The wastewater lift station of a municipality is old. Pumps are nearing the end of their service life, and controls need modernization and the access hatch has to be replaced. Even though the concrete wetwell is structurally sound, it needs to be modernized.
Should the entire station be destroyed and rebuilt? Not necessarily. The best question to consider is whether the current infrastructure can support pumps that meet current standards without compromising reliability or future capacity.
Image credit: romtecutilities.com
A carefully engineered pump station retrofit can preserve valuable infrastructure while replacing components that no longer meet operational requirements.
Begin with the Structure that nobody wants to replace.
The wet well is often one of the more expensive and challenging components to replace as it is submerged, connected to existing pipes, and crucial to wastewater collection.
If the concrete structure is in good condition, retaining it could minimize excavation and construction work.
However, deterioration near the access hatch could affect your choice. Romtec Utilities says that wet well hatches are usually replaced as part of retrofits. Instead of attaching the hatch to cement that has deteriorated, replacing the whole top layer might be a more reliable option. This approach can improve access and enhance the utility of the structure without re-building the entire wet well.
The technology behind an even more powerful pump is distinct
Imagine that the area of residence has grown significantly since the lift station’s initial installation. The current pumps might no longer provide sufficient capacity for increased flows of wastewater.
The modernization of a pumping system may include higher-horsepower equipment, but this isn’t possible without considering the entire system. The more powerful pumps could require adjustments to discharge elbows, pipes valves, electrical control and other parts.
Engineers must also take into consideration the hydraulic needs of the system. This includes flow and the total dynamic pressure. In the event of installing a larger pump, not taking a look at these requirements could cause problems with operation rather than addressing them. Planning for future capacity during the initial design stage can simplify future expansion.
Make sure that the Wastewater is moved during Construction
Retrofitting wastewater pumps is a unique problem that isn’t encountered by other projects. The station may need to be operational while construction is underway.
Even when contractors are working and preparing for the next project, wastewater is still arriving. According to the report, a temporary bypass pumping system is required to ensure service is maintained as the existing equipment is taken down or new components installed.
Romtec Utilities faced this kind of challenge in the Federal Law Enforcement Training Center at Brunswick, Georgia.
The project required replacing two old wastewater lift stations, while keeping the operation of the facility. The site-specific engineering, packaged systems and bypass pumping techniques were used to accommodate existing station footprints and operational needs. This is a good example of how the order of construction should be considered prior to installation.
When the Alternative is the Best Option
Some stations are not suitable to be renovated. If the sewer lift station is in need of replacement because of a damaged well, structural limitations or significant changes in hydraulic requirements, it might be more beneficial to replace rather than alter.
In making a final decision, it is crucial to take into consideration the structural health of the structure, its compatibility with equipment, accessibility to construction, the continuity of services and long-term requirements. Romtec Utilities begins retrofits and replacements by identifying elements that are to remain and those which need replacement.
The company then develops engineering solutions specific to the location, initial plans as well as budget estimations. Prefabricated parts are a great way to organize installation, and reduce the amount of construction work that is required on site.
The Project is Not Complete until the Pumps are In Place
Modern lift stations should work as a whole. Prior to returning a lift station to normal operation, initial testing, commissioning, and testing of equipment is required to confirm that all pumps, controls and equipment work according to design.
Training and manuals for operators are equally essential. Maintenance staff should be acquainted with the new equipment and operating procedures, in addition to the documentation before they take responsibility for the station.
A successful retrofit helps preserve the infrastructure, while addressing the shortcomings that required modernization.
This means that municipalities and owners of facilities need to take a look beyond the immediate fixes. The strongest project is one that integrates the new equipment into existing structures, maintains essential service throughout construction, and also prepares the pumping system to last for years of continued operation.