Arsenic
Cal-water Service Company - Marysville
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.
247
Samples
0
Samples exceeding legal limit (MCL)
246
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 4.49 ppb | 41 | 41 | 2.31 ppb - 6.30 ppb |
| 2019 | 4.88 ppb | 37 | 37 | 2.83 ppb - 8.58 ppb |
| 2020 | 4.48 ppb | 36 | 36 | 2.60 ppb - 7.64 ppb |
| 2021 | 4.40 ppb | 41 | 40 | ND - 6.40 ppb |
| 2022 | 4.51 ppb | 48 | 48 | 2.40 ppb - 5.50 ppb |
| 2023 | 4.24 ppb | 44 | 44 | 2.10 ppb - 5.60 ppb |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
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 |
|---|---|---|
| 2018-01-06 | CA5810001_023_023-201801061349 | 3.78 ppb |
| 2018-01-06 | CA5810001_016_016-201801061313 | 5.72 ppb |
| 2018-01-07 | CA5810001_009_009-201801070818 | 4.90 ppb |
| 2018-01-14 | CA5810001_015_015-201801141440 | 5.13 ppb |
| 2018-01-17 | CA5810001_009_009-201801171400 | 4.50 ppb |
| 2018-02-05 | CA5810001_023_023-201802051122 | 3.45 ppb |
| 2018-03-13 | CA5810001_011_011-201803131308 | 5.21 ppb |
| 2018-03-13 | CA5810001_023_023-201803131314 | 4.33 ppb |
| 2018-04-09 | CA5810001_016_016-201804091441 | 6.30 ppb |
| 2018-04-09 | CA5810001_023_023-201804091009 | 4.21 ppb |
| 2018-04-10 | CA5810001_009_009-201804100950 | 5.24 ppb |
| 2018-04-10 | CA5810001_013_013-201804101300 | 2.82 ppb |
| 2018-04-17 | CA5810001_010_010-201804171316 | 3.80 ppb |
| 2018-05-13 | CA5810001_023_023-201805131055 | 4.35 ppb |
| 2018-05-14 | CA5810001_015_015-201805141439 | 5.08 ppb |
| 2018-05-14 | CA5810001_020_020-201805141443 | 4.84 ppb |
| 2018-06-05 | CA5810001_020_020-201806051314 | 4.66 ppb |
| 2018-06-05 | CA5810001_023_023-201806051342 | 4.05 ppb |
| 2018-06-05 | CA5810001_011_011-201806051335 | 4.78 ppb |
| 2018-07-08 | CA5810001_009_009-201807081552 | 5.02 ppb |
| 2018-07-08 | CA5810001_016_016-201807081326 | 5.69 ppb |
| 2018-07-08 | CA5810001_020_020-201807081024 | 4.30 ppb |
| 2018-07-08 | CA5810001_023_023-201807081045 | 4.58 ppb |
| 2018-08-06 | CA5810001_015_015-201808060940 | 4.37 ppb |
| 2018-08-06 | CA5810001_020_020-201808060943 | 4.69 ppb |
| 2018-08-06 | CA5810001_023_023-201808061101 | 4.41 ppb |
| 2018-08-07 | CA5810001_015_015-201808071355 | 4.10 ppb |
| 2018-08-13 | CA5810001_011_011-201808131109 | 4.58 ppb |
| 2018-09-16 | CA5810001_011_011-201809161126 | 4.16 ppb |
| 2018-09-16 | CA5810001_020_020-201809160944 | 4.02 ppb |
| 2018-09-16 | CA5810001_023_023-201809161123 | 3.40 ppb |
| 2018-10-08 | CA5810001_008_008-201810081552 | 2.31 ppb |
| 2018-10-08 | CA5810001_016_016-201810081043 | 4.86 ppb |
| 2018-10-08 | CA5810001_020_020-201810081413 | 3.78 ppb |
| 2018-10-08 | CA5810001_009_009-201810081603 | 4.10 ppb |
| 2018-10-08 | CA5810001_023_023-201810081616 | 3.41 ppb |
| 2018-11-20 | CA5810001_015_015-201811201313 | 5.95 ppb |
| 2018-11-20 | CA5810001_023_023-201811201050 | 4.44 ppb |
| 2018-11-20 | CA5810001_020_020-201811201318 | 5.47 ppb |
| 2018-12-12 | CA5810001_011_011-201812121045 | 5.03 ppb |
| 2018-12-12 | CA5810001_023_023-201812121049 | 4.32 ppb |
