Improve safety, reduce maintenance costs, and optimize treatment equipment operation with Weir Washer Automated Cleaning Systems. Weir Washer Automated Cleaning Systems (ACS) remove algae, scum, and other foreign material from WasteWater Treatment Plant (WWTP) clarifier weirs and troughs. Our original designs were installed in 1995 and have been operating ever since. Through many years of research, development and testing, we have refined our products to their current state.