Wastewater Pump Station Rehabilitation to Increase Capacity and Decrease Grease, Odor and Sedimentation Maintenance Issues

摘要

Wastewater pump stations are an integral part of our nation's critical but aging infrastructure and many of these stations are approaching the end of their originally planned design life. As with many critical infrastructure components, budget strapped communities are looking to not only extend the life of these systems but to also increase the capacity. In many cases the systems are being asked to operate in conditions that were not anticipated during the original design. For example, significant development may be resulting in significantly larger than anticipated grease and grit loads which results in increased maintenance and operational downtime. Stations that may have been designed for slow moving approach flow to allow for entrained gases to rise to the surface may be providing the ideal environment for grease and sediment accumulation. Municipalities are continually faced with the need for additional capacity and with limited budgets, many are choosing to rehabilitate and increase the capacity of existing stations. This paper presents the results of physical modeling efforts for several different wastewater pump stations. Each station exhibited unique challenges and problems including excessive grease accumulation, grit and sediment accumulation, hydrogen sulfide formation and poor pump performance. The intention of this paper is to demonstrate how relatively minor modifications to existing wet wells can allow for relatively large increases in flow while also resulting in a significant improvement in approach flow and a decrease in required maintenance.