Chester County Lanchester Landfill

Narvon, Pennsylvania

ARM provided final design and construction-phase engineering services for the Phase 1 Closure of Area C and Stage 1 Construction of Area D for Lanchester Landfill. These services included the design of a landfill gas management system and modification of the existing system during construction of the "piggyback" liner system for Area D.

Modifications to of the existing gas management system were necessary because an existing closure cap was to be incrementally removed for placement of new waste, during which the existing system in the closed area was to remain operational. ARM completed engineering design and construction drawings for the modification of the existing gas system allowing gas management during the placement of additional waste.

Project Highlights

Important features of the gas management system design is allowing on-going use of the existing gas system without operational hardship, and overall gas management for the expansion relative to regulatory requirements, odor control, and a planned beneficial landfill gas re-use project.

Placement of Shallow Landfill Gas Collection Trenches, within the Existing Waste, Designed for Gas Collection at the Surface of the Existing Waste and Bottom of the New Waste
Installation of HDPE Lateral Pipes in the Trenches
Modification Existing Extraction Wells and Horizontal Gas Collectors which Connect to the Lateral Trench Pipes
Relocation of Existing Above-Ground HDPE Lateral and Header Pipes to Facilitate Continued Uninterrupted Gas Flow and Allow Construction of the Expansion
Installation of Condensate Traps at Low Points to Reduce Interference with Gas Flow Potentially Caused by Condensate
Installation of Control Valves to Provide Operational Control