Woodland Pulp, LLC
Woodland, Maine
Hydraulic Transient Analysis
Woodland Pulp, LLC
Woodland, Maine
Hydraulic Transient Analysis
Woodland Pulp plans to replace approximately 1,100 feet of the existing 2.3-mile-long pipeline that conveys process wastewater from the Woodland Mill Effluent Treatment Pump Station (EPS) to an aerated lagoon. The existing unlined steel pipeline has experienced several breaks due to significant deterioration of the pipe wall and will be replaced with 42-inch epoxy lined steel pipe. NHC performed pump power failure and pump startup simulations for the EPS and developed surge control measures to protect the integrity of the existing and new pipelines. We recommended that the existing surge tanks at the pump station be placed back in service after they are cleaned, tested, and if necessary, re-certified. It was also recommended that a controlled venting sewage vacuum relief valve be installed to control negative pressures in the pipeline and that a pressure relief valve be installed at the EPS to prevent over-pressurization of the surge tanks in the unlikely event that all three pumps at the pump station are operated.