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Flowmeter pivotal in upgrade of 100-year-old Nashville water plant

July 11, 2003
Nashville, Tennessee is best known to most people as home of the Grand Ole'' Opry and aspiring singers/songwriters. However, a little known fact about Music City USA is that it is also home to one of the oldest water pump stations in the United States.
Construction of the pumping station began in 1888, was completed in 1889 and it has been in continuous operation since that time. Although the plant has been modernized through the years, some of the equipment has been in continuous service since 1928. The station was officially named the George Reyer Pumping Station, in honor of Captain George Reyer, a Water Works superintendent for over 41 years. Today, the George Reyer pumping station, along with the R.L. Lawrence filtration plant located directly next door, are collectively known as the Omohundro water plant.

The plant, originally powered by steam, had a capacity of 10 mgd up until 1953 when the pumping station converted to electric power. The station is currently equipped with 12 electrically powered pumping units for raw and finished water that provide 139 million gallons of water daily. The Omohundro plant, along with one additional water treatment plant, provides all of the water for the City of Nashville and surrounding communities.
Presently, Metro Water Services, officially known as the Metropolitan Government of Nashville and Davidson County, Department of Water and Sewerage Services, is responsible for operation of the Omohundro Water Plant in addition to 2,571 miles of water mains that provide service to over 136,500 water accounts.
The Water Plant Operations group is also responsible for the maintenance and operation of approximately 156 water and sewerage pumping stations located throughout the country as well as 45 reservoirs.
In 2000, I.C. Thomassen Consulting Associates, Inc. (ICT) was contracted for Phase II of the Omohundro plant upgrade. This phase included the design of an automation package incorporating contractor -specified flowmeters. The general contractor for the project, W.L. Hailey & Company Inc., builds new treatment plants as well as construction expansions and modifications to existing facilities.
An important aspect to the plant upgrade would be flowmeters that would allow the plant to monitor pump flow activity for the automation system. Tommy Melton, assistant plant manager with the Water Plant Operations group, states that the turbine flowmeter manufacturer originally chosen to provide the flow instrumentation realized their product could not provide the accurate flow data necessary for efficient operation of the plant and withdrew from the project.
"At that point, just about every flowmeter manufacturer possible made a visit to the plant to review the application," adds Melton. "Marsh-McBirney was the only manufacturer that was certain their meter was up to task."
After review of the application, local Marsh-McBirney sales representative Southeastern Automation Group recommended the Multi-Mag Insertable Magmeter. W.L. Hailey purchased one flowmeter for a trial period to evaluate its performance.
The age of the facility provided numerous challenges for most available flowmeters. Restrictive piping configurations, including many bends as well as minimal straight pipe runs, make accurate and repeatable flow monitoring a challenge. The flowmeter was designed to accurately measure flow near bends, elbows and short pipe runs — in some cases even within the pipe itself. The meter also has the ability to indicate reverse flow and, in turn, provide an alarm to the automation system.
The flowmeter utilizes electromagnetic technology. The sensor has multiple electrodes that are precisely positioned according to pipe size. The electrodes constantly profile the flow to provide exceptionally high accuracy — even near the bends and elbows.
The trial period was a success. Six flowmeters were then installed in the Omohundro pumping station in April 2002. Accuracy is continuously cross-checked with data provided by the automation system and the meters are providing accurate data. The meter continues to accurately monitor and relay critical pump flow data without interruption of water services to the Nashville community.

For more information on the Multi-Mag Insertable Magmeter, contact Marsh-McBirney, Inc. at 301-847-5599 or visit