The sewer lift station of an urban municipality is old. Pumps are nearing the end of their useful life, while controls need modernization and the access hatch needs to be replaced. Although the concrete wetwell appears solid in its structure, it is in need of to be updated.
Should the station be gone? Not necessarily. The more important question to ask is whether the existing infrastructure can accommodate the pumping system of current standards without compromising reliability and capacity.
Image credit: romtecutilities.com
Retrofitting a pumping station can be a fantastic method to preserve infrastructure and replace components that have become obsolete.
Start with the Structures Nobody Wants To Replace
The wet well is typically one of the more expensive and challenging components to replace as it is submerged, connected to existing pipes, and crucial for wastewater collection.
Intentionally retaining the concrete structure could help in reducing excavation work and construction.
However, the deterioration of the access hatch can complicate the process. Romtec Utilities identifies wet well hatch replacement as a standard retrofit requirement. It could be more durable to replace the top slab instead of constructing a new hatch onto deteriorated concrete. This will allow for greater access to the structure as well as prolong its utility, without having to completely rebuild the wet well.
A More Powerful Pump Changes the Engineering
Imagine that the area of residence has increased significantly since the initial lift station installation. It is possible that the current pumps are not capable of handling the increased the flow of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers must also evaluate the requirements of the hydraulic system, including flow and total dynamic head. Installing a larger pump without checking these parameters can cause problems in operation instead of resolving these. Making plans for future capacity in the initial design stage can make later expansion considerably easier.
Keep waste water moving during construction
Retrofitting a wastewater pumping station has its own unique challenges, which is not faced by other construction projects. The station may have to be operational during construction.
Wastewater continues arriving even when contractors are in the process of working. According to the study an interim bypass pumping system could be required to sustain service while the equipment that is in use is removed or new components installed.
Romtec Utilities fought this kind of challenge in the Federal Law Enforcement Training Center located in Brunswick, Georgia.
The project consisted of replacing two older wastewater lift stations and ensuring the operation at the facility. Site-specific engineering packages, bypass pumping techniques helped accommodate existing station footprints as well as operational needs. This example shows the importance of focusing on construction sequencing prior to installation.
If you think replacement is the better alternative, then replacement is the best
It is not possible for every station to be renovated. Sewer lift stations might have to be replaced for a damaged wet well or a lack of structural capacity.
When making a choice, it is important to consider the structural integrity of the building, its compatibility with equipment, accessibility to construction, continuity of service and the long-term requirements. Romtec Utilities starts retrofitting and replacing projects by identifying the components that are to be kept and those that must be replaced.
The company also develops engineering solutions specific to the location, including preliminary designs and budget estimates. Prefabricated components can assist in facilitate installation and help reduce the amount of construction work that is required on site.
The Project isn’t Complete until the Pumps Get Started
Modern lift stations should be operated as an integrated system. Before returning it for regular maintenance, start-up testing and commissioning helps ensure that the pumps, controls, and the associated equipment work according to the established design.
Training and manuals for operators are equally essential. Maintenance staff should be acquainted with new equipment and operating procedures, in addition to the documentation before they take charge of the station.
Retrofitting successfully preserves the infrastructure while still addressing the limitations which required modernization.
Municipalities and facilities owners need to consider more than immediate repairs. Most successful projects blend new equipment with existing structures. They provide important services during construction and then prepare the pumping systems for a lifetime of operation.