Allegheny Land Trust
     Helping local people save local land

The Wingfield Pines AMD Project

Solutions to a Cleaner Chartiers Creek

Wingfield Pines has one of eight untreated Abandoned Mine Drainage (AMD) sites along Chartiers Creek.  Allegheny Land Trust is working in partnership with other local conservation organizations (PA Department of Environmental Protection, and Hedin Environmental Engineering) to build a passive AMD treatment system at Wingfield Pines.   This passive treatment system filters metals out of the mine drainage before it enters the creek using natural and sustainable technology.  This project is the first of many AMD remediation projects being considered in the Chartiers Creek Watershed.

How the Passive Treatment System Works

There is a large amount of ferrous iron dissolved in the mine drainage at Wingfield Pines.  When the ferrous iron comes in contact with the air, it turns to rust (ferric/iron oxide).  Each year, 43 tons of iron oxide are deposited into Chartiers Creek from the AMD discharge at Wingfield Pines.  Our plan is to capture these deposits in a series of settling ponds and wetlands before they reach the creek.

The Wingfield Pines AMD remediation plan (designed with assistance fromm Hedin Environmental) uses passive treatment methods to remove this metal from the water.  The drainage flows freely through a series of four pie-shaped settling ponds that capture the iron sediment.  An existing wetland filters out the last of this sediment using native plants.  The design also features observation paths that give students, scientists, and visitors a close-up view of how this system treats AMD...without getting their feet wet!

 

How deep are the settling ponds?

The ponds are designed to be 1.5 to 3.5 feet deep

Do the ponds have a strong smell?

There is little if any change to the smell of the water. Currently there is a faint odor from the hydrogen sulfide in the untreated discharge. The passive treatment system will not add any new chemicals to the water.

Is the water in the ponds toxic?

The water in the settling ponds is not toxice to humans. The sediment can smother insects and plants living on the bottom of health streams.

How many tons of iron oxide does the passive treatment system remove from the WP discharge water in a year?

About 43 tons per year.

Can mosquitoes breed in the ponds?

Mosquitoes breed more often in standing water. The depth and slow, steady flow of water through the settling ponds and into the wetland does not provide habitat for mosquitoes to breed.

How much does it cost to maintain the settling ponds and treatment system?

A unique and beneficial aspect of this system is that it works effectively using only natural processes. The water flows by gravity and the sediment accumulates as it fails to the bottom of the ponds. Operation and management is minimal. There are no mechanical components or additional chemicals used in the design.

What happens to all the iron oxide collected in the settling ponds??

Over time the iron oxide accumulates in the settling ponds. When it reaches one to two feet in depth it will be removed. The plan is to recycle the iron oxide and use it as pigment.

What is Abadoned Mine Drainage (AMD)?

Mineral laden water from abandoned deep and surface coal mines that forms sediment that coats the bottom of waterways and can significantly change the pH chemistry of streams.