The military will pay the University of Hawai'i $2 million to use sonar and manned and unmanned submersibles to survey chemical weapons dumped about five miles south of Pearl Harbor at the end of World War II.

Officials said the study could begin in late summer of next year, but what was dumped and where the dumping occurred remain questions that could complicate the search.

Tad Davis, deputy assistant secretary of the Army for the environment, safety and occupational health, said the project could establish procedures for determining whether munitions disposed of at sea pose a threat to human or marine health.

Some O'ahu residents, particularly on the Wai'anae Coast, have called for a cleanup in recent years of the munitions that are so rife in areas that one popular dive spot is called "Ordnance Reef."

The U.S. military has said about 2,600 tons of chemical mustard, cyanogens chloride, hydrogen cyanide and lewisite were dumped at two deep-water locations five to ten miles off the Wai'anae Coast and Pearl Harbor between 1944 and 1946.

The Army also has acknowledged that thousands more tons of chemical munitions were dumped at another unknown site off the coast of West O'ahu in fall 1945.