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
MS0760079 , Jamie Whitten Delta States Research Cent
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 | 0.166 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2023 – Dec 31, 2025 | 5 | 0.00372 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2022 – Dec 31, 2022 | 5 | 0.144 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2022 – Dec 31, 2022 | 5 | 0.0004 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2021 – Dec 31, 2021 | 5 | 0.087 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2021 – Dec 31, 2021 | 5 | 0.0003 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2018 – Dec 31, 2018 | 5 | 0.1909 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2018 – Dec 31, 2018 | 5 | 0.0009 mg/l | DS000 | Accepted |
| Copper | Jul 1, 2017 – Dec 31, 2017 | 10 | 0.2198 mg/l | DS000 | Accepted |
| Lead | Jul 1, 2017 – Dec 31, 2017 | 10 | 0.001 mg/l | DS000 | Accepted |
| Copper | Jan 1, 2017 – Jun 30, 2017 | 10 | 0.2674 mg/l | DS000 | Accepted |
| Lead | Jan 1, 2017 – Jun 30, 2017 | 10 | 0.0007 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.