The municipality has an old wastewater lift station. Pumps are nearing the end of their service life, and controls require modernization and the access hatch needs to be replaced. The concrete wet well is robust and solid.
Do you think the station should be destroyed and rebuilt? Not necessarily. The best question to ask is whether or not the current infrastructure will be able to support pumps that meet current standards without compromising reliability and capacity.
Image credit: romtecutilities.com
Retrofitting a pump station could be a fantastic way to save infrastructure and replace elements that have become obsolete.
Start With the Structure Nobody wants to replace.
Wet wells are often the most expensive and difficult element to replace because they are constructed underground and attached to existing pipes and are vital to wastewater collection.
Retaining a concrete construction which is still functional could reduce the excavation and construction.
The loss of space around the access hatch might complicate this decision. Romtec Utilities has identified wet-well hatch replacement as a crucial retrofit. Instead of attaching a brand new hatch to the deteriorated concrete, replacing the entire top slab may be a better option. This method can be used to improve access and the structural’s functionality without the need for rebuilding the entire wet well.
A new pump improves the way engineers work.
Imagine a neighborhood that has exploded in size since the original lift station was installed. The existing pumps may no longer provide sufficient capacity for increased flows of wastewater.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers should also evaluate the hydraulic requirements of the system, such as the flow rate as well as the dynamic head total. If you choose to upgrade a pump without taking into account these requirements this could result in operational problems rather than resolve the problem. Planning for future expansions in the initial design will enable you to grow in the future.
Make sure that the water for waste is flowing throughout construction
A wastewater pump station retrofit poses a challenge which normal replacement of equipment projects do not encounter: the facility may require operation through the entire construction.
When contractors aren’t busy the wastewater still flows in. In the case of the project the temporary bypass pumps could be required to keep services during removal and the installation of the existing equipment.
Romtec Utilities tackled this type of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.
The work involved replacing two of the old wastewater lift stations, while still maintaining the operation at the facility. The site-specific engineering, packaged systems and bypass pumping techniques allowed for the existing station footprints as well as operational requirements. This illustrates the importance of taking time to take into consideration the sequence of construction prior to constructing.
When Replacement Becomes the Better Choice
Each station is not able to be rehabilitated. If the sewer lift station needs to be replaced because of a severely degraded well, structural problems or significant changes to the needs for hydraulics, it may be more beneficial to replace rather than modify.
It is important that the decision taken takes into consideration structural requirements along with equipment compatibility, accessibility to construction, as well in the long-term requirements for operation. Romtec Utilities starts retrofitting and replacing projects by identifying the components that are to be kept and those that must be replaced.
From there, the company creates engineering solutions for specific sites as well as preliminary designs and budgetary estimates. Prefabricated components also aid in facilitate installation and cut down on construction-related requirements on site.
The Project is not Complete When the Pumps Are Started
A modern lift station should work as a complete system. Before returning it to normal service, it is necessary to start testing and commissioning help verify that the pumps, controls, and other equipment are operating according to the established design.
Operator training, as well as operation and maintenance manuals are equally crucial. Before taking over responsibility for the station, personnel responsible for maintenance must know about the latest equipment, procedures, and documentation.
A successful retrofit preserves the value of infrastructure and addresses the shortcomings that made modernization necessary.
Municipalities and facilities owners need to be aware of the need for more than just immediate repairs. The most successful projects combine new equipment and existing structures. They will maintain the vital services throughout construction and then prepare the pumping systems to run for many years.
