Unidirectional Flushing Program Is Clean Sweep

This article describes how the city of Virginia Beach, Virginia, modeled the city's entire water distribution system in a single computer file with all 6 in. and larger pipes included. The model was used to prepare unidirectional flushing program field books for use by city line maintenance crews. These crews had flushed approximately half of the city's 12‐in. and smaller distribution mains and were on schedule to complete the flushing citywide by the end of December 1999, well in advance of the planned conversion to chloramines. Customer complaints during the daytime flushing were few.