Commercial Dairy Processing Plant
Western Washington
The plant is occupied by a commercial milk production plant that produces and containerizes fat free, 1 percent, 2 percent, whole, chocolate, and butterfat milk, along with half n half, heavy cream, and at times eggnog. The purpose for performing the study was to determine the most cost effective, economically feasible, and workable alternative to reduce the County High Strength Surcharge levied for high strength industrial process wastewater.
The scope included reviewing the facility’s existing Conditional Discharge Authorization industrial process wastewater permit for sampling requirements, parameters, discharge limits, and sewer use fees. The facility’s products and process flow diagrams were reviewed to become familiar with the generation and passage of high-strength process wastewater throughout the entire plant.
Several time-proportioned composite wastewater samples were collected from several floor drains, the oil / water separator, and from the official sampling point to determine the strength and to estimate the flow being discharged into the public wastewater system. Samples were processed under Chain-of-Custody procedures to a Washington accredited lab for analysis of BOD5, TSS, Oil and Grease, and pH.
Based on the study, a cost and benefit analysis table was created with alternatives, recommendations, and implementation strategies. It was determined that these actions would reduce the strength of the process wastewater being discharged, reduce the volume of wastewater being discharged, reduce the volume of treatment chemicals used to treat wastewater, and reduce the County industrial wastewater sewer use fee.
The cost analysis table compared pre-treating the process wastewater at the facility prior to discharge with not pre-treating the wastewater. It was determined that pre-treating the wastewater would likely be economically feasible if the facility also installed a primary flow device with a flow meter at the discharge point to more accurately measure the concentration and flow of the process wastewater.
The facility made significant changes by reducing the volume of milk products released into the floor drain system and offering waste dairy products to local animal farms. Pretreating the wastewater and installing a primary flow device was also being considered. It was determined that the facility could realize a savings of about $100,000 on an annual basis for wastewater disposal surcharges by implementing the recommendations made during the study.