| 2019-01-08 | CA5810001_023_023-201901081347 | 4.14 ppb |
| 2019-01-09 | CA5810001_016_016-201901090901 | 6.18 ppb |
| 2019-01-09 | CA5810001_009_009-201901091348 | 5.02 ppb |
| 2019-02-05 | CA5810001_023_023-201902051456 | 3.58 ppb |
| 2019-02-13 | CA5810001_016_016-201902131035 | 5.30 ppb |
| 2019-03-19 | CA5810001_023_023-201903191326 | 3.89 ppb |
| 2019-03-19 | CA5810001_011_011-201903191316 | 4.10 ppb |
| 2019-03-19 | CA5810001_011_011-201903191324 | 4.70 ppb |
| 2019-04-08 | CA5810001_023_023-201904081419 | 4.20 ppb |
| 2019-04-08 | CA5810001_016_016-201904080940 | 6.57 ppb |
| 2019-04-09 | CA5810001_009_009-201904091451 | 5.35 ppb |
| 2019-04-09 | CA5810001_013_013-201904091701 | 2.83 ppb |
| 2019-05-06 | CA5810001_023_023-201905060937 | 3.40 ppb |
| 2019-05-16 | CA5810001_020_020-201905160905 | 4.00 ppb |
| 2019-05-16 | CA5810001_015_015-201905160850 | 4.60 ppb |
| 2019-06-17 | CA5810001_023_023-201906171018 | 4.91 ppb |
| 2019-06-17 | CA5810001_020_020-201906171315 | 5.65 ppb |
| 2019-06-17 | CA5810001_011_011-201906171017 | 4.80 ppb |
| 2019-07-08 | CA5810001_016_016-201907081313 | 8.58 ppb |
| 2019-07-08 | CA5810001_020_020-201907081429 | 5.30 ppb |
| 2019-07-08 | CA5810001_023_023-201907080900 | 4.73 ppb |
| 2019-07-09 | CA5810001_009_009-201907091110 | 7.21 ppb |
| 2019-08-05 | CA5810001_015_015-201908051017 | 4.91 ppb |
| 2019-08-05 | CA5810001_020_020-201908051023 | 5.22 ppb |
| 2019-08-05 | CA5810001_023_023-201908050935 | 4.19 ppb |
| 2019-09-10 | CA5810001_020_020-201909100901 | 4.93 ppb |
| 2019-09-10 | CA5810001_011_011-201909100920 | 5.21 ppb |
| 2019-09-10 | CA5810001_023_023-201909100921 | 4.53 ppb |
| 2019-10-14 | CA5810001_020_020-201910140903 | 4.36 ppb |
| 2019-10-14 | CA5810001_023_023-201910141137 | 3.87 ppb |
| 2019-10-14 | CA5810001_009_009-201910141550 | 4.68 ppb |
| 2019-10-14 | CA5810001_016_016-201910141404 | 6.26 ppb |
| 2019-11-11 | CA5810001_023_023-201911110749 | 4.01 ppb |
| 2019-11-12 | CA5810001_015_015-201911121310 | 4.97 ppb |
| 2019-11-12 | CA5810001_020_020-201911121312 | 4.99 ppb |
| 2019-12-02 | CA5810001_011_011-201912021050 | 5.00 ppb |
| 2019-12-02 | CA5810001_023_023-201912021054 | 4.39 ppb |
| 2020-01-13 | CA5810001_009_009-202001131430 | 4.61 ppb |
| 2020-01-13 | CA5810001_023_023-202001130914 | 3.58 ppb |
| 2020-01-13 | CA5810001_016_016-202001131210 | 7.64 ppb |
| 2020-02-04 | CA5810001_023_023-202002040954 | 3.98 ppb |
| 2020-03-19 | CA5810001_013_013-202003191352 | 2.60 ppb |
| 2020-03-23 | CA5810001_011_011-202003231054 | 4.86 ppb |
| 2020-03-23 | CA5810001_023_023-202003231055 | 4.34 ppb |
| 2020-04-06 | CA5810001_016_016-202004061352 | 6.95 ppb |
| 2020-04-06 | CA5810001_023_023-202004061420 | 4.35 ppb |
| 2020-04-07 | CA5810001_009_009-202004070648 | 5.22 ppb |
| 2020-04-07 | CA5810001_013_013-202004070917 | 2.87 ppb |
| 2020-05-04 | CA5810001_015_015-202005040944 | 5.82 ppb |
| 2020-05-04 | CA5810001_023_023-202005040911 | 3.90 ppb |
| 2020-05-04 | CA5810001_020_020-202005040944 | 5.50 ppb |
