A municipality has an outdated wastewater lift station. The pumps are nearing the final stage of their life and the controls are dated as well as the access hatch has deteriorated. Yet the concrete wet well remains structurally sound.
Should the entire station demolished and rebuilt? Not necessarily. The more useful question is whether the current infrastructure can accommodate a new pumping system without compromising security, maintenance access or capacity in the future.
Image credit: romtecutilities.com
Retrofitting a pumping station that is well-designed can help save precious infrastructure and also replace parts that are no longer in compliance with operational requirements.
Start with the structure that nobody wants to replace.
Wet wells are often the most costly and disruptive element to replace because they are buried and connected to existing pipes and are vital to wastewater collection.
If the concrete structure is usable, its retention could make it easier to dig and build.
The degrading of the area surrounding the access hatch may affect this decision. Romtec Utilities says that wet well hatches are typically replaced in retrofits. Instead of affixing a fresh hatch to the deteriorated concrete or replacing the entire top slab could offer a more long-lasting solution. This approach can improve access and improve the functionality of the structure without rebuilding the complete wet well.
The design of an even more powerful pump is distinct
Take a look at a neighborhood that has experienced significant expansion since the establishment of its lift station. The existing pumps may not be sufficient for increased flows of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
The engineers should also take into consideration the hydraulic requirements of the system, including flow rate and dynamic head total. If you add a larger pump without considering these factors this could result in operational issues rather than solve the problem. Planning for future expansion during your initial design process will enable you to expand later.
Make sure the wastewater is moving during Construction
Retrofitting a wastewater pumping station presents a unique challenge, that is not encountered in other projects. The station could need to be operational for the duration of construction.
Even when contractors are busy, wastewater continues to arrive. Based on the nature of the project the temporary bypass pumping might be required to keep service while existing equipment is removed, and new components are erected.
Romtec Utilities tackled this type of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.
The project involved the replacement of two old wastewater lifting stations, and maintaining the operation at the facility. The project was able adapt to existing station footprints as as operational requirements by using specific engineering for the site and system for replacement that is packaged. The example illustrates the need to be aware of construction sequencing prior to the installation process begins.
When replacement is the better option, replace it.
Not every station is suitable for rehabilitation. If the sewer lift station is in need of replacement due to a seriously degraded well, structural issues or significant changes in the needs for hydraulics, it may be more appropriate to replace the station rather than alter.
It is important that the choice taken into consideration structural conditions the compatibility of equipment and accessibility to construction as well longer-term operational requirements. Romtec Utilities begins retrofits and replacements by identifying the components which are expected to stay and those that need to be replaced.
The company develops site-specific engineering solutions initial designs, as well as budgetary estimates. Prefabricated parts can also help to organize installation and decrease some needs for construction on site.
The Project Isn’t Fully Complete Until the Pumps are Started
The modern lift station must work as a whole. Before returning it to normal service, it is necessary to start testing and commissioning help verify that the pumps, controls, and associated equipment perform according to the specifications of the design.
Manuals for maintenance and operation, as well as the training of operators are important. Before they can assume responsibility for the maintenance of a station, employees must know about the latest equipment, procedures, and documents.
A successful retrofit helps preserve the infrastructure, while addressing the issues that required modernization.
Municipalities and owners of facilities need to think beyond immediate repairs. The most successful plan is one that integrates the new equipment into existing structures, maintains essential services throughout construction, and then prepares the pumping system to last for years of continual operation.