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EWG's Tap Water Database — 2021 UPDATE

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Nitrate

City of Nampa

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.

MORE ABOUT THIS CONTAMINANT

 

98

Samples

0

Samples exceeding legal limit (MCL)

84

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20141.65 ppm15150.200 ppm - 6.80 ppm
20151.07 ppm1512ND - 6.70 ppm
20161.55 ppm1513ND - 6.40 ppm
20170.967 ppm2114ND - 6.20 ppm
20181.55 ppm1716ND - 6.10 ppm
20191.96 ppm1514ND - 6.30 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
2014-10-29N14432840.800 ppm
2014-10-29N14432836.80 ppm
2014-10-29N14432822.10 ppm
2014-10-29N14432810.800 ppm
2014-10-29N14432800.400 ppm
2014-10-29N14432790.200 ppm
2014-10-29N14432780.800 ppm
2014-10-29N14432770.200 ppm
2014-10-29N14432761.000 ppm
2014-10-30N14432751.40 ppm
2014-10-30N14432710.700 ppm
2014-10-30N14432720.500 ppm
2014-10-30N14432735.00 ppm
2014-10-30N14432742.00 ppm
2014-10-30N14432852.00 ppm
2015-11-18N15501611.000 ppm
2015-11-18N1550166ND
2015-11-18N1550165ND
2015-11-18N15501646.70 ppm
2015-11-18N15501630.800 ppm
2015-11-18N15501621.90 ppm
2015-11-18N15501600.900 ppm
2015-11-18N1550158ND
2015-11-18N15501570.200 ppm
2015-11-18N15501561.40 ppm
2015-11-18N15501551.000 ppm
2015-11-18N15501540.300 ppm
2015-11-18N15501671.30 ppm
2015-11-18N15501590.400 ppm
2015-12-02N15517990.200 ppm
2016-11-17I16529730.900 ppm
2016-11-17I1652984ND
2016-11-17I16529812.80 ppm
2016-11-17I16529802.90 ppm
2016-11-17I1652979ND
2016-11-17I16529890.900 ppm
2016-11-17I16529950.700 ppm
2016-11-17I16529912.80 ppm
2016-11-17I16529871.40 ppm
2016-11-17I16529850.300 ppm
2016-11-17I16529750.500 ppm
2016-11-17I16529711.30 ppm
2016-11-17I16529936.40 ppm
2016-11-17I16529822.10 ppm
2016-11-17I16529770.200 ppm
2017-01-31I17038061.50 ppm
2017-04-11I1714411ND
2017-08-09I1735777ND
2017-10-18I1748773ND
2017-10-18I1748772ND
2017-10-18I17487566.20 ppm
2017-10-18I17487491.000 ppm
2017-10-18I17487480.300 ppm
2017-10-18I17487552.60 ppm
2017-10-18I17487540.900 ppm
2017-10-18I17487501.40 ppm
2017-10-18I17487640.800 ppm
2017-10-18I17487660.200 ppm
2017-10-18I17487650.400 ppm
2017-10-18I1748773ND
2017-10-18I1748772ND
2017-10-18I1748771ND
2017-10-18I17487742.00 ppm
2017-10-18I17487631.70 ppm
2017-10-27I17504850.600 ppm
2017-11-08I17523000.700 ppm
2018-04-04I18144041.10 ppm
2018-10-08I18500142.50 ppm
2018-10-08I18500181.80 ppm
2018-10-08I1850020ND
2018-10-08I18500222.00 ppm
2018-10-08I18500212.00 ppm
2018-10-08I18501091.40 ppm
2018-10-08I18500156.10 ppm
2018-10-08I18500162.20 ppm
2018-10-08I18500260.400 ppm
2018-10-08I18500130.900 ppm
2018-10-08I18500192.10 ppm
2018-10-08I18500230.400 ppm
2018-10-08I18500250.900 ppm
2018-10-08I18500271.20 ppm
2018-10-08I18500280.300 ppm
2018-10-08I18500241.000 ppm
2019-09-17I19466660.400 ppm
2019-09-17I19466620.400 ppm
2019-09-17I1946660ND
2019-09-17I19466592.50 ppm
2019-09-17I19466610.400 ppm
2019-09-17I19466651.000 ppm
2019-09-17I19466641.70 ppm
2019-09-17I19466630.400 ppm
2019-09-18I19470165.70 ppm
2019-09-18I19470086.30 ppm
2019-09-18I19470092.70 ppm
2019-09-18I19470070.800 ppm
2019-09-18I19470101.000 ppm
2019-09-18I19470170.400 ppm
2019-09-18I19470155.70 ppm