Case Study 01.2021

City of Shelby, Ohio
WWTP Eliminates CSOs
while Upgrading to a
State-of-the-Art Facility
The City of Shelby, Ohio recently upgraded its activated-sludge wastewater
treatment plant to double its capacity to 5 MGD, while expanding its capability
to treat and disinfect combined high-volume stormwater and wastewater flows
generated by wet-weather conditions.
The project, designed to upgrade muchof the plant from its original equipment
installed in 1953, included improvements
to headworks, upgrading primary
settling tanks and aeration systems,
adding a new final clarifier, replacing
chlorination with ultraviolet disinfection,and implementation of a plant-wide
SCADA system. A major componentof the upgrade was the replacementof 18 existing Gorman-Rupp pumps
throughout the plant with new higherperformance pumps also supplied by
Gorman-Rupp. These included storm andraw wastewater pumps, secondary RAS/WAS pumps, and digester recirculation
pumps, many still operating from their
original 1953 installation.
Eliminating untreated wet-weather combined sewer
overflows (CSOs) is a significant issue facing manywater utilities nationally. CSOs contain stormwater-© 2021 Gorman-Rupp Pumps

flushed contaminants from the watershed, plus
untreated human and industrial wastes. These caninclude oxygen-consuming organics and nutrients,
toxic materials, pathogens and debris. They are amajor water pollution concern for the approximately

Super T Series® self-priming pumps replaced
submersible pumps in the plant’s stormwater
pump station making it safer, easier andmore economical to perform routine pump
maintenance.

1communities with combined sewer systems can meet
Clean Water Act goals in as flexible and cost-effective amanner as possible.

Need for Wastewater Treatment Plant(WWTP) Upgrade

Based on its proven durability and reliability,
this Classic T Series® pump (installed in 1977),
was a key factor in Shelby’s decision to continue
using Gorman-Rupp products throughout thetreatment plant upgrade.
800 cities in the United States that have combined
sewer systems, according to the U.S. Environmental
Protection Agency (EPA).
Combined sewer systems transport wastewater
to a treatment plant, where it is treated and thendischarged into creeks, streams, rivers or bodies ofwater. During periods of heavy rainfall, however, thewastewater volume in a combined sewer system canfar exceed the capacity of the downstream sewer
system or treatment plant. For this reason, combined
sewer systems have been designed to overflow whencapacity is exceeded, and discharge excess stormwater
and wastewater directly to nearby streams, rivers orother water bodies.
Driven by the Clean Water Act of 1972, communities
that have CSOs are required to develop plans to
mitigate their impacts on the environment. TheEPA’s CSO Control Policy, published in 1994 andlater made into law, is the national framework forcontrol of CSOs. The Policy provides guidance on how2

The City of Shelby is located between Columbus andCleveland in north-central Ohio, with a populationof approximately 8,900. The City’s wastewater
treatment plant is a Class 3 facility that processes
approximately 1.9 million gallons of wastewater
per day. Servicing 3,787 residential customers,
260 commercial businesses and 20 industrial
facilities, the plant uses an activated-sludge process
supported by a collection system of more than 70
miles of sewer lines.
The WWTP’s service area is subject to flooding witha significant amount of the system located within
the flood plain of the Black fork of the MohicanRiver, which flows through the city’s downtown.
Consequently, the city’s existing sewer system issusceptible to very high wet weather flows. Theseflows result in periodic sanitary sewer overflows(SSOs) and bypasses, and the existing treatment
plant did not have sufficient capacity to treat
very high flows during wet weather conditions.
Infiltration and inflow into the collection system wasestimated at 0.5 MGD, creating a serious problem
during rain events.
The WWTP was aged with a number of outdated
components, which contributed to wet weather
bypasses at the plant. Although Shelby’s originalplant dates back to 1889, an activated sludge process
was built in 1953, with subsequent upgrades in 1977,
1988 and 2005.
“The plant was designed to treat an average daily
flow of 2.5 million gallons per day (MGD), anda maximum daily flow of 5.0 MGD,” said Charlie
Brown, City of Shelby Wastewater Treatment Plant
Superintendent. “Flows in excess of 5.0 MGD would
overflow to the plant’s 2.0 million gallon (MG) storagebasin for temporary holding until the WWTP has© 2014 ©
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available capacity. When that basin fills completely itoverflows to a secondary 18 MG storage basin. And
when that basin fills to capacity during a storm event
it overflows, untreated, into the Black Fork of theMohican River.
“Every four years, the Ohio Environmental
Protection Agency issues a National Pollutant
Discharge Elimination System (NPDES) permit forallowable levels of effluent discharge into the state’s
waterways, including the Black fork of the MohicanRiver,” added Brown. “To meet the terms of theNPDES permit, the city was required to eliminate
its wet weather bypasses and improve secondary
treatment capacity.”

