The Fieldale Farms Corporation chicken further processing plant in Gainesville, Georgia, is located in a compact industrial area, leaving little room for many lower-rate poultry wastewater treatment systems typically found at large facilities. Its waste stream also includes a variety of further processing ingredients that result in wide fluctuation in pH, and it must handle occasional high volumes of stormwater.
Yet, the facility has operated for over three years without a permit violation and has not incurred a surcharge since 2013. Plus, Fieldale Farms' further processing facility received an honorable mention in the 2014 U.S Poultry & Egg Clean Water Award pretreatment category.
How does the Fieldale Farms Gainesville further processing plant overcome its poultry wastewater treatment challenges and achieve exemplary results?
Stand-alone poultry further processing plant
The Fieldale Farms facility is somewhat unique in that it is a stand-alone further processing plant. Far more common are combined first- and further-processing operations.
Many think that treating a single-source wastewater is easier than a combined operations effluent. But further processing can play havoc with existing wastewater treatment systems, especially those operated near or at capacity. For stand-alone further processing facilities, product variability adds to the challenge - especially for low-volume, concentrated waste streams - since the added equalization volume available from first processing waters is absent.
In Gainesville, the wide variety of further processing plant ingredients including breading, batter, flour, spices, marinations, oils and buttermilk create pH ranges of 4-12. Occasionally, stormwater volumes associated with the first 15-minute flush of parking lots exacerbate treatment.
Efficient, redundant poultry wastewater treatment
The complex process of treating wastewater at the Gainesville facility includes, among other things, a mixed activated sludge tank and dissolved air flotation (DAF) redundancy.
The facility produces roughly 300,000 pounds per day of fully- and partially-cooked, breaded and marinated chicken. Table 1 shows the average annual pretreatment system performance for the typical flow of a 300,000-gallon-per-day operation that includes approximately 50,000 gallons per day from ammonia refrigeration cooling towers.
Screening of poultry further processing wastes
Alex Sullivan, facility wastewater operations supervisor, explains that the compact operation includes screening, flow equalization, chemically enhanced DAFs and biological treatment. He adds, “Perhaps one of the most vital stages of our wastewater treatment is our screening process that is designed to remove large amounts of meat and other debris. We follow that with an equalization basin that provides about 1.5-hour holding time.”
Equalized flow goes through chemically enhanced DAF treatment and is then transferred to a completely mixed, activated sludge tank designed to address soluble biochemical oxygen demand (soluble BOD). The effluent is then polished in an additional DAF; two tanks are available for redundancy or additional capacity as needed.
With all of the DAF capacity, the Fieldale further processing plant generates a large volume of air-floated solids that requires a comparable fleet of tankers to remove the material for final disposal. To improve handling, a decanting kettle system was added to improve odor control and reduce the moisture content. In operation, the system uses a steam to heat batches to 160 F. He adds, “Our sludge volume is down by 65 percent, greatly reducing disposal costs.”
Improvements planned for equalization basin
Eric Lindemann, Fieldale Farms environmental compliance coordinator, notes, “Alex and his team have worked hard to make sure this is a first-class operation. They have an excellent relationship with the city of Gainesville and surrounding areas, and they keep open lines of communication with the city’s pretreatment coordinator. The team participates in local wastewater training events and community outreach, particularly with the Hall County Green Alliance where they have a seat on the steering committee."
Moving forward, Sullivan hopes to focus on improvements in the equalization basin and biological treatment process for nitrogen removal. “We do very well with nitrogen removal,” he said, “but the continuous changes in product mixes means we need to ensure we have flexibility. We also intend to stay on top of the system!"
The Clean Water Awards, sponsored by U.S. Poultry & Egg Association, recognize outstanding wastewater treatment facilities operated by poultry companies and allied industries. The pretreatment category, in which Fieldale Farms' Gainesville further processing facility was recognized, considers facilities that discharge process effluents to a local publicly owned treatment works (POTW).