| 2020-06-08 | CA5810001_011_011-202006081024 | 4.68 ppb |
| 2020-06-08 | CA5810001_020_020-202006081307 | 4.72 ppb |
| 2020-06-08 | CA5810001_023_023-202006081026 | 3.81 ppb |
| 2020-07-06 | CA5810001_020_020-202007060920 | 4.51 ppb |
| 2020-07-06 | CA5810001_009_009-202007061255 | 5.04 ppb |
| 2020-07-06 | CA5810001_023_023-202007060833 | 3.85 ppb |
| 2020-08-04 | CA5810001_015_015-202008041543 | 4.20 ppb |
| 2020-08-04 | CA5810001_020_020-202008041545 | 4.10 ppb |
| 2020-08-04 | CA5810001_023_023-202008041402 | 3.50 ppb |
| 2020-09-09 | CA5810001_023_023-202009090842 | 3.30 ppb |
| 2020-09-09 | CA5810001_011_011-202009090840 | 4.10 ppb |
| 2020-09-09 | CA5810001_020_020-202009090900 | 4.30 ppb |
| 2020-10-05 | CA5810001_009_009-202010051431 | 5.60 ppb |
| 2020-10-05 | CA5810001_020_020-202010051002 | 5.20 ppb |
| 2020-10-05 | CA5810001_023_023-202010050929 | 4.50 ppb |
| 2020-11-03 | CA5810001_015_015-202011030844 | 5.00 ppb |
| 2020-11-03 | CA5810001_020_020-202011030846 | 4.10 ppb |
| 2020-11-03 | CA5810001_023_023-202011030912 | 3.90 ppb |
| 2020-12-09 | CA5810001_023_023-202012091405 | 4.10 ppb |
| 2020-12-09 | CA5810001_011_011-202012091404 | 4.60 ppb |
| 2020-12-09 | CA5810001_020_020-202012091050 | 4.90 ppb |
| 2020-12-15 | CA5810001_008_008-202012151415 | 2.90 ppb |
| 2021-01-11 | CA5810001_009_009-202101111129 | 6.00 ppb |
| 2021-01-11 | CA5810001_020_020-202101111435 | 5.60 ppb |
| 2021-01-11 | CA5810001_009_009-202101111140 | 4.50 ppb |
| 2021-01-12 | CA5810001_023_023-202101121046 | 4.80 ppb |
| 2021-02-03 | CA5810001_023_023-202102031444 | 3.30 ppb |
| 2021-02-03 | CA5810001_020_020-202102031155 | 3.80 ppb |
| 2021-03-01 | CA5810001_023_023-202103011310 | 4.20 ppb |
| 2021-03-01 | CA5810001_011_011-202103011300 | 4.80 ppb |
| 2021-03-03 | CA5810001_015_015-202103031311 | 6.40 ppb |
| 2021-03-03 | CA5810001_020_020-202103031314 | 4.70 ppb |
| 2021-04-05 | CA5810001_023_023-202104051025 | 4.60 ppb |
| 2021-04-06 | CA5810001_010_010-202104061325 | ND |
| 2021-04-06 | CA5810001_020_020-202104060901 | 5.30 ppb |
| 2021-04-07 | CA5810001_009_009-202104071100 | 5.60 ppb |
| 2021-04-07 | CA5810001_013_013-202104070830 | 2.80 ppb |
| 2021-05-09 | CA5810001_015_015-202105090751 | 5.00 ppb |
| 2021-05-09 | CA5810001_020_020-202105090754 | 5.00 ppb |
| 2021-05-09 | CA5810001_023_023-202105090720 | 3.80 ppb |
| 2021-06-01 | CA5810001_020_020-202106011147 | 4.60 ppb |
| 2021-06-01 | CA5810001_011_011-202106011120 | 4.70 ppb |
| 2021-06-01 | CA5810001_023_023-202106011120 | 4.00 ppb |
| 2021-07-12 | CA5810001_020_020-202107121321 | 4.60 ppb |
| 2021-07-13 | CA5810001_009_009-202107131545 | 5.00 ppb |
| 2021-07-13 | CA5810001_023_023-202107131315 | 3.80 ppb |
| 2021-08-05 | CA5810001_015_015-202108051110 | 4.00 ppb |
| 2021-08-05 | CA5810001_020_020-202108051040 | 5.20 ppb |
| 2021-08-05 | CA5810001_023_023-202108050837 | 4.10 ppb |
| 2021-08-05 | CA5810001_015_015-202108051040 | 5.10 ppb |
| 2021-09-07 | CA5810001_020_020-202109071020 | 4.10 ppb |
| 2021-09-07 | CA5810001_023_023-202109071506 | 3.90 ppb |
