Arsenic
Laytonville County Water District
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 6.93 ppb | 53 | 53 | 3.70 ppb - 49.0 ppb |
2015 | 6.69 ppb | 51 | 51 | 2.70 ppb - 14.0 ppb |
2016 | 7.84 ppb | 53 | 53 | 3.80 ppb - 41.0 ppb |
2017 | 9.33 ppb | 53 | 53 | 4.90 ppb - 47.0 ppb |
2018 | 7.10 ppb | 53 | 53 | 4.60 ppb - 43.0 ppb |
2019 | 8.08 ppb | 53 | 53 | 5.60 ppb - 14.0 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 |
---|---|---|
2014-01-07 | 9534-003-0930 | 5.50 ppb |
2014-01-15 | 9534-003-0909 | 5.00 ppb |
2014-01-21 | 9534-003-1115 | 4.90 ppb |
2014-01-28 | 9534-003-1023 | 4.20 ppb |
2014-02-04 | 9534-003-0924 | 3.70 ppb |
2014-02-11 | 9534-003-0920 | 5.70 ppb |
2014-02-18 | 9534-003-1117 | 5.30 ppb |
2014-02-25 | 9534-003-0950 | 4.70 ppb |
2014-03-04 | 9534-003-1121 | 5.20 ppb |
2014-03-11 | 9534-003-1130 | 4.40 ppb |
2014-03-18 | 9534-003-1045 | 8.10 ppb |
2014-03-25 | 9534-003-0958 | 6.40 ppb |
2014-04-01 | 9534-003-1032 | 4.80 ppb |
2014-04-08 | 9534-003-1004 | 5.20 ppb |
2014-04-15 | 9534-003-0000 | 4.50 ppb |
2014-04-22 | 9534-003-1130 | 4.60 ppb |
2014-04-28 | 9534-003-1042 | 5.30 ppb |
2014-05-06 | 9534-003-1127 | 8.50 ppb |
2014-05-13 | 9534-003-1043 | 8.60 ppb |
2014-05-20 | 9534-003-1212 | 6.80 ppb |
2014-05-27 | 9534-003-1030 | 5.90 ppb |
2014-06-03 | 9534-003-0943 | 5.50 ppb |
2014-06-10 | 9534-003-0915 | 8.40 ppb |
2014-06-17 | 9534-003-0840 | 4.50 ppb |
2014-06-24 | 9534-003-0000 | 8.80 ppb |
2014-07-01 | 1610-003-1005 | 7.00 ppb |
2014-07-08 | 9534-003-0943 | 9.00 ppb |
2014-07-15 | 9534-003-0920 | 5.40 ppb |
2014-07-22 | 9534-003-0950 | 5.70 ppb |
2014-07-29 | 9534-003-0000 | 8.80 ppb |
2014-08-05 | 9534-003-0905 | 6.90 ppb |
2014-08-12 | 9534-003-0848 | 13.0 ppb |
2014-08-19 | 9534-003-0820 | 6.60 ppb |
2014-08-26 | 9534-003-0945 | 7.80 ppb |
2014-09-02 | 9534-003-1013 | 6.10 ppb |
2014-09-07 | 9534-003-0758 | 4.50 ppb |
2014-09-16 | 9534-003-0737 | 4.50 ppb |
2014-09-23 | 9534-003-0912 | 4.20 ppb |
2014-09-30 | 9534-003-0855 | 4.10 ppb |
2014-10-07 | 9534-003-0828 | 6.20 ppb |
2014-10-14 | 9534-003-0907 | 5.90 ppb |
2014-10-21 | 9534-003-0000 | 5.90 ppb |
2014-10-28 | 9534-003-0735 | 8.80 ppb |
2014-11-04 | 9534-003-0845 | 4.10 ppb |
2014-11-11 | 9534-003-0840 | 5.50 ppb |
2014-11-18 | 9534-003-1015 | 6.60 ppb |
2014-11-25 | 9534-003-0837 | 4.70 ppb |
2014-12-02 | 9534-003-0740 | 7.60 ppb |
2014-12-13 | 1610-003-1005 | 5.70 ppb |
2014-12-16 | 9534-003-0845 | 6.70 ppb |
2014-12-23 | 1610-001-0650 | 49.0 ppb |
2014-12-23 | 1610-003-0746 | 5.00 ppb |
2014-12-30 | 1610-003-0935 | 7.60 ppb |
2015-01-06 | 9534-003-0822 | 5.00 ppb |
