Issues of Environmental Management in the Gulf of the Farallones 



Disposal of Dredged Material and Other Waste on the Continental Shelf and Slope 



John L. Chin and Allan Ota 



The history of waste disposal in the Gulf 

 of the Farallones is directly linked with the 

 history of human settlement in the San Fran- 

 cisco Bay region. The California Gold Rush 

 of 1849 triggered a massive influx of people 

 and rapid, chaotic development in the bay 

 region. Vast quantities of contaminated sedi- 

 ment and water from mining in the Sierra 

 Nevada were carried by rivers into San 

 Francisco Bay, and some was carried by 

 currents through the Golden Gate and into 

 the gulf. The burgeoning region's inhabitants 

 also contributed to the waste that flowed or 

 was dumped into the bay. Eventually, waste 

 began to be dumped directly into the gulf. 



Hundreds of millions of tons of waste has 

 been dumped into the Gulf of the Farallones. 

 Since the 1940's, this has included sediment 

 (sand and mud) dredged from shipping chan- 

 nels, waste from oil refineries and fruit can- 

 neries, acids from steel production, surplus 

 munitions and ships from World War n, other 

 unwanted vessels, and barrels of low-level 

 radioactive waste. 



Because of navigational errors and inad- 

 equate record keeping, the location of most 

 waste dumped in the gulf is poorly known. 

 Between 1946 and 1970 approximately 

 47,800 containers of low-level radioactive 

 waste were dumped into the gulf south and 

 west of the Farallon Islands. From 1958 to 



1969, the U.S. military disposed of chemical 

 and conventional munitions at several sites in 

 the gulf, mostly by scuttling World War II era 

 cargo vessels. 



The hulks of ships, possibly dating as far 

 back as the 17 th century, litter the sea floor in 

 the gulf. From 1951 to 1987, many vessels 

 were deliberately sunk there. Most of these 

 probably pose little environmental hazard 

 because they were carefully prepared before 

 sinking. One exception may be the highly 

 radioactive World War n aircraft carrier USS 

 Independence, exposed in atomic tests at 

 Bikini Atoll in 1946 and sunk by the U.S. 

 Navy in 1951 at an unspecified location off 

 the California coast, possibly in the gulf. 



Since at least 1959, some sediment 

 dredged from San Francisco Bay and from 

 the sandbar outside the entrance to the bay 

 (the Golden Gate Bar) has been dumped onto 

 the Continental Shelf in the gulf. Much of 

 this material is from dredging to maintain 

 shipping channels into and within the bay, 

 but some is from other engineering projects. 



Until 1970, ocean disposal of both radio- 

 active and nonradioactive waste was accept- 

 able under government policy. That year, the 

 United States terminated all ocean disposal 

 of radioactive waste materials. In 1972, Con- 

 gress passed the Ocean Dumping Act, which 

 regulates the dumping of wastes into ocean 



waters. A global ban on the dumping of radio- 

 active waste in the oceans took effect in 1983. 



The Environmental Protection Agency 

 (EPA) is currently responsible for desig- 

 nating ocean disposal sites for the United 

 States. The U.S. Army Corps of Engineers 

 (USAGE), with EPA's concurrence, issues 

 permits for ocean disposal of dredged mate- 

 rial at designated sites. Only sediments eval- 

 uated as "clean" (non-toxic) by EPA stan- 

 dards may be disposed of in the marine 

 environment. 



San Francisco Bay's 85 miles of navi- 

 gable waterways require annual maintenance 

 dredging. The bay's average depth is about 

 19 feet, but oil tankers and container vessels 

 need from 40 to 60 feet of water for safe 

 transit. Environmental concerns and limited 

 disposal capacity for dredged material in 

 the bay have made it necessary to find suit- 

 able dumping sites in the ocean beyond the 

 Golden Gate. 



A new approach for the management of 

 dredging and disposal of dredged material 

 for San Francisco Bay was coordinated 

 under a regional effort begun in 1990 as 

 a Federal-State partnership of four agencies 

 and later joined by about 30 other public 

 and private organizations. This effort was 

 formally called the Long Term Management 

 Strategy (LTMS) for the San Francisco Bay 



region. The primary task of the LTMS was 

 to develop a long-range plan for meeting the 

 bay region's need to dispose of an estimated 

 300 million cubic yards of dredged material 

 over the next 50 years. The EPA, a leading 

 Federal agency in this effort, had the respon- 

 sibility for selecting a location for an ocean 

 disposal site for dredged material. 



In 1990, the U.S. Geological Survey 

 (USGS) was asked by EPA, USAGE, and 

 the Navy to investigate four study areas for 

 locating potential disposal sites for dredged 

 material in the Gulf of the Farallones. This 

 survey also tested the feasibility of using sid- 

 escan sonar to locate the radioactive-waste 

 containers in the gulf (see chapter on Search 

 for Containers of Radioactive Waste on the 

 Sea Floor). 



Each of the four study areas was evalu- 

 ated by the USGS for the presence of deposi- 

 tion and erosion, sediment transport path- 

 ways, and the likely effect deposited dredged 

 material might have on the stability of the sea 

 floor (see earlier chapters). 



Using the results of the USGS studies, 

 EPA in 1994 designated the San Francisco 

 Deep-Ocean Disposal Site. This site is 

 55 miles beyond the Golden Gate and 5 

 miles outside of the Gulf of the Farallones 

 National Marine Sanctuary in 8,200 to 9,800 

 feet of water. 



62 Issues of Environmental Management in the Gulf of the Farallones 