| 2021-09-07 | CA5810001_011_011-202109071504 | 4.30 ppb |
| 2021-10-18 | CA5810001_008_008-202110181200 | 1.40 ppb |
| 2021-10-18 | CA5810001_009_009-202110181444 | 4.00 ppb |
| 2021-10-19 | CA5810001_020_020-202110191320 | 4.40 ppb |
| 2021-10-19 | CA5810001_023_023-202110191135 | 3.80 ppb |
| 2021-11-01 | CA5810001_023_023-202111011050 | 4.40 ppb |
| 2021-11-01 | CA5810001_015_015-202111011326 | 4.40 ppb |
| 2021-11-01 | CA5810001_020_020-202111011326 | 4.60 ppb |
| 2021-12-08 | CA5810001_011_011-202112081415 | 5.50 ppb |
| 2021-12-08 | CA5810001_023_023-202112081415 | 5.00 ppb |
| 2021-12-09 | CA5810001_020_020-202112091306 | 5.10 ppb |
| 2022-01-10 | CA5810001_020_020-202201101325 | 4.30 ppb |
| 2022-01-10 | CA5810001_023_023-202201101045 | 4.00 ppb |
| 2022-01-12 | CA5810001_009_009-202201121305 | 4.80 ppb |
| 2022-02-10 | CA5810001_023_023-202202101355 | 5.00 ppb |
| 2022-02-10 | CA5810001_020_020-202202101100 | 5.30 ppb |
| 2022-03-15 | CA5810001_011_011-202203151320 | 3.90 ppb |
| 2022-03-16 | CA5810001_015_015-202203160910 | 5.30 ppb |
| 2022-03-16 | CA5810001_020_020-202203160910 | 5.00 ppb |
| 2022-03-16 | CA5810001_011_011-202203161146 | 4.60 ppb |
| 2022-03-16 | CA5810001_023_023-202203161146 | 4.60 ppb |
| 2022-04-14 | CA5810001_023_023-202204141426 | 4.70 ppb |
| 2022-04-14 | CA5810001_020_020-202204140855 | 4.60 ppb |
| 2022-04-14 | CA5810001_009_009-202204140908 | 5.00 ppb |
| 2022-04-14 | CA5810001_013_013-202204141109 | 2.40 ppb |
| 2022-05-11 | CA5810001_023_023-202205111425 | 5.00 ppb |
| 2022-05-11 | CA5810001_020_020-202205110902 | 5.00 ppb |
| 2022-05-11 | CA5810001_015_015-202205110900 | 4.50 ppb |
| 2022-06-08 | CA5810001_016_016-202206081142 | 4.70 ppb |
| 2022-06-08 | CA5810001_028_028-202206081142 | 4.00 ppb |
| 2022-06-08 | CA5810001_016_016-202206081143 | 2.50 ppb |
| 2022-06-09 | CA5810001_016_016-202206091000 | 4.90 ppb |
| 2022-06-13 | CA5810001_020_020-202206131314 | 4.90 ppb |
| 2022-06-13 | CA5810001_008_008-202206130855 | 2.80 ppb |
| 2022-06-13 | CA5810001_011_011-202206131040 | 4.40 ppb |
| 2022-06-13 | CA5810001_009_009-202206130726 | 5.50 ppb |
| 2022-06-13 | CA5810001_023_023-202206131040 | 5.30 ppb |
| 2022-07-11 | CA5810001_020_020-202207111259 | 4.60 ppb |
| 2022-07-12 | CA5810001_009_009-202207121050 | 5.50 ppb |
| 2022-07-12 | CA5810001_023_023-202207121405 | 4.70 ppb |
| 2022-07-13 | CA5810001_016_016-202207131125 | 5.40 ppb |
| 2022-08-07 | CA5810001_015_015-202208071511 | 4.80 ppb |
| 2022-08-07 | CA5810001_020_020-202208071514 | 4.60 ppb |
| 2022-08-08 | CA5810001_023_023-202208081100 | 5.50 ppb |
| 2022-09-12 | CA5810001_023_023-202209121523 | 4.20 ppb |
| 2022-09-12 | CA5810001_011_011-202209121519 | 4.00 ppb |
| 2022-09-13 | CA5810001_020_020-202209131331 | 4.00 ppb |
| 2022-10-06 | CA5810001_009_009-202210060848 | 4.80 ppb |
| 2022-10-06 | CA5810001_008_008-202210061311 | 2.40 ppb |
| 2022-10-10 | CA5810001_016_016-202210101549 | 4.60 ppb |
| 2022-10-10 | CA5810001_020_020-202210101150 | 4.20 ppb |
