An aging wastewater liftstation is located in a township. Pumps are nearing the end of their useful lives, controls require modernization, and the access hatch should be replaced. The concrete wet well is solid and structurally sound.
Do you think the station should be completely demolished? Not necessarily. The most important question is whether the current infrastructure can support a modern pumping system without compromising availability, reliability or future capacity.
Image credit: romtecutilities.com
The retrofitting of an pumping station that has been well-designed can help save precious infrastructure and also replace parts that are no longer in compliance with functional requirements.
Start with the Structures That Nobody wants to replace.
The wet well is usually one of the most expensive and disruptive components to replace, as it’s buried, connected to existing pipes, and crucial to the collection of wastewater.
If the concrete structure remains usable, its retention could decrease excavation and construction work.
The loss of space around the access hatch might make this difficult. Romtec Utilities identifies wet well hatch replacement as a common retrofit requirement. Instead of attaching a hatch to cement that is deteriorating, replacing the entire top layer might be more durable. This approach can improve access and improve the functionality of the structure without re-building the entire wet well.
A More Powerful Pump Changes the Engineering
Take a look at a neighborhood that has experienced a significant increase in population since the construction of a lift station. The existing pumps may no longer provide sufficient capacity for increased flows of wastewater.
Pumps with more horsepower may be used to upgrade an existing pumping station, however the equipment has to be integrated into the system. For pumps that are more powerful there is a possibility that you will need make adjustments to the discharge elbows or piping. You may also need to replace electrical controls or valves.
Engineers should also look at the hydraulic requirements of the system. This is a consideration for flow as well as total dynamic pressure. If you decide to install a larger pump without considering these factors, it can cause operational problems rather than resolve them. The planning for future expansions at the time of the initial design phase will allow for a much simpler process to grow later on.
Make sure that the water for waste is flowing during construction
A retrofit to a wastewater pump station introduces a challenge that ordinary project for replacement of equipment may not have to face: the pump station could require a continuous operation during construction.
Even if contractors are busy the wastewater still flows in. According to the plan, a temporary bypass pumping system may be necessary to maintain service as existing equipment is removed or new components installed.
Romtec Utilities tackled this type of issue at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project involved the replacement of two older wastewater lift stations as well as maintaining the operation of the facility. The project was able accommodate existing station footprints as as operational requirements by using local-specific engineering and modular replacement systems. This illustrates how important it is to think about the sequence of construction before constructing.
In the event that replacement is not an option, it’s the best option
Not every station can be repaired. A severely deteriorated wet well, inadequate structural capacity, or major changes in hydraulic requirements may make sewer lift station replacement more appropriate than modifying the existing installation.
It is vital that the decision made takes into account structural conditions, equipment compatibility and accessibility to construction, as well in the long-term requirements for operation. Romtec Utilities begins retrofits and replacements by identifying parts that are to remain and the ones that require replacement.
From there, the firm creates engineering solutions for specific sites as well as preliminary designs and budgetary estimates. Prefabricated parts can help to simplify installation and decrease construction on site.
The Project is Not Completion until the Pumps Have Started
Modern lift stations need to be operated as a system in one. Prior to returning a lift station to normal service, restart testing, commissioning, as well as verification of equipment are required to confirm that all pumps, controls and equipment work in accordance with the specifications.
Manuals for maintenance and operation and instruction for operators are essential. Maintenance personnel must know the latest equipment, operating procedures, and documentation before taking responsibility for the station.
Retrofitting infrastructure can preserve its value while addressing limitations that led to modernization.
This means that municipalities and facility owners need to think beyond immediate repairs. The most successful projects incorporate new equipment with existing structures. They ensure essential services during construction and then prepare the pumping systems to last for a long time.