A municipality has an outdated wastewater lift station. The pumps have reached the end of their life expectancy and the controls are inefficient, and the access hatch has degraded. Even though the concrete wetwell is structurally sound, it needs to be upgraded.
Should the station be removed? Not necessarily. The best question to consider is whether the existing infrastructure can support a pumping system that meets modern standards without compromising reliability and 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.
Start with the structure no one wants to replace
The wet well can be among the most expensive and disruptive parts to replace as it is buried, connected to existing pipes, and crucial to the collection of wastewater.
Intentionally retaining the concrete structure could make it easier to dig and build.
However, damage to the access hatch could affect your decision. Romtec Utilities says that wet well hatches are usually replaced in retrofits. Rather than attaching a new hatch to a damaged concrete structure, replacing the entire top layer could be a better option. This can increase access to the structure and extend its usefulness, without having to completely rebuild the wet well.
The engineering of a more powerful pump is distinct
Suppose a residential neighborhood has seen a significant increase in population since the first lift station was put in place. It is possible that the current pumps aren’t adequate to handle the increase in the flow of wastewater.
The upgrade of a pumping device could include more horsepower, but this isn’t possible without taking into consideration the system around it. Pumps with greater power may require changes to elbows for discharge, piping valves, electrical controls and other parts.
Engineers must also consider the requirements for hydraulics of the system. This includes the flow rate as well as the dynamic head total. A larger pump without considering the circumstances could cause more problems than it resolves. The planning for future expansions at the time of the initial design phase will help you to build in the future.
Ensure that the waste water is moving during construction
A wastewater pump station retrofit poses a challenge which normal construction projects for new equipment do not be able to overcome: the station might require to be operational throughout construction.
Contractors are still working, and wastewater continues to come in. According to the project it is possible that a temporary bypass pumping system might be required to sustain service while the existing equipment is taken down or new components installed.
Romtec Utilities took on this kind of challenge at the Federal Law Enforcement Training Center located in Brunswick, Georgia.
The project consisted of replacing two wastewater lift stations that were in use in the meantime, and maintaining the operation at the facility. Site-specific engineering, packaged replacement systems, and bypass pumping strategies helped accommodate the existing station footprints and operational demands. This example demonstrates why the construction sequence must be considered carefully prior to installation.
If replacing is the only alternative
Some stations are not suitable to be renovated. A seriously degraded wet well or a structural weakness or major changes in the hydraulic requirements can make the sewer lift station replacement more appropriate than changing the existing structure.
It is essential to take into account structural factors as well as equipment compatibility and construction accessibility, as well in the long-term requirements for operation. Romtec Utilities begins retrofit and replacement projects by determining which components will be retained and which require replacement.
The company then develops engineering solutions that are specific to the site, preliminary designs and budget estimates. Prefabricated components are also useful to facilitate installation and reduce certain requirements on site.
The Project isn’t Complete until the Pumps are Beginning
Modernized lift stations should operate as an integrated system. Before returning a lift facility to normal service, start-up testing, commissioning, as well as verification of the equipment are essential to verify that the pumps, controls and equipment work in accordance with their design.
Training and manuals for operators are equally vital. Prior to taking over the responsibility of a station, maintenance personnel must know about new equipment, procedures and documentation.
A successful retrofit preserves structures that are still useful while addressing the issues that made modernization necessary.
For facilities owners and municipal authorities This means looking beyond immediate repairs. The best initiatives are those that incorporate new equipment into existing structures and continue to provide essential services as construction progresses. Also, they prepare the pumping system for continued operation for many years.