A decrepit wastewater liftstation is located in a municipality. The pumps are nearing the end of their useful life span, the controls require modernization, as well as the access hatch has become damaged. The concrete wet well is structurally sound.
Should the entire station be destroyed and rebuilt? Not necessarily. The more important question to ask is whether the current infrastructure will be able to support a pumping system that meets modern standards without compromising reliability or future capacity.
Image credit: romtecutilities.com
Retrofitting an existing pump station can be a fantastic method to protect infrastructure, and also replace parts which are no longer in use.
Start With the Structure Nobody is Trying to Replace.
It’s expensive and time-consuming to replace the wet well due to its location in the ground and connected to piping and is essential for the collection of wastewater.
Retaining the concrete structure may decrease excavation and construction work.
But, any deterioration in the vicinity of the access hatch could affect your choice. Romtec Utilities says that wet well hatches are often replaced as part of retrofits. Rather than attaching a new hatch to deteriorated concrete replacement of the entire top slab might provide a more durable solution. This method can be used to increase accessibility and the structural’s functionality without the need to replace the entire wet well.
The engineering of a more powerful pump is different
Imagine a neighborhood that has exploded in size since the original lift station installation. It is possible that the current pumps are not able to handle increased water flow.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers should also look at the hydraulic needs of the system. This includes flow and total dynamic pressure. A larger pump prior to assessing the requirements could cause more problems than it resolves. Planning future capacity at the time of initial design makes future expansion easy.
Make sure that the wastewater is moving during construction.
Retrofitting a wastewater pump station is a unique problem that is not encountered in other projects. The station may have to be operational during construction.
The water continues to flow even when contractors are in the process of working. According to the report an interim bypass pumping system could be required to ensure service is maintained as the old equipment is removed, or new parts are installed.
Romtec Utilities tackled this type of challenge in the Federal Law Enforcement Training Center located in Brunswick, Georgia.
The project required the replacement of two older wastewater lift stations and ensuring the operations of the facility. Specialized engineering on site packages, bypass pumping techniques allowed for the existing station footprints as well as operational requirements. This is a good example of why it is important to think about the sequence of construction prior to constructing.
If replacing is the only option
Not every station can be rehabilitated. If the sewer lift station requires replacement because of a severely degraded well, structural limitations or major changes in the hydraulic requirements, it could be better to replace than modify.
The choice should take into account structural integrity, equipment compatibility, construction access, service continuity, as well as long-term requirements for operation. Romtec Utilities begins retrofit and replacement projects by determining what elements will remain and which need to be replaced.
The business will then design custom-designed engineering plans along with budget estimates and preliminaries of designs. Prefabricated components can also help with installation and can reduce needs for construction on site.
The Project is Not Completion until the Pumps Have Started
The modernized lift station should function as a complete system. Prior to returning the lift station back to service, tests of startup and commissioning are a way to make sure that the pumps and controls as well as other equipment work in accordance with an approved design.
Both manuals and training for operators are equally crucial. Before they can assume responsibility for an entire station, the personnel in charge of maintenance must know about the latest equipment, procedures, and the documentation.
A successful retrofit helps preserve the infrastructure that is still valuable as well as addressing the weaknesses which led to the need for modernization.
This means that municipalities and facility owners need to look beyond the immediate repairs. The most successful plan is one that integrates the new equipment with existing structures, provides essential service throughout construction and also prepares the pumping system to last for years to come of operation.