The Monastery Run Project consists of five separate projects completed through the cooperative efforts of all members of the Loyalhanna Mine Drainage Coalition. The project site is located 2 miles southwest of the small community of Latrobe, Pennsylvania, along with State Route 1045 (Beatty Road) adjacent to Saint Vincent College. Monastery Run is located in Westmoreland County, Pennsylvania, and is within the Loyalhanna Creek drainage system. Four Mile Run is a tributary of Monastery Run, which enters Loyalhanna Creek near the Borough of Latrobe.
Four Mile Run provides the first significant source of abandoned mine drainage (AMD) to Loyalhanna Creek. Upstream of this point, Loyalhanna Creek is a very popular fishery and provides recreational benefits to a densely populated area less than 40 miles from the city of Pittsburgh. Downstream of Four Mile Run, Loyalhanna Creek is severely impacted by iron precipitate coating the stream bottom from Monastery Run and adjacent discharges. About 2 miles further downstream, mine drainage enters from two tributaries, adding to the degradation of Loyalhanna Creek downstream of Loyalhanna Lake. A total distance of approximately 17 miles of Loyalhanna Creek, 1 mile of Four Mile Run, and 1 mile of Monastery Run are AMD impacted.
The coal mines in the region surrounding the Monastery Run project sites were in operation prior to 1889 through 1967. The bulk of the mining was performed between 1900 and 1940 utilizing primarily the room and pillar method of mining. This method creates rooms from which the coal is mined leaving only pillars to support the overburden. During second or retreat mining, most of the pillars are removed allowing the overburden to collapse under its own weight. The mining was confined almost exclusively to the Pittsburgh Coal seam, which was primarily mined for its exceptional value as a coking coal. The primary coal companies which operated mines in the Monastery Run Project area included the Benedictine Society, Westmoreland and Fayette Coal Company, Mount Pleasant Coke Company, Latrobe Coal Company and Mount Pleasant By-Product Coal Company.
The water in the mined out Pittsburgh Coal Seam under the project is hydraulically connected to a very large mine pool located in the Latrobe Syncline. The majority of the mine workings located throughout the syncline are flooded. Water infiltrating into the abandoned mine workings from groundwater floods the voids, due to the synclinal nature of the seam. The hydraulic head of the mine pool in the flooded coal seam is greater than the hydraulic head of the overlying aquifer creating upward pressure and subsequent flow of mine drainage into the groundwater table. This phenomenon is known as groundwater mounding. Groundwater mounding has caused the discharge of the mine drainage contaminated groundwater at the surface via fractures, open boreholes, and subsidence holes. Wetlands had developed along Four Mile Run since the cessation of mining and were the result of groundwater mounding.
Local efforts to address AMD problems in the Loyalhanna Creek were initiated in the early 1990’s with the formation of a group that eventually became known as the “Loyalhanna Creek Mine Drainage Coalition”. This very active and dynamic group consisted of several local organizations, including the Westmoreland County Conservation District, the Loyalhanna Creek Watershed Association, and the Katherine Mabis McKenna Foundation, as well as local businesses, and Saint Vincent College, which owned much of the land where the AMD surfaced. The local groups were assisted by state agencies, including DEP’s Bureau of Abandoned Mine Reclamation (BAMR), Bureau of Watershed Conservation and Greensburg District Mining Office, and Federal agencies, including the former Bureau of mines (now under the Department of Energy), the Natural Resources Conservation Service (NRCS), and the Office of Surface Mining.
The Coalition decided to take a “top-down” approach to tackling the water quality problems in Loyalhanna Creek, meaning that the upstream discharges would be addressed first, with the focus moving downstream upon successful abatement/treatment of the Monastery Run discharges. The Coalition formed two separate committees to keep the momentum going in this effort. The Steering Committee provided the organizational support, kept the local citizens informed and involved, and looked for funding sources and other assistance in addressing the AMD problems. The Technical Needs Committee grappled with the complex technical issues involved in collecting and treating the AMD and evaluating impacts to the watershed.
Three major funding sources eventually emerged: The NRCS, DEP’s Bureau of Abandoned Mine Reclamation, and EPA’s 319 Nonpoint Source Program, which was administered by DEP’s Bureau of Watershed Conservation. The NRCS, using the P. L. 566 Watershed Protection Program, would provide 50% of construction funds for five project sites, while the two DEP agencies would provide 50% match. Private Foundations also contributed financial assistance. The technical committee identified five primary project sites to address. The sites were identified as the Beatty Road Subsidence Area, Wetland No.1, Wetland No.2, Wetland No.3 and the Bubbler. As the project developed, the treatment of the discharge known as the “bubbler” was incorporated into the wetland treatment systems identified as Wetland No.2 and Wetland No.3.
In some respects, the AMD problem in Monastery Run was relatively simple to address. The discharges were primarily alkaline and iron being the only contaminant of any significance. This allowed for a much simpler design for the treatment of the discharges using passive facilities. In addition, three of the five project sites were on property owned by Saint Vincent College, whose staff and administration were very enthusiastic partners in this endeavor. These same three project sites had ample area available to construct passive treatment facilities. However, there remained several complex technical issues to overcome. The volume of some of the discharges fluctuated wildly. In particular, one of the discharges reached a high of 1600 gallons per minute (gpm) during high flow conditions, while this same discharge would stop flowing under low flow conditions. Treatment facilities needed to be designed to deal with these extremes. Another significant concern was capturing all the contaminated flow in the constructed facilities. Discharges surfaced as diffuse seeps in existing wetlands, and it was believed that base flow into Monastery Run was also contaminated. Lastly, one discharge had to be piped upslope to a treatment facility using the head artesian discharge to move the water. Careful analyses were needed to determine the feasibility of collecting the AMD and getting it to treatment facilities.