A municipality has an outdated wastewater lift station. The pumps are nearing the final stage of their life, the controls are outdated and the access hatch has deteriorated. The concrete wet well remains robust and solid.
Should the entire station demolished and rebuilt? Not necessarily. It is better to determine if the infrastructure is able to support modern pumps without compromising future capacity and reliability or maintenance accessibility.
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 that no one wants to replace
Wet wells are usually the most expensive and difficult component to replace, as they are underground and connected to existing pipes and are essential to the collection of wastewater.
Retaining a concrete construction which is still functional could minimize the digging and construction.
The degrading of the area close to the access hatch could affect this decision. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. It may be more durable to replace the top layer instead of installing a brand new hatch on deteriorated concrete. This approach can be employed to increase accessibility and enhance the structural’s functionality without needing to rebuild the entire wet well.
A new pump improves the way engineers work.
Imagine a neighborhood that has seen a significant increase in population from the time of the first lift station installation. The pumps that are in place may not be sufficient for increased flows of wastewater.
The modernization of a pumping system may comprise higher horsepower equipment, but this isn’t possible without considering the entire system. Pumps that have higher horsepower might require adjustments to discharge elbows and piping and electrical controls, valves, and other parts.
Engineers should also evaluate the requirements for hydraulics of the system. This includes flow rate and dynamic head total. The installation of a bigger pump prior to assessing the requirements can cause more problems than it resolves. Making plans for future expansions during the initial design phase will help you to add more capacity in the future.
Make sure the wastewater is moving during Construction
Retrofitting a pump station for wastewater presents a unique challenge, that isn’t encountered by other projects. The station may have to be operational during construction.
Contractors continue to work and wastewater continues to come in. According to the type of project it is possible that temporary bypass pumps will be required to maintain the service until existing equipment is removed and new equipment is installed.
Romtec Utilities accepted this challenge at the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project consisted of replacing two old wastewater lift stations while also maintaining the operation of the facility. Specific engineering for the site as well as packaged replacement systems and bypass pumping techniques helped make room for the existing station footprints as well as operational requirements. This example shows the importance of focusing on construction sequencing before the construction process starts.
If replacing is the only option
Not every station is suited to be renovated. If the sewer lift station requires replacement because of a severely degraded well, structural issues, or significant changes in hydraulic needs, it may be more appropriate to replace the station rather than modify.
It is crucial that the decision taken takes into account structural factors, equipment compatibility and accessibility to construction, as well longer-term operational requirements. Romtec Utilities begins retrofit and replacement projects by determining what components will be retained and which ones require replacement.
The company also develops engineering solutions specifically for the location, including preliminary designs and budget estimates. Prefabricated components help make installation easier and less time-consuming, as well as reduce construction on site.
The Project Isn’t Completion until the Pumps Have Beginning
Modernized lift stations must be operated as an integrated system. Before returning it to normal service, it is necessary to start testing and commissioning will help ensure that the controls, pumps, as well as the equipment that is associated with them, are in accordance to the specifications of the design.
Manuals as well as training for operators are equally important. Before they can assume responsibility for the maintenance of a station, employees must understand the latest equipment, procedures, and documents.
An effective retrofit will preserve the infrastructure that is still valuable while addressing the limitations which led to the need for modernization.
Municipalities as well as facility owners must take a look beyond the immediate fixes. The most successful initiatives are those that incorporate new equipment into existing structures to maintain essential service while construction is underway. Also, they prepare the pumping system to continue in operation for a number of years.