A municipality has an outdated wastewater lift station. The pumps have reached the end of their life expectancy The controls are old and the access hatch is degraded. Although the concrete wetwell is structurally sound, it needs to be upgraded.
Should the entire station be destroyed and rebuilt? Not necessarily. One of the most important questions to ask is whether or not the existing infrastructure can accommodate a pumping system that meets the latest standards, without compromising reliability and future capacity.
Image credit: romtecutilities.com
A thoughtfully designed retrofit of a pump station can help preserve vital infrastructure while replacing components that no longer meet operational standards.
Begin With the Structure No One is Trying to Replace.
Wet wells are often the most expensive and difficult part to replace, since they are buried and connected to existing pipes, and essential to the collection of wastewater.
Retaining a concrete construction that is still usable could reduce the excavation and construction.
However, damage to the access hatch can make the choice. Romtec Utilities says that wet well hatches are typically replaced in retrofits. Instead of affixing a fresh hatch to concrete that is deteriorating replacement of the entire top slab may make a more robust solution. This method can be used to increase access and improve the functionality of the structure, without needing to rebuild the whole wet well.
A More Powerful Pump Modifies the Engineering
Imagine that a residential area has increased significantly since the initial lift station installation. 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.
Engineers must also consider the hydraulic requirements of the system, including the rate of flow as well as dynamic head total. If you add a larger pump without evaluating these conditions the system could cause problems with operation rather than addressing them. Planning for future expansion during the initial design phase will help you to grow in the future.
Make sure that the wastewater is kept moving during Construction
Retrofitting a wastewater pump station introduces a challenge that ordinary project for replacement of equipment may not face: the station could require a continuous operation throughout the construction.
Even when contractors are working the wastewater still flows in. According to the project an interim bypass pumping system might be necessary to maintain service as existing equipment is removed or new components are added.
Romtec Utilities fought this kind of challenge in the Federal Law Enforcement Training Center located in Brunswick, Georgia.
The project involved replacing two outdated wastewater lifting stations while operating the facility. The site-specific engineering as well as packaged systems and bypass pumping techniques helped accommodate existing station footprints and operational needs. This example shows why the sequence of construction should be considered prior to the installation process begins.
When the Alternative is the Best Alternative
Some stations are not suitable for rehabilitation. Sewer lift stations might have to be rebuilt in the event of a badly damaged or insufficiently functioning wet well. structural capacity.
Before making a decision it is crucial to look at the structural health of the structure, its compatibility to equipment, accessibility to construction sites, service continuity and long-term needs. Romtec Utilities begins retrofit and replacement projects by determining which components will be retained and which ones require replacement.
The company will then create sites-specific engineering designs, budget estimates, as well as preliminary designs. Prefabricated components help organize installation, and reduce the time spent on construction.
The work isn’t over when the pumps kick in
Modern lift stations must function as a system in one. Before returning the lift station to service, testing the startup and commissioning tests will ensure that the pumps, controls as well as other equipment perform as per the accepted specifications.
Maintenance and operation manuals along with training of operators, are vital. Prior to taking over the responsibility of the station, personnel responsible for maintenance must understand the latest equipment, procedures, and the documentation.
A successful retrofit helps preserve infrastructure that still has value and addresses the shortcomings which led to the need for modernization.
This means that municipalities and owners of facilities need to think beyond immediate repairs. Most successful projects blend the latest equipment with the existing structures. They maintain essential services during construction and prepare the pumping systems for a lifetime of operation.