A municipality has an aging wastewater lift station. The pumps are at the end of their life expectancy The controls are old as well as the access hatch has damaged. Even though the concrete wetwell is solid structurally, it requires to be updated.
Should the entire station be demolished and rebuilt? Not necessarily. The best question to ask is whether the existing infrastructure will be able to support the pumping system of modern standards without compromising reliability or capacity.
Image credit: romtecutilities.com
A carefully engineered pump station retrofit can preserve valuable infrastructure while replacing components that no longer meet operational requirements.
Begin With the Structure No One Would Like to Replace
The wet well is usually one of the most expensive and disruptive parts to replace, as it’s hidden, connected to the existing piping and is essential to the collection of wastewater.
The retention of a concrete structure that is still usable could help in reducing the excavation and construction.
But, any deterioration in the vicinity of the access hatch can complicate your decision. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. It may be more durable to replace the top slab instead of attaching a new hatch on deteriorated concrete. This approach can improve access and improve the functionality of the structure without re-building the entire wet well.
The design of a more powerful pump is distinct
Take a look at a neighborhood that has experienced a significant expansion since the establishment of the lift station. It’s possible that current pumps are not adequate to handle the increase in the flow of wastewater.
Pumps with more horsepower may be used to improve pumps, but the equipment needs to fit within the system. Pumps with greater horsepower may require modifications to the discharge elbows and pipes and electrical controls, valves, and other parts.
Engineers should also consider the hydraulic requirements of the system. This is a consideration for flow as well as total dynamic pressure. If you choose to upgrade a pump without evaluating these conditions, it can cause operational problems rather than resolve them. Making plans for future expansions during your initial design process will allow for a much simpler process to add more capacity later.
Keep the water moving during construction
Retrofitting a wastewater pump station is a particular challenge which is not faced by other construction projects. The station may have to be operational during construction.
When contractors aren’t busy they continue to receive wastewater. According to the type of project the temporary bypass pumping might be required to keep services while existing equipment is removed and new components are installed.
Romtec Utilities faced this kind of issue at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project required replacing two aging wastewater lifting stations, and operating the facility. Specific engineering for the site packaging systems, packaged systems and bypass pumping techniques helped accommodate existing station footprints and operational requirements. The example illustrates why construction sequencing deserves attention before the construction process starts.
In the event that replacement is not an option, it’s the best alternative, then replacement is the best
Not every station can be restored. If the sewer lift station requires replacement due to a badly deteriorated well, structural limitations or major changes in the needs for hydraulics, it may be better to replace instead of alter.
It is important that the choice taken into account structural conditions along with equipment compatibility, accessibility to construction, as well longer-term operational requirements. Romtec Utilities begins retrofits and replacements by identifying the components to be left in place and those which need replacement.
The firm will then develop custom-designed engineering plans, budget estimates, and preliminary designs. Prefabricated parts are a great way to simplify installation and decrease the time spent on construction.
The Project is not Complete When the Pumps Are Set to Start
Modern lift stations should be able to function as a system. Before returning it to regular service, startup testing and commissioning will help ensure that the controls, pumps, and associated equipment perform according to the approved design.
Manuals for maintenance and operation, as well as instruction for operators are essential. Maintenance workers must be aware of the latest equipment, operating procedures and documents before they can assume responsibility for the station.
A successful retrofit helps preserve infrastructure that still has value and addresses the shortcomings which led to the need for modernization.
For facilities owners and municipal authorities, that means looking beyond the immediate repair. The most effective project is one that integrates new equipment into existing structures, ensures vital service during construction, and also prepares the pumping system for years of continual operation.