A municipality has an outdated wastewater lift station. The pumps are coming to the expiration date of their service lifespan, the controls require modernization as well as the access hatch has deteriorated. Yet the concrete wet well is solid and sturdy.
Should the station be removed? Not necessarily. The more useful question is whether the current infrastructure can support a modern pumping system without compromising availability, reliability and capacity.
Image credit: romtecutilities.com
The retrofitting of an pumping station that has been carefully designed can save valuable infrastructure and also replace components that are no longer meeting functional requirements.
Start with the Structures That Nobody Wants To Replace
It’s expensive and time-consuming to replace the wet well because it is buried in the ground, linked to pipes, and is necessary to collect wastewater.
If the concrete structure is functional, it is possible to reduce excavation and construction work.
However, the deterioration of the access hatch can complicate the process. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. Instead of affixing a new hatch to a damaged concrete structure replacement of the entire top slab may offer a more long-lasting solution. This approach can improve access and extend the structure’s usefulness without re-building the entire wet well.
A Powerful Pump Changes the Engineering
Let’s say a residential area has grown substantially since its first lift station was put in place. The existing pumps might not be able to cope with the increased flow of wastewater.
Pumps with greater horsepower can be used to improve pumps, but the equipment must also fit into the system. More powerful pumps may require modifications to elbows for discharge, pipes valves, electrical control and other elements.
Engineers must also evaluate the system’s hydraulic requirements, including flow and total dynamic head. A larger pump installed without reviewing these conditions can create problems with operation rather than addressing these. The ability to plan future capacity prior to initial design can make future expansion much easier.
Make sure that the wastewater is moving during construction.
Retrofitting an existing wastewater pump station can be the challenge of a completely new one. In contrast to other replacement projects, this one must continue to operate during construction.
Contractors are still working, and the wastewater will continue to flow. Depending on the scope of the project the temporary bypass pumps could be required in order to maintain service during removal and installation of the existing equipment.
Romtec Utilities accepted this challenge at the Federal Law Enforcement Training Center, Brunswick, Georgia.
The work involved replacing two older wastewater lift stations in the meantime, and maintaining the operation at the facility. Specific engineering for the site as well as packaged replacement systems and bypass pumping strategies helped allow for the existing station footprints and operational needs. This is a good example of the importance of taking time to think about the sequence of construction before installing.
When replacement is the better alternative, then replacement is the best
Not all stations are suited to be renovated. 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 crucial that the decision taken takes into account structural conditions along with equipment compatibility, accessibility to construction, as being long-term operational needs. Romtec Utilities begins retrofits and replacements by identifying elements which are expected to stay and the ones that require replacement.
The company also develops engineering solutions specific to the location, initial plans as well as budget estimations. Prefabricated components also aid in organize installation and reduce some on-site construction requirements.
The Project isn’t Fully Complete Until the Pumps are Beginning
The modern lift station must operate as a system. Prior to returning a lift station to normal service, start-up tests, commissioning and equipment verification are necessary to ensure that all pumps, controls, and the related equipment function according to design.
Operator training, as well as maintenance and operation manuals are equally important. Before taking on the responsibility of the station, personnel responsible for maintenance must be aware of the latest equipment, procedures and the documentation.
Retrofitting successfully preserves the infrastructure while also addressing the weaknesses that required modernization.
For municipal facilities and facility owners This means looking beyond the immediate repair. Most successful projects blend new equipment with existing structures. They maintain vital services throughout construction and then prepare the pumping systems to run for many years.
