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Red Gold Inc. is based in Orestes,
IN, and is the nation’s
largest privately owned
tomato processor. Prior to
1999, the facility’s process
water treatment system
consisted primarily of six facultative earthen
basins, two of which were equipped with
surface aerators. Process water was essentially
batch-treated for biochemical oxygen
demand (BOD) and total suspended solids
(TSS).
The treatment process could not efficiently
meet the Indiana Department of Environmental
Management’s (IDEM) newly
imposed National Pollutant Discharge Elimination
System (NPDES) permit parameters
for ammonia nitrogen (NH3). In addition,
the existing detention basins could not hold
the volume of water associated with planned
production requirements. With this in mind,
Red Gold took the opportunity to upgrade
to a more efficient process water treatment
facility.
The tomato processing operation is seasonal,
and, as a result, the desired process
water treatment system needed to have the
capacity to treat the accumulated process
water and subsequently shut down from the
end of November through May of the next
processing year. It was projected that when
the facility started up again in May, it would
take about a month to build enough biomass
to meet direct-discharge water-quality
standards associated with the effluent. The
biomass refers to the amount of solids under
aeration in the process water treatment facility.
This biomass typically comprises 30%
inorganic soils, sands, and solids, and 70%
organic solids, soluble sugars, microorganisms,
and other pollutant loadings inherent
to the process water. The microorganisms
consume the sugars and organic components,
breaking them down into waste products
(sludge), gases, and water. The biomass
settles in the final clarifier, and the treated
water or effluent flows from the treatment
facility to the receiving stream.
The Old Process
The Orestes facility’s old process water
treatment system consisted of six detention
basins.
The first basin was used essentially as
a primary clarifier. It was not uncommon
for spent process water from the cannery
to incorporate TSS as high as 20,000 mg/L.
Larger solids such as tomato skins, seeds,
and field soils would settle out in the first
anaerobic basin. Excess process water from
the initial basin would gravity-flow into a
second detention basin.
The second detention basin, with a
capacity of nearly 30 million gallons, was
utilized strictly for the accumulation of
process water.
The third and fourth detention basins,
approximately 5 million gallons each, were
equipped with surface aerators. Due to the
depth of the two aerated detention basins,
the surface aerators were not very efficient.
At best, the aerated detention basins were
facultative. Process water remained in
these basins until it reached a water-quality
level acceptable for discharge.
The aerated basins were followed by a
0.5-million-gallon basin that was used as a
final clarifier prior to discharge.
The year 2000 was exceptionally dry,
which resulted in below-average receiving-stream flows. IDEM allowed plants to discharge water prior to a plant upgrade, provided there was a sufficient dilution factor within the receiving stream or a safe stream load allocation. However, a low stream flow would make it difficult to discharge the previous year’s water prior to the next season’s accumulation. IDEM was willing to allow Red Gold a three-year compliance period to give the tomato processor enough time to meet the new, more stringent requirements of 22 mg/L of BOD, 26 mg/L of TSS, and 4.5 mg/L of NH3.
“We didn’t want to risk a potential business interruption or the possibility of stressing the receiving stream,” explains Mike Herrmann, Red Gold’s director of engineering. “We wanted to pick the best solution and get it up and running well before the three-year deadline.”
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Weighing Options
Red Gold distributed project requirements and information to several potential suppliers. Suggested solutions included simply increasing aeration in the detention basins, installing sequencing batch reactor or oxidation ditch technology, and installing a complete-mix, extended aeration system. The tomato processor dismissed the first option because it did not provide for the future growth of the company and required excessive land mass area. Red Gold concluded that it was not as familiar with the sequencing batch reactor and oxidation ditch alternatives, both of which also required a higher initial capital investment. Red Gold finally determined that USFilter’s complete-mix plug-flow aeration treatment system with internal clarifier would best meet its overall needs.
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| The facility’s wastewater is treated by USFilter’s complete mix plug flow aeration
treatment system, with internal clarifier. |
The plant was installed in July 2000—two and a half years before the compliance deadline. The state-of-the-art package treatment plant came online and was discharging quality effluent by mid-September that same year. USFilter had less than eight months from the purchase-order release to deliver and install the new 500,000-gpd system to meet that year’s harvest campaign.
