The sewer lift station of a municipality is old. The pumps are nearing the limit of their lifespan The controls are old and the access hatch has deteriorated. While the concrete wetwell is solid in its structure, it is in need of to be upgraded.
Should the station be completely removed? Not necessarily. The more important issue is whether the current infrastructure will be able to accommodate a modern pumping system without compromising availability, 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 No One Would Like to Replace
It’s expensive and difficult to replace the wet well since it is submerged in the ground and connected to pipes, and is necessary for wastewater collection.
Retaining a concrete construction that is still usable could help in reducing the excavation and construction.
But, any deterioration that occurs around the access hatch could complicate the process. Romtec Utilities identifies wet well hatch replacement as a typical retrofit requirement. It could be more durable to replace the top layer instead of attaching a new hatch on deteriorated concrete. This option can be utilized to increase accessibility and the structural’s functionality without needing to rebuild the entire wet well.
A more powerful pump alters the Engineering
If a neighborhood in the area has grown substantially since its first lift station was put in place. The existing pumps might not be able to deal with the increasing flow of wastewater.
The modernization of a pumping device could include higher-horsepower equipment, but this cannot be done without considering the entire system. Pumps that have higher horsepower might require modifications to the discharge elbows and pipes as well as electrical controls, valves, and other components.
Engineers must also take into consideration the hydraulic requirements of the system. This includes flow and total dynamic pressure. In the event of installing a larger pump, not reviewing these conditions can create operational issues rather than solving these. The planning for future expansions at the time of initial design will allow for a much simpler process to expand later.
Keep the water moving during construction
Retrofitting a pump station for wastewater is a particular challenge that isn’t encountered by other projects. The station could need to be operational throughout construction.
Even when contractors are working. Based on the nature of the project the temporary bypass pumps could be required to keep services during removal and the installation of existing equipment.
Romtec Utilities faced this kind of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project required the replacement of two wastewater lift stations that were in poor condition in the process of maintaining operation at the facility. Site-specific engineering, packaged systems and bypass pumping techniques allowed for the existing station footprints as well as operational requirements. This example demonstrates why the sequence of construction must be considered carefully prior to installation.
When replacing becomes the best alternative
It is not possible for every station to be repaired. If the sewer lift station needs to be replaced because of a severely degraded well, structural limitations or significant changes to hydraulic needs, it may be more appropriate to replace the station rather than modify.
When making a choice, it is important to consider the structural condition of the building, its compatibility equipment, the accessibility to construction, continuity of service and the long-term requirements. Romtec Utilities begins retrofit and replacement projects by determining which elements will remain and which ones require replacement.
The business will then design sites-specific engineering designs as well as budget estimates and initial designs. Prefabricated parts can also help to organize installation and decrease some construction-related requirements on site.
The Project Isn’t Complete until the Pumps are Started
The modern lift station needs to work as a whole. Prior to returning it back to normal service, it is necessary to start testing and commissioning helps ensure that the controls, pumps and associated equipment perform according to the approved design.
Maintenance and operation manuals along with instruction for operators are crucial. Maintenance personnel should be familiar with the new equipment and operating procedures, and the documents before taking charge of the station.
Retrofitting infrastructure successfully preserves its value while solving the shortcomings that led to modernization.
Municipalities and owners of facilities need to think beyond immediate repairs. The most successful projects incorporate the latest equipment in existing structures and maintain essential service even while construction is in progress. They also prepare the pumping system for continued service for a long period of time.