Located along the Duwamish River in Seattle, this 16-acre scrap metal transportation, sorting, and storage facility required treatment for turbidity, pH, TSS, copper, lead, zinc, hydrocarbons, and PCBs. Several years after the initial system deployment, the facility began transitioning from a general industrial stormwater permit to an individual permit with additional requirements. Clear Water ran a small-scale pilot treatment system to test additional treatment approaches and upgraded the original system with triplex adsorptive multi-media vessels. The pilot demonstrated that the addition of co-precipitation and adsorptive media to the existing system achieved the desired outcome and met the standards of all proposed low-level permit parameters.