North Fork Project
sponsorship, a new facility was installed to treat acidic,
metal-bearing drainage from an abandoned underground coal
mine on property at the Pittsburgh International Airport, adjacent to the Findlay Connector in Findlay Township,
The system is preventing about 16 tons (32,300 lbs) of acid
and more than 16 tons (32,000 lbs) of iron compounds
annually from entering the North Fork of Montour Run.
Prime subcontractor was BioMost, Inc.
The $674,281 total project cost was funded with $337,367
from the DEP’s Growing Greener program and $100,000 from
OSM's Watershed Cooperative Agreement Program.
In addition, in-kind services valued at $189,120
were provided by the PA Turnpike Commission in
conjunction with the building of the Southern Beltway's
Also, matching cash, goods, and services valued at $47,794
have been provided by BioMost and its partners.
that were entailed included design, permitting, erosion and
sedimentation controls, clearing, access road construction,
dewatering, grading, and revegetation of the restoration
site, which is situated at the Pittsburgh International
The system consists of:
mine drainage conveyance pipe running beneath the Findlay
Connector, including alkaline bedding stone, installed by
the Turnpike Commission for purposes of de-watering the
Clinton Block mine complex.
Three settling ponds installed by the Turnpike Commission
for mine de-watering and modified for long-term use during
the course of this project.
A significant portion of the dissolved iron
precipitates and settles in these ponds.
pair of vertical flow ponds that can operate either in
parallel or in series.
These are basically limestone- and mulch-filled
basins that neutralize acidity and generate alkalinity.
1/3-acre treatment wetland that completes the precipitation
of the iron.
on the results of initial after-construction sampling, this
passive treatment system has reduced the acidity from an
influent level of about 110 mg/l CaCO3
to an effluent level of
-166 (net alkaline).
The iron has been reduced from an influent level of
95 mg/l to an effluent level of less than 1 mg/l.
The acid and iron loadings to the
receiving stream from the North Fork site have also been
reduced, and the health of an estimated 2 miles’ length of
this stream has been substantially improved.
Water quality in the main trunk of Montour Run has
also been positively impacted by the cleanup of the North
Fork, improving the survivability of fish and other aquatic
PO Box 15509
Pittsburgh PA 15224-0509
© 2008 Montour Run Watershed Association