Environmental surveys of open-ocean dredge material disposal sites

Two 100-fathom open ocean disposal sites were monitored to assess the impact of the dumping of dredged materials upon the marine environment. One site was located 35 miles from San Francisco, CA near the Farallon Islands and the other 7.7 miles from San Diego, CA. Water quality and sediment parameters were measured and photographic surveys of the bottom were made with the Naval Undersea Center´s remote-controlled research vehicle CURV III. The objectives of the Farallon site survey were to obtain qualitative descriptions of the physical, chemical and biological environment of the area and of the general release pattern of dredged material. Although the material was deposited unevenly over the deposition area, most fell directly below the path of the hoppers. The purpose of the San Diego site survey was to monitor a previously unused dump site before, during and after dumping. Results of the pre-dump survey showed the physical-chemical con- ditions of the area to be comparable to other near-shore areas of Southern California.