Before revision: When initially charging the tremie a wad of empty cement bags or a foam rubber plug known as a pig may be stuffed into the pipe to keep the flow under control while the first concrete forces the plug down the pipe and displaces the water.
After revision: ,When initially charging the tremie a wad of empty cement bags or a foam rubber plug known as a pig may be stuffed into the pipe to keep the flow under control while the first concrete forces the plug down the pipe and displaces the water.