The sewer lift station of a municipality is old. The pumps are approaching the expiration date of their useful life, the controls need modernization, as well as the access hatch has degraded. The concrete wet well remains structurally sound.
Image credit: romtecutilities.com
Do you think the station should be completely demolished and rebuilt? Not necessarily. The more important question to ask is whether the existing infrastructure will be able to support the pumping system of current standards without compromising reliability and future capacity.
A carefully engineered retrofit of a pump station can help preserve valuable infrastructure while replacing components which no longer meet the operating requirements.
Begin with the structure nobody would like to replace.
The wet well is typically one of the more expensive and disruptive components to replace since it is located underground, linked to existing piping and is essential to the process of removing wastewater.
Retaining the concrete structure may decrease excavation and construction work.
However, damage to the access hatch can make the choice. Romtec Utilities has identified wet-well hatch replacement as an important retrofit. Instead of affixing a hatch to cement that has deteriorated, replacing the whole top layer can be more durable. This technique can be utilized to improve access and the structural’s functionality without the need for rebuilding the whole wet well.
The design of the pump with more power is different
If a neighborhood in the area has seen an increase in population since its first lift station was put in place. The current pumps might not be able to handle the demand for increased flows of wastewater.
The upgrading of a pumping unit could comprise higher horsepower equipment, but this can’t be accomplished without considering the entire system. Pumps that have higher horsepower might require modifications to the discharge elbows and pipes along with electronic controls, valves and other parts.
The engineers should also take into consideration the hydraulic requirements of the system, such as the rate of flow and the dynamic head total. In the event of installing a larger pump, not studying these factors can lead to problems with operation rather than addressing them. Making plans for future capacity at the time of initial design makes later expansion considerably easier.
Keep waste water moving during construction
A wastewater pump station retrofit introduces a challenge that ordinary equipment replacement projects may not face: the station may need to remain operational throughout construction.
Contractors continue to work, and wastewater continues to come in. According to the report an interim bypass pumping system might be needed to keep service running while the existing equipment is taken down or new parts are installed.
Romtec Utilities was able to address this kind of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project included replacing two older wastewater lift stations in the process of maintaining operation at the facility. The site-specific engineering packaging systems, packaged systems and bypass pumping techniques were used to accommodate existing station footprints and operational needs. This illustrates the reasons why the sequence of construction is important to consider prior to installation.
If you think replacement is the better alternative
There are many stations that can be renovated. Sewer lift stations might need to be rebuilt when they have a seriously damaged wet well, or have a low capacity for structural strength.
Before making a decision it is essential to think about the structural integrity of the structure, its compatibility with equipment, its accessibility to construction, service continuity and long-term needs. Romtec Utilities begins retrofits and replacements by identifying parts that will remain as well as the ones that require replacement.
The company also develops engineering solutions tailored to the location, initial designs and budget estimates. Prefabricated components are also able to help facilitate installation and cut down on on-site construction requirements.
The Project isn’t Complete until the Pumps Are Running
Modern lift stations should function as a complete system. Prior to returning the lift station back to service, testing the startup and commissioning tests will ensure that the pumps, controls and other equipment work in accordance with established specifications.
Training for operators and operation and maintenance manuals are equally crucial. Maintenance staff should be acquainted with new equipment and operational procedures, as well as the manuals before they assume responsibility for the station.
A successful retrofit will preserve the infrastructure, while addressing the limitations which required modernization.
This means that municipalities and owners of facilities must think beyond immediate repairs. The most successful projects combine new equipment and existing structures. They maintain essential services during construction and then prepare the pumping systems to last for a long time.
