May, 2006- Poultry plant wastewater is a combination of organic and inorganic compounds dissolved or suspended in water, and wastewater treatment plants use physical, chemical and biological processes to remove these dissolved and suspended substances. Eutrophication, or nutrient enrichment, of many rivers, lakes and streams in this country has led to a tightening of effluent limits for municipal and industrial wastewater treatment plants, and this has forced many poultry plants to change or upgrade their wastewater treatment systems.
Some poultry wastewater treatment plants have come up with unique ways to use natural systems as part of their treatment processes and have still been able to economically meet new tighter effluent and stormwater limits. The U.S. Poultry & Egg Association recognized four wastewater treatment plants with Clean Water Awards at the association’s Environmental Management Seminar in Raleigh, N.C. Whether the plants were in town or out in the country, workers at each of these four facilities displayed a passion for protecting the environment and a willingness to use every means at their disposal to be good stewards of the environment and good neighbors.
Gold Kist Russellville: Home On The Range
Gold Kist’s Northwest Alabama division processing plant in Russellville, Ala., has a zero discharge wastewater treatment system. Coastal Bermuda grass overseeded with winter rye or oats is irrigated with the effluent from the treatment system. That effluent is pumped to the 454-acre spray-field and distributed by seven center-pivot irrigators. The processing plant and wastewater treatment system went into operation in 1990, and the output of both has grown over the years.
Currently, the plant processes 1.65 million head of 7.25-pound broilers per week, and the plant cuts up and debones these birds, makes IQF products and marinates and portions meat. The wastewater treatment system now has an average flow of between 2.1 to 2.5 million gallons per day. To accommodate the growth at the processing plant, the acreage in the spray fields has been increased by around 50 percent from start-up, and the number of irrigators has been increased from the original four to the current seven.
Hay was grown on the spray fields as a means of utilizing nutrients in the effluent, so that they did not build up in the soil. But, in order to cut and cure hay in a field, spraying in the field had to be stopped for a period of time, and this meant that, eventually, even more acreage would need to be added to the spray fields to accommodate continued production growth and increased water usage. Gold Kist maintains around 800 acres of land as a buffer around the spray fields, so they wouldn’t have to buy more land to expand the spray fields, but they would have to invest in more irrigators and pipes. Also, grass doesn’t cut itself, and the wastewater treatment staff was spending a lot of time on tractors trying to keep up with all the mowing. They decided that there had to be a better way to convert the nutrients in the wastewater into something that didn’t require as much labor as making hay.
Cattle have provided the answer that the Russellville staff had been looking for. Angus cattle rotationally graze the irrigated pastures, which are divided into 12 separate paddocks and three corrals by around 18 linear miles of fencing. Cattle stocking rates are based on seasonal grass growing conditions; typically there are more cattle during warm months and fewer during the winter. By using cattle to harvest the grass, the plant has been able to increase water usage without adding acreage to the spray fields. Several measures have been taken to insure that the movement of the cattle does not lead to erosion in the pastures. Waterways, stormwater outfalls and streams have exclusion fencing and permanent vegetative buffers, and cattle are not allowed direct access to streams.
With the switch from hay to cattle production, the land management function of the wastewater treatment operation has been changed from a cost center, averaging $25,000 for maintenance and upkeep costs, to an income center, averaging a net of $45,000 for each of the past two years. Revenues have exceeded expenses for five of the past six years.Eighty acres of the buffer land around the spray fields were planted in Piedmont Loblolly Pine trees to serve as windbreaks and provide habitat for wildlife species, prevent soil erosion, improve aesthetic value and eventually yield income. Fifteen years later, the trees are now approaching their first scheduled commercial thinning and are expected to yield around $2,200 per acre on the forest products market.
The Russellville plant has gone more than 10 years without exceeding permit limitations, and it has had few compliance issues in its history. Russellville recycles 150,000 gallons of water per day for non-product contact uses in the plant, and they are testing a system that would allow extensive reuse of water in product contact areas. Wastewater treatment costs at Russellville have been cut by over 40 percent per hundred weight of finished product since the plant opened in 1990. Last year, the total treatment cost was $3.40 per thousand gallons, which was the lowest cost for any Gold Kist plant.
Careful management of the wastewater treatment system at Russellville has yielded more than just good economic results. Harris Creek runs through the plant’s property, and it was on Alabama’s impaired waters list before the plant was built. Gold Kist is the largest land owner in the Harris Creek watershed, and the creek was recently removed from Alabama’s list of impaired streams.
Russellville was chosen as the Clean Water Award winner in the full-treatment category, and the Russellville plant became the first two-time winner of this award, having won the award in 2001.
Pilgrim’s Farmerville: Wetlands Treatment
Pilgrim’s Pride Corporation’s Farmerville Complex, Farmerville, La., uses a unique wetlands treatment system coupled with modern state-of-the-art wastewater treatment processes to treat its wastewater and stormwater. The wetlands system was a key component of the original wastewater treatment system for the plant, which began processing in 1992. A series of plant expansions led to increased water usage and nutrient loading, which ultimately outstripped the wetlands treatment system’s capacity. The wetlands system already covered 120 wetted acres and had 17 cells, so the decision was made to add a Schreiber activated sludge treatment system and only use the wetlands to polish the treated effluent and provide wildlife habitat.
