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City of Akron, Ohio
Water Pollution Control Division"People dedicated to protecting the
environment, for this and future generations, through innovative and cost effective
means." |
| Technology gives us the capability to treat
wastewater so that the processed water can be safely returned to the environment. The City
of Akron Water Pollution Control Station utilizes proven treatment processes such as the
Activated Sludge process. The existing plant has been in continuous service since 1928.
There have been, and continue |
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| to be, numerous expansions and
improvements to the Akron facility to keep up with changing environmental conditions and
restrictions. |
| POPULATION
SERVED and CAPACITIES |
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The City of Akron treats
its own wastewater and that of several neighboring communities. The total area served is
about 96 square miles with an estimated population of 330,000. Neighboring communities
served include Cuyahoga Falls, Stow, Springfield, Mogadore, Lakemore, Tallmadge, Fairlawn,
Bath, Montrose and some unincorporated areas in the county.
The
daily average flow to the plant in 2012 was 71.3 MGD, with peak flows (rain, snow/thaw)
reaching 275 MGD. Part of the collection system has combined sewers, which means sanitary
wastewater and stormwater is carried to the treatment plant through the same pipes.
Presently the Akron WPCS is considered to have a firm, Preliminary treatment capacity of
210 MGD, a Primary treatment capacity of 150 MGD, and a Secondary treatment capacity of
110 MGD. |
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| CUYAHOGA
STREET STORAGE FACILITY |
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 The Cuyahoga Street Storage Facility was put into
service in late 2006 as a 10 million gallon storage basin capturing combined sewer
overflows from Racks 40, 31 and 30. When a major storm occurs, wastewater that would have
spilled out of the overflows and into the Little Cuyahoga River is routed to the basin
where it is stored until it can be pumped back to the wastewater treatment plant. In 2012,
95.4 MG were captured by this facility. |
INFLUENT SCREENING
There are 4 continuously cleaned screens which are rotated in and out of service to
distribute wear evenly among the units. These influent screens remove material such as
rags, leaves, sticks, etc., that would clog pumps and pipelines. This material is disposed
of by land filling.
GRIT REMOVAL
The grit removal tanks remove sand, stones and other grit-like materials that would cause
wear to pumps and clog pipelines. Four quick settling tanks are designed to remove the
grit, but not the light organic solids. The grit is disposed of by land filling. |
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STORM RETENTION
The function of the Storm Retention Tanks is to provide flow equalization through
temporary storage of wastewater during periods of high flow. When high flows subside,
wastewater is pumped back into the plant for treatment. |
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SEDIMENTATION AND FLOATATION
Primary treatment removes organic solids by
sedimentation and flotation. The solids that settle to the bottom of the 24 Primary
settling tanks are collected and pumped to the Gravity Thickener Tanks. The treated
primary effluent goes on to the Activated Sludge Process for further treatment. Grease and
other floating matter are removed from the surface of the tanks and dewatered prior to
disposal. |
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SECONDARY
AERATION (Activated Sludge)
The Activated Sludge Process is an aerobic, suspended growth, biological treatment
method. It uses the metabolic reactions of microorganisms to produce a high quality
effluent by converting and removing substances that have an oxygen demand. To sustain the
aerobic bacteria, approximately 40 million cubic feet per day of air (oxygen) is required. |
SECONDARY CLARIFIERS
After a period of approximately 8 hours in the aeration tanks, the wastewater flows into
Secondary Clarifiers. The solids are separated from the treated wastewater by gravity
settling. The treated wastewater leaves the clarifiers and then flows to the Chlorine
Contact Tanks. The solids (microorganisms) that settle to the bottom of the clarifiers are
mostly |
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| returned to the Aeration Tanks to
feed on the incoming organic waste. The solids that are not returned are sent to the
Gravity Belt Thickeners for volume reduction prior to further treatment. |
EFFLUENT DISINFECTION
Before the water is released to the Cuyahoga River, it is disinfected with Sodium
Hypochlorite (a strong bleach) to kill pathogenic organisms. Approximately 30 minutes of
contact time is allotted for the disinfecting process to take place. To reduce the
chlorine residual of the treated effluent, Sodium Bisulfite is fed just prior to the plant
discharge point. |
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EFFLUENT OXYGEN
An Oxygen Enhancement System is utilized at the CCT area. Its purpose is to ensure
that the Dissolved Oxygen of the plant effluent is no less than 5.0 mg/L which is mandated
by the OhioEPA. Liquid Oxygen is vaporized and released during periods of possible low
D.O. events such as during the beginning of a high flow event. |
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| SOLIDS
HANDLING AND DISPOSAL |
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PRIMARY GRAVITY THICKENERS
Solids removed from the Primary Settling Tanks are pumped to the Primary Gravity
Thickeners, where they are thickened by gravity settling. The thickened solids are then
pumped to the Mixing and Holding Tanks. |
GRAVITY BELT THICKENING
Waste activated solids from the Activated Sludge Process flow to the Gravity Belt
Thickeners. Gravity belt thickening concentrates conditioned solids through the gravity
separation of water and solids on a continuously moving porous horizontal belt. The
thickened solids are then pumped to the Mixing and Holding Tanks. |
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MIXING and HOLDING TANKS
Thickened Primary and Waste Activated solids are pumped to the Mixing and Holding
Tanks and blended together and stored for further processing. There are a total of six
tanks, each with a one million gallon capacity. |
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COMPOST FACILITY
The blended thickened sludge is pumped under the Cuyahoga River to the City of Akron
Composting Facility. The composting process is based upon an agitated in-vessel system
utilizing four 720ft. long rectangular reactor vessels. The sludge is dewatered using Belt
Filter Presses then mixed with bulking agents such as yard waste, hardwood bark, and
sawdust. Air is blown into the mixture to provide oxygen for the biological decomposition
process. Odors are contained and controlled with 12 two-stage packed tower scrubbers. |
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2677 Riverview Road
Akron, Ohio 44313
330/867-2228
Commonly Asked Questions (137k pdf)
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Learn more about our products at
www.kbcompost.com
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| There are dozens of support activities performed daily to
ensure the wastewater treatment processes operate correctly and efficiently. For example,
a complete laboratory is staffed with chemists and technicians who conduct continuous
tests as a quality control measure. |
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A computerized distributive control system (DCS) aids in
control and optimization of each step of treatment. Maintenance and repair of the complete
process is carried out routinely by teams of mechanics and technicians. |
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| The Akron Water Pollution Control Division continues its
tradition of exceptional performance and was recognized once again with a Peak Performance
Award presented by the National Association of Clean Water Agencies in 2010. 
2010 Award Winner
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Wastewater Web Links
AKRON WATER
POLLUTION CONTROL STATION
PROCESS FLOW DIAGRAM
Click graphic to enlarge
Click here for brochure. (2,000k pdf)
Operation Data Summary (12k pdf)
City of Akron
Water Pollution Control Division
2460 Akron-Peninsula Rd.
Akron, Ohio 44313
Phone (330) 375-2963
Fax (330) 375-2966 |
| Brian M. Gresser, P.E. |
Sewer Bureau Manager |
| Vince Zampelli |
Acting Superintendent |
| Mark Harshbarger |
Operations Team Leader |
| Jim Florin |
Maintenance Team Leader |
| Monica Williams |
Administration &
Technology Team Leader |
| Kathy Richards |
Environmental Compliance Team
Leader |
| Thomas F. Smith, P.E. |
Plant Engineer |
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