EFFUSIONS AND THEIR DISTRIBUTION 



Periodically, the desalination plant produced a second type of 

 discharge; low in temperature and salinity but high in copper, 

 nickel, and iron. During most of the study copper discharge was 

 high; amounting to between 50 to 100 pounds (22.7 to 45.4 kg) lost 

 per day. When the plant shut down for maintenance the corroded 

 copper-nickel surfaces dried and oxidized. When resumption of 

 activities began, the loosened copper powder and scale was washed into 

 the sump with the first water circulated through the system. 



For the first few hours of operation, when the plant was building up 

 vacuum and heating brine, there was little concentration of the well 

 water and the discharge was, consequently, close to normal seawater 

 in salinity and temperature. Copper contamination, however, was two 

 to three times higher than 'normal' and the discharge was turbid and 

 black. Because the salinity and temperature were close to ambient 

 levels, the turbid, copper-laden effusions mixed well with ambient 

 water and did not sink. Consequently, the shallower areas of the 

 harbor and surrounding flats were inundated by copper effusions each 

 time the plant started up. 



The dispersion of effusions varied with wind currents and tidal movements. 

 They maintained their turbid characteristics for some distance from the 

 plant and could be visually identified by the black water extended 

 from the inner harbor to the Thalassia flats west of the turning basin. 



GENERAL BIOLOGICAL IMPACT OF THE EFFLUENT AND EFFUSIONS 



The fauna and flora of Safe Harbor were adversely affected by the 

 effluent from the desalination plant. Some species of animals were 

 prolific in the harbor, however, including foraminifera, serpulid and 

 sabellid annelid worms, and barnacles. Other organisms, such as fish, 

 were abundant in the canal but were continuously recruited from 

 adjacent areas and could also avoid the periodic, turbid effusions. 



All of the biological experiments showed the effluent had a pronounced 

 impact on the biological system within Safe Harbor. Even the organisms 

 which were more abundant at Safe Harbor stations than at control 

 stations were adversely affected in the immediate vicinity of the discharge. 



A variety of organisms vanished from the harbor during the course of 

 the fifteen months of field work. Sea squirts (Ascidia nigra), various 

 species of algae, bryozoans, and sabellid worms were excluded during at 

 least a portion of the study. Dead shells of various clams and oysters 

 were abundant in the harbor, many of them still attached to the coral 

 rock canal walls. Live specimens were relatively common when the pre- 

 liminary survey was conducted in 1968 and 1969 (Clarke et at 1970) but 



