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Wastewater Treatment
Design
The existing wastewater treatment plant is designed to at a maximum
daily flow rate of 950,000 gallons per day, with an average flow of
approximately 600,000 gallons per day. The major treatment units consist of
the following: bar screen, grit chambers, primary settling tank, flow
meter, aeration tanks, final settling tanks, chlorination, sludge
digestion, sludge drying beds and appropriate devices for controlling each.
Location
The
existing wastewater treatment plant is located in the northwest corner of
the city, on Westgate drive, just north of Main Street, U.S. Route 30. The effluent of the
treatment plant is discharged into a tributary of Paramour Creek about
2,000 feet from its confluence with Paramour Creek. Paramour Creek flows
westerly about three miles, where it forms the Sandusky River near Leesville. Paramour Creek
is the headwater of the Sandusky River. There are no residential
buildings located within five hundred feet of the plant site.
Water
Treatment
The City of Crestline Water Treatment Plant is designed to remove iron,
manganese and various gases from the raw water pumped from the City’s
wellfield.
An aerator is located at the head of the plant, upstream
of the detention tank. The purpose of the aerator is to oxidize iron and
manganese and to remove a potion of the hydrogen sulfide and carbon dioxide
gases in the raw water. The aerator also removes some volatile organic
compounds. The oxidation of iron and manganese and removal of gases reduces
the amount of chlorine and potassium permanganate which must be added to
accomplish these reactions.
Water flows from the aerator to the detention tank where chlorine
solution is added. The chlorine solution further oxidizes the iron in the
raw water. Some of the oxidized iron will settle out in the detention tank.
Water from the detention tank flows to the gravity filters in the
control building. The gravity filters are made up of 24” of Manganese
Anthrasand with a 6” Anthracite Cap. The Manganese Anthrasand was coated with
manganic oxides after it was installed in the filters. The coating process
activates the filter media so that it can remove iron and manganese.
The filtration process is both a physical and a chemical process.
The iron and manganese precipitates are filtered out by the filter media.
The iron and manganese which is not fully oxidized by the potassium
permanganate is oxidized a reaction with the filter media coating.
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