A municipality has an aging wastewater lift station. The pumps are approaching the expiration date of their useful life, the controls need modernization, and the access hatch has deteriorated. Although the concrete wetwell is solid in its structure, it is in need of to be upgraded.
Should the station be completely destroyed? Not necessarily. The better question to ask is whether the current infrastructure will support an efficient pumping system that is in line with the latest standards, without compromising reliability or future capacity.
Image credit: romtecutilities.com
A carefully engineered pump station retrofit can preserve valuable infrastructure while replacing components that no longer meet operational requirements.
Begin with the Structures No One wants to replace.
It is expensive and disruptive to replace the wet well due to its location in the ground, connected to piping and is essential for the collection of wastewater.
Retaining a concrete construction which is still functional could make it easier to dig and build.
But, any deterioration in the vicinity of the access hatch may complicate your decision. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. It might be more reliable to remove the top slab instead of attaching a new hatch to a deteriorated concrete. This could increase the accessibility to the structure, and extend its lifespan, without needing to completely rebuild the wet well.
The design of a more powerful pump is different
Imagine that a residential area has increased significantly since the initial lift station installation. The existing pumps may no longer provide sufficient capacity for the increasing flow of wastewater.
The upgrading of a pumping system could comprise higher horsepower equipment, but it is not possible to do this without considering the surrounding system. Higher horsepower pumps might require adjustments to discharge elbows, pipes valves, electrical control, and other components.
Engineers must also consider the hydraulic requirements of the system. This includes the flow rate as well as the dynamic head total. Installing a larger pump without evaluating the situation can cause more problems than it solves. Planning for future capacity during the initial design can simplify future expansion.
Make sure that the Wastewater is moved during Construction
Retrofitting wastewater pumps is a unique problem that isn’t encountered by other construction projects. The station might need to be operational for the duration of construction.
Wastewater continues arriving even when contractors are at work. Based on the nature of the project, temporary bypass pumping may be required to keep operation while the existing equipment is removed and new equipment is installed.
Romtec Utilities accepted this challenging task at the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project involved replacing two aging wastewater lifting stations while operating the facility. The project was able to adapt to the footprints of existing stations as well as operational requirements by using customized engineering on site and packaged replacement systems. This illustrates why the construction sequence is important to consider prior to installation.
If replacing is the only alternative
Not every station can be renovated. Sewer lift stations could need to be replaced when they have a seriously damaged wet well or inadequate capacity for structural strength.
The selection should consider structural condition, equipment compatibility access to construction to the site, service continuity, as well as long-term requirements for operation. Romtec Utilities begins retrofit and replacement projects by identifying which elements will remain and which require replacement.
From there, the business designs site-specific engineering solutions initial designs, as well as budgetary estimates. Prefabricated components can also help to organize installation and decrease some construction-related requirements on site.
The Project isn’t Complete until the Pumps Get Started
Modern lift stations must work as a complete system. Before returning a lift-station to normal service, restart tests, commissioning and equipment verification are necessary to ensure that all pumps, controls and equipment work in accordance with the specifications.
Operator training and maintenance and operation manuals are equally crucial. Before taking over responsibility for the maintenance of a station, employees must be aware of the latest equipment, procedures and documents.
A successful retrofit helps preserve infrastructure that still has value as well as addressing the weaknesses that forced modernization.
This means that municipalities and facility owners need to think beyond immediate repairs. The most successful projects combine new equipment and existing structures. They ensure essential services during construction and prepare the pumping systems for a lifetime of operation.
