A municipality is home to an aging wastewater lift station. The pumps are nearing the maximum lifespan, the controls are outdated as well as the access hatch is deteriorated. But the concrete wet well is structurally sound.
Image credit: romtecutilities.com
Should the station be destroyed? Not necessarily. The more important question to ask is whether or not the existing infrastructure will support pumps that meet the latest standards, without compromising reliability or capacity.
The retrofitting of an pumping station that has been well-designed can help save precious infrastructure, and can also help in replacing parts that are no longer in compliance with functional requirements.
Start with the structure nobody wants to replace.
The wet well is typically one of the most costly and difficult components to replace, as it’s located underground, linked to existing pipes, and crucial to the process of removing wastewater.
Retaining the concrete structure could make it easier to dig and build.
The degrading of the area surrounding the access hatch may make this difficult. Romtec Utilities identifies wet well hatch replacement as a standard retrofit requirement. Instead of attaching the hatch to deteriorated cement, replacing the whole top layer could be more durable. This method can increase accessibility and increase the usefulness of the structure without having to rebuild the entire wet well.
A more powerful pump alters the Engineering
Imagine a neighborhood that has grown significantly since the initial lift station installation. The current pumps might not be able to handle the demand for increased wastewater flows.
Pumps with higher horsepower could be used to improve a pumping station, but the equipment must also fit into the system. Pumps with greater horsepower may require adjustments to discharge elbows and piping and electronic controls, valves and other parts.
Engineers should also assess the system’s hydraulic requirements, including the flow rate and the total dynamic head. If you install a bigger pump without considering these factors, it can cause operational problems rather than resolve the problem. Planning future capacity in the initial design makes future expansion significantly easier.
Keep waste water moving during construction
A wastewater pump station retrofit introduces a challenge that ordinary equipment replacement projects may not face: the station may need to remain operational throughout construction.
Contractors are still working, and wastewater continues to come in. According to the project, a temporary bypass pumping system might be needed to keep service running while existing equipment is removed or new parts are installed.
Romtec Utilities took on this kind of problem in the Federal Law Enforcement Training Center at Brunswick, Georgia.
The work involved replacing two older wastewater lift stations, while still maintaining the operation of the facility. Specialized engineering on site packaging systems, packaged systems and bypass pumping techniques allowed for the existing station footprints as well as operational needs. The scenario illustrates why construction sequencing deserves attention before the construction process starts.
In the event that replacing becomes the best alternative
Not all stations are suitable for rehabilitation. Sewer lift stations may need to be replaced for a damaged wet well or inadequate structural capacity.
It is important that the decision made takes into account structural conditions, equipment compatibility and accessibility to construction, as in the long-term requirements for operation. Romtec Utilities begins retrofits and replacements by identifying parts to be left in place and those that need to be replaced.
From there, the firm creates engineering solutions that are specific to the site initial designs, as well as budgetary estimates. Prefabricated parts are a great way to organize installation, and reduce the amount of construction work that is required on site.
The Project isn’t Complete until the Pumps Are Running
The modern lift station needs to work as a whole. Prior to returning it back to normal service, it is necessary to start testing and commissioning helps ensure that the pumps, controls and the associated equipment work according to the design approved.
Manuals for operation and maintenance along with training of operators, are essential. Maintenance staff should be acquainted with the latest equipment and operational procedures, as well as the documentation before they take responsibility for the station.
A successful retrofit preserves infrastructure that still has value while addressing the limitations which led to the need for modernization.
Municipalities and property owners have to think beyond repairs that are immediate. The best projects incorporate new equipment into existing structures to maintain essential service during construction. Also, they prepare the pumping system to keep in operation for a number of years.