Mayor Mufi Hannemann said he met with officials from U.S. Pacific Command this week and was given assurances "the military's top brass and the office of the Secretary of Defense consider chemical munitions dumped in the ocean off O'ahu to be a top priority."

More importantly, Hannemann said, the military will be conducting an in-depth investigation. Hannemann has asked for "timely" progress reports from Pacific Command, headquartered at Camp Smith, as the investigation proceeds.

U.S. Rep. Ed Case, D-Hawai'i, said a 2001 study of Army records showed the service disposed of chemical weapons in 73 sites around the world from World War I to the early 1970s.

The report states that more than 8,000 tons of corrosive or toxic chemical munitions were dumped off O'ahu in 1944 and 1945, some off Pearl Harbor and some off Wai'anae.

The Army disposed of 16,000 mustard bombs in 1944 five miles from shore off Pearl Harbor.

"As mayor, the health and safety of the people of Honolulu is my administration's highest priority," Hannemann said.

Asked if he were angry that the public is finding out about the dumping only now, Hannemann said: "I think my feeling has always been there's only so much we can control about the past. I'm more interested in terms of where do we go from here. And if I was being stonewalled about this meeting that I asked for, if they weren't forthcoming with information, you'd probably have a different reaction."

But Hannemann said military officials were "very forthcoming."

Elected officials including Hannemann, Case and U.S. Rep. Neil Abercrombie, D-Hawai'i, have raised concern about the dumping and launched inquiries.

Addison D. Davis IV, deputy assistant secretary of the Army for the environment, safety and occupational health, said the Army and other U.S. military branches are working "very deliberately" to research archival records to determine the locations and dates of munitions dumping off Hawai'i.

The National Oceanic and Atmospheric Administration lists a number of the sites on nautical charts, and military officials are working with NOAA to update those charts, Davis said.

Past scientific studies also are being examined to determine the effects of sea water on chemical munitions and the potential environmental effects, he said.

Hannemann said he recently started a military affairs working group — the Armed Forces Committee — to have an ongoing dialogue with the military.

Reach William Cole at wcole@honoluluadvertiser.com.