[1] It is approximately three miles long and drains the western portion of a coal basin near Kelayres.
[3] The Audenried Tunnel is located approximately 2 miles (3.2 km) east of the community of Sheppton, Pennsylvania.
[2] In 1931, the Glen Alden Coal Company reported that 8,499 feet (2,590 m) from the mouth of the Audenried Tunnel, there was a fissure that discharged close to 800 gallons (approximately 211 liters) per minute.
All of the mine workings in the Jeansville Coal Basin likely drain into the tunnel, as does some water from the surface.
The discharge from the Audenried Tunnel contributes currently as much as 80% of the acid flowing through Catawissa Creek, with previous studies showing up to 84%.
[3] The total concentration of iron in the waters at the confluence of the Audenried Tunnel and Catawissa Creek is 0.7 milligrams per liter, which equates to a load of 71.3 pounds (32.3 kg) per day.
The total concentration of manganese at the confluence is 2.28 milligrams per liter, which equates to a load of 232.4 pounds (105.4 kg) per day.
The total concentration of aluminum is 7.93 milligrams per liter, which equates to a load of 808.2 pounds (366.6 kg) per day.
The total concentration of alkalinity is 2.31 milligrams per liter, which equates to 235.4 pounds (106.8 kg) per day.
[3][5] The tunnel was originally created to decrease the elevation of the area's water table without resorting to the use of pumps, thus allowing the drilling of deep coal mine shafts.
It was successful in doing this, but rendered 33 miles (53 km) of Catawissa Creek devoid of life for 75 years.
[3] In 2006, part of the treatment plant at the mouth of the Audenried Tunnel was buried by a landslide, putting it out of commission.