The processing plant now slaughters 268,000 5.5-pound birds per day, and it produces 300,000 pounds per day of further-processed product as well. The on-site protein recovery plant renders 120 tons of by-products per day. Average flow through the wastewater treatment system from all of these operations is 1.9 million gallons per day.
Water conservation and recycling programs at the Farmerville plant have been very successful. Conservation efforts have reduced water consumption from 9.0 gallons per bird in 2001 to 6.74 gallons per bird in 2005. The plant has installed two separate water screening and filtering systems to treat and recycle approximately 200 gallons per minute from processes within the plant for reuse. The total wastewater treatment cost averages less than $2.30 per thousand gallons. City water cost is relatively inexpensive at $0.75 per thousand gallons. In order to reuse even more water and help save the local aquifer, the plant has started chemically treating 200,000 gallons per day of effluent for targeted reuse. This process costs approximately $1.15 per thousand gallons, more than what the city water costs, but the plant wants to do as much as possible to conserve water since the aquifer that the city draws water from is being depleted.
Conservation at the Farmerville plant goes beyond water reuse. Waste heat from the cooking process in the rendering plant is used to preheat hot water for the processing plant. A cardboard recycling program has reduced the amount of waste sent to the landfill by an estimated 250 tons per year, and the plant repairs and recycles wooden pallets. The Farmerville plant was awarded honorable mention in the full-treatment category.
Cargill Meat Solutions: Play Ball
The Cargill Meat Solutions plant in California, Mo., began processing in 1963, when it was owned by Purina. The plant originally discharged untreated wastewater to the California, Mo., publicly-owned treatment works (POTW), which consisted of a series of lagoons built near the plant. In 1994, Cargill constructed its current pretreatment facility to reduce the nutrient load on the POTW. In 1998, the city decided to build a new treatment system to meet more stringent Missouri Department of Natural Resources (DNR) requirements. At the same time, Cargill switched its pretreatment system to a polymer system and partnered with the city on the construction of the new treatment facility and closing of the old lagoons. The land where the old lagoons had been was donated by Cargill to the city and now is used for ball fields.
Around 26,000 head of heavy hens are processed each day on one shift at the California plant. An average of 610,000 gallons of wastewater are pretreated each processing day at the plant. The California, Mo., division has implemented an aggressive energy and water conservation plan, and solid waste reduction program. Since 2001, per-pound water usage in the plant has been reduced by 26 percent, energy usage reduced by 30 percent, and solid waste generation reduced by 33 percent. This was accomplished through engineering and administrative improvements including the following: redesigned equipment washes; replacement of all domestic water lines; control of water pressure; increased water recycling; installation of more efficient equipment; implementation of water conservation audits to insure water is used efficiently, including water conservation as part of their incentive program for key hourly and salaried personnel.
Water is measured and reviewed daily with the management team, while operations management constantly monitors water use within the plant and takes action to reduce usage whenever an improvement opportunity is identified.
Cargill operates under a stormwater permit issued by the Missouri DNR. All stormwater runoff is currently being treated through a pass-through treatment system. This treatment reduces fecal coliform counts, total suspended solids, biological oxygen demand and other parameters to protect wildlife in the area. Cargill has submitted to the Missouri DNR a construction request to build two wetland cells to handle the facilities’ stormwater, and this project has a budgeted cost of $600,000. The use of sedimentation and natural sunlight in the wetland cells will eliminate the use of chlorine as a disinfectant and will enhance natural wildlife and plant life. Cargill’s California, Mo., plant was chosen as the winner in the pretreatment category, which covers facilities that discharge pretreated effluent to publicly-owned full-treatment facilities.
BioFuel At Fieldale
Fieldale’s plant in Cornelia, Ga., which is the original Fieldale plant, began processing in the 1950s. This facility has grown from a small, in-town hilltop processing plant to a 275,000 5.75-pound birds per day complex with on-site protein recovery spanning several city blocks. In addition to the traypack chicken that is produced at the processing plant, the rendering facility processes 700,000 pounds of by-products every day. An in-town plant always faces special challenges, and Fieldale has worked aggressively to respond.
A grease trap is the first stage of the wastewater treatment process; the grease is skimmed off the surface of the trap and is used to fire the cookers in the rendering plant. A strong operator training program and a well-equipped DAF pretreatment system produce an outstanding pretreated effluent, with some pollutants reduced to levels only expected from a full-treatment plant. Average water flow through the treatment system is 1.64 million gallons per day, and the plant reuses around 70,000 gallons of water per day. The protein recovery plant is tightly sealed to prevent loss of odors, and exhaust air is carefully cooled and scrubbed prior to release. Importantly, the community knows Fieldale will immediately respond to an odor complaint, and appreciates that quick responsiveness.
Since the plant is located a few feet from a small stream tributary, several things have been done to prevent overflows and spills. Street drains and diversion curb are installed in the trailer load-out area. Stormwater presents a special challenge because of the site topography, so Fieldale has dedicated time and resources to preventing exposure of potential pollutants to rainfall. Stormwater flows are diverted to minimize pavement and stormwater contact, and extensive curbing and diking have been constructed to prevent pollutants from reaching stormwater.