Paper No. 63
Presentation Time: 9:00 AM-6:00 PM
ASSESSING GROUNDWATER CONTRIBUTION FROM AMD TREATMENT PONDS TO LAKE ARTHUR, MORAINE STATE PARK, PA
It is well-known that legacy coal mining has had significant impacts on the environment, particularly in the Appalachian coal regions. Legacy underground mining is pervasive, especially in the western part of Pennsylvania. Moraine State Park is an example of an area with demonstrated impacts to water quality from mine effluent. Lake Arthur, the centerpiece of the park, is a reservoir of Muddy Creek, a low-order tributary of the Ohio River. Established in 1970, the lake is a destination for recreational fishermen, boaters, and wildlife observers. In order to create the lake and protect local surface streams, many of the underground mines were sealed. However, over time several have failed and it is not uncommon to find the characteristic orange effluent in tributary streams and seeps. In 1996, a passive wetland treatment system was established and singled out as an educational example of impacts of coal mining in the area and the potential remediation efforts. The three-pond system was estimated to have a life span of twelve years. Over the past several years, the ponds have been monitored by students at California University of PA for educational and research purposes. It has become apparent during that time that the ponds have begun to fail and are no longer buffering Lake Arthur from mine effluent. Iron hydroxide precipitates have accumulated in the beds of the first two ponds, reducing their volume and residence times. Low pH water continues through the system to the third pond where it is not adequately treated before emptying into the lake. In addition to the obvious surface water discharges, it is hypothesized that groundwater contributions through the beds of the ponds is also negatively impacting the lake. Topography alone would indicate that water from the ponds is emerging as a distributed discharge to the shores of the lake. Four piezometers have been placed in series to ascertain the impact of groundwater flow. Piezometric head data suggest a groundwater contribution from Pond 1 and possibly Pond 2, toward the lake. Additionally, temperature data suggest good communication between the groundwater system and the lake. With continued degradation of the ponds, it is likely that the impacts to Lake Arthur will increase over time and will negatively affect water quality.