Five years after an entirely new wastewater treatment plant was built in Chehalis, Washington, the plant faced an unexpected near catastrophe. The Grit King grit removal system at the plant would typically capture enough grit to fill a 1-cubic-yard dumpster with clean, dry grit each week at this 13 mgd (peak) flow plant. Then something very strange began to happen. The grit removal system started capturing enough grit to fill up that same dumpster in just days. Upon investigation the plant staff immediately noticed that all this extra grit looked suspiciously similar to the silica sand they used in their sand filters. In fact, it looked identical. One of the airlift pumps that was used to recirculate sand back into the filters had become plugged and was instead sending a tremendous amount of grit to the headworks.

Despite this massive increase in grit loading, the Grit King was able to continue to operate and protect plant processes. During the entire event, the Grit King prevented the need to shut down any downstream equipment. Download this case study to learn how the Grit King prevented what could have been a major incident at this plant.