The sewer lift station of municipal facilities is outdated. The pumps have reached the end of their life expectancy and the controls are dated and the access hatch has damaged. However, the concrete wet well is solid and sturdy.
Image credit: romtecutilities.com
Should the station be totally destroyed? Not necessarily. It is important to determine if the infrastructure in place can support a modern system of pumping without compromising capacity in the future, reliability, or maintenance access.
Retrofitting a pump station could be a fantastic way to save infrastructure and replace components that are no longer functional.
Begin With the Structure No One is Trying to Replace.
The wet well is typically one of the most costly and disruptive components to replace, as it’s located underground, linked to existing piping and is essential to the collection of wastewater.
The retention of a concrete structure that is still serviceable can help in reducing the excavation and construction.
The degradation of the area around the access hatch might cause problems with this decision. Romtec Utilities identifies wet well hatch replacement as a standard retrofit requirement. It might be more reliable to repair the top slab instead of installing a brand new hatch onto deteriorated concrete. This method can be used to improve access and the usability of the structure without the need to replace the entire wet well.
A more powerful pump alters the Engineering
Imagine a neighborhood that has grown substantially since its initial lift station was constructed. The pumps that are in place may no longer provide sufficient capacity for increased flows of wastewater.
The upgrade of a pumping device could comprise higher horsepower equipment, but this cannot be done without considering the whole system. Pumps with greater power may require changes to discharge elbows, pipes valves, electrical controllers as well as other components.
Engineers must also take into consideration the hydraulic needs of the system. This is a consideration for flow as well as total dynamic pressure. A larger pump prior to assessing the requirements could cause more problems than it resolves. Planning for future expansion during initial design will help you to grow later on.
Make sure that the wastewater is 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.
The water continues to flow even when contractors are in the process of working. Based on the nature of the project an interim bypass pumping system may be necessary to keep operation while the existing equipment is removed and new equipment is installed.
Romtec Utilities was able to take on this challenge at the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project consisted of replacing two old wastewater lift stations as well as maintaining the operation at the facility. Site-specific engineering as well as packaged replacement systems and bypass pumping techniques helped make room for the existing station footprints and operational demands. The example illustrates why construction sequencing deserves attention prior to installation.
If replacement is the best alternative, then replacement is the best
There are many stations that can be restored. A badly degraded wet-well or a structural weakness or major changes in hydraulic requirements may make an upgrade to a sewer lift station more suitable than altering the current installation.
It is important that the decision made takes into account structural factors the compatibility of equipment and accessibility to construction, as well longer-term operational requirements. Romtec Utilities begins retrofit and replacement projects by determining what components will remain and which will require replacement.
From there, the company creates engineering solutions for specific sites as well as preliminary designs and budgetary estimates. Prefabricated components are also useful for organizing installation and reducing certain requirements on site.
The Project isn’t Complete until the Pumps are Started
Modernized lift stations must be operated as an integrated system. Prior to returning the lift station back to service, testing its startup and commissioning can help to ensure that the pumps and controls as well as other equipment are operating in accordance with the accepted specifications.
Operator training and operation and maintenance manuals are equally important. Maintenance personnel must know the latest equipment, operating procedures and the documentation prior to taking over for the station.
Retrofitting infrastructure can preserve its value, while also fixing the issues that caused modernization.
For facilities owners and municipal authorities This means looking beyond the immediate repair. The strongest project is one that integrates new equipment with existing structures, ensures vital service during construction, and then prepares the pumping system for years of continued operation.