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EWG's Tap Water Database — 2021 UPDATE

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Arsenic

Dana Ranch

Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.

MORE ABOUT THIS CONTAMINANT

 

111

Samples

4

Samples exceeding legal limit (MCL)

48

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201417.0 ppb2217.0 ppb
201512.7 ppb3310.00 ppb - 17.0 ppb
20162.13 ppb248ND - 10.00 ppb
20172.18 ppb2818ND - 5.50 ppb
20181.76 ppb2811ND - 7.20 ppb
20190.788 ppb266ND - 4.70 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.004 ppb

The EWG Health Guideline of 0.004 ppb for arsenic was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL) 10 ppb

The legal limit for arsenic, established in 2001, was based on costs for arsenic removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to arsenic exposure.

ppb = parts per billion

All test results

Date Lab ID Result
2014-08-042210-001-105217.0 ppb
2014-11-032210-001-135517.0 ppb
2015-02-112210-001-101517.0 ppb
2015-08-042210-001-122110.00 ppb
2015-11-172210-001-093511.0 ppb
2016-01-112210-001-09408.00 ppb
2016-02-092210-002-1010ND
2016-02-092210-003-1012ND
2016-03-082210-002-1005ND
2016-03-082210-003-1010ND
2016-04-052210-002-1005ND
2016-04-052210-003-1006ND
2016-05-032210-001-09306.00 ppb
2016-06-152210-002-1200ND
2016-06-152210-003-1200ND
2016-07-261233-002-1136ND
2016-07-261233-003-1140ND
2016-08-141233-001-10409.30 ppb
2016-08-141233-002-1042ND
2016-08-141233-003-1045ND
2016-09-201233-002-1034ND
2016-09-201233-003-10352.10 ppb
2016-10-171233-002-10056.80 ppb
2016-10-171233-003-1010ND
2016-11-221233-001-085010.00 ppb
2016-11-221233-002-09004.40 ppb
2016-11-221233-003-09034.50 ppb
2016-12-131233-002-0954ND
2016-12-131233-003-0957ND
2017-01-101233-002-0950ND
2017-01-101233-003-0951ND
2017-02-081233-001-10304.90 ppb
2017-02-081233-002-10282.90 ppb
2017-02-081233-003-10262.90 ppb
2017-03-071233-002-1018ND
2017-03-071233-003-1020ND
2017-04-041233-002-09132.80 ppb
2017-04-041233-003-09152.70 ppb
2017-05-021233-001-09555.00 ppb
2017-05-021233-002-09592.10 ppb
2017-05-021233-003-10002.10 ppb
2017-06-071233-002-08142.10 ppb
2017-06-071233-003-08152.40 ppb
2017-07-101233-002-16003.60 ppb
2017-07-101233-003-1605ND
2017-08-091233-001-11005.40 ppb
2017-08-091233-001-11155.20 ppb
2017-08-091233-002-11162.80 ppb
2017-08-091233-003-1117ND
2017-09-071233-003-08052.50 ppb
2017-10-111233-002-0754ND
2017-10-111233-003-0753ND
2017-11-071233-001-11105.50 ppb
2017-11-071233-002-10583.90 ppb
2017-11-071233-003-10592.20 ppb
2017-12-051233-002-1017ND
2017-12-051233-003-1020ND
2018-01-031233-002-1027ND
2018-01-031233-003-1030ND
2018-02-071233-001-09426.40 ppb
2018-02-071233-002-09503.20 ppb
2018-02-071233-003-0951ND
2018-03-081233-002-09122.30 ppb
2018-03-081233-003-0914ND
2018-04-041233-002-11123.30 ppb
2018-04-041233-003-1110ND
2018-05-021233-001-11507.20 ppb
2018-05-021233-002-11555.60 ppb
2018-05-021233-003-11562.80 ppb
2018-06-061233-002-1059ND
2018-06-061233-003-1100ND
2018-07-111233-002-08413.00 ppb
2018-07-111233-003-08402.20 ppb
2018-08-081233-001-10186.90 ppb
2018-08-081233-002-1019ND
2018-08-081233-003-1020ND
2018-09-051233-002-1238ND
2018-09-051233-003-1239ND
2018-10-021233-002-0615ND
2018-10-021233-003-0613ND
2018-11-081233-001-11006.30 ppb
2018-11-081233-002-1111ND
2018-11-081233-003-1115ND
2018-12-031233-002-1437ND
2018-12-031233-003-1435ND
2019-01-071233-002-12222.60 ppb
2019-01-071233-003-1225ND
2019-02-041233-001-13194.00 ppb
2019-02-041233-002-1320ND
2019-02-041233-003-1322ND
2019-04-011233-002-1218ND
2019-04-011233-003-1220ND
2019-05-061233-001-13553.10 ppb
2019-05-061233-002-1347ND
2019-05-061233-003-1346ND
2019-06-031233-002-1158ND
2019-06-031233-003-1201ND
2019-07-011233-002-1159ND
2019-07-011233-003-1201ND
2019-08-051233-001-14553.90 ppb
2019-08-051233-002-1504ND
2019-08-051233-003-1506ND
2019-09-021233-002-1147ND
2019-09-021233-003-1148ND
2019-10-081233-002-1158ND
2019-10-081233-003-1159ND
2019-11-041233-001-11394.70 ppb
2019-11-041233-002-1133ND
2019-11-041233-003-1136ND
2019-12-091233-002-11202.20 ppb
2019-12-091233-003-1122ND