Audenried Tunnel  The Audenried Tunnel (also known as the Audenried Mine Tunnel) is a drainage tunnel located in East Union Township, Schuylkill County, Pennsylvania, in the United States. It is approximately three miles long and drains the western portion of a coal basin near Kelayres. It is among the largest sources of acid mine drainage into Catawissa Creek. It also contributes up to 80% of the acidity to Catawissa Creek. The Audenried Tunnel's pH is approximately 4. However, there have been somewhat successful attempts at treating the tunnel outflow in the 21st century. The bedrock in the vicinity of the tunnel is mostly shale and sandstone. The Audenried Tunnel is long. The tunnel runs between the Audenried Mine and the watershed of Catawissa Creek. It is filled with debris and the air inside the tunnel is not breathable. The tunnel roughly follows the synclinal axis of the coal basin it is in. The tunnel drains the Jeansville Coal Basin, which is located between Hazleton and McAdoo. The Audenried Tunnel is located approximately east of the community of Sheppton, Pennsylvania. The tunnel is in width and in height. When the Audenried Tunnel was first built, the first were fully lined with timber due to the low quality of the rock in that part of the tunnel. The next were also supported by timber, but to a lesser extent. In 1931, the Glen Alden Coal Company reported that from the mouth of the Audenried Tunnel, there was a fissure that discharged close to 800 gallons (approximately 211 liters) per minute. It is possible that there is a fault at this location. The Audenried Tunnel is the most downstream mine drainage tunnel to discharge into Catawissa Creek. The Audenried Tunnel discharges into Catawissa Creek near where the Green Mountain Tunnel and the Catawissa Tunnel discharge into the creek. The Audenried Tunnel discharges in a strip mine not far from Catawissa Creek's headwaters. 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%. The average discharge of the tunnel is 12.22 million gallons per day, or about 8500 gallons per minute. However, during heavy rainstorms, the discharge can reach 300,000 gallons per minute.