United States Environmental Protection Agency Water Engineering Research Laboratory Cincinnati OH 45268 Research and Development EPA/600/S2-85/076 Aug. 1985 Project Summary Strategies for Water and Waste Reduction in Dairy Food Plants W. J. Harper, R. A. M. Delaney, I. A. Igbeka, M. E. Parkin, W. E. Schiffermiller, T. E. Ross, and R. A. Williams A study was undertaken to reduce water and waste discharges in a com- plex, multiproduct dairy food plant through management control and mod- ifications of equipment and processes. The objectives were to develop ap- proaches that would be broadly appli- cable throughout the dairy industry and to determine the economic and envi- ronmental impacts of the programs in- stituted. The Kroger Dairy Company at Indi- anapolis, Indiana, was the study site. This plant was chosen because it was well engineered, discharged its wastes to a municipality, was under average management control, and had not pre- viously had an extensive waste control program. As such, it was typical of more than two-thirds of the dairy plants in this country. Detailed studies were made to deter- mine the plant areas contributing major waste loads and the economic feasibil- ity of reducing these loads. A manage- ment control program was developed and implemented over a 6-month pe- riod. This program included major in- creases in direct supervision of waste control. A computer linear program was applied to the four processing areas to determine economic factors in- volved in wastewater discharges and to help select the most economical pro- cess and equipment changes that could be made. The study concluded that material re- duction can be achieved economically in dairy food plants that have not previ- ously given attention to this matter. This Project Summary was devel- oped by EPA's Water Engineering Re- search Laboratory, Cincinnati, OH, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction As regulations of effluents from mu- nicipal water treatment plants become more restrictive, dairies and other major contributors of organic matter will face considerable pressure to re- duce their loads, increase pretreatment, or provide full secondary treatment. The Kroger Dairy Company at Indiana- polis, Indiana, has conducted a 2-year investigation to reduce processing wastewater through a combination of management control and process equipment modification. The objectives were to develop approaches that would be broadly applicable throughout the dairy industry and to determine the eco- nomic and environmental impacts of the programs instituted. The Kroger plant receives up to 2 mil- lion Ib of fluid milk per day, and it man- ufactures fluid milk products, cottage cheese, and frozen desserts. The com- pany operates three shifts per day 5 to 6 days per week. All wastewater is dis- charged to the Indianapolis Municipal Treatment Plant. Plant Description Before control procedures were intro- duced, the plant discharged 400,000 to ------- 800,000 gal of wastewater per process- ing day. This water contained 10,000 to 15,000 Ib of BOD. The composition of the wastewater was typical of other dairy plants of the same type and size. The mean strength of the wastewater components is listed in Table 1. Procedures Detailed studies were made to deter- mine the areas that contributed major waste loads, and an investigation was conducted of the economic feasibility of reducing these loads. Determinations were made of the unavoidable and pre- ventable wastes in each department. Preventable waste made up about 50% of the total waste load and was consid- ered to be controllable by the applica- tion of good management practices. Unavoidable wastes were associated with the design of the plant. Studies were therefore done to determine the feasibility of altering the process, or the equipment, or both to reduce these wastes further. A management control program was developed and implemented in the plant over a 6-month period. This pro- gram included appointing two waste control supervisors (first and second shift), increasing supervision on the second shift by creating a new position of general foreman, implementing an educational program, altering the maintenance program to cover items that caused major losses of water or in- gredients, and implementing plant sur- veys and recordkeeping. A computer linear program was ap- plied to the four different processing areas to determine the economic fac- tors involved in wastewater discharges and to provide a basis for determining the most economical process and equipment changes that could be made. Results and Conclusions As long as direct supervision was maintained on a regular basis, water use in the plant was reduced by one- third and the organic waste load was reduced by one-half. When this empha- sis was decreased because of other re- sponsibilities of the waste supervisors, the wastewater volume and strength re- turned to the level that existed before the introduction of the program. For this reason, a full-time resource control manager was appointed to work on a flexible time program. With renewed emphasis, the waste loads were again reduced and maintained at the levels previously achieved. Table 1. Composition of Kroger Dairy Wastewater* in Indianapolis, Indiana Parameter Mean Concentration (mg/L) COD BODS Total solids Suspended solids Volatile suspended 4100 2200 3130 566 solids Fat Protein Carbohydrate Chloride Phosphorus Sodium Calcium Magnesium 500 260 446 1300 400 52 230 168 28 *pH = 6.6. Process and equipment changes were made that reduced water discharges by 100,000 gal per day and reduced waste strength about 20% at an economic sav- ings projected at $200,000 per year. The study at the Kroger plant in Indi- anapolis indicates that material reduc- tion can be achieved economically in dairy food plants that have not previ- ously given attention to this matter. The full report was submitted in fulfill- ment of Grant No. R 803374 by The Ohio State University and the Kroger Com- pany under the sponsorship of the U.S. Environmental Protection Agency. ------- W. J. Harper. R. A. M. Delaney. I. A, Igbeka. andM. E. Parkin are with Ohio State University, Columbus. OH 432)0; W. E. Schiffermiller, T. E. Ross, and R. A. Williams are with the Kroger Company. Cincinnati. OH 45202. Kenneth Dostal is the EPA Project Officer (see below). The complete report, entitled "Strategies for Water and Waste Reduction in Dairy Food Plants," {Order No. PB 85-216 505/AS; Cost: $25.00, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield. VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Water Engineering Research Laboratory U.S. Environmental Protection Agency Cincinnati, OH 45268 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 O*f:cial Business Penaltv tor Private Use $300 EPA.600/S2-85/076 OCQG3Z9 PS U $ ENVIR PROTECTION AGENCY REGION 5 LIBRARY 230 S DEARBORN STREET CHICAGO IL ------- |