problems of relatively minor fish and wildlife concern, but may be 

 of significant concern to human health unless storage tanks are 

 equipped with efficient vapor recovery systems. 



Subproject: Navigational Improvement (SP-1) 



Disturbing Activities: Dredging; spoil deposit 



Dredging may be required in existing harbors to meet the water depth 

 renuirements of the expected marine terminal vessel traffic. The size of 

 the vessels will vary depending on the projected volume of oil or gas to 

 be handled, and the available depth of water. Vessels of 120,000 and 

 250,000 dead weight tons (DWT) typically require water depths of 60 feet 

 and 80 feet, respectively [9]. A 500,000 DWT supertanker would need 105 

 feet of water (note that these depths are minimums). During the 

 construction phases of the terminal much barge traffic can be expected in 

 order to deliver steel sheets for storage tank fabrication, and other 

 materials. 



A new shoreside marine terminal system may require extensive channel, 

 berthing, and turning basin dredging, as well as maintenance dredging, to 

 the depth necessary to accommodate the vessels. Therefore, nearshore 

 terminals are often preferred, since they reduce dredging requirements and 

 subsequent alterations to shoreline systems. 



A nearshore terminal often is located in relatively deep water. When 

 such a pier is located in an area sheltered from the prevailing wind, 

 waves, and currents, and in sufficiently deep water, navigational dredging 

 requirements may be minimal, or even unnecessary. Furthermore, this 

 alternative greatly reduces the need for costly, environmentally harmful 

 maintenance dredging necessary for shoreside marine terminals located in 

 existing harbors. 



Subproject: Piers (SP-2) 



Disturbing Activity: Installation 



Shore terminals are of conventional design. Nearshore terminals are 

 connected to shore by a causeway, trestle, or submarine pipeline. Tanker 

 characteristics such as length or maneuvering capabilities determine 

 terminal dimensions. The components of the terminal may include: a load- 

 ing platform, breasting dolphins, mooring dolphins, loading arms, a 

 walkway, and a fire protection system. 



Breasting and mooring dolphins are normally pile supported structures 

 with concrete decks. Mooring dolphins, designed to hold a ship's lines 

 securely, may range from 30 by 30 feet to 70 by 70 feet [9]. Breasting 

 dolphins also are equipped with mooring lines and typically measure 40 by 

 40 feet (see Figure 3). 



30 



