The wastewater lift station of the municipality is old. The pumps are at the expiration date of their useful lifespan, the controls require modernization, and the access hatch has become damaged. The concrete wet well is robust and sturdy.

Do you think the station should be destroyed and rebuilt? Not necessarily. The more important issue is whether the infrastructure in place will be able to accommodate a modern pumping system without compromising the reliability, accessibility to maintenance and capacity.

Image credit: romtecutilities.com

Retrofitting a pump station could be a fantastic method to save infrastructure and replace elements which are no longer in use.

Start with the structure that nobody would like to replace.

Wet wells can be the most expensive and difficult component to replace as they are underground and connected to existing pipes, and vital to wastewater collection.

Retaining the concrete structure could make it easier to dig and build.

However, damage to the access hatch could affect the decision. Romtec Utilities has identified wet-well hatch replacement as an essential retrofit. Instead of affixing a hatch to cement that has deteriorated, replacing the whole top layer can be a more reliable option. This technique can be utilized to increase access and improve the structure’s usability without having to rebuild the entire wet well.

A better pump alters the way engineers work.

Imagine a neighborhood that has increased significantly since the original lift station installation. The pumps that are in place may no longer provide sufficient capacity to handle the increased flow of wastewater.

A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.

The engineers must also assess the requirements for hydraulics of the system, such as flow rate and dynamic head total. Installing a larger pump without studying these factors can lead to problems in operation instead of resolving the issues. Planning for future expansions in the initial design will allow for a much simpler process to grow later.

Make sure that the wastewater is moving during construction.

Retrofitting an existing pump station can present a new challenge. Contrary to other equipment replacement projects, this one will need to continue operating during construction.

The water continues to flow even when contractors are working. According to the scope of the project temporary bypass pumps could be needed to maintain services during removal and the installation of existing equipment.

Romtec Utilities took on this kind of challenge in the Federal Law Enforcement Training Center in Brunswick, Georgia.

The project involved replacing two wastewater lift stations that were in poor condition while maintaining operations at the facility. The site-specific engineering, packaged systems and bypass pumping techniques were used to accommodate existing station footprints and operational requirements. This example shows the importance of taking time to take into consideration the sequence of construction prior to constructing.

In the event that replacing becomes the best option

It is not possible for every station to be renovated. Sewer lift stations might have to be rebuilt for a damaged wet well, or have a low structural capacity.

It is important that the decision made takes into account structural factors as well as equipment compatibility and accessibility to construction, as in the long-term requirements for operation. Romtec Utilities begins retrofits and replacements by identifying components which are expected to stay and those that need to be replaced.

The company designs site-specific engineering solutions as well as preliminary designs and budgetary estimates. Prefabricated components help organize installation, and reduce the time spent on construction.

The Project isn’t Fully Complete Until the Pumps are Beginning

Modern lift stations must operate as an integrated system. Before returning it to regular service, startup testing and commissioning will help ensure that the pumps, controls, as well as the equipment that is associated with them, are in accordance to the established design.

Operator training and operation and maintenance manuals are equally crucial. Maintenance personnel should be familiar with the latest equipment and operational procedures, as well as the necessary documentation prior to taking charge of the station.

An effective retrofit will preserve the value of infrastructure as well as addressing the weaknesses which led to the need for modernization.

Municipalities and owners of facilities must look beyond immediate repair. The most successful projects combine new equipment with existing structures. They maintain important services during construction and then prepare the pumping systems for years of continuous operation.