When thirty-six-year-old Tim Nelson got a call from the U.S. Army Corps of Engineers this spring, he already knew it was serious. It's always serious. As a hazmat (hazardous materials)-trained scuba diver, Nelson makes a living plunging into heavily polluted rivers, where he has, for example, swum through raw sewage and pulp-mill effluent to check on leaking pipes. But this job was particularly risky.
The corps representatives told him that tissue samples taken from clams and crawfish in Oregon's Columbia River showed PCB levels up to 7,500 times the acceptable limits for human consumption. Some 800 feet upstream from the intakes of the Bonneville Dam lay the source of the problem: forty years' worth of decaying and deadly PCB-filled electrical equipment, the forgotten remains of an old Army Corps landfill. Since most of the toxic wreckage lay 60 feet underwater, army officials needed Nelson's employer, the Oregon City-based scuba company Advanced American Diving, to help them get rid of it. "We treated it as a worst-case scenario," says Nelson.
As the monitoring of U.S. waterways becomes more rigorous, the need for hazmat divers is on the rise. Since 1980, more than 400 people have graduated from the Environmental Protection Agency's hazmat scuba school in Gulf Breeze, Florida, where divers also learn the skills needed to work on scientific projects, such as measuring the progression of coral diseases or the growth of sea grass. But not every job is so pacific. Take the unhappy 1990 discovery of 1,163 decaying drums of toxic chemicals in a quarry near Kokomo, Indiana. EPA and Coast Guard divers found every one. Or the case of the Alaskan seafood processors who were heaving mounds of leftover fish heads and innards into the ocean. EPA cold-water divers gathered the evidence that led to nearly $700,000 in fines and tighter dumping regulations.
For the PCB job, Nelson and his seven-man team deployed underwater video cameras to map the site and brought in a barge and crane for heavy lifting. To eliminate any chance of skin exposure, they wore specially made neoprene drysuits, gloves, and hard hoods, and employed the utmost "decon" protocol, which includes high-pressure, post-dive wash-downs. Over two weeks they hauled more than 40 cubic yards of debris from the river, about enough to cover a football field's end zone a foot deep.
While the removal of the debris seems to be complete, the river's shellfish won't be PCB-free for a long time. Through a process called biomagnification, PCBs remain in the food chain for years and, in addition to causing bacterial infections and liver lesions in animals, are a probable human carcinogen. When the corps tests the invertebrates again in August, it hopes to find that PCB levels have declined.
In the meantime, Oregonians should count themselves lucky. There aren't many who would choose to handle toxics and swim through sludge, but Nelson is into his job. Asked if he plans to continue in his line of work, Nelson's reply was automatic. "Oh yeah, you bet," he replied. "I love it."
-- Christian DeBenedetti