The wastewater lift station of an urban municipality is old. Pumps are about to expire their usefulness, the controls need modernization and the access hatch has to be replaced. Although the concrete wetwell appears structurally sound, it’s time to be updated.
Image credit: romtecutilities.com
Should the station be totally removed? Not necessarily. It is more important to consider whether the infrastructure already in place is capable of supporting a modern system of pumping without compromising capacity in the future, reliability, or maintenance accessibility.
A thoughtfully designed retrofit of the pump station could preserve important infrastructure and replace components that do not meet current operating requirements.
Start with the structure that nobody would like to replace.
The wet well can be one of the more expensive and challenging components to replace, as it’s submerged, connected to existing piping and is essential to wastewater collection.
The retention of a concrete structure that is still serviceable can help in reducing the excavation and construction.
However, damage to the access hatch may complicate your decision. Romtec Utilities has identified wet-well hatch replacement as an essential retrofit. It might be more reliable to replace the top layer instead of installing a brand new hatch on concrete that has deteriorated. This can make it easier to access and extend the structure’s usefulness without re-building the entire wet well.
A better pump alters the way engineers work.
If a neighborhood in the area has grown substantially since its original lift station was installed. The existing pumps might not be able with increased wastewater flows.
The upgrade of a pumping device could include more horsepower, but it is not possible to do this without considering the entire system. To get more powerful pumps there is a possibility that you will need change the discharge elbows or pipe. It is also possible to upgrade electrical controls and valves.
Engineers should also assess the hydraulic requirements of the system, including the flow and head total dynamic. If you decide to install a larger pump without considering these factors, it can cause problems in operation instead of resolving these. Planning for future expansions in the the initial design phase will help you to expand later on.
Make sure that the Wastewater is moved 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.
The water continues to flow even when contractors are in the process of working. Based on the nature of the project, temporary bypass pumps may be required to keep the service throughout the removal and installation of existing equipment.
Romtec Utilities addressed this type of problem at the Federal Law Enforcement Training Center in Brunswick, Georgia.
The work involved replacing two of the old wastewater lift stations in the meantime, and maintaining the operation of the facility. Specific engineering for the site, packaged replacement systems, and bypass pumping methods helped adapt to the station’s footprints and operational demands. This example shows how important it is to think about the sequence of construction prior to installing.
When replacement becomes the better Choice
Some stations are not suitable for rehabilitation. A seriously degraded wet well structure that is not strong enough, or major changes in the hydraulic requirements can make the sewer lift station replacement more suitable than altering the existing installation.
Before making a decision it is important to consider the structural integrity of the building, its compatibility with equipment, access to construction sites, service continuity and long-term requirements. Romtec Utilities begins retrofits and replacements by identifying parts that are to remain and the ones that require replacement.
The company then develops engineering solutions that are specific to the site, as well as preliminary plans and budget estimates. Prefabricated components can assist in organize installation, and reduce construction on site.
The Project isn’t Complete until the Pumps Are Running
Modern lift stations must function as a system in one. Before returning the lift station back to service, tests of startup and commissioning can help to ensure that the pumps, control equipment and other components are operating in accordance with the established specifications.
Operator training and maintenance and operation manuals are equally important. Maintenance personnel must know the latest equipment, operating procedures and the documentation prior to taking over for the station.
Retrofitting infrastructure is a great way to preserve its value while addressing limitations that led to modernization.
This means that municipalities and owners of facilities need to think beyond immediate repairs. The most successful plan is one that integrates new equipment with existing structures, ensures vital service during construction, and also prepares the pumping system to last for years of continual operation.