A disused wastewater liftstation can be situated in a municipality. Pumps are about to expire their useful life, while controls require modernization and the access hatch needs to be replaced. Even though the concrete wetwell is solid structurally, it requires to be upgraded.
Should the entire station be destroyed and rebuilt? Not necessarily. The better question is whether the existing infrastructure can support a modern pumping system, without compromising reliability, maintenance access and capacity.
Image credit: romtecutilities.com
The retrofitting of an pumping station that has been meticulously designed could save valuable infrastructure, and can also help in replacing components no longer meeting operational requirements.
Start with the Structure That No One is Trying to Replace.
It’s costly and inconvenient to replace the wet well because it is beneath the earth, and is connected to piping and is essential for wastewater collection.
The retention of a concrete structure which is still functional could make it easier to dig and build.
However, damage to the access hatch can complicate the choice. Romtec Utilities has identified wet-well hatch replacement as an essential retrofit. Instead of affixing a new hatch to a damaged concrete structure or replacing the entire top slab might be a better option. This can increase access to the structure as well as prolong its use, without the need to rebuild the entire wet well.
A better pump alters the engineering
Imagine a place that has increased significantly since the initial lift station installation. It’s possible that existing pumps are no longer adequate to handle the increase in flows of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers must also consider the requirements of the hydraulic system, including the flow and head total dynamic. If you install a bigger pump without evaluating these conditions, it can cause problems in operation instead of resolving the problem. Planning future capacity prior to designing the initial design makes expansion later much easier.
Make sure that the waste water is moving throughout the construction process
Retrofitting wastewater pumps presents a unique challenge, which is not faced by other projects. The station may need to be operational during construction.
Wastewater continues arriving even when contractors are at work. According to the project it is possible that a temporary bypass pumping system might be necessary to maintain service as the old equipment is removed, or new parts are installed.
Romtec Utilities was able to take on this task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project involved replacing two wastewater lift stations that were in use in the meantime, and maintaining the operation of the facility. Site-specific engineering and packaged replacement systems and bypass pumping techniques helped make room for the existing station footprints and operational requirements. The example illustrates why the sequence of construction should be considered prior to installation.
If replacement is the best option, replace it.
Not all stations are suited for rehabilitation. A seriously damaged wet well insufficient structural capacity or significant changes in hydraulic requirements might make a the sewer lift station replacement more suitable than altering the current installation.
Before making a decision it is crucial to look at the structural condition of the structure, its compatibility to equipment, access to construction, service continuity and long-term requirements. Romtec Utilities begins retrofits and replacements by identifying parts that will remain as well as those which need replacement.
The company will create custom-designed engineering plans, budget estimates, as well as preliminary designs. Prefabricated parts can help to facilitate installation and help reduce on-site construction.
The Project is not Complete until the Pumps are Set to Start
Modernized lift stations should operate as an integrated system. Prior to returning a lift station to normal operation, initial testing, commissioning, as well as verification of the equipment are essential to make sure that all pumps, control systems, and other equipment are operating in accordance with the specifications.
Maintenance and operation manuals, as well as the training of operators are essential. Maintenance workers must be aware of the latest equipment, operating procedures and documents before they can assume responsibility for the station.
Retrofitting successfully preserves infrastructure that still has value while addressing the issues that led to modernization being necessary.
Municipalities and owners of facilities must look beyond immediate repair. The most successful projects integrate new equipment and existing structures. They ensure essential services while construction is underway and set up the pumping system to last for a long time.