Two 66-inch reinforced concrete stormwater retention tunnels in the mountains near Bristol, Va., were beginning to flood nearby roads. The tunnels, installed in 1990 by the state Department of Transportation, were never cleaned.Atlantic Plumbing and Utilities in Virginia Beach won the per-hour bid with a maximum of 120 man-hours. “We didn’t know how much material to expect,” says foreman Clint Carpenter. “In fact, nobody knew.” He considered using a mini-excavator, but the track was too wide to fit down the manhole vaults, and the bucket was too wide to scour the last two feet of sediment off the pipe floor.Other
