A decrepit wastewater liftstation is located in a municipal. The pumps have reached the end of their life expectancy, the controls are outdated as well as the access hatch is damaged. The concrete wet well remains solid and sturdy.
Should the entire station be destroyed and rebuilt? Not necessarily. The more useful question is whether the current infrastructure is able to support a modern pumping system without compromising availability, reliability or future capacity.
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 Structure Nobody Wants to Replace
It’s expensive and difficult to change the wet well due to its location beneath the earth, and is connected to pipes and essential for wastewater collection.
Retaining the concrete structure could reduce excavation work and construction.
The degrading of the area around the access hatch might complicate this decision. Romtec Utilities says that wet well hatches are typically replaced in retrofits. Instead of attaching a brand new hatch to deteriorated concrete, replacing the entire top slab could make a more robust solution. This method can be used to increase access and improve the structural’s functionality without needing to rebuild the whole wet well.
The development of the pump with more power is different
Take a look at a neighborhood that has experienced significant increase in population since the construction of the lift station. The current pumps might no longer provide sufficient capacity for increased wastewater flows.
The modernization of a pumping system may include higher-horsepower equipment, but this isn’t possible without considering the whole system. For pumps that are more powerful you might need modify the discharge elbows or the piping. You might also have to alter electrical controls and valves.
Engineers should also look at the hydraulic requirements of the system. This includes flow and total dynamic pressure. If you decide to install a larger pump without considering these factors the system could cause problems with operation rather than addressing them. Planning future capacity at the time of initial design can make future expansion significantly easier.
Keep Wastewater Moving during Construction
Retrofitting an existing pump station could be challenges that are new. Unlike other equipment replacement projects, the station will have to remain operational for the duration of construction.
The water continues to flow even when contractors are at work. According to the study an interim bypass pumping system might be necessary to maintain service as existing equipment is removed or new equipment is installed.
Romtec Utilities tackled this type of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project consisted of replacing two old wastewater lift stations, while still maintaining the operation of the facility. Site-specific engineering, packaged replacement systems, and bypass pumping strategies were used to adapt to the station’s footprints as well as operational requirements. This example shows how important it is to think about the sequence of construction before constructing.
In the event that replacing becomes the best alternative
Not every station can be restored. A severely deteriorated wet well insufficient structural capacity or major changes in the hydraulic requirements can make the sewer lift station replacement better than making changes to the current installation.
It is essential to take into consideration structural requirements the compatibility of equipment and accessibility to construction as well as long-term operational requirements. Romtec Utilities begins retrofit and replacement projects by determining which components will remain and which require replacement.
From there, the firm develops site-specific engineering solutions as well as preliminary designs and budgetary estimates. Prefabricated components are also able to help with installation and can reduce building requirements that are required on-site.
The Project is Not Complete When the Pumps Are Set to Start
The modern lift station must function as a complete system. Before returning it to regular service, startup testing and commissioning ensures that the pumps, controls as well as the equipment that is associated with them, are in accordance to the approved design.
Training for operators and maintenance and operation manuals are equally crucial. Maintenance personnel should be familiar with the new equipment and operating procedures, and the necessary documentation prior to taking responsibility for the station.
Retrofitting successfully preserves the value of infrastructure while addressing the limitations that led to modernization being necessary.
Municipalities as well as facility owners must look beyond the immediate repairs. The most successful initiatives are those that incorporate the latest equipment in existing structures, and continue to provide essential services during construction. Also, they prepare the pumping system to keep service for a long period of time.