EWG's Tap Water Database — 2019 UPDATE



Northwestern W and Sd-wtln 200

NOTE: Northwestern W and Sd-wtln 200 purchases water from Oregon City which is required to test for nitrate. Sample information shown below was taken by Oregon City.

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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20121.18 ppm1210ND - 2.84 ppm
20131.38 ppm1211ND - 4.94 ppm
20141.63 ppm129ND - 4.78 ppm
20151.25 ppm1211ND - 3.30 ppm
20161.51 ppm129ND - 5.02 ppm
20171.64 ppm1210ND - 3.99 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

NOTE: Northwestern W and Sd-wtln 200 purchases water from Oregon City which is required to test for nitrate. Sample information shown below was taken by Oregon City.

Date Lab ID Result
2012-01-11AG128972.59 ppm
2012-02-07AG144982.84 ppm
2012-03-06AG161812.72 ppm
2012-04-12AG188412.61 ppm
2012-05-09AG206400.630 ppm
2012-06-14AG233090.540 ppm
2012-07-03AG245260.210 ppm
2012-08-07AG269120.310 ppm
2012-11-15AG341230.270 ppm
2012-12-04AG351851.48 ppm
2013-01-04AG371960.550 ppm
2013-02-05AG390112.23 ppm
2013-03-22AG420384.94 ppm
2013-04-04AG427920.920 ppm
2013-05-13AG455802.36 ppm
2013-06-14AG479142.02 ppm
2013-07-09AG496930.960 ppm
2013-08-20AG530901.24 ppm
2013-09-04AG540690.290 ppm
2013-11-14AG591380.460 ppm
2013-12-03AG602770.610 ppm
2014-01-09AG623754.22 ppm
2014-02-06AG641074.78 ppm
2014-03-19AG667092.55 ppm
2014-04-03AG675582.74 ppm
2014-05-19AG708382.08 ppm
2014-06-04AG720341.16 ppm
2014-07-09AG749730.720 ppm
2014-11-17AG851300.490 ppm
2014-12-04AG866190.760 ppm
2015-01-05AG883970.300 ppm
2015-02-09AG904762.04 ppm
2015-03-03AG916021.88 ppm
2015-04-08AG939922.13 ppm
2015-05-11AG961712.08 ppm
2015-06-10AG986141.39 ppm
2015-07-09AH007773.30 ppm
2015-08-18AH038820.510 ppm
2015-10-08AH075270.380 ppm
2015-11-17AH102330.630 ppm
2015-12-03AH112610.300 ppm
2016-01-14AH136473.51 ppm
2016-02-09AH150991.07 ppm
2016-03-22AH177915.02 ppm
2016-04-13AH192851.50 ppm
2016-05-20AH220872.25 ppm
2016-06-09AH235561.55 ppm
2016-07-12AH257541.63 ppm
2016-11-08AH355340.360 ppm
2016-12-06AH374461.20 ppm
2017-01-12AH404180.960 ppm
2017-02-09AH427052.22 ppm
2017-03-08AH446952.14 ppm
2017-04-11AH468562.31 ppm
2017-05-23AH503302.91 ppm
2017-06-06AH512703.99 ppm
2017-07-11AH542192.90 ppm
2017-08-10AH571020.800 ppm
2017-11-15AH644301.13 ppm
2017-12-06AH657810.290 ppm