U.S. Rep. Ed Case said he will co-sponsor the legislation.

"Given the hazardous risks that these munitions may pose, it is important for Congress to send the right message ... and ensure that the Army completes its survey, monitors the sites and provides a plan for remediation," said a written statement from Akaka.

The Army decades ago dumped more than 8,000 tons of chemical munitions, which contained blister agents and nerve agents, in at least three places off south O'ahu and Wai'anae, but the exact locations and depth of the weaponry are not clearly known. The Hawai'i lawmakers said they are concerned about leakage from the toxic weapons that are known to have been dumped in 1944 and 1945 and other disposal programs that may have started as early as 1941 and continued to as late as 1972.

The legislation calls for a complete report by September 2009 to include the location and size of dump sites, the kinds of material present, sampling and monitoring of the sites, and recommendations on how to deal with them and how much that will cost.

Hawai'i environmental groups said they support the legislation, but would like to see it extended to include other kinds of munitions at other Hawai'i sites on both the land and in the sea.

"I would expand it to look at all the areas where munitions have been dumped off Hawai'i," said Henry Curtis, executive director of Life of the Land. "For example, when the military cleaned up Kaho'olawe, they never looked at munitions in the water. I would hope for a comprehensive report on both chemical and nonchemical weapons."

Marjorie Ziegler, director of the Conservation Council for Hawai'i, said there also are concerns about unexploded munitions at present and former training ranges on land. "Munitions are of great concern. They are a deadly form of land contamination that precludes future use. Let's not forget Makua, Schofield Barracks, Waikane, Kane'ohe and Pohakuloa," Ziegler said.

Case said the Army already has done considerable research on the ocean-dumped chemical munitions, but he said the records apparently are not complete.

"It's crucial that we basically do three things here: identify, isolate and clean up," he said. The legislation will "build a larger statutory framework for what the department is already doing and it will formalize what the department has already undertaken to do," he said.

Abercrombie said he is pleased with the military's progress, but wants a legislative role so that if additional money is needed for the process, it can be handled quickly.

"Our goal is to get the facts and then move to a well-thought-out plan of action. The Department of Defense will have to be deeply involved in gathering this information, and that's why we're using the annual national defense authorization bill as the legislative vehicle," Abercrombie said. If more resources are needed, "we will already have it there and we will not have to invent it on the spot."

Reach Jan TenBruggencate at jant@honoluluadvertiser.com