The wastewater lift station of municipal facilities is outdated. Pumps are advancing towards the end of their service life, and controls need to be modernized and the access hatch must be replaced. The concrete wet well is robust and sturdy.
Image credit: romtecutilities.com
Should the entire station be destroyed and rebuilt? Not necessarily. The more important question to consider is whether the existing infrastructure can accommodate the pumping system of the latest standards, without compromising reliability and capacity.
The retrofitting of pumps that are well-designed can help save precious infrastructure, and can also help in replacing parts that are no longer in compliance with the operational standards.
Begin With the Structure No One is Trying to Replace.
It’s expensive and difficult to repair the wet well due to its location in the ground, connected to pipes and is vital for the collection of wastewater.
Intentionally retaining the concrete structure could reduce excavation work and construction.
However, deterioration near the hatch could complicate the decision. Romtec Utilities identifies wet well hatch replacement as an usual retrofit requirement. It may be more durable to replace the top slab instead of installing a brand new hatch to a deteriorated concrete. This method can increase accessibility and extend the structure’s usefulness without rebuilding the complete wet well.
A More Powerful Pump Modifies the Engineering
Imagine a neighborhood that has seen a significant increase in population from the time of the first lift station installation. The pumps that are in place may not be sufficient for increased flows of wastewater.
Pumps with higher horsepower could be used to upgrade pumps, but the equipment has to be integrated into the system. Pumps with greater horsepower could require modifications to discharge elbows, piping and pipework along with electrical controls, valves, and other components.
Engineers should also look at the hydraulic needs of the system. This includes flow and total dynamic pressure. Installing a larger pump before evaluating the conditions may cause more issues than it solves. Planning future capacity prior to initial design makes future expansion considerably easier.
Keep the Wastewater Moving 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.
When contractors aren’t busy and preparing for the next project, wastewater is still arriving. In the case of the project temporary bypass pumps might be needed to maintain the service throughout the removal and installation of existing equipment.
Romtec Utilities faced this kind of problem in the Federal Law Enforcement Training Center at Brunswick, Georgia.
The work involved replacing two older wastewater lift stations in the meantime, and maintaining the operation of the facility. Site-specific engineering packaging systems, packaged systems and bypass pumping techniques allowed for the existing station footprints and operational needs. The case study illustrates the importance of focusing on construction sequencing prior to installation.
When replacing becomes the best alternative
Not every station is suited to be renovated. A seriously degraded wet well insufficient structural capacity or significant changes in hydraulic requirements may make the replacement of a sewer lift station better than making changes to the existing structure.
It is vital that the decision taken takes into account structural conditions as well as equipment compatibility and accessibility to construction as well in the long-term requirements for operation. Romtec Utilities starts retrofitting and replacing projects by identifying the components to be kept as well as those that require to be replaced.
The company will then create custom-designed engineering plans including budget estimates, site-specific designs, and initial designs. Prefabricated parts are also helpful to facilitate installation and reduce certain on-site demands.
The Project isn’t Over Until the Pumps Get Started
The modern lift station must work as a whole. Before returning a lift-station to normal operation, initial tests, commissioning as well as verification of equipment are required to verify that the pumps, controls and other equipment are operating in accordance with their design.
Manuals as well as training for operators are equally crucial. Before taking over responsibility for an entire station, the personnel in charge of maintenance must understand new equipment, procedures and also the documents.
Retrofitting successfully preserves the infrastructure while still addressing the issues that made modernization necessary.
Municipalities and facilities owners need to think beyond repairs that are immediate. The most successful projects combine the latest equipment with the existing structures. They will maintain the important services during construction and prepare the pumping systems for years of continuous operation.
