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
MS0070007 , Duncan Hill Water Supply
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, 2024 – Dec 31, 2026 | 5 | 0.509 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2024 – Dec 31, 2026 | 5 | 0.0009 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2023 – Dec 31, 2025 | 5 | 0.0661 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2023 – Dec 31, 2025 | 5 | 0 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2020 – Dec 31, 2022 | 5 | 0.474 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2020 – Dec 31, 2022 | 5 | 0.0005 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.1681 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2017 – Dec 31, 2019 | 5 | 0.001 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2015 – Dec 31, 2017 | 5 | 0.265 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2015 – Dec 31, 2017 | 5 | 0.0011 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2012 – Dec 31, 2014 | 5 | 0.3054 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2012 – Dec 31, 2014 | 5 | 0.0021 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2009 – Dec 31, 2011 | 5 | 0.1412 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2009 – Dec 31, 2011 | 5 | 0.0011 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2006 – Dec 31, 2008 | 5 | 0.078 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2006 – Dec 31, 2008 | 5 | 0.0003 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2003 – Dec 31, 2005 | 5 | 0.1676 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2003 – Dec 31, 2005 | 5 | 0.0008 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2000 – Dec 31, 2002 | 5 | 0.094 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2000 – Dec 31, 2002 | 5 | 0.003 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1996 – Dec 31, 1996 | 5 | 0.304 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1996 – Dec 31, 1996 | 5 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1995 – Dec 31, 1995 | 5 | 0.244 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1995 – Dec 31, 1995 | 5 | 0 mg/l | DS000 | Accepted |
| Copper | Jan 1, 1994 – Jun 30, 1994 | 10 | 0.357 mg/l | DS000 | Accepted |
| Lead | Jan 1, 1994 – Jun 30, 1994 | 10 | 0.002 mg/l | DS000 | Accepted |
| Copper | Jul 1, 1993 – Dec 31, 1993 | 10 | 0.185 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.