The municipality has an old wastewater lift station. The pumps are approaching the expiration date of their useful life, the controls need modernization, and the access hatch has become damaged. Even though the concrete wetwell is structurally sound, it’s time to be modernized.
Should the station be gone? Not necessarily. The more important issue is whether the infrastructure in place will be able to accommodate a modern pumping system with no compromise in reliability, maintenance access, or future capacity.
Image credit: romtecutilities.com
The retrofitting of pumps that are precisely designed can help save infrastructure, and can also help in replacing components that no longer meet the operational standards.
Begin with the structure nobody wants to replace.
It is expensive and disruptive to replace the wet well because it is in the ground, linked to pipes, and is necessary to collect wastewater.
Intentionally retaining the concrete structure could make it easier to dig and build.
But, any deterioration that occurs around the access hatch may complicate the process. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. Rather than attaching a new hatch to the deteriorated concrete or replacing the entire top slab may provide a more durable solution. This approach can improve access and enhance the utility of the structure without the need to replace the entire wet well.
A More Powerful Pump Modifies the Engineering
Imagine a neighborhood which has seen significant growth since the installation of a lift station. It’s possible that the current pumps are not able to handle increased wastewater flow.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers should also evaluate the hydraulic requirements of the system, which includes the flow rate as well as the dynamic head total. In the event of installing a larger pump, not checking these parameters can cause operational problems rather than solving the issues. The planning of future capacity at the initial design process can simplify future expansion.
Make sure that the Wastewater is moved during Construction
Retrofitting a pump station for wastewater is a unique problem which isn’t faced by other projects. The station could need to be operational during construction.
Even when contractors are working they continue to receive wastewater. According to the study the project, a temporary bypass pumping system is necessary to maintain service as existing equipment is removed or new components are added.
Romtec Utilities tackled this type of issue at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project required the replacement of two older wastewater lift stations in the process of maintaining operation at the facility. The project was able to accommodate existing station footprints as the operational needs by utilizing site-specific engineering and integrated replacement systems. This illustrates how the order of construction is important to consider prior to installation.
When replacement is the better option, replace it.
Each station is not able to be restored. If the sewer lift station is in need of a replacement due to a seriously degraded well, structural constraints, or significant changes in hydraulic requirements, it might be better to replace than modify.
The selection should consider the condition of the structure, compatibility with equipment access to construction as well as service continuity and long-term operating needs. Romtec Utilities starts retrofitting and replacing projects by identifying the components that are to be kept and those that will need to be replaced.
The company also develops engineering solutions specifically for the site, preliminary plans as well as budget estimations. Prefabricated components can be useful to organize installation and reduce certain requirements on site.
The Project is not Complete When the Pumps Are Started
Modernized lift stations should work as a complete system. Prior to returning the lift station back to service, startup tests and commissioning can help to ensure that the pumps and control equipment and other components perform as per the approved design.
Training and manuals for operators are equally important. Maintenance personnel should be knowledgeable with the latest equipment and operating procedures as well as the manuals before they assume charge of the station.
A successful retrofit helps preserve infrastructure that still has value as well as addressing the weaknesses that led to modernization being necessary.
This means that municipalities and owners of facilities need to think beyond immediate repairs. The most successful projects combine new equipment and existing structures. They will maintain the essential services during construction and then prepare the pumping systems to last for a long time.