vulnerable to fishing gear or anchors which may rupture the line causing 

 an oil or gas leak. 



Corridor siting is of vital concern to fish and wildlife, because 

 pipeline construction through the habitat, especially in wetlands, may 

 bisect the area. This may create changes in the water circulation 

 patterns, salinity, temperature, or other parameters whose stability is 

 necessary to the survival of various species in the area. 



Design : The high potential for adverse aquatic impacts of the 

 nearshore and landfall location requires that the sponsor exert maximum 

 care in design of the landfall, including provisions for: (1) maintaining 

 the natural shoreline; (2) minimizing dredging; (3) arranging proper 

 disposal of spoil; (4) avoiding wetlands; (5) reducing problems of 

 runoff discharge; (6) backfilling; (7) maintaining tidal exchange; (8) 

 restoring vegetation; and (9) construction and maintenance of bulkheads 

 or pilings at all crossing of natural tidal creeks and rivers. Roadway 

 and maintenance corridors should follow the same precautions. 



Construction : The sponsor must perform the terrestrial construction 

 with the utmost care to protect adjacent aquatic and terrestrial areas. 

 The scheduling of construction must avoid sensitive annual periods of 

 species, including breeding/spawning, rearing of young, etc. Operation 

 of heavy equipment must be performed to protect fragile environments, 

 such as barrier beaches, wetlands, and productive shallow flats. In 

 many cases, especially in landfall areas, mats can reduce the impact of 

 heavy equipment operations and access to construction sites can be 

 accomplished by existing service roads. 



Dredging of pipeline trenches in coastal areas should be done in a 

 manner which will minimize turbidity and sedimentation, such as sediment- 

 screen employment and other techniques. If pipeline trenches are dug 

 through wetlands, excavated material should be replaced in the trench 

 instead of along the sides where it can interrupt water flow and change 

 circulation patterns. In addition, new fill material should be added 

 where necessary to keep the elevation of the trenched area the same as 

 the surrounding wetland. 



Terrestrial crossings require that special care be taken to reduce 

 effects on wildlife and endangered species, their habitats, and the fresh- 

 water system. A major factor is prevention of erosion and sedimentation 

 into local streams and rivers where fish habitats could be adversely af- 

 fected. River crossings can be particularly complicated and can yield un- 

 necessary impacts to downstream areas. Use of the subterranean drilling 

 method virtually eliminates disturbances. As part of the construction, a 

 restoration program should be instituted to revegetate the excavated 

 areas as soon as possible. Temporary stockpiling of dredged material 

 from trench construction should not be on river bottoms or productive 

 riverine habitats. 



98 



