Arsenic
Woodland Heights Mutual Water Company
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 9.31 ppb | 26 | 26 | 5.00 ppb - 25.7 ppb |
| 2019 | 10.7 ppb | 28 | 28 | 5.60 ppb - 25.9 ppb |
| 2020 | 7.62 ppb | 30 | 30 | 5.40 ppb - 10.4 ppb |
| 2021 | 11.0 ppb | 29 | 29 | 5.70 ppb - 29.6 ppb |
| 2022 | 7.89 ppb | 30 | 29 | ND - 22.6 ppb |
| 2023 | 9.92 ppb | 32 | 32 | 6.90 ppb - 22.8 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 |
|---|---|---|
| 2018-02-05 | CA2702439_004_004-201802051200 | 8.00 ppb |
| 2018-02-13 | CA2702439_001_001-201802130815 | 5.00 ppb |
| 2018-02-19 | CA2702439_004_004-201802191155 | 7.00 ppb |
| 2018-03-05 | CA2702439_004_004-201803051200 | 7.00 ppb |
| 2018-03-19 | CA2702439_004_004-201803191715 | 7.00 ppb |
| 2018-04-16 | CA2702439_004_004-201804161330 | 7.00 ppb |
| 2018-04-21 | CA2702439_004_004-201804210800 | 7.00 ppb |
| 2018-04-26 | CA2702439_002_002-201804261000 | 11.0 ppb |
| 2018-05-11 | CA2702439_004_004-201805111445 | 9.00 ppb |
| 2018-05-14 | CA2702439_004_004-201805141300 | 6.00 ppb |
| 2018-06-11 | CA2702439_004_004-201806111415 | 8.40 ppb |
| 2018-07-09 | CA2702439_002_002-201807091200 | 16.0 ppb |
| 2018-07-09 | CA2702439_004_004-201807091215 | 10.1 ppb |
| 2018-07-23 | CA2702439_004_004-201807231230 | 10.6 ppb |
| 2018-08-06 | CA2702439_004_004-201808061345 | 8.80 ppb |
| 2018-08-20 | CA2702439_004_004-201808201215 | 7.40 ppb |
| 2018-09-03 | CA2702439_004_004-201809031415 | 6.80 ppb |
| 2018-09-18 | CA2702439_004_004-201809181015 | 6.10 ppb |
| 2018-10-01 | CA2702439_004_004-201810011345 | 7.70 ppb |
| 2018-10-15 | CA2702439_004_004-201810151245 | 9.60 ppb |
| 2018-10-15 | CA2702439_002_002-201810151145 | 25.7 ppb |
| 2018-10-30 | CA2702439_004_004-201810301000 | 9.00 ppb |
| 2018-11-12 | CA2702439_004_004-201811121440 | 10.6 ppb |
| 2018-11-26 | CA2702439_004_004-201811261130 | 11.1 ppb |
| 2018-12-10 | CA2702439_004_004-201812101415 | 10.8 ppb |
| 2018-12-24 | CA2702439_004_004-201812241200 | 9.30 ppb |
| 2019-01-07 | CA2702439_002_002-201901071140 | 20.3 ppb |
| 2019-01-07 | CA2702439_004_004-201901071130 | 10.2 ppb |
| 2019-01-21 | CA2702439_004_004-201901211420 | 11.2 ppb |
| 2019-02-04 | CA2702439_004_004-201902041015 | 10.4 ppb |
| 2019-02-18 | CA2702439_004_004-201902181415 | 8.20 ppb |
| 2019-03-11 | CA2702439_004_004-201903110940 | 8.40 ppb |
| 2019-03-18 | CA2702439_004_004-201903181400 | 9.30 ppb |
| 2019-04-03 | CA2702439_004_004-201904031200 | 8.90 ppb |
| 2019-04-03 | CA2702439_002_002-201904031215 | 11.7 ppb |
| 2019-05-17 | CA2702439_004_004-201905171105 | 7.40 ppb |
| 2019-05-27 | CA2702439_004_004-201905271110 | 7.70 ppb |
| 2019-06-10 | CA2702439_004_004-201906101235 | 8.40 ppb |
