Askam Borehole
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The Askam Borehole is a major discharge point for acid mine drainage (AMD) located in Hanover Township, Luzerne County, Pennsylvania, near the village of Askam in the United States. Constructed by the Pennsylvania Department of Environmental Protection in the early 1970s, the borehole was drilled to relieve pressure from rising groundwater in the South-East Mine Pool Complex, which threatened to flood local basements.[1]
One of two primary outlets for this mine pool, alongside the South Wilkes-Barre Boreholes, it released between 3,500 and 7,000 US gallons (13 to 26 m3) of contaminated water per minute into the Nanticoke Creek watershed.[2] The discharge contained high levels of iron, sulfates, and acidity, with a pH of 3.7 and acidity at 633 parts per million as reported in the 1970s by "Operation Scarlift" studies, posing a significant environmental challenge.[3] The borehole, with a diameter of 30 inches (76 cm), operated until it collapsed in 2008, after which replacement boreholes and active treatment systems took over AMD management at the location.[1]
Water that flows from the Askam Borehole contains a significant amount of iron deposits. Upon exposure to air, the iron precipitates in the form of iron hydroxide, a reddish-orange compound that coats stream channels.[4] The borehole contributes pollution to Nanticoke Creek.[5]
In the 1970s, an Operation Scarlift report found the concentration of acidity in the discharges of the Askam Borehole to be 633 parts per million and the pH was measured to be 3.7. The concentration of iron was 384 parts per million and the sulfate concentration was 1936 parts per million. The daily load of acidity was found to be 29,100 pounds (13,200 kg) and the daily load of iron was 17,660 pounds (8,010 kg).[6]
The Askam Borehole discharges 3,500 US gallons (13 m3) of acid mine drainage per minute into Nanticoke Creek. The discharge of the borehole can reach up to 7,000 US gallons (26 m3) per minute during heavy rain.[7] In the 1970s, an Operation Scarlift report found the discharge of the borehole to be 5.51 million gallons per day.[6]
Geography
The Askam Borehole is located in Hanover Township, in the central part of Luzerne County.[4][8] The borehole is in the watershed of Nanticoke Creek, whose watershed has been deep mined and strip mined in the past. The borehole is near Dundee Road and Pennsylvania Route 29.[4]
The Askam Borehole is one of two major outlets for mine water from the South-East Mine Pool Complex, with the other being the South Wilkes-Barre Boreholes.[9] The borehole itself has a diameter of 30 inches (76 cm).[10]
The Askam Borehole is the main point by which the T-B[clarification needed] mine workings discharge acid mine drainage into Nanticoke Creek. The borehole is the only source of water for the lower reaches of Nanticoke Creek.[10] It discharges in two different locations.[11]