poison stuff under

Military barrels potentially containing hazardous waste are seen through the corroded shell of the container in the sea off Vieques, Puerto Rico. Provided by C. Torres, University of Georgia

Unexploded bombs, poison gas and barrels of radioactive waste — hundreds of thousands of tons of it — litter the sea bottom off South Carolina.

Detonating or setting any of it loose might be the unacknowledged threat from seismic blasts and oil-drilling pursuits being considered for offshore. 

Where did it come from?

Pentagon ammo dumps.

As concern turns toward what fossil fuels might be harvested off the coast, the S.C. Small Business Chamber of Commerce is making it known there are bigger than expected risks in the Trump administration's plans to open the region to oil and natural gas exploration.

"If we're going to go blasting on the bottom of the ocean, we ought to know what we're blasting," said Frank Knapp, the chamber president.

"This is serious stuff," he said. "Even the Department of Defense has said don't disturb it."

Another problem: Nobody appears to know for sure exactly how much is out there or exactly where it is.

'Get rid of your steel'

The heaps of unused munitions half-buried in the sands offshore are a legacy of World War II.

The dumping, carried out from the war years until 1970, took place all around the country after the military deemed the sea the safest place to dispose of it.

Queries to the Army about the status of the sites off South Carolina and whether they have been surveyed, were referred to the Navy. As of Friday, the Navy had not responded with any information.

But according to a 2009 Department of Defense report to Congress, more than 17,000 tons of different types of poisonous gas were dumped off the East Coast in the 25 years following the end of World War II.

Off South Carolina, the military also dumped about 800,000 tons of weapons and explosives.

The disposals start about 20 miles off Charleston, at two spots called the Baker sites, just beyond the farthest artificial fishing reef managed by the S.C. Department of Natural Resources.

On top of Baker, four sites just off the Continental Shelf — beginning about 50 miles off South Carolina — were among 50 sites around the country where tens of thousands of containers of radioactive waste were dumped, The Wall Street Journal reported this month.

The specific number of sites and tonnage of waste have not been revealed.

The unknowns are maybe the worst of the problem, said James Porter, a University of Georgia ecologist who studied underwater munition dumps off the Puerto Rican island of Vieques.

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A 2,000-pound Mark 84 bomb dropped off Vieques, Puerto Rico, is inspected by a diver. Provided by James Porter, University of Georgia

At the close of the fighting, the War Department sent out an order to base commanders, "Get rid of your field of steel," he said, meaning excess munitions. Also, it was common during the war years to hold target practice offshore.

Off Vieques, where more than a million of tons of munitions were dumped, Porter found every marine animal he tested was positive for some sort of carcinogen, or cancer-causing substance, that came from the munitions.

Onshore, he found "significantly elevated levels of cancer and several other types of chronic illnesses" among island residents.

"In the coastal zone, you have a special problem because (the dump) is out of sight, out of mind. That stuff is corroding and the casements have been breached," he said. "I'm frustrated that the military has not investigated these legitimate concerns of coastal residents."

The corroding containers also might well be polluting the waters and marine life with cancer-causing substances, endangering people who eat seafood.

The degree of risk

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big long bomb underwater

A canister used to drop thousands of grenade-sized bomblets lies on the ocean floor off Vieques, Puerto Rico. Provided by C. Torres, University of Georgia

The entire program was kept so secret that the dumping from Navy ships often took place at night, according to a veteran of the missions and other information reported by the Tampa Bay Times. The radioactive waste alone was so poorly secured that the sailors afterward tested high for radiation.  

The chemical warfare materials dumped off South Carolina, according to the Center for Non-proliferation Studies in Monterey, California, include:

  • 8,050 tons and four railroad cars dumped intact with unspecified amounts poisonous gas bombs and mines — 20 to 30 miles out.
  • 1,507 1-ton containers of lewisite (an arsenic compound similar to mustard gas) — 20 to 30 miles out.
  • 63 1-ton containers of nitrogen mustard (chemical weapons derived from mustard gas) — 20 to 30 miles out.
  • More than 20 tons of mustard gas bombs, projectiles, mines and bulk containers — 20 to 30 miles out.

After the congressional report and wide media coverage, the Defense Department in 2016 reported the munitions don't pose significant harm when left in place. Trying to remove or clean them up would cause more harm and the potential health effects appear to be minimal, it said.

The report conceded there would be public health concerns if contaminated seawater is contributing to illnesses among sea life as well as seafood eaters and beach bathers, and that the munitions could potentially wash ashore.

It said those illnesses have been documented in the United States and abroad, but "they are relatively rare relative to the thousands of weapons dumped in the ocean," the report said. "Assessing the degree of risk is difficult because of a lack of information."

The Non-proliferation Center report suggested the reality could be far worse.

"There is little concrete data on how and to what extent CW (chemical weapon) agents may cause environmental harm," the center reported in 2017. "It is feasible, however, that the damage to primary producers in the marine environment, as well as the food webs of which they are members, could be substantial."

Several studies have been made but haven't determined the risk, the report continued. The studies did find the degradation of the containers and the spread of the chemicals "vary greatly between dump sites."

'Turn that rock over'

The bottom line in the exploration debate is simple for both Knapp and Porter.

"You should turn that rock over" and find out what's there, Porter said.

Knapp openly confirms his aim is to stop the oil and natural gas work and wants to crank up public opposition to sway federal lawmakers and regulators. But he said if the work goes ahead, he hopes to force the federal government or the exploration companies involved to mitigate the risk.

"The issue here is we don't really know where (the munitions) are," he said, adding even near the coast is suspect.

"In the early days they were relatively close to shore," he said.

Europe has its own approach. There, the Convention for the Protection of the Marine Environment of the North-East Atlantic is a multi-national group convened to identify the sites and stop threats to the marine environment.

Convention reports indicate there are about 900 encounters with the dumped material each year off the European coasts.

More than half are entanglements with fishing gear.

In 2005, three fishermen in the North Sea were killed when their nets pulled up a bomb that exploded on board, according to the convention.

The public comment period on the Trump offshore leasing proposal ended in March, but Knapp is filing the concerns as additions to comments he posted earlier. They will have a lot of company. More than 1.86 million people have commented on the leasing plans, according to the federal Bureau of Ocean Energy Management. BOEM will publish the comments and its assessment of them later this year, said spokeswoman Tracey Moriarty.

Porter said the munitions dumping isn't an issue that's going to stay buried.

"We're just scratching the surface of this problem," he said. "Mostly, we don't know what we need to know."

Reach Bo Petersen Reporter at Facebook, @bopete on Twitter or 1-843-937-5744.

Science and environment reporter. Author of Washing Our Hands in the Clouds.