Know Your Environment. Protect Your Health.

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.

 

133

Samples

0

Samples exceeding legal limit (MCL)

62

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.764 ppm16160.0250 ppm - 2.71 ppm
20190.465 ppm24240.0150 ppm - 3.37 ppm
20200.648 ppm25250.0120 ppm - 1.98 ppm
20210.552 ppm20200.0190 ppm - 2.51 ppm
20220.468 ppm2221ND - 2.74 ppm
20230.761 ppm2624ND - 2.95 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.14 ppm

The EWG 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
2018-01-16BZ73475NOX0.280 ppm
2018-03-30CA11466NOX0.170 ppm
2018-03-30CA11463IOCR0.150 ppm
2018-06-04CA63507NOX0.200 ppm
2018-06-13CA69714NOX0.0500 ppm
2018-06-13CA69718NOX2.71 ppm
2018-06-13CA69716NOX1.01 ppm
2018-06-13CA69715NOX2.17 ppm
2018-06-13CA69717NOX1.76 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 2005399960.426 ppm
2019-07-10NOX 2005399980.426 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
2020-01-09NOX 2005623650.164 ppm
2020-01-20NOX 2005635091.36 ppm
2020-01-20NOX 2005635211.38 ppm
2020-01-21NOX 2005634990.0190 ppm
2020-01-21NOX 2005635151.89 ppm
2020-01-21NOX 2005635161.91 ppm
2020-01-28NOX 2005642111.98 ppm
2020-01-28NOX 2005642121.97 ppm
2020-02-10NOX 2005655310.158 ppm
2020-02-11NOX 2005657990.154 ppm
2020-02-11NOX 2005657970.139 ppm
2020-02-11IOCR 2005657970.139 ppm
2020-02-25NOX 2005672751.60 ppm
2020-02-25NOX 2005672761.59 ppm
2020-03-03NOX 2005679750.138 ppm
2020-04-06NOX 2005724890.101 ppm
2020-05-05NOX 2005745870.0740 ppm
2020-06-02NOX 2005777140.0720 ppm
2020-07-08NOX 2005820000.0810 ppm
2020-07-13NOX 2005824771.11 ppm
2020-08-12NOX 2005863680.0120 ppm
2020-09-15NOX 2005903670.0220 ppm
2020-10-21NOX 2005950660.0160 ppm
2020-11-02NOX 2005964240.0220 ppm
2020-12-09NOX 2006008160.118 ppm
2021-01-05NOX 2006027531.45 ppm
2021-01-06NOX 2006029940.0410 ppm
2021-01-11NOX 2006034570.217 ppm
2021-01-25NOX 2006047681.53 ppm
2021-02-17NOX 2006071360.253 ppm
2021-03-01NOX 2006081350.197 ppm
2021-04-20NOX 2006139970.0570 ppm
2021-05-12NOX 2006168760.0450 ppm
2021-06-02NOX 2006192840.0420 ppm
2021-06-29NOX 2006227102.19 ppm
2021-07-01NOX 2006228410.0550 ppm
2021-07-07NOX 2006236500.965 ppm
2021-07-20NOX 2006254472.51 ppm
2021-08-09NOX 2006276440.0480 ppm
2021-09-21300064946 3000649490.0780 ppm
2021-09-30R300072099 3000721010.0460 ppm
2021-10-04N300073657 3000736600.0620 ppm
2021-11-01N300093127 3000931300.0190 ppm
2021-11-15N300102725 3001027261.15 ppm
2021-12-08N300115259 3001152620.0860 ppm
2022-01-11CK140951.11 ppm
2022-01-11CK141052.01 ppm
2022-01-27CK243070.170 ppm
2022-02-15CK682980.150 ppm
2022-02-28CK761920.01000 ppm
2022-03-07CK809001.04 ppm
2022-03-28CK961210.0900 ppm
2022-04-25CL163060.0400 ppm
2022-05-11CL276110.0400 ppm
2022-06-06CL493870.0700 ppm
2022-06-14CL564762.74 ppm
2022-07-20CL838070.0300 ppm
2022-08-15CM056351.37 ppm
2022-08-15CM056361.10 ppm
2022-08-24CM148270.0700 ppm
2022-08-29CM178300.0300 ppm
2022-08-29CM178310.0200 ppm
2022-09-28CM431030.0500 ppm
2022-10-04CM495640.0300 ppm
2022-11-02CM75295ND
2022-12-01CM946400.0400 ppm
2022-12-01CM946440.0800 ppm
2023-01-04CN174972.02 ppm
2023-01-05CN170200.170 ppm
2023-01-09CN196032.03 ppm
2023-01-10CN207981.33 ppm
2023-02-08CN393780.190 ppm
2023-02-13CN418580.120 ppm
2023-02-13CN418590.160 ppm
2023-03-13CN591720.130 ppm
2023-04-05CN774920.0900 ppm
2023-05-10CO033500.0600 ppm
2023-06-05CO199780.0700 ppm
2023-06-13CO272770.930 ppm
2023-08-10CO713520.0900 ppm
2023-08-28CO851020.110 ppm
2023-09-05CO906920.1000 ppm
2023-09-12CO958742.45 ppm
2023-09-12CO958750.540 ppm
2023-09-12CO958771.82 ppm
2023-10-12CP236291.31 ppm
2023-10-23CP318680.0700 ppm
2023-11-06CP420680.0300 ppm
2023-11-28CP55321ND
2023-11-28CP55320ND
2023-11-29CP564322.90 ppm
2023-11-29CP564342.95 ppm
2023-12-04CP596880.110 ppm