A municipality is home to an aging wastewater lift station. The pumps have reached the maximum lifespan and the controls are dated, as well as the access hatch has damaged. Although the concrete wetwell is structurally sound, it’s time to be modernized.
Should the entire station be demolished and rebuilt? Not necessarily. The best question to ask is whether the current infrastructure will support the pumping system of the latest standards, without compromising reliability and capacity.
Image credit: romtecutilities.com
The retrofitting of the pumping station precisely designed can help save infrastructure, and can also help in replacing components no longer meeting the operational standards.
Start With the Structure Nobody is Trying to Replace.
It’s expensive and difficult to repair the wet well due to its location in the ground and connected to pipes and essential for the collection of wastewater.
A concrete structure which is still functional could reduce the excavation and construction.
The deterioration of the area around the access hatch could cause problems with this decision. Romtec Utilities says that wet well hatches can be replaced as part of retrofits. Instead of affixing a new hatch to a damaged concrete structure replacement of the entire top slab may make a more robust solution. This could increase the accessibility to the structure and prolong its usefulness, without having to rebuild the entire wet well.
The design of a more powerful pump is different
Imagine a neighborhood that has grown significantly since the lift station’s initial installation. The existing pumps might not be able to deal with the increasing flow of wastewater.
The upgrade of a pumping unit could include higher-horsepower equipment, but this isn’t possible without taking into consideration the system around it. Pumps with greater horsepower may require adjustments to discharge elbows, piping and pipework, as well as electric controls, valves and other parts.
Engineers must also take into consideration the hydraulic requirements of the system. This includes flow and the total dynamic pressure. If you choose to upgrade a pump without considering these factors this could result in operational problems rather than resolve these. Making plans for future capacity in the initial design makes later expansion considerably easier.
Make sure the wastewater is moving during Construction
Retrofitting wastewater pumps presents a unique challenge, which isn’t faced by other construction projects. The station may need to be operational while construction is underway.
Even if contractors are busy the wastewater still flows in. Depending on the scope of the project, temporary bypass pumps may be required to keep operation during the removal and installation of existing equipment.
Romtec Utilities was able to address this kind of problem at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project involved replacing two older wastewater lifting stations, and operating the facility. Specific engineering for the site as well as packaged systems and bypass pumping techniques were used to accommodate existing station footprints and operational needs. This example shows why it is crucial to take into consideration the sequence of construction before installing.
In the event that replacing becomes the best alternative
Each station is not able to be restored. A severely deteriorated wet well, inadequate structural capacity, or major changes in hydraulic requirements may make sewer lift station replacement more appropriate than modifying the existing installation.
The choice should take into account structural health, equipment compatibility, construction access to the site, service continuity, and long-term operational requirements. Romtec Utilities starts retrofitting and replacing projects by identifying components that will be retained and those that need to be replaced.
The company then develops engineering solutions specific to the location, initial plans and budget estimates. Prefabricated components can also help organize installation and reduce some on-site construction requirements.
The Project Isn’t Finished When the Pumps Begin to Run
Modernized lift stations should be able to function as an integrated system. Before returning a lift station to normal service, restart tests, commissioning as well as verification of the equipment are essential to verify that all pumps, controls, and related equipment operate in accordance with their design.
Operator training, as well as maintenance and operation manuals are equally crucial. Before taking over responsibility for the maintenance of a station, employees must be aware of new procedures, equipment and also the documents.
Retrofitting successfully preserves the infrastructure, while addressing the limitations which required modernization.
Municipalities and facility owners need to look beyond the immediate repairs. The most successful projects incorporate new equipment into existing structures. They ensure important services during construction and then prepare the pumping systems to last for a long time.