2015-01-13 | 9534-003-0842 | 6.20 ppb |
2015-01-20 | 9534-003-0916 | 9.90 ppb |
2015-01-27 | 9534-003-0919 | 11.0 ppb |
2015-02-03 | 9534-003-1030 | 14.0 ppb |
2015-02-10 | 9534-003-0830 | 7.20 ppb |
2015-02-17 | 9534-003-0850 | 6.60 ppb |
2015-02-24 | 9534-003-1001 | 5.70 ppb |
2015-03-03 | 9534-003-0912 | 7.30 ppb |
2015-03-10 | 9534-003-0925 | 5.90 ppb |
2015-03-17 | 9534-003-0936 | 6.10 ppb |
2015-03-24 | 9534-003-1230 | 7.60 ppb |
2015-04-01 | 9534-003-0919 | 4.60 ppb |
2015-04-07 | 1610-003-0857 | 7.10 ppb |
2015-04-14 | 9534-003-1030 | 4.60 ppb |
2015-04-21 | 9534-003-1243 | 10.00 ppb |
2015-04-28 | 9534-003-1120 | 12.0 ppb |
2015-05-05 | 9534-003-0929 | 7.00 ppb |
2015-05-15 | 1610-003-1130 | 9.10 ppb |
2015-05-19 | 9534-003-1145 | 5.90 ppb |
2015-05-26 | 9534-003-1157 | 5.20 ppb |
2015-06-03 | 9534-003-1211 | 7.20 ppb |
2015-06-09 | 9534-003-1142 | 11.0 ppb |
2015-06-16 | 9534-003-1235 | 6.60 ppb |
2015-06-23 | 9534-003-1157 | 7.40 ppb |
2015-06-30 | 9534-003-1137 | 5.80 ppb |
2015-07-07 | 9534-003-1216 | 5.30 ppb |
2015-07-14 | 9534-003-1132 | 7.30 ppb |
2015-07-21 | 9534-003-1130 | 7.60 ppb |
2015-07-28 | 9534-003-1211 | 10.00 ppb |
2015-08-04 | 9534-003-1147 | 7.40 ppb |
2015-08-12 | 9534-003-1118 | 5.20 ppb |
2015-08-18 | 9534-003-1123 | 9.60 ppb |
2015-08-25 | 9534-003-1110 | 7.20 ppb |
2015-09-01 | 9534-003-1118 | 5.40 ppb |
2015-09-08 | 9534-003-1037 | 6.60 ppb |
2015-09-18 | 1610-003-0722 | 5.70 ppb |
2015-09-22 | 1610-003-0908 | 7.00 ppb |
2015-09-29 | 1610-003-0830 | 7.30 ppb |
2015-10-06 | 1610-003-0806 | 6.50 ppb |
2015-10-13 | 1610-003-0757 | 2.70 ppb |
2015-10-27 | 1610-003-0744 | 4.60 ppb |
2015-11-03 | 1610-003-0735 | 4.80 ppb |
2015-11-10 | 1610-003-0713 | 5.00 ppb |
2015-11-17 | 1610-003-0702 | 3.50 ppb |
2015-11-24 | 1610-003-0719 | 5.60 ppb |
2015-12-01 | 1610-003-0709 | 5.30 ppb |
2015-12-08 | 1610-003-0737 | 3.20 ppb |
2015-12-15 | 1610-003-0731 | 3.30 ppb |
2015-12-22 | 1610-003-0740 | 4.80 ppb |
2015-12-29 | 1610-003-0720 | 4.20 ppb |
2016-01-05 | 1610-003-0755 | 6.00 ppb |
2016-01-12 | 1610-003-0736 | 4.70 ppb |
2016-01-19 | 1610-003-0739 | 4.60 ppb |
2016-01-28 | 1610-003-0758 | 5.10 ppb |
2016-02-02 | 1610-003-0755 | 4.90 ppb |
2016-02-09 | 1610-003-0731 | 4.70 ppb |
2016-02-16 | 1610-003-0730 | 5.60 ppb |
2016-02-23 | 1610-003-0733 | 5.90 ppb |
2016-03-01 | 1610-003-0823 | 4.80 ppb |
2016-03-08 | 1610-003-0802 | 6.70 ppb |
2016-03-15 | 1610-003-0851 | 6.10 ppb |
2016-03-22 | 1610-003-0755 | 3.80 ppb |
2016-03-29 | 1610-003-0924 | 7.60 ppb |
2016-04-05 | 1610-003-0834 | 6.60 ppb |
2016-04-12 | 1610-003-0707 | 5.20 ppb |
2016-04-19 | 1610-003-0800 | 5.80 ppb |
