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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

California American Water Company - Monterey

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.

 

63

Samples

0

Samples exceeding legal limit (MCL)

31

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND10ND
20153.52 ppm65ND - 6.00 ppm
20162.01 ppm3219ND - 5.80 ppm
2017ND10ND
2018ND20ND
20190.598 ppm217ND - 5.80 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
2014-12-231225-085-0915ND
2015-02-101225-085-1330ND
2015-09-295810-083-13252.30 ppm
2015-10-135810-083-11002.60 ppm
2015-10-135810-075-11206.00 ppm
2015-10-135810-077-11054.80 ppm
2015-10-135810-076-11255.40 ppm
2016-01-121225-046-1355ND
2016-01-205810-076-10053.70 ppm
2016-01-205810-075-09503.90 ppm
2016-01-205810-077-10153.20 ppm
2016-02-081225-017-1000ND
2016-02-081225-047-1100ND
2016-02-081225-044-1230ND
2016-02-081225-016-1030ND
2016-02-081225-045-1200ND
2016-03-025810-083-09302.00 ppm
2016-04-061225-024-14101.80 ppm
2016-04-075810-076-11554.90 ppm
2016-04-075810-083-10403.10 ppm
2016-04-075810-075-11505.80 ppm
2016-04-071225-082-1010ND
2016-04-075810-077-11353.40 ppm
2016-04-191225-051-11005.60 ppm
2016-04-191225-029-10005.70 ppm
2016-05-121225-052-1010ND
2016-06-071225-026-1045ND
2016-06-071225-073-1020ND
2016-06-071225-072-1000ND
2016-06-081225-002-13300.400 ppm
2016-06-081225-074-1315ND
2016-06-081225-006-13000.500 ppm
2016-08-221225-070-1010ND
2016-08-291225-050-12153.00 ppm
2016-09-285810-083-13001.90 ppm
2016-10-045810-083-09551.50 ppm
2016-10-045810-077-09503.40 ppm
2016-10-045810-075-10155.50 ppm
2016-10-045810-076-10205.00 ppm
2017-03-141225-085-1300ND
2018-05-011225-082-0920ND
2018-07-091225-070-1005ND
2019-02-071225-016-1335ND
2019-02-071225-017-13000.400 ppm
2019-02-071225-044-1650ND
2019-02-071225-047-1515ND
2019-02-071225-046-14300.460 ppm
2019-02-071225-045-1710ND
2019-03-191225-051-12302.70 ppm
2019-03-191225-029-13305.80 ppm
2019-03-201225-024-12281.90 ppm
2019-03-211225-050-1415ND
2019-04-221225-087-1630ND
2019-04-221225-073-1600ND
2019-04-221225-072-1640ND
2019-04-241225-002-14300.700 ppm
2019-04-241225-074-1450ND
2019-04-241225-052-1330ND
2019-04-241225-006-14000.600 ppm
2019-05-061225-082-1350ND
2019-07-241225-048-1420ND
2019-08-071225-026-1230ND
2019-08-081225-070-1530ND