Reclamation

“I know of no other project in the world that’s making such exemplary use of their mineral resources. Turning mine-scarred land into a botanic garden takes the concept of ‘higher and better use’ to a new level.” — J. Scott Roberts, Deputy Secretary, Pennsylvania Department of Environmental Protection, Harrisburg

When Allegheny County agreed to the lease the land to the Pittsburgh Botanic Garden, the site seemed nearly perfect: great location, wooded slopes, wide plateaus, beautiful vistas – quintessential Pittsburgh. While everyone knew the property sat above abandoned coal mines, like a lot of land in Pittsburgh, two things occurred that seriously downgraded the assessment of “perfect.”

  • A water quality study conducted by Hedin Environmental in 2003, funded by a $50,000 PA DEP grant, found the future Garden’s main water source was so polluted with Acid Mine Discharge (pH 2.8) it could not be used for irrigation. Acid Mine Drainage occurs when iron pyrite in the mines is exposed to oxygen and water, producing salts and heavy metals including iron, manganese, nickel and cobalt.
  • Hurricane Ivan dumped 6 inches of rain on Pittsburgh in September 2004.  The abandoned mines overflowed, causing flooding and landslides.

This news was dire, as a botanic garden needs a cheap reliable supply of clean water during the summer to keep the gardens growing. Simply “cleaning” the Acid Mine Discharge on the site would have been cost prohibitive.  The only logical alternative was to remove the mines. The expense and complexity of such an effort initially seemed out of reach.

An innovative plan was developed working with Allegheny County, the PA Department of Environmental Protection (DEP), and the U.S. Office of Surface Mining and Reclamation (OSMRE).  The Garden re-negotiated its lease with Allegheny County to allow removal of the coal mines by a process known as reclamation. Even more important, the owner of the coal beneath the site donated his royalties to help pay for reclamation activities.  And so we began extracting the residual coal in the mines before collapsing them in November 2010.  The sale of the coal will pay for the $7.9 million reclamation.

Removing the mines reaps multiple benefits:  It stabilizes the land, protecting future buildings from mine subsidence.  It cleans the water for irrigation and reduces pollution entering Robinson Run, a major tributary of Chartiers Creek.  to date, we have built 3 irrigation ponds, capable of holding 2 million gallons of water to eliminate future reliance on municipal water.