23 Geologic frameworks and conceptual site models for investigating hydrogeologic conditions in overburden and bedrock aquifers at remediation sites (Posters)

This session will include talks on investigation of impacted groundwater aquifers in a variety of overburden & bedrock lithologies, subsurface architecture controlling flow & transport, and associated remedial solutions.

Monday, 23 March 2026
8:00 AM - 12:00 PM
CCC, Ballroom C

Assessing the Scarlift 15 AMD Treatment System, Northumberland Co., PA

Paper number: 23-1
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

Shamokin Creek is among the approximately 39% of streams in Northumberland County, PA that are impaired.  A major issue for Shamokin Creek is Abandoned Mine Drainage (AMD) from historic anthracite coal mining operations. In Fall 2025, we assessed water quality in Shamokin Creek and the Scarlift 15 Vertical Flow Pond (VFP) treatment system, installed in 2006 near Ranshaw, PA, to evaluate its effectiveness in treating AMD from the Corbin Mine Drift before discharge into Shamokin Creek. Twelve water samples were collected in November 2025 from various locations throughout the treatment system and analyzed for pH, dissolved oxygen, conductivity, alkalinity, acidity, and iron, and manganese concentrations, with results compared to 2023 data.

The VFP system showed pH values ranging from 3.3 to 6.8 throughout the treatment cells, with effluent from the final vertical flow cell achieving pH values between 6.0 and 7.0, approaching the target range of 6.2-7.0 for optimal performance. Dissolved oxygen levels were elevated in oxygenation ponds but decreased in pipe outflows. Total alkalinity increased and total acidity decreased substantially by the final treatment stage, though earlier treatment cells showed minimal change. Iron concentrations decreased by approximately 50% through the system, demonstrating effective removal. However, manganese concentrations showed no significant reduction and in some cases increased, indicating the system is ineffective for manganese remediation.

The Scarlift 15 VFP is underperforming relative to design specifications, with inconsistent pH elevation and delayed alkalinity improvement suggesting potential dysfunction in limestone layers within intermediate treatment cells. In addition, significant precipitate accumulation has altered the intended vertical flow pattern, allowing some untreated mine drainage to bypass treatment. Despite these issues, the system achieves partial treatment success, particularly for iron removal and acidity reduction, demonstrating net positive environmental benefit but requiring maintenance to restore design performance.

Effective AMD treatment at the Scarlift 15 site is critical for restoration of Shamokin Creek and protection of the Susquehanna River watershed, enhancing water quality, supporting aquatic ecosystem recovery, and reducing the environmental legacy of abandoned mining operations affecting Northumberland County.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411499

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