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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Fairfax County Water Authority

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.

MORE ABOUT THIS CONTAMINANT

 

135

Samples

0

Samples exceeding legal limit (MCL)

135

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20141.07 ppm17170.480 ppm - 2.03 ppm
20150.927 ppm12120.570 ppm - 1.32 ppm
20160.933 ppm15150.480 ppm - 1.64 ppm
20171.16 ppm24240.760 ppm - 1.69 ppm
20181.17 ppm34340.570 ppm - 1.87 ppm
20191.15 ppm33330.620 ppm - 1.68 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
2014-01-30FW13122701-03_NI2.03 ppm
2014-01-30FW13122702-03_NI0.990 ppm
2014-02-27FW14012839-03_NI1.31 ppm
2014-02-27FW14012840-03_NI0.860 ppm
2014-03-27FW14022109-03_NI1.10 ppm
2014-03-27FW14022110-03_NI0.760 ppm
2014-04-24FW14032669-03_NI1.02 ppm
2014-04-24FW14032670-03_NI0.480 ppm
2014-07-24FW14061907-03_NI0.950 ppm
2014-07-24FW14061906-03_NI0.780 ppm
2014-09-25FW14081481-03_NI1.18 ppm
2014-09-25FW14081479-03_NI0.940 ppm
2014-10-30FW140923099-03_N1.59 ppm
2014-10-30FW140923098-03_N0.840 ppm
2014-11-13FW141022038-03_N1.45 ppm
2014-11-13FW141022037-03_N0.850 ppm
2014-12-03FW141113029-02_N1.07 ppm
2015-01-2700125-FAIRFAX CO1.32 ppm
2015-02-1200125-FAIRFAX CO1.32 ppm
2015-03-1200125-FAIRFAX CO0.950 ppm
2015-04-0900125-FAIRFAX CO0.620 ppm
2015-05-0700125-FAIRFAX CO0.900 ppm
2015-06-1100125-FAIRFAX CO0.830 ppm
2015-07-0900125-FAIRFAX CO1.26 ppm
2015-08-0600125-FAIRFAX CO0.650 ppm
2015-09-1000125-FAIRFAX CO0.740 ppm
2015-10-1500125-FAIRFAX CO1.22 ppm
2015-11-1200125-FAIRFAX CO0.570 ppm
2015-12-0300125-FAIRFAX CO0.740 ppm
2016-01-14FW151231001-02_N1.64 ppm
2016-02-04FW160121044-02_N1.13 ppm
2016-03-10FW160224042-02_N1.42 ppm
2016-04-14FW160316067-02_N0.650 ppm
2016-05-12FW160422080-02_N0.790 ppm
2016-06-09FW160525077-02_N1.11 ppm
2016-07-14FW160617069-02_N0.740 ppm
2016-08-11FW160725068-02_N0.850 ppm
2016-09-08FW160825057-02_N0.480 ppm
2016-10-13FW160922038-02_N1.02 ppm
2016-11-03FW161018056-02_N0.680 ppm
2016-12-01FW161121047-01_N0.880 ppm
2016-12-01FW161121047-03_N0.880 ppm
2016-12-01FW161121047-02_N0.860 ppm
2016-12-01FW161121047-04_N0.860 ppm
2017-01-26FW161216029-03_N1.53 ppm
2017-01-26FW161216028-03_N1.11 ppm
2017-02-23FW170126072-03_N1.14 ppm
2017-02-23FW170126071-03_N1.06 ppm
2017-03-09FW170227041-03_N1.16 ppm
2017-03-09FW170227045-03_N0.990 ppm
2017-04-13FW170328070-03_N0.870 ppm
2017-04-13FW170328069-03_N0.760 ppm
2017-05-11FW170426060-03_N0.950 ppm
2017-05-11FW170426062-03_N0.910 ppm
2017-07-13FW170628091-03_N1.56 ppm
2017-07-13FW170628092-03_N1.32 ppm
2017-08-10FW170724080-03_N1.37 ppm
2017-08-10FW170724081-03_N0.920 ppm
2017-09-14FW170821082-03_N1.04 ppm