Facility Planning Addresses CSOs andPlant Capacity Improvements
To achieve this goal, in 2015 the city retained CT
Consultants, a multidisciplinary architectural,engineering and planning firm, to prepare acomprehensive facility plan designed to identify
existing plant shortcomings, review wet-weather
treatment alternatives and develop an overall plant
improvement plan.
“We reviewed five engineering firms and asked
them how they would upgrade the plant,” continuedBrown. “Based on their suggested plans, we selected
CT Consultants. It took approximately two years toengineer because we wanted to review a number ofequipment options. We visited many WWTPs in other
cities within the state looking at installed equipment,talking with plant operators and maintenance crews
before we settled on a system design.”
The resultant planning encompassed improvements
to multiple plant processes, designed to enhancesystem capacity, operability and reliability:• Replacement of old and outdated headworks
equipment

23In addition to the pumping equipment controls,
Gorman-Rupp provided control technology
overseeing complete operation of the plant.
• Replacement of storm and raw wastewater influentpumps• Upgrade to primary settling tanks and aerationsystems• Adding a new final clarifier• Replacement of digester recirculation pumps• Replacement of floating digester covers• Replacement of chlorination with UV disinfection• Replacement of secondary RAS/WAS pumps• Construction of a new septage receiving station© 2014 ©
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• Replacement of blowers with turbo and positive
displacement blowers• Implementation of a plant-wide SCADA system“We took a holistic look at the plant in its current state
to deal with wastewater and stormwater,” said Chuck
Hall, Senior Business Development manager with CT
Consultants. “One of the major issues was equipmentthat had long since outlived its useful life. Some of thepumps and blowers dated back to 1953. They werestill running, but needed to be upgraded to handle
higher capacity.”“The Ohio EPA wanted the overflows stopped orsignificantly minimized,” added Hall. “To achieve this weincreased the capacity of the stormwater intake pumps

to maximize use of the stormwater basins. We also
added a 60-foot diameter third clarifier to increase thestorm capacity of the plant, and had the existing two
clarifiers rebuilt and upgraded.”
In 2019, a bid to perform construction for the upgrade
to the plant was awarded to NorthBay Construction, afull-service mechanical, civil, electrical, engineering andgeneral contracting company.
“NorthBay performed the electrical, mechanical,process mechanical, concrete work, site excavation
and all equipment purchases, installation andcommissioning,” said Peter Manns, President with North
Bay Construction. “Essentially, the project was a fullplant upgrade.”

Plant-Wide Replacement of Pumping
Systems“A critical aspect of the project was the pumping
systems within the plant, which were all upgraded,”
added Manns. “The original pumps weremanufactured by Gorman-Rupp and all 18 newpumps installed in the plant were also provided by
Gorman-Rupp.”
Gorman-Rupp has been manufacturing pumps formore than 85 years, and provides an extensive lineof pump products for municipal WWTPs, as wellas for applications in sewage, industrial, mining,construction, petroleum, OEM, government,agriculture and fire markets. Some of the 18 pumps
in operation at Shelby WWTP had been in continuous
operation since 1953 and the remainder since theplant’s 1977 upgrade.

The plant upgrade specified a variety
of Gorman-Rupp products including
multiple submersible pumps (this one
used to transfer sludge), one ReliaSource®
packaged pumping system and one
general purpose, portable, engine-driven,priming-assisted dewatering pump.

