The
History of Wastewater Treatment in
Princeton Indiana: The
New Wastewater
Treatment Plant Completed in 1998
In 1998 The City of Princeton’s newly renovated state-of-the art WWTP is
nearly 100% complete. The plant has been expanded from 2 MGD, to 4.2 MGD to
service the new Toyota Truck Plant and the future growth of Princeton, at a
total cost of approximately 10 million dollars, 7.8 million of this expense
was paid by the Gibson County and the rest by the WWTP Utility.
In 1998 - Toyota began production in December 1998 and is Princeton's
largest Industrial discharger. At start-up Toyota is be 27% of the treatment
plants flow. The Industry will be monitored closely by Princeton's
Wastewater Pretreatment Program. Toyota began production of its Tundra
pickup and is discharge approximately 300,000 gallons per day and hopefully
with future expansion could go as high as 1.2 million gallons per day.
Toyota will produce approximately 100,000 Tundra Trucks per year.
Raw wastewater (influent) entering the
plant will vary over a wide range of variables depending on such things as
time of day, seasonal variation, infiltration and percent of industrial and
domestic flow.
Raw wastewater enters the plant at the Headworks; at this point large
inorganic solids and grit are removed. Such as (sticks, sand, rags, etc.)
Following the head works the flow can be divided into two treatment systems,
the west system is the existing facility built in 1977 and has been mostly
rehabbed with a fine air bubble system and has the capacity to treat 1.35
MGD of wastewater per day.
The new east plant has a capacity of 2.85 MDG.
Princeton is the third wastewater treatment plant (WWTP) in the Midwest to
employ phased oxidation ditch technology to produce a high-quality effluent.
The east plant consists of a three - (3) stage anaerobic selector and two
oxidation ditches operating in the BioDenipho modes of (PID) Phased
Isolation Ditch Technology and (2) Clarifies. During the time in the
oxidation ditches, the mixed liquor is aerated to add dissolved oxygen into
the mixed liquor, and to provide mixing of sludge and wastewater. The
equipment associated with the Ditches includes horizontal brush aerators,
submersible mixers, motor actuated weirs and dissolved oxygen probes. All
the equipment is monitored and controlled by PLC-based control panels and
(SCADA) Advanced System Control and Data Acquisition computer system. The
SCADA system also optimises plant performance and provides continuous
monitoring of the treatment facility and will alert operating staff
immediately, 24 hours a day if there is an equipment problem or malfunction
via pagers.
Utilizing the BioDenipho process will provide several beneficial results.
First, the Kruger BioDenipho process will allow the facility to recover a
fraction of the alkalinity that is consumed during the nitrification
process. As a result, the system will be more resistant to shock loading and
will be able to maintain a suitable pH for biological activity. Second, the
process will allow the facility to reduce their daily operational cost by
reducing the BOD loading that must be oxidized in the ditches.
The process of denitrification consumes influent BOD without oxygen and
therefore reduces the demand on the aeration equipment. Third, utilizing the
anaerobic selector will inhibit the growth of filamentous organisms and
insure optimum settling conditions in the secondary clarifiers. For these
reasons, the WWTP will take advantage of the benefits that can be achieved
through controlled denitrification and biological phosphorus removal.
The final Clarifiers provide a calm environment necessary for the separation
of active solids (sludge) and wastewater. The solids settle to the bottom
and are either returned to the oxidation ditches or wasted to the biosolids
processing system.
After leaving the clarifiers, the flow from the east and west plant are
combine and enter the disinfection process of the plan. This process uses
ultraviolet (UV) light. Ultraviolet light kills bacteria and viruses by
destroying their genetic material.
At this point the effluent cascading over a series of steps adding dissolved
oxygen to the effluent to help support the aquatic life down stream of the
plant. The flow is then discharged to Richland Creek.
Discharge requirements, the National Pollutant Discharge Elimination System
requires that the all WWTP’s meet certain effluent limitations as set in
their permit. A NPDES permit will contain plant operation requirements,
sampling procedures, limits for pollutants that must be monitored such as
pH, Dissolved Oxygen, E. Coli, Ammonia Nitrogen, Total Suspended Solids,
Oxygen Demand, Cadmium, Copper, Cyanide, Lead, Mercury, Nickel, Zinc,
sampling and analysis of sludge, bio monitoring (the toxicity of the
effluent on aquatic life down stream). The NPDES permits requires that a
WWTP be under the direct supervision of a licensed operator.
In 1999 Toyota has announced it will begin production of a new SUV vehicle
in January 2001, approximately 50,000 SUV’s a year will be produced. We have
adequate capacity at the wastewater treatment plant for future expansion of
the Toyota Manufacturing Plant.
In 2003 there are about 25 industries in and around the City of Princeton
which discharge industrial wastewater to the Wastewater Treatment Plant. Six
of these industries were required to obtain a discharge Permit. Of the six
industries 2 are (SIU’s) and 2 of them are categorical. |
