EWG's Tap Water Database — 2021 UPDATE



Choctaw Utilities Inc.

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
20140.500 ppm440.300 ppm - 0.620 ppm
20150.318 ppm440.230 ppm - 0.390 ppm
20160.340 ppm220.300 ppm - 0.380 ppm
20170.480 ppm220.430 ppm - 0.530 ppm
20180.331 ppm21ND - 0.661 ppm
20190.797 ppm220.634 ppm - 0.960 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
2014-01-27A1401477120.300 ppm
2014-04-15A1400413180.600 ppm
2014-07-15A1402015790.480 ppm
2014-10-20A1402405670.620 ppm
2015-01-20A1502591430.230 ppm
2015-04-21A1502777960.370 ppm
2015-07-28A1502233120.390 ppm
2015-12-15A1503192540.280 ppm
2016-06-21A1604126010.300 ppm
2016-11-28A1601205710.380 ppm
2017-09-26A1705348840.430 ppm
2017-11-21A1705479940.530 ppm
2018-11-198K02322-010.661 ppm
2019-07-169G02462-030.634 ppm
2019-10-159J02375-010.960 ppm