2016-04-26 | 1610-003-0907 | 7.90 ppb |
2016-05-03 | 1610-003-0815 | 6.10 ppb |
2016-05-10 | 1610-003-0900 | 5.50 ppb |
2016-05-17 | 1610-003-0910 | 6.80 ppb |
2016-05-24 | 1610-003-0841 | 4.70 ppb |
2016-06-01 | 1610-003-0713 | 8.10 ppb |
2016-06-07 | 1610-003-0838 | 7.20 ppb |
2016-06-14 | 1610-003-0726 | 7.60 ppb |
2016-06-21 | 1610-003-0743 | 6.90 ppb |
2016-06-28 | 1610-003-0739 | 8.80 ppb |
2016-07-05 | 1610-003-0807 | 12.0 ppb |
2016-07-12 | 1610-003-0810 | 5.50 ppb |
2016-07-19 | 1610-003-0918 | 8.00 ppb |
2016-07-26 | 1610-003-1000 | 8.60 ppb |
2016-08-02 | 1610-003-0817 | 10.00 ppb |
2016-08-09 | 1610-003-0812 | 9.60 ppb |
2016-08-16 | 1610-003-0906 | 8.50 ppb |
2016-08-23 | 1610-003-0748 | 9.50 ppb |
2016-08-30 | 1610-003-0719 | 10.00 ppb |
2016-09-07 | 1610-003-0850 | 10.00 ppb |
2016-09-13 | 1610-003-0826 | 7.80 ppb |
2016-09-22 | 1610-003-0728 | 8.60 ppb |
2016-09-28 | 1610-003-1009 | 7.80 ppb |
2016-10-04 | 1610-003-0740 | 7.80 ppb |
2016-10-11 | 1610-003-0820 | 7.40 ppb |
2016-10-18 | 1610-003-0805 | 6.10 ppb |
2016-10-25 | 1610-003-0753 | 6.60 ppb |
2016-11-01 | 1610-003-0756 | 6.30 ppb |
2016-11-08 | 1610-001-0655 | 41.0 ppb |
2016-11-08 | 1610-003-0811 | 7.50 ppb |
2016-11-15 | 1610-003-0741 | 7.60 ppb |
2016-11-22 | 1610-003-0809 | 7.50 ppb |
2016-11-30 | 1610-003-0826 | 8.00 ppb |
2016-12-06 | 1610-003-1034 | 9.50 ppb |
2016-12-13 | 1610-003-1003 | 11.0 ppb |
2016-12-20 | 1610-003-1102 | 8.40 ppb |
2016-12-27 | 1610-003-1010 | 7.00 ppb |
2017-01-03 | 1610-003-1004 | 7.00 ppb |
2017-01-10 | 1610-003-0938 | 9.30 ppb |
2017-01-17 | 1610-003-0912 | 8.00 ppb |
2017-01-24 | 1610-003-0935 | 6.70 ppb |
2017-01-31 | 1610-003-0952 | 7.20 ppb |
2017-02-07 | 1610-003-0946 | 6.80 ppb |
2017-02-15 | 1610-003-1105 | 6.60 ppb |
2017-02-21 | 1610-003-1022 | 12.0 ppb |
2017-03-01 | 1610-003-0928 | 5.40 ppb |
2017-03-07 | 1610-003-1006 | 7.90 ppb |
2017-03-15 | 1610-003-1041 | 5.50 ppb |
2017-03-21 | 1610-003-1010 | 6.60 ppb |
2017-03-28 | 1610-003-1003 | 5.60 ppb |
2017-04-04 | 1610-003-1141 | 15.0 ppb |
2017-04-11 | 1610-003-1016 | 9.00 ppb |
2017-04-18 | 1610-003-1020 | 8.20 ppb |
2017-04-25 | 1610-003-0854 | 9.20 ppb |
2017-05-02 | 1610-003-0845 | 9.70 ppb |
2017-05-09 | 1610-003-0811 | 12.0 ppb |
2017-05-16 | 1610-003-0750 | 11.0 ppb |
2017-05-23 | 1610-003-0832 | 12.0 ppb |
2017-05-30 | 1610-003-0733 | 12.0 ppb |
2017-06-06 | 1610-003-0748 | 13.0 ppb |
2017-06-13 | 1610-003-0750 | 14.0 ppb |
2017-06-20 | 1610-003-0924 | 9.40 ppb |
2017-06-27 | 1610-003-0822 | 11.0 ppb |
2017-07-05 | 1610-003-1004 | 5.40 ppb |
2017-07-11 | 1610-003-0909 | 11.0 ppb |
