Characterization of Milking Center Wash Water for Treatment Feasibility Using On-Site Septic Systems

Dairy farm wash water is generated during the cleaning of milking pipelines, which involves a four-step cycle: prerinse, detergent rinse, acid rinse, and sanitizer rinse. This water contains various organic and inorganic contaminants that must be managed in compliance with regulations. Although septic systems are a common treatment method, inconsistencies in the Ontario legislation have raised concerns about their use for on-site treatment. This study examines the feasibility of utilizing on-site systems to treat milking center wash water and highlights inconsistencies within the existing regulations. Based on the findings, implementing an air rinse before the wash cycle is recommended. This step significantly reduces organic contaminants, lowering chemical oxygen demand and total suspended solids by approximately 73% and 81%, respectively, before the water enters the septic system.