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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

CTWC - Shoreline Region-Guilford System

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

 

92

Samples

0

Samples exceeding legal limit (MCL)

54

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20141.11 ppm2318ND - 3.30 ppm
2015N/A00N/A
20160.866 ppm1814ND - 2.83 ppm
20170.875 ppm11110.0600 ppm - 2.31 ppm
20180.764 ppm16160.0250 ppm - 2.71 ppm
20190.465 ppm24240.0150 ppm - 3.37 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
2014-01-06142NOX0.200 ppm
2014-01-29140130CWCDNOX0.240 ppm
2014-01-2991887NOX2.62 ppm
2014-01-29140130CWCEIOC10.190 ppm
2014-01-2991886NOX2.52 ppm
2014-02-0691982NOX2.24 ppm
2014-02-2492178NOX2.04 ppm
2014-03-052669IOC13.30 ppm
2014-03-052673IOC12.80 ppm
2014-03-052674IOC12.40 ppm
2014-03-052676IOC12.00 ppm
2014-04-014079NOX0.1000 ppm
2014-06-1293879NOX1.000 ppm
2014-06-1293881NOXND
2014-06-1293880NOX0.800 ppm
2014-06-128367IOC11.000 ppm
2014-06-128366IOC10.800 ppm
2014-07-2210660NOXND
2014-08-13140915-0115IOC1ND
2014-08-13141007-0044IOC10.680 ppm
2014-08-13BG93593NOXND
2014-08-13BG93595NOX0.680 ppm
2014-11-20BH44138NOXND
2016-01-11BK50864NOX1.70 ppm
2016-01-11BK50861NOX1.86 ppm
2016-01-12BK51721NOX0.110 ppm
2016-01-19BK54776NOX0.900 ppm
2016-01-19BK54777NOX2.64 ppm
2016-01-27BK58354NOX0.140 ppm
2016-01-27BK58355IOCR0.160 ppm
2016-02-11BK64352NOX0.160 ppm
2016-03-14BK78121NOXND
2016-04-06BN07656NOX0.0700 ppm
2016-06-01BN44876NOX1.10 ppm
2016-07-06BN67632NOXND
2016-07-12BN71483NOX1.32 ppm
2016-07-12BN71475NOX0.910 ppm
2016-07-13BN72281NOXND
2016-07-13BN72289NOX2.83 ppm
2016-07-13BN72288NOX1.68 ppm
2016-10-12BV46547NOXND
2017-01-17BX30298NOX0.0600 ppm
2017-01-17BX30299NOX1.61 ppm
2017-01-18BX31347NOX0.120 ppm
2017-01-30BX40966NOX1.31 ppm
2017-03-08BX82063NOX2.31 ppm
2017-03-08BX82062NOX2.28 ppm
2017-04-03BX97712NOX0.1000 ppm
2017-06-07BY34926IOCR0.0800 ppm
2017-07-17BY61083NOX0.120 ppm
2017-10-24BZ27135NOX1.47 ppm
2017-12-04BZ49884NOX0.170 ppm
2018-01-16BZ73475NOX0.280 ppm
2018-03-30CA11466NOX0.170 ppm
2018-03-30CA11463IOCR0.150 ppm
2018-06-04CA63507NOX0.200 ppm
2018-06-13CA69715NOX2.17 ppm
2018-06-13CA69717NOX1.76 ppm
2018-06-13CA69716NOX1.01 ppm
2018-06-13CA69718NOX2.71 ppm
2018-06-13CA69714NOX0.0500 ppm
2018-06-20CA75544NOX0.260 ppm
2018-09-19NOX 2005061690.125 ppm
2018-10-09NOX 2005083670.124 ppm
2018-11-08NOX 2005121980.0250 ppm
2018-11-21NOX 2005135471.50 ppm
2018-11-26NOX 2005139311.60 ppm
2018-12-10NOX 2005153240.0780 ppm
2019-01-07NOX 2005177480.118 ppm
2019-01-30NOX 2005200570.123 ppm
2019-02-06NOX 2005208590.155 ppm
2019-02-07NOX 2005210390.159 ppm
2019-02-27IOCR 2005230020.112 ppm
2019-03-05NOX 2005235180.126 ppm
2019-04-02NOX 2005267020.108 ppm
2019-04-08NOX 2005274390.101 ppm
2019-05-06NOX 2005309190.0480 ppm
2019-06-05NOX 2005350540.0620 ppm
2019-06-24NOX 2005376250.0150 ppm
2019-07-09NOX 2005399600.123 ppm
2019-07-10NOX 2005399980.426 ppm
2019-07-10NOX 2005399960.426 ppm
2019-07-16NOX 2005410913.37 ppm
2019-07-16NOX 2005406480.924 ppm
2019-07-16NOX 2005406442.13 ppm
2019-08-05NOX 2005450650.0740 ppm
2019-09-11NOX 2005484350.0400 ppm
2019-09-17NOX 2005492381.02 ppm
2019-09-18NOX 2005494651.33 ppm
2019-10-02NOX 2005510870.0260 ppm
2019-11-12NOX 2005566370.0620 ppm
2019-12-05NOX 2005591080.0980 ppm