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Wastewater Department

Construction and Expansions
The Dyer Wastewater Treatment Plant was constructed in 1963 with an average flow capacity of 0.9 million gallons per day (MGD). The facility was first expanded in 1982 to increase the average daily flow capacity to 1.5 MGD (3.0 MGD peak capacity) along with the provision for sand filtration and chlorine disinfection. The second expansion completed in 1994 provided an increase in the average daily flow capacity to 1.8 MGD (5.0 MGD peak capacity) along with the addition of ammonia removal and dechlorination. Its third expansion completed in 1999 increased the average daily flow capacity to 2.6 MGD (7.5 MGD peak capacity). This expansion was necessary to keep pace with the population growth in Dyer.

Control Building - 1965

Control Building - 2005

As the Town of Dyer increases to grow in size and population, the Wastewater Treatment Facility
will continue to develop when necessary. Currently, there are no upcoming expansions.

Operators and Duties

The Dyer Wastewater Department is staffed by eight operators. Duties from corrective and preventative maintenance, laboratory analysis, observation of ten sanitary lift stations, as well as standard operations are performed on a daily basis. All operators are licensed by the Indiana Department of Environmental Management in Wastewater Treatment Plant Operation and continue to expand their education in this field of work.

Current wastewater treatment plant personnel as well as retired operators from the Town of Dyer.

Jeff Dzurovcak (1990-Present)
Phil Fiske (1993-Present)
Ed Scott (2001-Present)
Robert Jureczko (2001-Present)
Edward Popovich (2002-Present)
Joe Williams (2008-Present)
Ken Decrescenzo (2013-Present)

Rich Lushbaugh
John Jachim

Wastewater Treatment Plant Process
Our treatment process consists of five fundamental stages:
  • Preliminary Treatment
  • Secondary Treatment
  • Tertiary Filtration
  • Disinfection
  • Solids Handling

The Preliminary Treatment is purely physical stage consisting of Coarse Screening, Raw Influent Pumping, Static Fine Screening, Grit Removal, and Selector Tanks. The raw wastewater enters from the collection system into the Coarse Screening process. The Coarse Screening consists of a basket shaped bar screen that collects larger debris (several inches in diameter) prior to the Raw Influent Pumping. This debris is removed and placed into a dumpster for disposal into a landfill. The wastewater passes into the Raw Influent Pumping process that consists of three centrifugal pumps. These influent pumps operate under variable frequency drives, which allow them to vary their pump rate hydraulically.

The flow then passes into the Static Fine Screening process consisting of two stationary (or static) screens that remove finer debris not captured by the coarse screens. This debris is then dewatered using screw compaction and collected in hoppers for disposal into the same landfill used for larger debris. The wastewater then passes into

the Grit Removal process that consists of two vortex grit separators, producing a whirlpool action to force the finest debris to the outside perimeter for subsequent collection. This debris is then disposed into large metal hoppers, dewatered by gravity, and disposed into via landfill. The screened and degritted wastewater then enters into the Selector Tanks are composed of two rectangular tanks, which combine the flow with Return Activated Sludge (consisting mainly of microorganisms) for entry into the biological, or Secondary treatment stage.

The Secondary Treatment stage consists of a biological process, Oxidation Ditches and a physical process, Secondary Clarification. The Preliminary Treatment stage removed as much solids as possible using physical processes, however, very fine solids are still present that cannot be removed physically. Therefore, the wastewater enters from Preliminary Treatment into the Oxidation Ditches process which is a biological process consisting of two large oval shaped basins that hold nearly 2 million gallons of activated sludge.

This is accomplished by maintaining a population of microorganisms within the oxidation basins that consume the very fine solids (which are primarily organic) and also adhere to the solids themselves. By consuming and adhering to these finer solids they form larger and heavier aggregates that can by physically separated. Thus, after this process has taken place within the Oxidation Ditches Process the wastewater then enters Secondary Clarification process that can provide this physical separation.

The Secondary Clarification process consists of four rectangular tanks and one large circular tank that provide quiescent (or calm) conditions that allow the larger aggregates of solids and microorganisms to settle out for collection. The clear overflow (or upper layer) is collected at the end of the tanks and passed onto the Tertiary Filtration process for additional treatment.

The majority of microorganism-rich underflow (or lower layer) is recirculated to Selector Tanks as Return Activated Sludge to help sustain the microorganism population in the Oxidation Ditches process. However, if all the underflow was returned to the Selector Tanks, the plant would soon become overloaded with solids, therefore, a small portion of this mixture termed Waste Activated Sludge, is removed from the system for disposal. This waste is transported into the Solids Handing process for disposal.

The Tertiary Filtration stage consists of a physical process of the filtration of the overflow from the Secondary Clarification process through a bed of sand. This is accomplished using the newly constructed Traveling Bridge Filters or the previously existing Rapid Sand Filters.

Both units operate using the same process of filtration through a bed of sand; however, the Traveling Bridge Filters utilize a bridge which backwashes (cleans) the filter as it travels down its length. This minimizes the percentage of the filter unused when the filter is being backwashed. In comparison, the Rapid Sand Filters consist of three cells that lose an entire cell with each backwash compared to the 50 total cells in the Traveling Bridge Filters. The filtered wastewater then passes on to the Disinfection stage.

The Disinfection stage consists of a Chlorination process and a Dechlorination process. The Chlorination process consists of application of application of chlorine gas into the wastewater from the Tertiary Filtration process. As the water passed through the contact chambers, the chlorine kills the microorganisms in the wastewater that may be harmful to fish life. The disinfected wastewater is then passed on to the Dechlorination process that applies Sulfur Dioxide to remove the Chlorine added during the Chlorination process. This is necessary since the Chlorine itself can combine with other chemicals and become harmful to fish life. After the wastewater has achieved disinfection it is discharged into Plum Creek and thereby returned to the ecosystem.

The Solids Handling stage is a physical and chemical side process that properly prepares the Waste Sludge generated in the Secondary stage for disposal. This stage consists of the Sludge Holding process and the Sludge Dewatering process. The Sludge Holding process consists of two cylindrical tanks that hold the Waste Sludge and allow it to further settle. The clear overflow is then returned back into the treatment process and the thickened underflow is then pumped to the Sludge Dewatering process. The Sludge Dewatering process consists of two Belt Presses which physically press the water out of the thickened sludge which is chemically conditioned to improve the dewatering. The semi-dry cake produced then drops into a truck bed or dumpster for disposal to land or landfill. The water pressed out is returned back to the treatment process.