2017-07-19 | 1610-003-0718 | 9.80 ppb |
2017-07-25 | 1610-003-0737 | 32.0 ppb |
2017-08-01 | 1610-003-1056 | 18.0 ppb |
2017-08-08 | 1610-003-0718 | 5.70 ppb |
2017-08-15 | 1610-003-0836 | 5.00 ppb |
2017-08-24 | 1610-003-0931 | 6.00 ppb |
2017-08-29 | 1610-003-0941 | 8.30 ppb |
2017-09-05 | 1610-003-0748 | 8.70 ppb |
2017-09-12 | 1610-003-0825 | 7.60 ppb |
2017-09-19 | 1610-003-0743 | 5.50 ppb |
2017-09-27 | 1610-003-0844 | 4.90 ppb |
2017-10-03 | 1610-003-1010 | 6.40 ppb |
2017-10-10 | 1610-003-0815 | 6.50 ppb |
2017-10-17 | 1610-003-0733 | 6.50 ppb |
2017-10-24 | 1610-003-0826 | 7.10 ppb |
2017-10-31 | 1610-003-0749 | 5.80 ppb |
2017-11-07 | 1610-001-0710 | 47.0 ppb |
2017-11-07 | 1610-003-0901 | 6.50 ppb |
2017-11-14 | 1610-003-0929 | 5.60 ppb |
2017-11-21 | 1610-003-0924 | 6.20 ppb |
2017-11-28 | 1610-003-0928 | 6.00 ppb |
2017-12-05 | 1610-003-1045 | 6.10 ppb |
2017-12-12 | 1610-003-0902 | 6.20 ppb |
2017-12-19 | 1610-003-0847 | 5.00 ppb |
2017-12-26 | 1610-003-1031 | 5.40 ppb |
2018-01-02 | 1610-003-0839 | 6.60 ppb |
2018-01-09 | 1610-003-0910 | 6.90 ppb |
2018-01-16 | 1610-003-0833 | 6.00 ppb |
2018-01-23 | 1610-003-0802 | 5.80 ppb |
2018-01-30 | 1610-003-0840 | 5.50 ppb |
2018-02-07 | 1610-003-0832 | 6.10 ppb |
2018-02-13 | 1610-003-0918 | 6.50 ppb |
2018-02-20 | 1610-003-0832 | 6.50 ppb |
2018-02-27 | 1610-003-0847 | 5.40 ppb |
2018-03-06 | 1610-003-0755 | 6.00 ppb |
2018-03-13 | 1610-003-0842 | 6.30 ppb |
2018-03-20 | 1610-003-0827 | 6.30 ppb |
2018-03-27 | 1610-003-0820 | 7.00 ppb |
2018-04-03 | 1610-003-0742 | 6.30 ppb |
2018-04-10 | 1610-003-0850 | 6.00 ppb |
2018-04-17 | 1610-003-0825 | 5.90 ppb |
2018-04-24 | 1610-003-0843 | 5.90 ppb |
2018-05-01 | 1610-003-0808 | 5.70 ppb |
2018-05-08 | 1610-003-0805 | 7.60 ppb |
2018-05-15 | 1610-003-0825 | 5.80 ppb |
2018-05-22 | 1610-003-0854 | 6.40 ppb |
2018-05-29 | 1610-003-0837 | 5.40 ppb |
2018-06-05 | 1610-003-0917 | 6.10 ppb |
2018-06-12 | 1610-003-0838 | 5.40 ppb |
2018-06-20 | 1610-003-0818 | 6.10 ppb |
2018-06-26 | 1610-003-0827 | 4.90 ppb |
2018-07-05 | 1610-003-0832 | 6.20 ppb |
2018-07-10 | 1610-003-0831 | 4.60 ppb |
2018-07-17 | 1610-003-0842 | 5.90 ppb |
2018-07-24 | 1610-003-0915 | 5.40 ppb |
2018-07-31 | 1610-003-0740 | 6.20 ppb |
2018-08-07 | 1610-003-0821 | 5.00 ppb |
2018-08-14 | 1610-003-0900 | 6.40 ppb |
2018-08-21 | 1610-003-1029 | 5.10 ppb |
2018-08-28 | 1610-003-0805 | 6.70 ppb |
2018-09-04 | 1610-003-0733 | 4.70 ppb |
2018-09-11 | 1610-003-1101 | 4.60 ppb |
2018-09-18 | 1610-003-0815 | 5.10 ppb |
2018-09-25 | 1610-003-0816 | 6.80 ppb |
2018-10-02 | 1610-003-0821 | 7.30 ppb |
2018-10-09 | 1610-003-0906 | 6.40 ppb |
