Blackstone Environmental assisted the City of St. Joseph, Missouri landfilling operations in designing and installing non-traditional high-density polyethylene (HDPE) solutions on the existing landfill gas (LFG) gas collection system. Landfill staff discovered failing factory gusset welds on two LFG condensate collection sumps with unusually high oxygen levels in the collected gas streams at the on-site gas-to-energy plant operated by Kansas City Power and Light (KCPL). Landfill staff collected several bids from contractors to repair the condensate sumps with traditional HDPE welding solutions that mainly consisted of rebuilding the sumps with new parts and replacing the failing welds with new ones. Blackstone proposed a unique solution that involved using new HDPE connection technology which would not require any welding.
The overall objective of this project was to provide solutions to repair failing gusset welds on two LFG condensate collection sumps. Blackstone teamed with Victaulic to design a solution that utilized mechanical HDPE couplings to join new pieces of HDPE pipe in the condensate sump systems. Blackstone provided conceptual designs to the landfill staff and provided estimated costs for installing the mechanical coupling solution. After landfill staff approved Blackstone and Victaulic to move forward with the solution, Blackstone provided project management and construction oversight services during completion of the sump re-construction. The first sump was re-constructed in February of 2018 in below freezing conditions. The second sump was re-constructed in April of 2018.
Sump re-construction with the mechanical couplings provided a quick and economical solution which allowed landfill staff to complete the repairs without needing to rely on an outside contractor. Methane levels in the gas collection system have returned to normal rates indicating the re-constructed sumps are functioning properly. The City was pleased with the end product and will be utilizing the mechanical couplings for future repairs to the gas system. Blackstone was able to provide the City of St. Joseph an out-of- the-box solution which ultimately saved them time and money.