Mapping and estimating the damage is the first phase of what is expected to be a two-year project for an eight-block area around the site of the Sept. 11 terrorist attacks.
Planning includes digging test pits to locate utility lines. GPR is helping determine where to dig to get the best information. "One of the problems is that there are no integrated maps," says Mike Oristaglio, chief scientist at Witten Technologies Inc., Boston, whose GPR system is being used. "Each utility maintains its own map, and the depth of the line almost never is indicated."