2018-10-16 | 1610-003-0716 | 8.10 ppb |
2018-10-23 | 1610-003-0808 | 6.80 ppb |
2018-10-30 | 1610-003-0814 | 9.40 ppb |
2018-11-06 | 1610-001-0720 | 43.0 ppb |
2018-11-06 | 1610-003-0832 | 9.80 ppb |
2018-11-14 | 1610-003-0805 | 7.40 ppb |
2018-11-21 | 1610-003-0817 | 7.90 ppb |
2018-11-27 | 1610-003-0823 | 6.90 ppb |
2018-12-04 | 1610-003-0823 | 8.50 ppb |
2018-12-11 | 1610-003-0812 | 8.90 ppb |
2018-12-18 | 1610-003-0749 | 6.30 ppb |
2018-12-26 | 1610-003-0754 | 8.60 ppb |
2019-01-02 | 1610-003-0804 | 7.10 ppb |
2019-01-08 | 1610-003-0800 | 7.90 ppb |
2019-01-15 | 1610-003-0748 | 7.90 ppb |
2019-01-22 | 1610-003-0832 | 7.50 ppb |
2019-01-29 | 1610-003-0849 | 8.50 ppb |
2019-02-05 | 1610-003-0825 | 7.70 ppb |
2019-02-12 | 1610-003-0757 | 7.50 ppb |
2019-02-19 | 1610-003-0826 | 7.70 ppb |
2019-02-26 | 1610-003-0818 | 7.00 ppb |
2019-03-05 | 1610-003-0811 | 7.10 ppb |
2019-03-13 | 1610-003-0830 | 6.60 ppb |
2019-03-19 | 1610-003-0815 | 8.70 ppb |
2019-03-27 | 1610-003-0752 | 8.80 ppb |
2019-04-02 | 1610-003-0829 | 6.70 ppb |
2019-04-09 | 1610-003-0812 | 7.20 ppb |
2019-04-16 | 1610-003-0817 | 8.50 ppb |
2019-04-23 | 1610-003-0758 | 8.30 ppb |
2019-04-30 | 1610-003-0757 | 9.50 ppb |
2019-05-07 | 1610-003-0726 | 8.60 ppb |
2019-05-14 | 1610-003-0738 | 9.50 ppb |
2019-05-21 | 1610-003-0755 | 9.00 ppb |
2019-05-28 | 1610-003-0813 | 9.30 ppb |
2019-06-04 | 1610-003-0755 | 9.90 ppb |
2019-06-11 | 1610-003-0803 | 9.60 ppb |
2019-06-19 | 1610-003-0804 | 6.50 ppb |
2019-06-25 | 1610-003-0759 | 8.20 ppb |
2019-07-02 | 1610-003-0812 | 6.40 ppb |
2019-07-10 | 1610-003-0753 | 7.30 ppb |
2019-07-16 | 1610-003-0834 | 8.50 ppb |
2019-07-23 | 1610-003-0827 | 8.40 ppb |
2019-07-30 | 1610-003-0807 | 8.80 ppb |
2019-08-06 | 1610-003-0807 | 8.30 ppb |
2019-08-14 | 1610-003-0820 | 7.60 ppb |
2019-08-20 | 1610-003-0839 | 5.60 ppb |
2019-08-27 | 1610-003-0724 | 9.10 ppb |
2019-09-03 | 1610-003-0813 | 8.90 ppb |
2019-09-10 | 1610-003-0855 | 6.80 ppb |
2019-09-18 | 1610-003-0841 | 7.40 ppb |
2019-09-25 | 1610-003-0819 | 7.80 ppb |
2019-10-01 | 1610-003-0857 | 7.70 ppb |
2019-10-08 | 1610-003-0745 | 6.30 ppb |
2019-10-15 | 1610-003-0800 | 6.40 ppb |
2019-10-22 | 1610-003-0811 | 7.60 ppb |
2019-10-30 | 1610-003-0741 | 7.80 ppb |
2019-11-05 | 1610-003-0757 | 7.00 ppb |
2019-11-12 | 1610-003-0748 | 7.10 ppb |
2019-11-19 | 1610-003-0723 | 6.10 ppb |
2019-11-26 | 1610-003-0738 | 8.30 ppb |
2019-12-03 | 1610-003-0750 | 8.90 ppb |
2019-12-10 | 1610-003-0741 | 9.80 ppb |
2019-12-17 | 1610-003-0803 | 9.80 ppb |
2019-12-26 | 1610-003-0746 | 10.00 ppb |
2019-12-31 | 1610-003-0855 | 14.0 ppb |