| 2019-06-25 | CA2702439_004_004-201906251320 | 11.3 ppb |
| 2019-07-08 | CA2702439_002_002-201907080925 | 13.4 ppb |
| 2019-07-08 | CA2702439_004_004-201907080920 | 11.8 ppb |
| 2019-07-22 | CA2702439_004_004-201907221115 | 6.70 ppb |
| 2019-08-05 | CA2702439_004_004-201908051530 | 25.9 ppb |
| 2019-08-19 | CA2702439_004_004-201908191045 | 7.60 ppb |
| 2019-09-02 | CA2702439_004_004-201909021100 | 12.4 ppb |
| 2019-09-16 | CA2702439_004_004-201909161030 | 8.00 ppb |
| 2019-10-02 | CA2702439_002_002-201910021100 | 13.2 ppb |
| 2019-10-02 | CA2702439_004_004-201910021110 | 8.60 ppb |
| 2019-10-16 | CA2702439_004_004-201910161000 | 13.4 ppb |
| 2019-10-28 | CA2702439_004_004-201910281130 | 11.0 ppb |
| 2019-11-14 | CA2702439_004_004-201911141300 | 8.20 ppb |
| 2019-11-25 | CA2702439_004_004-201911251345 | 13.4 ppb |
| 2019-12-09 | CA2702439_004_004-201912091300 | 5.60 ppb |
| 2019-12-23 | CA2702439_004_004-201912231330 | 6.80 ppb |
| 2020-01-06 | CA2702439_004_004-202001061140 | 6.40 ppb |
| 2020-01-06 | CA2702439_002_002-202001061135 | 8.60 ppb |
| 2020-01-22 | CA2702439_004_004-202001221030 | 7.30 ppb |
| 2020-02-03 | CA2702439_004_004-202002031120 | 7.00 ppb |
| 2020-02-17 | CA2702439_004_004-202002171400 | 6.40 ppb |
| 2020-03-02 | CA2702439_004_004-202003021140 | 9.50 ppb |
| 2020-03-16 | CA2702439_004_004-202003161100 | 10.4 ppb |
| 2020-03-30 | CA2702439_004_004-202003301115 | 8.80 ppb |
| 2020-04-13 | CA2702439_002_002-202004131235 | 7.40 ppb |
| 2020-04-13 | CA2702439_004_004-202004131230 | 5.40 ppb |
| 2020-04-27 | CA2702439_004_004-202004271135 | 7.10 ppb |
| 2020-05-11 | CA2702439_004_004-202005111144 | 6.10 ppb |
| 2020-05-26 | CA2702439_004_004-202005261400 | 6.10 ppb |
| 2020-06-08 | CA2702439_004_004-202006081345 | 8.70 ppb |
| 2020-06-22 | CA2702439_004_004-202006221315 | 7.90 ppb |
| 2020-07-06 | CA2702439_004_004-202007061055 | 7.40 ppb |
| 2020-07-06 | CA2702439_002_002-202007061050 | 10.00 ppb |
| 2020-07-20 | CA2702439_004_004-202007201145 | 9.50 ppb |
| 2020-08-03 | CA2702439_004_004-202008031135 | 9.50 ppb |
| 2020-08-19 | CA2702439_004_004-202008191000 | 10.3 ppb |
| 2020-09-01 | CA2702439_004_004-202009011345 | 5.80 ppb |
| 2020-09-14 | CA2702439_004_004-202009141230 | 5.80 ppb |
| 2020-09-28 | CA2702439_004_004-202009281530 | 8.90 ppb |
| 2020-10-12 | CA2702439_002_002-202010121115 | 8.40 ppb |
| 2020-10-12 | CA2702439_004_004-202010121110 | 5.50 ppb |
| 2020-10-26 | CA2702439_004_004-202010261120 | 5.70 ppb |
| 2020-11-09 | CA2702439_004_004-202011091245 | 6.70 ppb |
| 2020-11-23 | CA2702439_004_004-202011231300 | 9.80 ppb |
| 2020-12-07 | CA2702439_004_004-202012071210 | 5.80 ppb |
| 2020-12-21 | CA2702439_004_004-202012211440 | 6.40 ppb |
