The report said this increase of two to three per cent in Square sales would not linduce the construction of new retail shops, restaurants or hotels.

The impact statment also considered 36 alternative sites for the library, including the Watertown arsenal and the Charlestown Naval Yard.

The GSA concluded that while five of the sites could "physically accommodate the library, availability and cost factors are serious concerns with respect to all of them."

The agency prepared the draft report with the assistance of C.E. Maguire Inc., a Waltham engineering firm, which last spring won a $186,000 contract to undertake the research.

Under the National Environmental Policy Act of 1969, completion of an environmental impact statment is required before construction on a government project may begin.

Preparation and release of the study have been delayed four times, principally because the Kennedy Library Corporation decided to redesign the complex last spring.

Architect I.M. Pei last June unveiled his design for a scaled-down library and museum facing the Charles River