The sewer lift station in an urban municipality is old. Pumps are advancing towards the end of their useful life, while controls require modernization and the access hatch needs to be replaced. The concrete wet well is structurally sound.
Do you think the station should be demolished and rebuilt? Not necessarily. It is more important to determine if the infrastructure in place can support a modern system of pumping without compromising capacity in the future in terms of reliability, reliability, or accessibility.
Image credit: romtecutilities.com
Retrofitting a pumping station can be an excellent way to save infrastructure and replace components that are no longer functional.
Begin with the Structure that nobody Would Like to Replace
It’s expensive and time-consuming to replace the wet well due to its location in the ground and connected to pipes, and is necessary for wastewater collection.
If the concrete structure is serviceable, retaining it may reduce excavation and construction work.
The degradation of the area close to the access hatch could cause problems with this decision. Romtec Utilities identifies wet well hatch replacement as an usual retrofit requirement. It might be more reliable to replace the top slab rather than attach a new hatch on concrete that has deteriorated. This could improve access to the structure and extend its utility, without having to replace the entire structure as well.
An improved pump can alter the way engineers work.
Imagine a place that has seen a significant increase in population from the time of the first lift station installation. The current pumps might not be sufficient to handle the increased flow of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
The engineers must also assess the hydraulic requirements of the system, including the flow rate as well as the dynamic head total. Installing a larger pump without considering the circumstances could cause more problems than it resolves. The ability to plan future capacity in the initial design makes later expansion considerably easier.
Keep the Wastewater Moving During Construction
Retrofitting wastewater pumps presents a unique challenge, which is not faced by other construction projects. The station may need to be operational for the duration of construction.
Contractors continue to work, and wastewater is still expected to arrive. According to the scope of the project temporary bypass pumps could be required in order to maintain services during removal and the installation of the existing equipment.
Romtec Utilities addressed this type of issue at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The work involved replacing two wastewater lift stations that were in use in the meantime, and maintaining the operation at the facility. Specific engineering for the site, packaged systems and bypass pumping techniques were used to accommodate existing station footprints as well as operational needs. This is a good example of the importance of taking time to look at the construction process prior to constructing.
If replacing is the only alternative
Not every station is suitable to be renovated. Sewer lift stations may need to be replaced for a damaged wet well, or have a low structural capacity.
It is important to take into consideration structural requirements, equipment compatibility and accessibility to construction, as well being long-term operational needs. Romtec Utilities starts retrofitting and replacing projects by identifying the components that will be retained as well as those that require to be replaced.
The company develops site-specific engineering solutions including preliminary designs, as well as budgetary estimates. Prefabricated components are also able to help facilitate installation and cut down on building requirements that are required on-site.
The project won’t be finished until the pumps kick in
Modern lift stations need to be operated as an integrated system. Before returning a lift facility to normal service, start-up tests, commissioning and verification of the equipment are essential to confirm that all pumps, control systems, and other equipment are operating according to design.
Manuals for operation and maintenance and instruction for operators are essential. Maintenance staff must understand the new equipment, operating procedures, and documents before they can assume responsibility for the station.
A successful retrofit preserves the infrastructure while still addressing the weaknesses that led to the need for modernization.
Municipalities and facilities owners need to be aware of the need for more than just immediate repairs. The most successful projects incorporate the latest equipment in existing structures, and keep essential services running while construction is underway. They also prepare the pumping system to continue service for a long period of time.