A municipality has an outdated wastewater lift station. The pumps are nearing the end of their life expectancy The controls are old, as well as the access hatch has deteriorated. The concrete wet well is robust and sturdy.
Should the station be totally demolished? Not necessarily. The better question is whether the existing infrastructure is able to support a modern pumping system with no compromise in availability, reliability or capacity in the future.
Image credit: romtecutilities.com
Retrofitting an existing pump station can be an excellent way to maintain infrastructure, and also replace parts that are no longer functional.
Begin with the Structure that nobody Wants to Replace
The wet well is usually one of the more expensive and disruptive parts to replace since it is hidden, connected to the existing piping, and essential to the collection of wastewater.
Retaining the concrete structure may decrease excavation and construction work.
The degradation of the area around the access hatch could complicate this decision. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. It could be more durable to replace the top layer rather than attach a new hatch to a deteriorated concrete. This option can be utilized to improve access and the functionality of the structure, without the need for rebuilding the entire wet well.
A new pump improves the engineering
Imagine a neighborhood that has exploded in size since the original lift station was installed. Existing pumps may not be able to cope with the increased flow of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers must also evaluate the system’s hydraulic requirements including the head of flow and total dynamic head. Installation of a larger pump without evaluating the situation may cause more issues than it solves. Making plans for future capacity at the time of initial design makes later expansion much easier.
Make sure that the water for waste is flowing throughout construction
Retrofitting a wastewater pump station has its own unique challenges, that isn’t encountered by other construction projects. The station may have to be operational while construction is underway.
The water continues to flow even when contractors are at work. In the case of a project the temporary bypass pumping might be required to keep operation while the existing equipment is taken away and new components are erected.
Romtec Utilities tackled this type of problem at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project involved the replacement of two older wastewater lift stations in the meantime, and maintaining the operation of the facility. Specialized engineering on site packaging systems, packaged systems and bypass pumping techniques were used to accommodate existing station footprints as well as operational requirements. This is a good example of the reasons why the sequence of construction should be considered prior to installation.
When replacing becomes the best alternative
Some stations are not suitable to be renovated. If the sewer lift station is in need of replacement because of a severely degraded well, structural issues, or significant changes in the needs for hydraulics, it may be more appropriate to replace the station rather than alter.
The choice should take into account structural integrity, equipment compatibility access to construction along with service continuity as well as long-term requirements for operation. Romtec Utilities starts retrofitting and replacing projects by identifying the components to be kept and those that must be replaced.
The company designs site-specific engineering solutions, preliminary designs, and budgetary estimates. Prefabricated parts can help to make installation easier and less time-consuming, as well as reduce construction on site.
The Project isn’t Complete until the Pumps Start
Modernized lift stations must be operated as an integrated system. Before returning a lift facility to normal service, startup tests, commissioning and testing of equipment is required to confirm that all pumps, control systems, and other equipment are operating in accordance with the specifications.
Manuals for operation and maintenance and also the training of operators are important. Maintenance workers must be aware of the new equipment, operating procedures and documents before they can assume responsibility for the station.
An effective retrofit will preserve the infrastructure that is still valuable while addressing the issues that forced modernization.
Municipalities and owners of facilities need to take a look beyond the immediate fixes. The most successful projects integrate new equipment into existing structures, and continue to provide essential services as construction progresses. They also make preparations for the pumping system for continued running for a long time.