SugarHouse got permission from the Army Corps of Engineers on Aug. 1 to begin limited work to install test pilings, as well as to remove underground obstructions.

The company said it needs to complete the work to move ahead with construction bids for the casino project along Delaware Avenue at Frankford Avenue.

Some criticize the corps for allowing even limited excavation. Under federal law, the corps must determine the historical significance of a property before it can issue a permit. That review is ongoing.

"By going ahead with construction, you're basically cheating on the process," said Douglas Mooney, a professional archaeologist and member of the Philadelphia Archaeological Forum, a group dedicated to the protection and preservation of Philadelphia's archaeological heritage.

Khaalid Walls, a spokesman for the corps, said the work under way would not have an impact on the review of historic or archaeological resources that may exist elsewhere on the site.

Leigh Whitaker, a spokeswoman for SugarHouse, said the company got permission from the corps, which, in turn, consulted with the Pennsylvania Historical and Museum Commission and the Advisory Council on Historic Preservation, a federal group.

The 22-acre site is in Fishtown and Northern Liberties. In 1777, English troops built a redoubt, or small fort, in an area thought to be under Penn Street, which has not yet been disturbed. SugarHouse also found relics dating back 3,000 years from American Indians.

In the 18th and 19th centuries, this stretch of waterfront had commercial establishments, wharves and homes.

"This is stuff that if we lose it, we'll never have an opportunity to recover our history at that site," said Debbie King, a representative of the Northern Liberties Neighborhood Association, which is one of the "consulting parties" to the corps during the historical review process.