Carmel issues boil advisory after 36-inch transmission main failure; officials say system likely safe

A failure on a 36-inch transmission main early Monday left large sections of Carmel’s west-side water distribution system under low pressure and prompted a precautionary boil-water advisory, city utility staff said.

City utility staff said the connection that failed was a hydrant tee off a high‑pressure transmission main that feeds the west tower. The main lost pressure as crews were working to bleed and isolate the line; the city estimated about 13,000,000 gallons were being used during a roughly four‑hour high‑demand period early that morning, contributing to rapid loss of system pressure in the affected area.

The advisory was issued under state rules because system pressure fell below 28 pounds per square inch (psi) in parts of the distribution network, city staff said. “Once we get below or we know an area drops…