Leachate Treatment Facilities Research Articles

The Lycoming County, Pennsylvania, Sanitary Landfill: State‐of‐the‐Art in Ground‐Water Protectiona

ABSTRACTA 120‐acre sanitary landfill site is being developed in north‐central Pennsylvania to serve a six‐county area. The design of the site will prevent ground‐water contamination by leachate from the refuse through the use of a 20‐mil (.5 mm) PVC plastic liner which will lie between two protective layers of sand containing drainpipe networks.Sampling of the composite ground‐water flow from the underdrainpipe network in the sand blanket under the liner will provide sensitive monitoring of the liner performance. In the unlikely event of a leak, the pipe draining that area would be diverted to the leachate treatment facility, thus providing a backup leachate collection system. A thick (15 to 75 feet, 4.6 to 22.9 metres) glacial till deposit is present at the site and confines ground‐water flow within the underlying shale bedrock. The low permeability of the till and the artesian head within the bedrock flow system provide additional protection against ground‐water contamination.Operation of the site will be by the area‐fill method; the refuse will be deposited in 8‐foot (2.4‐metre) lifts up to a maximum height of 120 feet (36.6 metres). Based on an initial refuse deposit rate of 400 tons (363 metric tons) per day, the site is expected to have a 20‐year life at a disposal cost of approximately $5.00 per ton.Local residents who felt this project posed a severe threat to their wells strenuously opposed the project and appealed the State permit. The Pennsylvania Environmental Hearing Board upheld the permit; the decision was appealed to Commonwealth Court and was upheld. Residents remain unconvinced the design and site conditions will provide adequate protection and have petitioned the Pennsylvania Supreme Court to consider another appeal.A baseline water‐quality monitoring program has been undertaken to establish on‐site conditions and a private‐well sampling program will begin before the landfill is in operation. Till and bedrock monitoring wells at the site will be used to evaluate the performance of this landfill; analysis of the nearby private wells will be provided to the owners to demonstrate confidence in the design and the satisfactory operation of the ground‐water protection measures.