The contaminants under greatest regulatory scrutiny in paint wastewater streams are total suspended solids (TSS), and to a somewhat lesser extent, heavy metals, biological oxygen demand (BOD) and chemical oxygen demand (COD). The exceptionally high levels of TSS that in part account for a coating's performance, come back to present the most significant disposal obstacle in more ways than one. Without treatment, a clogged water line on the premises becomes an immediate production problem that is expensive, dirty and time-consuming to correct. Untreated wastewater that does reach POTW facilities are met with tightening discharge standards and escalating surcharges. In a worst-case scenario that is all too common, when untreated wastewater results in obstructed lines somewhere between the origin and the destination, the disposal problem is instantly transformed into an infrastructure problem, and decisions begin to be made beyond the control of the facility that is out of compliance.
All these factors, in combination with pollution-control technologies that have simultaneously become more user friendly, more effective and more affordable, have made on-site treatment a viable option for a growing number of paint wastewater generators. By and large, they recognize that today's coatings are just too good to keep hoping "dilution is the solution to pollution." They also recognize the significant potential for creating a resource management system that lowers certain costs, such as those for incoming fresh water within a design that emphasizes reuse and recycling. That counts for something in an economy that equates cost control with revenue generation.