Effects : Pipe burial operations have the potential for many 

 ecological effects, including release of toxic matter from the sediments; 

 increased turbidity and oxygen demand; and direct destruction of valuable 

 habitat. 



Environmental effects may be reduced by employing special construction 

 and restoration techniques and by installing the most environmentally 

 sensitive segments of the pipeline during periods of least vulnerability, 

 avoiding spawning periods, rainy seasons, and spring blooms. The follow- 

 ing construction techniques should be used: 



1. Utilize the "double ditch" method in excavating trench spoil 

 where the first six to twelve inches of soil with the vegetative 

 root systems is stockpiled separately for replacement on the 

 surface of the backfilled trench. 



2. Backfill excavated trench materials from wetlands as soon as 

 possible to minimize oxidation and releases of toxic chemicals 

 into adjacent waterways or habitats. 



3. Utilize clean, upland fill to supplement backfill material of 

 trenches; fill to be at the same elevation as surrounding area 

 to protect freshwater drainage patterns. 



4. Do not deposit pipeline spoil materials in vital areas, such as 

 wetlands, barrier beaches and estuaries. Provide frequent 

 openings in trench spoil to prevent disruption to water 

 circulation patterns of the area. 



5. Utilize bulkheads (dams) in open trenches at each natural water 

 crossing to maintain existing parameters of salinity, to retain 

 salt/freshwater interfaces, to prevent saltwater intrusion and to 

 restrict boat traffic which leads to erosion. 



6. Confine heavy equipment operations to the area of construction 

 and excavate only the area sufficient for pipeline operations. 

 In coastal areas conduct construction activities from existing 

 roads and causeways to avoid dredging canals for building 

 purposes. 



7. Utilize existing service roads and the pipeline corridors for 

 access to protect previously undisturbed areas. If necessary, 

 all roadways should be improved with strengthened shoulders and 

 proper-sized culverts to insure unrestricted water exchanges. 



In the course of laying a pipeline through marshland, open water may 

 be traversed. The crossing of small water bodies or rivers has always 

 presented environmental problems of excess siltation and sedimentation of 

 the water body or downstream areas. Silts can be carried by currents 



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