An Ocean Blueprint for the 21st Century - California Ocean ...

Changing Sediment QualityOver the last fifty years, lakes, rivers, and harbors have accumulated bottom sedimentcontaminated with heavy metals (such as lead, copper, and arsenic) from mining andindustrial activities, as well as long-lived toxic chemicals (such as DDT, MTBE, PCBs, anddioxin)(Box 12.2). Continued discharges from municipal waste and industrial plants, andpolluted runoff from agricultural and urban sources, perpetuate the problem, while newlyidentified contaminants such as flame retardants are now being detected in ocean andcoastal sediments. Toxic chemicals from sediment can accumulate in marine plants andanimals, causing reproductive failure, impaired growth, disease, and death. They may alsopose health risks to humans who consume or come in contact with tainted marine products.Of the 12 billion cubic yards of sediment that comprise the top 2 inches underlyingU.S. waters, an estimated 10 percent is thought to be contaminated at levels that pose possiblerisks to marine life, wildlife, and humans. 1 Of the 300 million cubic yards of sedimentthe USACE dredges annually to facilitate navigation, an estimated 5 to 10 percent iscontaminated. 2 Once a portion of sediment becomes contaminated, it becomes a source offurther contamination downstream.Currently, six laws and seven federal agencies are involved in the dredging or remediationof contaminated sediment, depending on whether the material is to be removed, deposited, ortreated. Different sets of laws apply when navigational dredging or environmental cleanup isthe primary focus of activity. A 1997 National Research Council report concluded that thispatchwork of laws generally fails to manage contaminated sediment according to the risk itposes to the environment, does not adequately weigh the costs and benefits of different solutions,and imposes lengthy and unnecessary delays in addressing problems. 3The Comprehensive Environmental Response, Compensation and Liability Act (CER-CLA) established the federal Superfund program to clean up the nation’s uncontrolled orabandoned hazardous waste sites. At over one hundred locations, bottom sediments inrivers and harbors are so contaminated they are designated as Superfund sites. The EPAestimates that cleanup of the thirty most highly contaminated sites in rivers, lakes, andcoastal areas may cost hundreds of millions of dollars. 4The presence of contaminated sediment greatly complicates the management ofdredged material. For example, such sediment would be inappropriate for use in wetlandrestoration or erosion control projects. Costs are also much higher for the safe and securedisposal of these materials. The very process of dredging contaminated sediment increasesecological and human health risks because some of the sediment inevitably becomesresuspended and carried to new locations during removal.Box 12.2 The Legacy of Sediment ContaminationLong-term remedial response action is required at areas on EPA’s Superfund list, one ofwhich is Fox River and Green Bay, Wisconsin. From 1954 to 1971, PCBs were releasedduring the manufacture of carbonless copy paper by seven companies along the banks of theriver. The chemical releases left 11 million cubic yards of contaminated sediment in Fox Riverand Green Bay. The EPA estimates that up to 70 percent of the PCBs entering Lake Michiganvia its tributaries come from the Fox River. This contamination has affected water quality,recreation, and the health of people, fish, and birds. Elevated PCB concentrations in someLake Michigan fish have prompted health advisories. Native Americans in the area have beenparticularly affected because of the importance of subsistence fishing to their community. i,iiiiiBalas, M. “Fox River Cleanup Is Talk of the Town, But What About Restoration.” The Green Bay News-Chronicle.October 22, 2003.Wisconsin Department of Natural Resources and U.S. Environmental Protection Agency. Superfund Record of Decisionfor Operable Units 3, 4, and 5. Madison, WI, and Washington, DC, June 2003.C HAPTER 12: MANAGING S EDIMENT AND S HORELINES183