| 2022-10-11 | CA5810001_023_023-202210111129 | 3.40 ppb |
| 2022-11-09 | CA5810001_020_020-202211090749 | 5.10 ppb |
| 2022-11-09 | CA5810001_015_015-202211090746 | 5.00 ppb |
| 2022-11-14 | CA5810001_023_023-202211140845 | 4.90 ppb |
| 2022-12-05 | CA5810001_008_008-202212051408 | 2.40 ppb |
| 2022-12-06 | CA5810001_020_020-202212061505 | 5.20 ppb |
| 2022-12-14 | CA5810001_011_011-202212141135 | 5.30 ppb |
| 2022-12-14 | CA5810001_023_023-202212141138 | 4.70 ppb |
| 2023-01-09 | CA5810001_020_020-202301091320 | 5.10 ppb |
| 2023-01-09 | CA5810001_016_016-202301091137 | 5.60 ppb |
| 2023-01-22 | CA5810001_009_009-202301221114 | 4.60 ppb |
| 2023-01-23 | CA5810001_023_023-202301230927 | 3.60 ppb |
| 2023-02-01 | CA5810001_023_023-202302011358 | 4.60 ppb |
| 2023-02-06 | CA5810001_020_020-202302061131 | 4.90 ppb |
| 2023-03-06 | CA5810001_023_023-202303060949 | 4.30 ppb |
| 2023-03-06 | CA5810001_011_011-202303060949 | 4.70 ppb |
| 2023-03-08 | CA5810001_015_015-202303081120 | 4.90 ppb |
| 2023-03-08 | CA5810001_020_020-202303081120 | 4.60 ppb |
| 2023-03-23 | CA5810001_013_013-202303231211 | 2.20 ppb |
| 2023-04-04 | CA5810001_013_013-202304041429 | 2.10 ppb |
| 2023-04-10 | CA5810001_020_020-202304101425 | 4.40 ppb |
| 2023-04-11 | CA5810001_016_016-202304111112 | 4.40 ppb |
| 2023-04-17 | CA5810001_023_023-202304171005 | 3.70 ppb |
| 2023-04-20 | CA5810001_013_013-202304201303 | 2.40 ppb |
| 2023-04-20 | CA5810001_009_009-202304201049 | 5.00 ppb |
| 2023-05-05 | CA5810001_020_020-202305051048 | 4.70 ppb |
| 2023-05-05 | CA5810001_015_015-202305051042 | 5.10 ppb |
| 2023-05-08 | CA5810001_023_023-202305081058 | 4.40 ppb |
| 2023-06-07 | CA5810001_020_020-202306071053 | 4.50 ppb |
| 2023-06-14 | CA5810001_023_023-202306141522 | 4.40 ppb |
| 2023-06-14 | CA5810001_011_011-202306141522 | 4.80 ppb |
| 2023-07-11 | CA5810001_009_009-202307111042 | 4.50 ppb |
| 2023-07-11 | CA5810001_023_023-202307111050 | 3.60 ppb |
| 2023-07-16 | CA5810001_020_020-202307161437 | 4.40 ppb |
| 2023-07-17 | CA5810001_016_016-202307171100 | 4.70 ppb |
| 2023-08-09 | CA5810001_015_015-202308091356 | 3.80 ppb |
| 2023-08-09 | CA5810001_020_020-202308091359 | 3.70 ppb |
| 2023-08-21 | CA5810001_023_023-202308210931 | 4.10 ppb |
| 2023-09-07 | CA5810001_020_020-202309071429 | 3.60 ppb |
| 2023-09-12 | CA5810001_011_011-202309120945 | 3.50 ppb |
| 2023-09-12 | CA5810001_023_023-202309120941 | 3.40 ppb |
| 2023-10-05 | CA5810001_023_023-202310051126 | 4.70 ppb |
| 2023-10-09 | CA5810001_008_008-202310091004 | 2.80 ppb |
| 2023-10-09 | CA5810001_016_016-202310091343 | 5.50 ppb |
| 2023-10-09 | CA5810001_020_020-202310091051 | 4.90 ppb |
| 2023-10-09 | CA5810001_009_009-202310090946 | 5.30 ppb |
| 2023-11-07 | CA5810001_015_015-202311071110 | 4.80 ppb |
| 2023-11-14 | CA5810001_023_023-202311141028 | 4.70 ppb |
| 2023-11-27 | CA5810001_020_020-202311271507 | 4.90 ppb |
| 2023-12-07 | CA5810001_011_011-202312071106 | 3.80 ppb |
| 2023-12-07 | CA5810001_023_023-202312071105 | 2.40 ppb |
| 2023-12-18 | CA5810001_020_020-202312181326 | 4.60 ppb |