A deteriorating 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 is deteriorating. The concrete wet well is structurally sound.
Should the entire station be destroyed and rebuilt? Not necessarily. The more useful question is whether the infrastructure in place is able to support a modern pumping system with no compromise in security, maintenance access or capacity in the future.
Image credit: romtecutilities.com
A carefully engineered pump station retrofit can preserve valuable infrastructure while replacing components that no longer meet operational requirements.
Start with the Structures Nobody Will Want to Replace
It’s expensive and time-consuming to repair the wet well due to its location in the ground, connected to pipes, and is necessary for wastewater collection.
The retention of a concrete structure which is still functional could help in reducing the excavation and construction.
However, deterioration around the access hatch can make the choice. Romtec Utilities says that wet well hatches are usually replaced in retrofits. It could be more durable to remove the top slab instead of installing a brand new hatch on deteriorated concrete. This method can increase accessibility and improve the functionality of the structure without having to rebuild the entire wet well.
The technology behind a more powerful pump is distinct
Think about a community that has seen significant growth since the installation of a lift station. The existing pumps may not be able to handle the demand for increased wastewater flows.
The improvement of a pumping system may include higher-horsepower equipment, but this isn’t possible without taking into consideration the system around it. Pumps with greater horsepower may require modifications to discharge elbows, piping and pipework along with electrical controls, valves and other parts.
Engineers should also evaluate the hydraulic requirements of the system. This includes the flow rate as well as the dynamic head total. If you decide to install a larger pump without considering these factors the system could cause operational problems rather than resolve these. The ability to plan future capacity at the time of initial design makes future expansion significantly easier.
Make sure the wastewater is moving during Construction
A retrofit to a wastewater pump station creates a challenge that regular replacement of equipment projects do not face: the station could require a continuous operation through the entire construction.
Even when contractors are busy and preparing for the next project, wastewater is still arriving. In the case of the project temporary bypass pumps could be required to keep service during removal and installation of existing equipment.
Romtec Utilities faced this kind of challenge in the Federal Law Enforcement Training Center located in Brunswick, Georgia.
The project included replacing two older wastewater lift stations while also maintaining the operation of the facility. The project was able to accommodate the existing footprints of stations as well the operational needs by utilizing specific engineering for the site and system for replacement that is packaged. This is a good example of the importance of taking time to take into consideration the sequence of construction before constructing.
In the event that replacing becomes the best alternative
Not every station is suitable for rehabilitation. Sewer lift stations may need to be replaced for a damaged wet well or inadequate capacity for structural strength.
Before making a decision it is important to consider the structural condition of the building, its compatibility with equipment, the accessibility to construction, continuity of service and long-term requirements. Romtec Utilities begins retrofit and replacement projects by identifying which components will be retained and which require replacement.
The company will create custom-designed engineering plans along with budget estimates as well as preliminary designs. Prefabricated components can assist in simplify installation and decrease the amount of construction work that is required on site.
The Project Doesn’t End When the Pumps Begin to Run
Modern lift stations have to be operated as an integrated system. Before returning it to regular maintenance, initial testing and commissioning ensures that the pumps, controls and other equipment are operating according to the approved design.
Operator training, as well as operation and maintenance manuals are equally crucial. Maintenance personnel must know the latest equipment, operating procedures and other documentation before they take over responsibility for the station.
A successful retrofit helps preserve the infrastructure that is still valuable and addresses the shortcomings that forced modernization.
For facilities owners and municipal authorities, that means looking beyond the immediate repair. The most successful project is one that integrates the new equipment with existing structures, ensures vital service throughout construction, and prepares the pumping system to last for years of continued operation.