By Mike Pindelski
Due to the dangers associated with entering confined spaces, municipalities are now, more than ever, addressing the issues of below ground pump stations to protect both entrants into confined spaces and the investment of systems themselves.
Metropolitan Industries of Romeoville, IL, recently renovated three below ground pump stations, giving each municipality the ability to interface with the controls without entering the confined space. Potential future projects such as submersible pump retro-fits into the existing wetwell would be the next appropriate step to completely eliminate confined space entry.
Calumet City, IL
The City of Calumet City required an emergency rehabilitation project following the flooding of a below ground water pump station.
"It is suspected that the reservoir fill valve stuck open causing an overflow condition and thus, water filled the below ground pump station," said Metropolitan Industries's Keith Girup. "The existing booster station was constructed many years ago when below ground systems were common. Metropolitan was able to repair and replace equipment with an above ground solution quickly and in the process, improve the operation and energy efficiency of the station by implementing variable frequency drives for constant pressure control."
Another new piece of equipment included in the upgrade was a low-flow shutdown bladder storage tank, which supports water system leak loads during low flow periods of time.
The pump station was also integrated into a city-wide SCADA system for enhanced monitoring and alarm notification. A flood switch was added to the pump room to provide notification in the event of a flood. The pumps and valves remain below ground and are subjected to the hazards associated with such a location.
The upgrades reduced the frequency of confined space entry and improve overall protection of the equipment.
South Palos Sanitary District
A similar project was completed for the South Palos Sanitary District of Palos Park, IL.
"In this project, the municipality decided to keep their drywell sanitary lift station pumps below ground, but implemented new above grade controls into a new prefabricated concrete building with an exposed aggregate finish," said Girup.
The prefabricated building contains the controls and generator. While the drywell pumps will remain below ground, the frequency of confined space entry has decreased dramatically with the implementation of above ground controls.
Village of Burr Ridge, IL.
The Village of Burr Ridge implemented an above ground traffic box to eliminate the frequency of entering a confined space by placing all controls and electrical distribution equipment above ground. The municipality plans to replace the existing pumps with submersible pumps in a second phase.
"In the previous configuration, the customer was going down into the pit quite often to monitor controls, but with the upgrade, they have to do so less often," Girup said.
Conclusion
With each upgrade, the customer not only gained capital investment protection by implementing above grade control systems to protect controls from potential flooding, they also improved safety conditions by reducing the frequency of confined space entry.
About the Author: Mike Pindelski is the Marketing Coordinator at Metropolitan Industries, Inc. Based in Romeoville, Ill. he can be reached at [email protected].
