Conference Abstract A City Grew — The Pretreatment Program Did Not: Building Compliance and Collaboration Through Program Development and Industry Transformation Scott McRae Pretreatment Coordinator III City of Lebanon, Tennessee scott.mcrae@lebanontn.org / 615-364-4806 As cities grow and industrial activity expands, pretreatment programs must evolve at the same pace. When they do not, wastewater treatment plants (WWTPs) can experience chronic operational stress, regulatory scrutiny, and strained relationships with industrial users. This presentation examines the redevelopment of the City of Lebanon, Tennessee’s pretreatment program and presents a detailed case study illustrating how an initially adversarial enforcement action ultimately became a model for collaboration and shared success. Seven years ago, the City of Lebanon’s pretreatment program was under state scrutiny and significantly underdeveloped relative to the City’s industrial growth. At that time, only five industrial users were permitted despite numerous active dischargers. Over the subsequent years, the program was rebuilt to meet state expectations and now oversees eighteen permitted industries. During this transition, the WWTP experienced repeated toxic and unknown industrial contributions, and collection system interference (BOD, rags, towels, etc), largely due to decades of unregulated discharges. The presentation first addresses the challenges faced by municipalities whose infrastructure and regulatory oversight lag behind growth. It discusses program development strategies, internal alignment within municipal departments, and the importance of leadership support when introducing pretreatment requirements to long-standing industries. The second portion of the presentation focuses on a single industry case study. Initially resistant to pretreatment oversight, the industry challenged enforcement actions and focused blame on regulatory personnel rather than addressing the root causes of its discharge. Despite data confirming toxicity to the WWTP, the industry continued to discharge, ultimately resulting in a Consent Order. During this time, a significant slug discharge occurred damaging the biological process at the WWTP. This occurred during a critical point of mixed liquor transfer amid aeration basin rehabilitation; resulting in reseeding of the biomass, and ultimately led to a surprise state inspection of the Industry. This event marked a turning point. The industry engaged consultants and corporate environmental leadership, installed on-site pretreatment, and began meaningful process improvements. Through consistent communication, patience, and enforcement, the relationship transitioned from contentious to cooperative. Today, the industry is one of the City’s strongest partners and proudly demonstrates its pretreatment system during state inspections. This case study highlights that successful pretreatment programs are not solely about enforcement, but about education, persistence, and building alignment between municipalities, regulators, and industry to protect public infrastructure and achieve long-term compliance.