This is a rebuild of Drinking Water Watch and not yet the official record. Use the agency’s current Drinking Water Watch for anything you need to rely on.
Lead and copper
MS0730010 , Lake Arrowhead
Every monitoring period on record is listed here. This page applies no date range. The same list limited to the last two years.
| Analyte | Monitoring period | Samples | 90th percentile | Facility | Data quality |
|---|---|---|---|---|---|
| Copper | Jan 1, 2021 – Dec 31, 2023 | 5 | 0.0066 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2021 – Dec 31, 2023 | 5 | 0 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2018 – Dec 31, 2020 | 5 | 0.011 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2018 – Dec 31, 2020 | 5 | 0.0004 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.1019 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.003 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2016 – Dec 31, 2016 | 5 | 0.0455 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2016 – Dec 31, 2016 | 5 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2015 – Dec 31, 2015 | 5 | 0.036 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2015 – Dec 31, 2015 | 5 | 0.0033 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2014 – Dec 31, 2014 | 5 | 0.046 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2014 – Dec 31, 2014 | 5 | 0.0017 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2013 – Dec 31, 2013 | 5 | 0.0216 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2013 – Dec 31, 2013 | 5 | 0.0099 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2012 – Dec 31, 2012 | 5 | 0.1639 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2012 – Dec 31, 2012 | 5 | 0 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2011 – Jun 30, 2011 | 5 | 0.1132 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2011 – Jun 30, 2011 | 5 | 0.0035 mg/l | DS000 | Accepted |
| Copper | Jul 1, 2010 – Dec 31, 2010 | 5 | 0.0746 mg/l | DS000 | Accepted |
| Lead | Jul 1, 2010 – Dec 31, 2010 | 5 | 0.0025 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2010 – Dec 31, 2010 | 5 | 0.2885 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2010 – Dec 31, 2010 | 5 | 0.0483 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2009 – Dec 31, 2009 | 6 | 0.0068 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2009 – Dec 31, 2009 | 6 | 0.0002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2008 – Dec 31, 2008 | 6 | 0.015 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2008 – Dec 31, 2008 | 6 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2006 – Dec 31, 2006 | 5 | 0.0498 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2006 – Dec 31, 2006 | 5 | 0.0002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2004 – Dec 31, 2004 | 5 | 0.0175 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2004 – Dec 31, 2004 | 5 | 0.0005 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2000 – Dec 31, 2000 | 5 | 0.055 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2000 – Dec 31, 2000 | 5 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1996 – Dec 31, 1996 | 4 | 0.052 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1996 – Dec 31, 1996 | 4 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1995 – Jun 30, 1995 | 5 | 0 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1995 – Jun 30, 1995 | 5 | 0.004 mg/l | DS000 | Accepted |
| Copper | Jul 1, 1994 – Dec 31, 1994 | 10 | 0 mg/l | DS000 | Accepted |
| Lead | Jul 1, 1994 – Dec 31, 1994 | 10 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jul 1, 1993 – Dec 31, 1993 | 6 | 0.063 mg/l | DS000 | Accepted |
| Lead | Jul 1, 1993 – Dec 31, 1993 | 6 | 0.002 mg/l | DS000 | Accepted |
No date of receipt is recorded for any of these summaries.
What the 90th percentile is
The 90th percentile of all samples collected from the distribution system is the standard that the US Environmental Protection Agency has chosen for determining compliance with the Lead and Copper Action Level under the federal Lead and Copper Rule. The 90th percentile is determined by ranking all sample results from lowest to highest and finding a result that is 90% of the number of sample results from the top. For example, if there are 10 sample results, the 90th percentile would be the 9th sample result from the top.
From the help text published with these pages.