An aging wastewater liftstation is located in a municipal. Pumps are nearing the end their useful lives, controls need modernization and the access hatch should be replaced. While the concrete wetwell is solid in its structure, it is in need of to be upgraded.
Do you think the station should be completely demolished and rebuilt? Not necessarily. One of the most important questions to consider is whether the current infrastructure will support an efficient pumping system that is in line with modern standards without compromising reliability or future capacity.
Image credit: romtecutilities.com
Retrofitting the pumping station precisely designed can help save infrastructure, while also replacing components that no longer meet the operational standards.
Start With the Structure Nobody Wants to Replace
It’s expensive and time-consuming to repair the wet well due to its location in the ground and connected to pipes and essential for the collection of wastewater.
Retaining the concrete structure may decrease excavation and construction work.
However, damage to the access hatch could affect your decision. Romtec Utilities says that wet well hatches are typically replaced in retrofits. Instead of gluing a hatch to cement that has deteriorated, replacing the whole top layer may be a more durable option. This technique can be utilized to improve access and the structural’s functionality without needing to rebuild the entire wet well.
A new pump improves the engineering
Imagine that a residential area has seen a significant increase in population since the initial lift station installation. It could be that the existing pumps are no longer adequate to handle the increase in flows of wastewater.
An upgrade to the pumping station could involve higher-horsepower pumps, but the choice of equipment cannot be made independently from the rest of the system. Pumps with greater power may require changes to discharge elbows, piping valves, electrical controls and other elements.
The engineers must also assess the hydraulic requirements of the system, including the flow rate as well as the dynamic head total. The installation of a bigger pump prior to assessing the requirements could cause more problems than it resolves. Planning for future expansion during the initial design phase will help you to build later.
Make sure that the waste water is flowing during construction
Retrofitting a pump station for wastewater is a particular challenge that is not encountered in other projects. The station could need to be operational for the duration of construction.
Contractors continue to work and wastewater will still arrive. According to the scope of the project temporary bypass pumps might be required in order to maintain service during removal and installation of the existing equipment.
Romtec Utilities was able to take on this challenging task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project consisted of 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 made it possible to meet existing station footprints and operational needs. This example shows the need to be aware of construction sequencing before installation begins.
In the event that replacement is not an option, it’s the best option, replace it.
Some stations are not suitable to be renovated. A severely deteriorated wet well, inadequate structural capacity, or major changes in hydraulic requirements may make sewer lift station replacement more appropriate than modifying the existing installation.
In making a decision, it is crucial to take into consideration the structural health of the building, its compatibility equipment, its accessibility to construction sites, service continuity and long-term needs. Romtec Utilities starts retrofitting and replacing projects by identifying the elements that will remain and those that must be replaced.
The company then develops engineering solutions tailored to the location, including preliminary plans and budget estimates. Prefabricated components are also beneficial for organizing installation and reducing the number of on-site requirements.
The Project is Not Fully Complete Until the Pumps are Set to Start
A modern lift station should be able to function as an integrated system. Before returning a lift station to normal service, startup tests, commissioning and verification of equipment are required to confirm that all pumps, controls, and related equipment operate in accordance with their design.
Manuals for operation and maintenance along with training of operators, are essential. Maintenance personnel should be knowledgeable with the new equipment and operating procedures, and the necessary documentation prior to taking responsibility for the station.
Retrofitting successfully preserves the infrastructure that is still valuable while addressing the issues that led to modernization being necessary.
Municipalities and owners of facilities must be aware of the need for more than just immediate repairs. The most successful plan is one that integrates the new equipment into existing structures, ensures vital services throughout construction, and prepares the pumping system for years to come of operation.
