A municipality is home to an aging wastewater lift station. The pumps are nearing the limit of their lifespan and the controls are dated as well as the access hatch has worn out. While the concrete wetwell is solid structurally, it requires to be upgraded.
Should the entire station be destroyed and rebuilt? Not necessarily. The more important question to consider is whether or not the existing infrastructure can accommodate pumps that meet modern standards without compromising reliability and future capacity.
Image credit: romtecutilities.com
Retrofitting an existing pump station can be a fantastic method to save infrastructure and replace elements that are no longer functional.
Begin with the Structures that nobody Would Like To Replace
The wet well is often one of the most costly and disruptive parts to replace as it is located underground, linked to existing pipes, and crucial to the process of removing wastewater.
A concrete structure that is functional can reduce the excavation and construction.
The loss of space close to the access hatch could complicate this decision. Romtec Utilities identifies wet well hatch replacement as a standard retrofit requirement. Instead of affixing a fresh hatch to the deteriorated concrete replacement of the entire top slab may make a more robust solution. This approach can be employed to increase accessibility and the structural’s functionality without the need to replace the whole wet well.
An improved pump can alter the way engineers work.
Think about a community that has experienced a significant growth since the installation of the lift station. The pumps that are in place may not be able to handle the demand for increased wastewater flows.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers should also look at the hydraulic needs of the system. This includes flow and total dynamic pressure. If you install a bigger pump without evaluating these conditions, it can cause operational issues rather than solve these. The planning for future expansions at the time of the initial design phase will enable you to grow later.
Keep waste water moving during construction
Retrofitting wastewater pumps has its own unique challenges, which isn’t faced by other construction projects. The station could need to be operational throughout construction.
Contractors continue to work, and wastewater continues to come in. Depending on the project, temporary bypass pumping may be necessary to keep service while existing equipment is removed, and new components are erected.
Romtec Utilities embraced this task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project involved the replacement of two old wastewater lift stations and ensuring the operation at the facility. The site-specific engineering packaging systems, packaged systems and bypass pumping techniques were used to accommodate existing station footprints as well as operational requirements. This example shows the importance of focusing on construction sequencing before installation begins.
If you decide to replace, it is the best Alternative
There are many stations that can be repaired. Sewer lift stations might need to be replaced for a damaged wet well, or have a low capacity for structural strength.
Before making a decision it is important to consider the structural integrity of the building, its compatibility with equipment, accessibility to construction, service continuity and long-term needs. Romtec Utilities begins retrofits and replacements by identifying parts to be left in place and those which need replacement.
The company then develops engineering solutions specifically for the location, initial designs and budget estimates. Prefabricated components are also able to help organize installation and reduce some needs for construction on site.
The work isn’t done until the pumps are turned on
The modern lift station needs to operate as a system. Prior to returning a lift station to normal service, startup testing, commissioning, as well as verification of equipment are required to verify that the pumps, controls and other equipment are operating according to design.
Training and manuals for operators are equally crucial. Maintenance workers must be aware of the new equipment, operating procedure, and other documentation before they take over responsibility for the station.
A successful retrofit helps preserve the value of infrastructure as well as addressing the weaknesses that forced modernization.
Municipalities as well as facility owners must think beyond immediate repairs. Most successful projects blend new equipment and existing structures. They ensure important services during construction and also prepare the pumping systems to run for many years.