2017-09-14FW170821081-03_N0.990 ppm
2017-10-12FW170927068-03_N1.69 ppm
2017-10-12FW170927067-03_N0.820 ppm
2017-11-02FW171024046-03_N1.61 ppm
2017-11-02FW171024045-03_N1.09 ppm
2017-12-07FW171120061-02_N1.25 ppm
2017-12-07FW171120061-04_N1.23 ppm
2017-12-07FW171120061-03_N1.22 ppm
2017-12-07FW171120061-01_N1.21 ppm
2018-01-25FW171226071-04_N1.63 ppm
2018-01-25FW171226072-04_N1.87 ppm
2018-02-08FW180117063-04_N1.28 ppm
2018-02-08FW180117064-04_N1.74 ppm
2018-02-21FW180212011-01_N1.49 ppm
2018-02-21FW180212011-02_N1.49 ppm
2018-02-21FW180212011-03_N1.49 ppm
2018-02-21FW180212011-04_N1.49 ppm
2018-03-22FW180220072-04_N1.50 ppm
2018-03-22FW180220073-04_N1.05 ppm
2018-04-12FW180315012-02_N1.16 ppm
2018-04-12FW180315012-03_N1.15 ppm
2018-04-12FW180315012-04_N1.15 ppm
2018-04-12FW180315012-05_N1.13 ppm
2018-04-12FW180315013-04_N0.960 ppm
2018-05-10FW180424075-04_N0.700 ppm
2018-05-10FW180424076-04_N0.570 ppm
2018-06-21FW180522063-04_N0.930 ppm
2018-06-21FW180522064-04_N0.700 ppm
2018-07-12FW180615025-02_N0.870 ppm
2018-07-12FW180615025-03_N0.870 ppm
2018-07-12FW180615025-04_N0.870 ppm
2018-07-12FW180615025-06_N0.870 ppm
2018-07-12FW180615026-04_N0.660 ppm
2018-08-09FW180716073-04_N1.06 ppm
2018-08-09FW180716074-02_N0.610 ppm
2018-09-06FW180824050-04_N1.20 ppm
2018-09-06FW180824051-04_N0.810 ppm
2018-10-18FW181017007-01_N1.40 ppm
2018-10-18FW181017007-02_N1.39 ppm
2018-10-18FW181017007-03_N1.40 ppm
2018-10-18FW181017007-04_N1.40 ppm
2018-11-01FW181023017-04_N1.32 ppm
2018-11-01FW181023018-04_N1.42 ppm
2019-01-03FW181218030-02_N1.48 ppm
2019-01-03FW181218030-03_N1.47 ppm
2019-01-03FW181218030-04_N1.47 ppm
2019-01-03FW181218031-02_N0.700 ppm
2019-02-07FW190124008-04_N1.68 ppm
2019-02-07FW190124009-02_N0.790 ppm
2019-03-21FW190219085-04_N1.34 ppm
2019-03-21FW190219086-02_N0.870 ppm
2019-04-11FW190319015-02_N1.08 ppm
2019-04-11FW190319015-03_N1.07 ppm
2019-04-11FW190319015-04_N1.08 ppm
2019-04-11FW190319015-05_N1.08 ppm
2019-04-11FW190319016-02_N0.740 ppm
2019-05-09FW190422080-05_N1.09 ppm
2019-05-09FW190422081-02_N0.670 ppm
2019-06-06FW190521052-05_N1.09 ppm
2019-06-06FW190521053-02_N0.810 ppm
2019-07-11FW190626014-02_N1.58 ppm
2019-07-11FW190626014-03_N1.58 ppm
2019-07-11FW190626014-04_N1.59 ppm
2019-07-11FW190626014-05_N1.56 ppm
2019-07-11FW190626015-02_N1.05 ppm
2019-08-08FW190725066-05_N1.03 ppm
2019-08-08FW190725067-02_N0.620 ppm
2019-09-05FW190827033-05_N1.06 ppm
2019-09-05FW190827034-02_N1.02 ppm
2019-10-03FW190923067-02_N1.11 ppm
2019-10-03FW190923067-03_N1.11 ppm
2019-10-03FW190923067-04_N1.11 ppm
2019-10-03FW190923067-05_N1.11 ppm
2019-10-03FW190923068-02_N1.30 ppm
2019-11-14FW191029061-05_N1.34 ppm
2019-11-14FW191029062-02_N1.28 ppm