Some businesses, commercial facilities, and industries have their septic tank wastes hauled to King County's South Treatment Plant. King County requires many businesses to get formal authorization before it accepts their waste. King County needs to evaluate whether the waste could harm the treatment plant or the environment.
Sources that generate domestic septage and non-domestic septage shall use a hauler approved by King County for the collection, transport, and discharge of their waste into the King County POTW.
South Plant is the only King County-operated facility that accepts waste from septic systems.