The municipality has an old wastewater lift station. The pumps are nearing the limit of their lifespan and the controls are inefficient, as well as the access hatch is degraded. However, the concrete wet well is robust and solid.

Image credit: romtecutilities.com

Should the station be totally destroyed? Not necessarily. The better question to ask is whether or not the current infrastructure will be able to support a pumping system that meets modern standards without compromising reliability or future capacity.

Retrofitting a pump station could be a great way to preserve infrastructure and replace elements which are no longer in use.

Begin with the structure that isn’t being replaced by anyone.

It’s expensive and time-consuming to repair the wet well because it is buried in the ground, linked to piping and is essential for wastewater collection.

The retention of a concrete structure that is still serviceable can minimize the digging and construction.

The deterioration of the area around the access hatch might make this difficult. Romtec Utilities says that wet well hatches are often replaced as part of retrofits. Instead of attaching a brand new hatch to the deteriorated concrete or replacing the entire top layer could offer a more long-lasting solution. This option can be utilized to improve access and the functionality of the structure, without the need for rebuilding the entire wet well.

A more powerful pump alters the Engineering

Think about a community that has experienced a significant growth since the installation of the lift station. It could be that the pumping system is no longer adequate to handle the increase in flows of wastewater.

Pumps with greater horsepower can be used to upgrade the pumping station, however the equipment has to be integrated within the system. To make the pumps more powerful you might need to make changes to the discharge elbows or piping. You might also have to alter electrical controls and valves.

Engineers should also assess the system’s hydraulic requirements, including the head of flow and total dynamic head. The installation of a bigger pump without reviewing these conditions can create problems with operation rather than addressing these. Making plans for future capacity in the 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.

Even when contractors are working they continue to receive wastewater. According to the scope of the project temporary bypass pumps might be required in order to maintain services during removal and the installation of the existing equipment.

Romtec Utilities faced this kind of problem in the Federal Law Enforcement Training Center located in Brunswick, Georgia.

The project required the replacement of two old wastewater lift stations in the process of maintaining operation at the facility. Specialized engineering on site, packaged systems and bypass pumping techniques made it possible to meet existing station footprints as well as operational requirements. This is a good example of why the construction sequence is important to consider prior to installation.

If you think replacement is the better option, replace it.

It is not possible for every station to be repaired. A seriously degraded wet well or a structural weakness or major changes in hydraulic requirements might make a the replacement of a sewer lift station better than making changes to the current installation.

It is important that the decision made takes into consideration structural requirements the compatibility of equipment and construction accessibility, as well in the long-term requirements for operation. Romtec Utilities starts retrofitting and replacing projects by identifying components that are to be kept as well as those that require to be replaced.

The firm will then develop sites-specific engineering designs as well as budget estimates and preliminaries of designs. Prefabricated components can assist in facilitate installation and help reduce the time spent on construction.

The Project Isn’t Finished When the Pumps Are Running

The modern lift station must be able to function as a system. Before returning the lift station to service, tests of startup and commissioning can help to ensure that the pumps and controls and other equipment are performing according to approved design.

Operator training, as well as operation and maintenance manuals are equally important. Maintenance personnel should be knowledgeable with new equipment and operating procedures, and the necessary documentation prior to taking charge of the station.

Retrofitting infrastructure effectively preserves its value, while solving the shortcomings that led to modernization.

Municipalities and owners of facilities must take a look beyond the immediate fixes. The best initiatives are those that incorporate new equipment into existing structures to continue to provide essential services even while construction is in progress. They also make preparations for the pumping system for continued service for a long period of time.