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Chapter 27  
Waste Management 
 

LEARNING OBJECTIVES        The old "dilute and disperse"  concept of waste management no longer works, and the newer concept of "concentrate and contain" is giving way to a concept called integrated waste management.  This section should foster your understanding of concepts covered in the text regarding the following:  That management of hazardous chemical waste is one of our most serious environmental concerns. The major pathways by which hazardous waste pollutants from a disposal site may enter the environment. Problems related to ocean dumping and why these problems are likely to persist for some time. ENVIRONMENTAL ISSUE: Should We Dispose of Waste in the Ocean?      The New York Bight, the coastal water off the Long Island and New Jersey shores, includes Newark Bay, an important commercial shipping port.  To keep this $20 billion industry open to large vessels, accumulated sediments must be dredged periodically to maintain a minimum depth of 12.8 m.  Since 1976, 5.3 million cubic meters (7 million cubic yards) a year of dredged material has been dumped at the Mud Dump site, an area of about 5.2 square kilometers (2 square miles) about 9.6 kilometers (6.0 miles)  from shore, with an average depth of 22 meters (72 feet).  The site is in the midst of rich fishing grounds; only 1.6 kilometers (1 mile)  away is the famous 17 fathoms, a prime fishing spot for bluefish, bonitos, false albacore, blackfish, and flukes and the focus of a $100 million a year industry.      Much of the sediment originates as runoff from the three rivers feeding the estuary in the bight: the Hudson, Passaic, and Raritan.  But with the sediment come many metallic and organic toxic wastes from industries along the rivers, among them dioxin, one of the most toxic substances known.  Because dioxin has been associated with  cancer and immune deficiencies in animals and is suspected to have many other adverse health effects, dredging the dioxin-contaminated sediments became highly controversial in the early 1990s.      A request by the Port Authority of New York to dredge and dump 383,000 cubic meters (500,000 cubic yards) of contaminated sediment at the Mud Dump site was held up while questions regarding the impact on the marine environment and human health were debated.  Differing opinions as to the lower and upper limits of moderate dioxin contamination complicated the decision on disposal of the dredged materials.  Concentrations greater than 4 parts per trillion (pptr) would have required capping, and ocean disposal was prohibited for concentrations above 25 pptr.  Some experts felt these limits were too liberal, but other pointed out that Europe and Canada accepted even higher levels.        By 1991 scientists had reached a consensus on the mechanism by which dioxin acts on living cells and agreed on the need to question existing guidelines for safe exposure.  The average dioxin concentration various for different parts of Newark Bay, from 39.4 pptr to 110.6 pptr.  The average level in sandworms at the Mud Dump site is 27 pptr of dry weight.  Dioxin is highly fat soluble and accumulates in fatty tissue.  Predators of the sandworms and other marine organisms can be expected to accumulate concentrations as much as 1000 times greater than those in their prey.  As dioxin is passed up a food chain, concentrations in fatty tissues of fish can be as much as 10,000 times those in the surrounding water. .  FAQs . Photo Credit: US EPA