328174645.000.780 ppm
2023-01-1728174647.000.630 ppm
2023-02-0628175129.002.01 ppm
2023-02-0728175131.000.620 ppm
2023-02-2128351357.003.74 ppm
2023-02-2128351106.000.580 ppm
2023-03-0728351651.000.620 ppm
2023-03-2128523038.000.590 ppm
2023-04-0328704458.002.85 ppm
2023-04-0328704460.001.52 ppm
2023-04-0328704462.001.85 ppm
2023-04-0328704464.003.82 ppm
2023-04-0328704466.002.00 ppm
2023-04-0428704468.000.520 ppm
2023-04-1728704476.000.490 ppm
2023-05-0228704844.000.520 ppm
2023-05-2228901990.000.440 ppm
2023-06-0628902581.000.400 ppm
2023-06-1929110139.001.96 ppm
2023-06-1929110137.000.340 ppm
2023-07-1029303745.003.82 ppm
2023-07-1129303747.000.400 ppm
2023-07-2529303751.000.380 ppm
2023-08-0829304457.000.530 ppm
2023-08-2229499556.000.440 ppm
2023-09-1229701896.000.620 ppm
2023-10-0229702361.003.67 ppm
2023-10-0329702363.000.700 ppm
2023-10-1729888455.000.620 ppm
2023-11-1330073017.000.510 ppm
2023-12-0530073584.000.490 ppm
2023-12-1830247652.000.420 ppm