Ocean Dumping of Municipal and Industrial Wastes in the United States: An Analysis of Environmental Effects

The volume of ocean dumped municipal wastes (sewage sludge) has increased 32%, while that of industrial wastes has declined 43% in the United States since the enactment of P.L. 92-532, the Marine Protection Research and Sanctuaries Act of 1972 (for the period of 1973 to 1980). In 1980, the total tonnage of industrial and municipal wastes ocean-dumped was over 10 million metric tons. The environmental effects of the disposal of these wastes is determined by the nature of the waste (quality and quantity) combined with the dynamics of natural physical, chemical, and biological processes. The most pronounced environmental effects have occured at waste accumulating and low dispersing dumpsites. At sewage sludge dumpsites, benthic community structure and function have been altered by the build-up of organic matter in bottom sediments. The same sediments exhibit enhanced concentration of: 1) several metals (Cr, Ni, Cu, Zn, and Pb) and organic compounds (PCBs), 2) coliform and fecal coliform bacteria, 3) bacteria resistant to antibiotics and metals, and 4) pathogenic protozoans of the genus Acanthamoeba. Dumping of industrial wastes, inorganic (acid-iron wastes) and organic (process and pharmaceutical wastes), leaves amounts of contaminants in the water column which depend on the rate and frequency of dumping and the flushing characteristics of dumpsites. Phytoplankton response (laboratory bioassays with cultered organisms) varies with species, and growth inhibition occurs usually at concentrations greater than those existing in the ocean subsequent to dumping. Field studies indicate that there may be a short term, small scale alteration of phytoplankton communities. The response of zooplankton is manifested in decreases of fecundity which, again, is of small spatial scale and, since subsequent generations are unaffected, are not of long term consequence.