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Risk-Based Treatment Needs for Water Reuse in Protein Processing Facilities
Citation:
Brinkman, N., M. Jahne, J. Garland, S. Keely, E. Wheaton, M. Nagarkar, S. Homa, S. Thimons, E. Medlock Kakaley, N. Evans, K. Dirks, D. Snow, AND C. Williams. Risk-Based Treatment Needs for Water Reuse in Protein Processing Facilities. Presented at 2024 WateReuse Symposium, Denver, CO, March 11 - 14, 2024.
Impact/Purpose:
Processing operations in meat and poultry production require significant quantities of water availability and wastewater disposal capacity. These facilities are therefore strong candidates for onsite water reuse, provided that potential health risks are appropriately managed. This study presents a risk-based assessment of protein processing wastewater quality to inform treatment needs. Attendees will: 1. Understand the context of water reuse in protein processing facilities. 2. Recognize microbial and chemical contaminants of concern for onsite reuse of protein processing wastewaters. 3. Identify potential treatment processes to achieve risk-based treatment needs.
Description:
Protein processing operations include animal slaughtering, meat and poultry product production, and/or rendering of byproducts. These facilities utilize large volumes of water for hair/hide/feather removal, carcass washing, chilling, trimming and cutting, cooking, and cleaning/sanitation, from which wastewater is usually treated onsite and discharged to municipal treatment plants or local surface waters. Recognizing the high economic and environmental costs of both water use and wastewater discharges, water reuse within these facilities is permitted under certain circumstances, e.g., within the same washing, chilling, or cooking process or throughout the facility for solids flushing and washing of trucks, pens, or floors provided that it does not contact edible products. Broad water reuse for most purposes, including in processes that involve product contact, is also allowed following treatment by an “onsite advanced wastewater treatment facility” as long as the water has never contained human waste and complies with National Primary Drinking Water Standards – i.e., that the reconditioned water is potable – and that contacted surfaces undergo a final rinse with non-reconditioned water. However, specific treatment requirements for potable reuse of this unique source water have not been clearly defined. To address this need, U.S. EPA Office of Research and Development (EPA-ORD) has partnered with Tyson Foods to develop risk-based treatment guidance for onsite potable reuse of protein processing wastewaters (WRAP Action 3.5). The goal of this collaborative research effort is to establish a process for whole-facility protein processing wastewater reuse that maintains protection of food quality and consumer health. Specific objectives are to: (1) characterize the microbial and chemical quality of protein processing wastewaters; (2) determine the treatment requirements necessary to achieve public health benchmarks; (3) identify potential treatment train configurations to meet the treatment targets. To do so, process wastewater samples were collected from ten Tyson Foods facilities reflecting different protein types (beef, pork, and poultry), geographic locations, and processing configurations. Samples were analyzed for a suite of microbial indicators (Enterococcus spp., total coliforms, and Escherichia coli) and pathogen genes (Campylobacter spp., Salmonella enterica, Listeria monocytogenes, E. coli O157:H7, Cryptosporidium spp., and Giardia spp.) using culture-based and molecular methods, respectively. Results were used to conduct quantitative microbial risk assessment (QMRA) to determine pathogen-specific log-reduction targets (LRTs) that meet a risk target of 10-4 infections per person per year for drinking water use. Unit processes that could achieve these removals in process water treatment trains are identified. As a secondary objective, we conducted a screening-level assessment of potential chemical contaminants (plant-use cleaning compounds, antibiotics, and hormones) in the source waters to evaluate whether they would be adequately addressed by treatment processes necessary to achieve microbial targets. The result of this work is an initial framework for managing risks during the multipurpose reuse of protein processing waters within these facilities.