The bill goes to Gov. Rendell, who plans to sign it. When he does, Pennsylvania will become the last of eight Great Lakes states to adopt the compact, which still requires approval from Congress and the president to become law. In Canada, Ontario and Quebec also have adopted laws nearly identical to the compact.

The compact would prohibit piping or shipping Great Lakes water outside the system's vast drainage basin, with rare exceptions.

Also, the states would be required to adopt plans to improve water quality, protect ecosystems, and ensure that use of the water does not threaten its supply. The compact applies to water both in the Great Lakes and inland waterways.

The chain of lakes - Erie, Huron, Michigan, Ontario and Superior - constitutes one-fifth of the world's fresh-water supply.