In 2019, US researchers added fluorescent dye to a Pennsylvania mine-water wetland and flew 12 drone missions; a system designed for 29-hour retention held water for only 4.65 hours
- Visual observations indicated a retention time of about 61 minutes in Cell 3 and 66 minutes in Cell 4.
- Monastery Run Wetland 1, near Latrobe, Pennsylvania, was built in 1997-1998 as a passive treatment system for several discharges from an abandoned underground mine.
- Adequate retention time for iron removal from mine water before discharge to Four Mile Run is provided by the use of settling ponds and wetlands.
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- Visual observations indicated a retention time of about 61 minutes in Cell 3 and 66 minutes in Cell 4.
- Monastery Run Wetland 1, near Latrobe, Pennsylvania, was built in 1997-1998 as a passive treatment system for several discharges from an abandoned underground mine.
- Adequate retention time for iron removal from mine water before discharge to Four Mile Run is provided by the use of settling ponds and wetlands.
Sources: Times of India