Nitrate and nitrite
Delaware City PWS
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.
76
Samples
0
Samples exceeding legal limit (MCL)
50
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 | 0.918 ppm | 17 | 10 | ND - 4.60 ppm |
| 2015 | 0.623 ppm | 12 | 11 | ND - 3.35 ppm |
| 2016 | 0.414 ppm | 12 | 9 | ND - 1.34 ppm |
| 2017 | 0.894 ppm | 12 | 11 | ND - 2.20 ppm |
| 2018 | 0.449 ppm | 13 | 8 | ND - 1.59 ppm |
| 2019 | 0.243 ppm | 10 | 4 | ND - 0.700 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EWG Health Guideline 0.14 ppm
The 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
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-15 | A140034461 | 1.40 ppm |
| 2014-02-12 | A140047998 | 1.80 ppm |
| 2014-03-12 | A140104571 | 0.950 ppm |
| 2014-04-09 | A140128809 | 2.30 ppm |
| 2014-04-22 | 14-14820-01 | ND |
| 2014-04-29 | 14-15064-01 | ND |
| 2014-05-06 | 14-15329-01 | ND |
| 2014-05-15 | A140137348 | 1.95 ppm |
| 2014-06-12 | A140141059 | 4.60 ppm |
| 2014-07-09 | A140151495 | 1.20 ppm |
| 2014-08-06 | 14-20325-01 | ND |
| 2014-08-06 | 14-20325-02 | ND |
| 2014-08-13 | A140160285 | 0.680 ppm |
| 2014-09-10 | A140170178 | 0.530 ppm |
| 2014-10-08 | A140240742 | 0.200 ppm |
| 2014-11-12 | A140176224 | ND |
| 2014-12-17 | A140213089 | ND |
| 2015-01-14 | A150240713 | 0.640 ppm |
| 2015-02-12 | A150270008 | 0.530 ppm |
| 2015-03-11 | A150242459 | 0.230 ppm |
| 2015-04-08 | A150240734 | ND |
| 2015-05-13 | A150255103 | 0.500 ppm |
| 2015-06-10 | A150257800 | 3.35 ppm |
| 2015-07-08 | A150257798 | 1.09 ppm |
| 2015-08-12 | A150262721 | 0.200 ppm |
| 2015-09-09 | A150269815 | 0.210 ppm |
| 2015-10-14 | A150278163 | 0.1000 ppm |
| 2015-11-11 | A150282592 | 0.340 ppm |
| 2015-12-09 | A150288914 | 0.290 ppm |
| 2016-01-13 | A160294549 | ND |
| 2016-02-10 | A160318653 | 0.560 ppm |
| 2016-03-09 | A160322551 | 0.340 ppm |
| 2016-04-13 | A160322553 | 0.500 ppm |
| 2016-05-11 | A160322555 | 0.860 ppm |
| 2016-06-08 | A160322558 | 0.820 ppm |
| 2016-07-13 | A160335131 | 1.34 ppm |
| 2016-08-10 | A160348380 | 0.270 ppm |
| 2016-09-14 | A160353595 | 0.130 ppm |
| 2016-10-12 | A160197280 | ND |
| 2016-11-09 | A160363567 | 0.150 ppm |
| 2016-12-14 | A160371581 | ND |
| 2017-01-04 | A170376580 | 1.76 ppm |
| 2017-02-08 | A170383345 | 0.880 ppm |
| 2017-03-08 | A170403596 | 1.08 ppm |
| 2017-04-12 | A170412800 | 1.12 ppm |
| 2017-05-10 | A170420799 | 2.20 ppm |
| 2017-06-14 | A170430120 | 1.46 ppm |
| 2017-07-12 | A170444510 | 1.18 ppm |
| 2017-08-09 | A170453147 | 0.290 ppm |
| 2017-09-13 | A170438301 | ND |
| 2017-10-11 | A170462470 | 0.140 ppm |
| 2017-11-08 | A170455751 | 0.230 ppm |
| 2017-12-13 | A170438272 | 0.390 ppm |
| 2018-01-10 | A180471356 | 0.500 ppm |
| 2018-01-24 | A180481000 | 0.410 ppm |
| 2018-02-14 | A180490356 | 0.400 ppm |
| 2018-03-14 | A180493005 | 0.260 ppm |
| 2018-04-11 | A180511888 | ND |
| 2018-05-02 | A180514822 | 0.700 ppm |
| 2018-06-06 | A180514823 | 1.40 ppm |
| 2018-07-03 | A180516598 | 1.59 ppm |
| 2018-08-01 | A180527721 | ND |
| 2018-09-05 | A180533127 | ND |
| 2018-10-03 | A180545655 | ND |
| 2018-11-07 | 8K00957-01 | ND |
| 2018-12-05 | 8L00613-01 | 0.580 ppm |
| 2019-01-02 | 9A00304-01 | ND |
| 2019-02-06 | 9B00685-01 | ND |
| 2019-03-06 | 9C00780-01 | 0.610 ppm |
| 2019-04-03 | 9D00527-01 | ND |
| 2019-05-01 | 9E00240-01 | 0.600 ppm |
| 2019-06-05 | 9F00827-02 | 0.700 ppm |
| 2019-07-02 | 9G00236-01 | ND |
| 2019-08-07 | 9H01221-02 | ND |
| 2019-09-04 | 9I00659-01 | 0.520 ppm |
| 2019-10-02 | 9J00610-01 | ND |