“We decided to go with USFilter—and the Davco package plant in particular—for a number of reasons,” says Herrmann, who is also the state-certified operator in charge of the Elwood, IN, and Orestes process water treatment facilities. “First and foremost, we wanted a partner in the process water business with the experience and track record to deliver the equipment and get the job done. Economics, an accelerated delivery schedule, an excellent supplier reputation, and the ability to expand in the future were also key.
“Plus, USFilter was already familiar with our process stream, as it had installed a similar system at our sister plant in Elwood six years before,” he continues. “Elwood’s experience proved that USFilter stands behind its designs and recommended hardware.”
The field-erected package treatment plant includes all accessories such as pumps, blowers, and controls that compose an operating continuous-flow process water treatment plant. A submersible pump sends influent to two anoxic zones located at the head of the plant. Water
from these zones flows equally into two aeration cells. The process
water flow then joins the plug flow and continues to be treated
aerobically in two additional aeration zones. NH3 treatment occurs
primarily in the last two zones, while BOD treatment occurs in
the first two zones. Water from the fourth aeration zone flows into
the clarifier, where the biomass settles to the bottom and is then
recycled to the head of the plant. The excess clarified water gently
flows over a weir into a collection trough and into a wet well to be
discharged into the receiving stream.
“We didn’t have to incorporate a digester,” adds Herrmann. “We simply moved waste sludge to the head of the treatment process or
the first anaerobic detention basin. We remove about 20% of the
solids from the basin annually and land-apply them on approved
farm fields.”
Red Gold personnel established the appropriate BOD, TSS,
NH3, fats, oils and grease, and hydraulic capacity requirements for
the new treatment system, based on grab samples taken throughout
the previous year’s process cycle. Incoming levels include BOD of
2,000 mg/L, TSS of 500 mg/L, and total Kjeldahl nitrogen (TKN) of
220 mg/L. The effluent of the new system is pumped to a receiving
stream and fully meets new discharge parameters.
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All-Around Efficiency
The new treatment process from USFilter has successfully handled
the Orestes plant’s constantly acclimating biomass. The loading
profile changes as the season progresses. BOD rises as the freshpack
campaign proceeds. The volume of water treated per day also
increases from 100,000 gpd to 500,000 gpd. As the organic components
break down in the lagoon, the NH3 begins to climb.
“Overall, the plant is performing well, with NH3 levels of 1
mg/L or less and BOD/TSS levels far less than those required to be
compliant,” says Herrmann. “Properly maintained and serviced, the
system will continue to deliver good-quality effluent that will meet
and exceed all the quality parameters established by IDEM.”
In March 2006, the facility filled in three of its ponds, keeping
only the two holding ponds that preceded the lagoons (the 7-million
gallon and 30-million gallon cells).
Red Gold is building a 329,000-square-foot warehouse on the
original lagoon site, which is “a substantially better utilization of
space,” in Herrmann’s opinion.
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| Red Gold removes about 20% of the solids from the detention
basin annually and land-applies them on approved farm fields. |
According to Herrmann, Red Gold feels it is truly in a partnership
with USFilter. For instance, to help control costs and to
expedite the tomato processor’s schedule, USFilter assumed certain
responsibilities, such as supervising owner-contracted labor. This
allowed Red Gold to use local labor for pouring and finishing
concrete under the supervision of the process water company’s
experienced field representative. Local talent and skills were also
called upon for work in the equipment room and associated piping
requirements.
“We have been really happy with both the system and USFilter,”
reports Herrmann. “USFilter provided quality components and
stood behind them. Regardless of the issue, the company let us know
that if it wasn’t right, it would take care of it—and USFilter did.”
Red Gold takes pride in its operators and the system’s performance.
The system is recognized as a well-run operation in the
state of Indiana. On April 19, 2006, the Indiana Industrial Opera-tors Association Inc. presented Jamie Sisson, Red Gold’s process
water treatment plant operator, with its distinguished annual Individual
Operator Award. Red Gold management believes the award
is truly a good reflection of Sisson’s conscientious work as well as a
credit to the quality equipment he uses.
SHANE WINGLER is corporate environmental health and safety
manager for Red Gold Inc. in Orestes, IN. GREG STINSON is an application engineer for USFilter, a Siemens company, in
Thomasville, GA. DONALD A. KING, PE, is a former application
engineering manager for USFilter in Thomasville.
OW - July/August 2006 |