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“One of the biggest reasons why I pushed forGorman-Rupp pumps to be specified in the bid wasbecause our four major sewage and stormwater influent
pumps, which were Gorman-Rupp pumps, had beenrunning non-stop every day since 1977,” explained
Brown. “The equipment was well maintained and therear plates, rotating assemblies and impellers wereroutinely changed out, but if this rotary equipment
lasted that long it has proven performance capability.”© 2014 ©
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2021
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Wastewater treatment facilities have their own
brand of influent wastewater, a mixture of organic
material, plastic, grit, rags, sand and other debris,
notorious for clogging pumps in pump stations andplant headworks, requiring more robust pumps.
The performance of pumps under these conditions
is determined by the characteristics of the solids,
their concentration, the viscosity of the liquid, thematerials used in the construction of the pump and theoperating conditions.
“Influent pumps are critical to WWTP operation
because they control the flow of wastewater andstormwater into the plant,” explained Hall. “As design
engineers, we would concur that these pumps
running continuously for more than 40 years is
testament to the design of the equipment and theirproper maintenance.”
These four influent pumps were replaced with selfpriming, centrifugal Super T Series® 10-inch pumps.
The self-priming suction lift design of the pumps
allows the design engineer to physically locate thepumps where access is a non-issue and routine
maintenance can be completed quickly and easily.
The pumps’ superior solids-handling capability makes
them ideally suited for Shelby’s solids-laden influent.
“We were able to provide better control of the plant’sinfluent pumping by replacing and upsizing all of thosepumps,” added Hall.
It is not just the influent pumps that have been
replaced in the plant. Every process in the facility
where wastewater and stormwater flows has beenequipped with new pumps, and all of those pumps
were manufactured and tested by Gorman-Rupp.
“Our pumps are installed at the WWTP’s new influent
and stormwater pumping stations, as well as pumps
in the clarifiers’ return activated sludge and waste
activated sludge (RAS/WAS) systems,” said Vince
Baldasare, Sales Manager for Engineered Systems at
Gorman-Rupp. “We also installed sludge recirculating
and transfer pumps in the anaerobic primary digester,and miscellaneous pumps throughout every process
on the site where wastewater and stormwater flows.”

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Charlie Brown, plant superintendent, with
two of the new 18 Gorman-Rupp pumps
installed during the upgrade.
“Gorman-Rupp was able to provide a complete mixof individual pumps for the plant’s specific processes,
along with full, above-ground stormwater andactivated-sludge pumping stations,” added Baldasare.

SCADA
Another improvement to the WWTP was theimplementation of a plant-wide SCADA system.
Designed and manufactured by Gorman-Rupp, theSCADA, for the first time, enabled an automatedprocess capability of the plant’s operation.
“The difference is like night and day,” said Brown. “Theoperation of the plant has been transformed from 1950’s
technology to state-of-the-art. We now have readouts inreal time on what is occurring in the facility as far as DO
and pH levels, what equipment is running and how well
it is performing.”

Performance
Completed in 2019, these improvements have eliminated
wet weather bypasses at the Shelby WWTP, addressed
NPDES permit obligations, upgraded plant processes andinfrastructure and improved treatment capacity.

© 2014 ©
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2021
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Replacing the 1952-vintage blower turbines with newsystems has resulted in a $6,000 - $8,000 monthly
savings on electrical power usage.

manufactured pumps for municipal, sewage, industrial,mining, construction, petroleum, OEM, government,agriculture and fire markets.

“The quality of the effluent being discharged isdefinitely better,” added Brown. “Dissolved oxygen(DO) and total suspended solids, although withinrequirements prior, are now improved. The digestion
rate has improved 25 percent, with less solids going out
to landfill.”

The company’s extensive line of pump products include
self-priming centrifugal pumps, standard centrifugal
pumps, submersible pumps, rotary gear pumps,
diaphragm pumps, engine-driven pumps, and priming
assist pumps. In addition, Gorman-Rupp manufactures
a complete line of state-of-the-art packaged lift stations
and booster stations that include pumps, motors,controls, piping, accessories and enclosures.

Long-term water quality benefits associated with thereduction of a public and environmental health threat
related to contact with untreated sewage bypassing
the city’s WWTP has been achieved.

About Gorman-Rupp Pumps
For more than 85 years Gorman-Rupp Pumps USA has

For more information, contact Cyndi Hoffner,Advertising Manager, Gorman-Rupp Pumps USA; 600
South Airport Road, Mansfield, OH 44903-7831; Phone:419-755-1011; email choffner@gormanrupp.com;
www.grpumps.com.

GORMAN-RUPP PUMPS | P.O. BOX 1217 | MANSFIELD, OHIO 44901-1217 | USA | 419.755.1011 | GRSALES@GORMANRUPP.COM | GRPUMPS.COM2
6© 2014 ©
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Gorman-Rupp
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