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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Lake Arrowhead CSD

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

 

52

Samples

0

Samples exceeding legal limit (MCL)

8

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND80ND
2015ND80ND
20160.139 ppm72ND - 0.510 ppm
20170.128 ppm164ND - 0.670 ppm
20180.174 ppm72ND - 0.700 ppm
2019ND60ND

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
2014-06-263761-004-1108ND
2014-07-093761-013-1204ND
2014-07-093761-012-1228ND
2014-07-093761-010-1221ND
2014-07-093761-009-1238ND
2014-07-093761-007-1253ND
2014-07-093761-006-1216ND
2014-07-093761-002-0843ND
2015-04-223761-004-1110ND
2015-07-083761-002-1007ND
2015-07-083761-007-1112ND
2015-07-083761-006-1047ND
2015-07-083761-009-1105ND
2015-07-083761-011-1042ND
2015-07-083761-012-1056ND
2015-08-123761-013-1010ND
2016-06-083761-004-1057ND
2016-07-133761-002-1302ND
2016-07-143761-013-1010ND
2016-07-143761-012-1033ND
2016-07-143761-006-10270.460 ppm
2016-07-143761-007-10520.510 ppm
2016-07-143761-009-1043ND
2017-02-233761-004-0900ND
2017-04-193761-002-0955ND
2017-04-193761-005-09210.670 ppm
2017-06-073761-005-0924ND
2017-06-073761-002-1221ND
2017-06-073761-604-1152ND
2017-07-183761-002-1136ND
2017-07-193761-009-0837ND
2017-07-193761-007-09050.500 ppm
2017-07-193761-012-0936ND
2017-07-193761-006-09200.470 ppm
2017-07-193761-013-09170.400 ppm
2017-07-193761-013-1011ND
2017-09-063761-002-0900ND
2017-09-063761-004-1204ND
2017-09-063761-604-1315ND
2018-02-143761-004-0925ND
2018-05-233761-007-09300.700 ppm
2018-07-113761-013-0932ND
2018-07-113761-013-0917ND
2018-07-113761-012-0955ND
2018-07-113761-006-09440.520 ppm
2018-08-153761-002-0855ND
2019-02-273761-004-1000ND
2019-07-103761-002-0843ND
2019-07-173761-013-1000ND
2019-07-173761-012-1025ND
2019-07-173761-009-1030ND
2019-07-173761-006-1018ND