| 2021-01-04 | CA2702439_002_002-202101041010 | 18.4 ppb |
| 2021-01-04 | CA2702439_004_004-202101041000 | 7.90 ppb |
| 2021-01-18 | CA2702439_004_004-202101180700 | 7.30 ppb |
| 2021-02-03 | CA2702439_004_004-202102031215 | 8.20 ppb |
| 2021-02-15 | CA2702439_004_004-202102150700 | 11.0 ppb |
| 2021-03-03 | CA2702439_004_004-202103030945 | 10.2 ppb |
| 2021-03-15 | CA2702439_004_004-202103150730 | 8.10 ppb |
| 2021-03-29 | CA2702439_004_004-202103290640 | 11.2 ppb |
| 2021-04-12 | CA2702439_002_002-202104120725 | 19.0 ppb |
| 2021-04-26 | CA2702439_004_004-202104261415 | 9.50 ppb |
| 2021-05-12 | CA2702439_004_004-202105120800 | 13.9 ppb |
| 2021-05-28 | CA2702439_004_004-202105280700 | 10.5 ppb |
| 2021-06-01 | CA2702439_004_004-202106010700 | 10.7 ppb |
| 2021-06-07 | CA2702439_004_004-202106070740 | 9.90 ppb |
| 2021-06-21 | CA2702439_004_004-202106210730 | 9.70 ppb |
| 2021-07-06 | CA2702439_004_004-202107060800 | 13.3 ppb |
| 2021-07-06 | CA2702439_002_002-202107060810 | 29.6 ppb |
| 2021-07-21 | CA2702439_004_004-202107210615 | 10.9 ppb |
| 2021-08-16 | CA2702439_004_004-202108160725 | 10.8 ppb |
| 2021-08-30 | CA2702439_004_004-202108300630 | 12.8 ppb |
| 2021-09-15 | CA2702439_004_004-202109150720 | 8.90 ppb |
| 2021-09-27 | CA2702439_004_004-202109270745 | 10.4 ppb |
| 2021-10-15 | CA2702439_004_004-202110150725 | 7.20 ppb |
| 2021-10-15 | CA2702439_002_002-202110150720 | 14.5 ppb |
| 2021-10-25 | CA2702439_004_004-202110250800 | 9.40 ppb |
| 2021-11-08 | CA2702439_004_004-202111080715 | 6.30 ppb |
| 2021-11-22 | CA2702439_004_004-202111220745 | 6.30 ppb |
| 2021-12-08 | CA2702439_004_004-202112080815 | 6.20 ppb |
| 2021-12-20 | CA2702439_004_004-202112200830 | 5.70 ppb |
| 2022-01-05 | CA2702439_002_002-202201050850 | 12.6 ppb |
| 2022-01-05 | CA2702439_004_004-202201050845 | 8.80 ppb |
| 2022-01-17 | CA2702439_004_004-202201170740 | 8.20 ppb |
| 2022-02-02 | CA2702439_004_004-202202020800 | 6.60 ppb |
| 2022-02-14 | CA2702439_004_004-202202140745 | 8.80 ppb |
| 2022-02-28 | CA2702439_004_004-202202280715 | 9.40 ppb |
| 2022-03-14 | CA2702439_004_004-202203140915 | 8.30 ppb |
| 2022-03-28 | CA2702439_004_004-202203280900 | 8.10 ppb |
| 2022-04-13 | CA2702439_002_002-202204130855 | 15.4 ppb |
| 2022-04-13 | CA2702439_004_004-202204130850 | 8.00 ppb |
| 2022-04-27 | CA2702439_004_004-202204270730 | 7.40 ppb |
| 2022-05-09 | CA2702439_004_004-202205090815 | 8.00 ppb |
| 2022-05-23 | CA2702439_004_004-202205231040 | 5.50 ppb |
| 2022-06-06 | CA2702439_004_004-202206061025 | 6.60 ppb |
| 2022-06-20 | CA2702439_004_004-202206201115 | 6.30 ppb |
| 2022-07-06 | CA2702439_002_002-202207060945 | 22.6 ppb |
