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
MS0140010 , Town of Lyon
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, 2023 – Dec 31, 2025 | 5 | 0.406 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2023 – Dec 31, 2025 | 5 | 0.0019 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2020 – Dec 31, 2022 | 5 | 0.758 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2020 – Dec 31, 2022 | 5 | 0.0017 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.627 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.0014 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2015 – Dec 31, 2017 | 5 | 0.4521 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2015 – Dec 31, 2017 | 5 | 0.0014 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2012 – Dec 31, 2014 | 6 | 0.7452 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2012 – Dec 31, 2014 | 6 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2009 – Dec 31, 2011 | 6 | 0.6032 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2009 – Dec 31, 2011 | 6 | 0.0071 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2006 – Dec 31, 2008 | 5 | 0.309 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2006 – Dec 31, 2008 | 5 | 0.0028 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2003 – Dec 31, 2005 | 5 | 0.5049 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2003 – Dec 31, 2005 | 5 | 0.0007 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2000 – Dec 31, 2002 | 5 | 0.862 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2000 – Dec 31, 2002 | 5 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1996 – Dec 31, 1996 | 5 | 0.415 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1996 – Dec 31, 1996 | 5 | 0.003 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1995 – Dec 31, 1995 | 5 | 0.437 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1995 – Dec 31, 1995 | 5 | 0.001 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1994 – Jun 30, 1994 | 10 | 0.293 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1994 – Jun 30, 1994 | 10 | 0.003 mg/l | DS000 | Accepted |
| Copper | Jul 1, 1993 – Dec 31, 1993 | 10 | 0.236 mg/l | DS000 | Accepted |
| Lead | Jul 1, 1993 – Dec 31, 1993 | 10 | 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.