Three World War I-era mustard-gas-filled artillery shells were dredged up from about 130 feet of water in the summer of 2004 off New Jersey.
They were either jettisoned by the Army before reaching a deep-water dump zone or tossed in an undocumented location after World War I.
After World War II, the Army went into deeper water, creating five dumps off Virginia.
In 1945, more than seven shiploads of chemical munitions were thrown into one dumpsite on the Virginia-Maryland line in water more than 2,000 feet deep.
In 1957, the Army dumped 48 1-ton containers of Lewisite - a blister agent akin to mustard gas - in 12,600 feet of water off Virginia Beach.
After dumping chemical weapons off other states, the Army returned to the Virginia-Maryland line in the early 1960s to create three more deep-water dumpsites. One site contains about 317 tons of unidentified radioactive waste and two 1-ton containers of Lewisite.
Another site, created in 1962, contains more than 700 mustard-gas-filled artillery shells, 209 drums of cyanide, 5,000 white-phosphorus munitions and more than 400,000 pounds of radioactive waste. In 1964, 1,700 mustard-gas-filled 75 mm artillery shells were dumped nearby, along with 800 55-gallon drums of radioactive waste.
Army records don't reveal what kind of radioactive waste was dumped. But National Archives records give one indication that it could be very dangerous nuclear waste with a half-life spanning generations.
Records of the chemical weapons escort unit - which planned and guarded shipments - reveal dozens of trips in the 1950s from a nuclear development laboratory in Oak Ridge, Tenn., to Army bases where chemical weapons were slated for ocean disposal.
Oak Ridge was where thermonuclear weapons were being developed at the time.
"This report certainly raises concerns, and the governor will be closely monitoring the military's response to this," said Kevin Hall, a spokesman for Gov. Mark R. Warner.