According to the World Bank, the planet’s growing population of 7.6 billion generates about 2 billion tons of waste annually. And that figure is growing—experts predict that wastes will increase 70 percent by 2050.
Waste management practices range from basic recycling to complete destruction by incineration. Most difficult to manage are highly toxic wastes, byproducts of commercial and governmental activities. On land, common disposal methods are injecting fluids into dedicated wells, dumping at landfills, storing in specially built and lined containment ponds, or incineration.
On-land burning uses purpose-built incinerator facilities or boilers and furnaces on the site where materials initially are produced. Advanced-design incinerators handle both liquid and solid wastes, with operational efficiencies close to 100 percent. Understandably, there are continuing societal and political objections to the siting of these facilities. The primary concern is for public safety at locations where an on-site accident could release highly toxic materials into the local environment.
For centuries, the World Ocean has been a major “sump” for global wastes. In the early 1970s, global concerns about damage to the oceans resulted in a near-total prohibition against ocean dumping. The major governing regulations are the U.S. Ocean Dumping Act of 1972 and the London Convention on the Prevention of Maritime Pollution of 1972. Ocean incineration still could be done, but only if the host government granted a permit. (At-sea burning is defined as ocean dumping, because the smoke plume and disposal of ash residue will enter the ocean.)
Nevertheless, some wastes are best destroyed at sea. Highly toxic liquid wastes, containing compounds such as dioxins and polychlorinated biphenyls, are among them. These compounds are difficult to safely store or destroy on land. While liquid wastes represent only 8 to 10 percent of the total volume of highly toxic wastes, it is not their quantity but their quality that makes destruction at sea a favored choice.
Ocean incineration is not new. From 1969 to 1990 in the North Sea, six commercially operated incinerator ships successfully destroyed toxic chlorinated wastes at a temperature of 2,500 degrees Fahrenheit, to reach an efficiency of 99.99 percent. By 1987, the ships were burning 110,000 tons per year. Over 320 voyages, the liquid wastes were effectively and safely eliminated. Even though results were excellent, by 1990, regional public opposition resulted in the ban of at-sea incineration.
Commercial activities for at-sea incineration never started in the United States. However, from 1974 to 1982, the Environmental Protection Agency (EPA) permitted five “experimental burns” to compile data to create rules and regulations for this activity.
In the Gulf of Mexico, three approved operations destroyed 30,000 tons of highly toxic wastes that had been stored on land. In 1977, at Johnston Atoll in the Pacific, 11,500 tons of stored Agent Orange were destroyed. The EPA’s last research activity was in 1983 at a North Sea site to observe a U.S. contractor conduct liquid waste destruction. The incinerator ship was the first purpose-built incinerator ship, Vulcanis II.
At the end of the tests, the EPA determined that the science, technology, and results of this type of waste disposal were sound and, indeed, preferable to some on-land incineration operations. However, some ocean conservationists were concerned that at-sea incineration would open the door to a new form of ocean dumping. At a 1983 EPA public hearing on a proposed waste incineration in the Gulf of Mexico, 6,600 people attended to protest. In 1984, at the end of the public comment period, the EPA stopped its rule-making process for ocean incineration. By 1988, this waste-disposal option was effectively terminated in the United States.
In 1996, an extensive follow-on to the London Convention banned ocean incineration, with no provision for permitting. Since it is a treaty, the signatory governments are required to comply. Ocean incineration was dead.
Why is this history from 30 years ago relevant today? Because the global accumulation of toxic materials continues to increase. Also, since that time, considerable progress has been made in waste-
disposal technologies, so revisiting ocean-based incineration should be undertaken. It could be one of many tools to help mitigate the problem. At the least, an experimental program should be undertaken.