All users.... The smaller the pipe, the bigger the risk of clogging. We close off our smaller piping system for a period of time, treat it with Zequanox or chlorine, and then flush it through to make sure there are no live zebra mussels in the system. We do that annually. We have six stations where we have to do that, as well as the nuclear stations.
On May 6th, 2019. See this statement in context.