| 2022-07-06 | CA2702439_004_004-202207060940 | 8.40 ppb |
| 2022-07-18 | CA2702439_004_004-202207181010 | 8.50 ppb |
| 2022-08-03 | CA2702439_004_004-202208031030 | 6.00 ppb |
| 2022-08-15 | CA2702439_004_004-202208151020 | ND |
| 2022-08-29 | CA2702439_004_004-202208291150 | 2.80 ppb |
| 2022-09-12 | CA2702439_004_004-202209121045 | 6.00 ppb |
| 2022-09-26 | CA2702439_004_004-202209261145 | 5.70 ppb |
| 2022-10-10 | CA2702439_002_002-202210101000 | 9.20 ppb |
| 2022-10-10 | CA2702439_004_004-202210100950 | 5.20 ppb |
| 2022-10-24 | CA2702439_004_004-202210241015 | 6.60 ppb |
| 2022-11-07 | CA2702439_004_004-202211071130 | 7.00 ppb |
| 2022-11-21 | CA2702439_004_004-202211210810 | 6.00 ppb |
| 2022-12-08 | CA2702439_004_004-202212080715 | 6.10 ppb |
| 2022-12-19 | CA2702439_004_004-202212191115 | 8.70 ppb |
| 2023-01-04 | CA2702439_002_002-202301041020 | 13.7 ppb |
| 2023-01-04 | CA2702439_004_004-202301041025 | 10.2 ppb |
| 2023-01-16 | CA2702439_004_004-202301161145 | 9.70 ppb |
| 2023-01-30 | CA2702439_004_004-202301300740 | 10.2 ppb |
| 2023-02-06 | CA2702439_004_004-202302061130 | 9.90 ppb |
| 2023-02-20 | CA2702439_004_004-202302201350 | 9.80 ppb |
| 2023-03-06 | CA2702439_004_004-202303061100 | 9.50 ppb |
| 2023-03-21 | CA2702439_004_004-202303210900 | 9.90 ppb |
| 2023-04-03 | CA2702439_004_004-202304031025 | 8.80 ppb |
| 2023-04-17 | CA2702439_002_002-202304171040 | 14.5 ppb |
| 2023-04-17 | CA2702439_004_004-202304171045 | 8.70 ppb |
| 2023-05-01 | CA2702439_004_004-202305010745 | 8.70 ppb |
| 2023-05-15 | CA2702439_004_004-202305151100 | 9.50 ppb |
| 2023-05-29 | CA2702439_004_004-202305290700 | 7.50 ppb |
| 2023-06-16 | CA2702439_004_004-202306160800 | 7.60 ppb |
| 2023-06-26 | CA2702439_004_004-202306260825 | 7.10 ppb |
| 2023-07-05 | CA2702439_002_002-202307051100 | 14.4 ppb |
| 2023-07-05 | CA2702439_004_004-202307051055 | 8.60 ppb |
| 2023-07-17 | CA2702439_004_004-202307171120 | 7.30 ppb |
| 2023-07-31 | CA2702439_004_004-202307311415 | 8.80 ppb |
| 2023-08-02 | CA2702439_002_002-202308021150 | 13.0 ppb |
| 2023-08-14 | CA2702439_004_004-202308141305 | 8.60 ppb |
| 2023-08-28 | CA2702439_004_004-202308281450 | 6.90 ppb |
| 2023-09-13 | CA2702439_004_004-202309131310 | 8.30 ppb |
| 2023-09-25 | CA2702439_004_004-202309251220 | 9.40 ppb |
| 2023-10-09 | CA2702439_002_002-202310091325 | 22.8 ppb |
| 2023-10-09 | CA2702439_004_004-202310091320 | 9.60 ppb |
| 2023-10-23 | CA2702439_004_004-202310231310 | 8.10 ppb |
| 2023-11-06 | CA2702439_004_004-202311061140 | 10.3 ppb |
| 2023-11-20 | CA2702439_004_004-202311201145 | 10.6 ppb |
| 2023-12-04 | CA2702439_004_004-202312041115 | 8.10 ppb |
| 2023-12-21 | CA2702439_004_004-202312210915 | 7.40 ppb |