Line depth below surface. 



B-91 The top of the pipeline shall be placed not less than 0.9 m 

 (3 ft) below the present surface of the land. 



B-92 The top of the pipeline shall be placed not less than 2.4 m 

 8 ft) below the bottom of existing canals and waterways for a 

 distance of 15.2 m (50 ft) on each side of said canals and 

 waterways. 



Line placement. 



B-24P To the greatest extent possible, installation of all flowlines, 

 supply lines, and utility lines shall be confined to existing 

 leveed roads or dredged canal rights-of-way. 



B-25P If flowlines must be placed through marsh, they should be laid 

 directly on the marsh surface and allowed to sink and settle 

 naturally. They should not be buried since vehicle movement as 

 well as digging and backfilling would result in further channel- 

 ization and marsh alterations. 



Backfilling. 



B-97M All pipeline ditches shall be completely backfilled with all 



available spoil removed during excavation operations, such that 

 final surface contours approach original site conditions as 

 nearly as possible. In the event additional fill material is 

 required to compensate for settlement, it shall be removed from 

 scattered deep holes within the easement, rather than from con- 

 tinual surface cuts. 



Plugs along banks for pipeline ditches. 



B-lOO Where the right-of-way intercepts existing tidal drains (guts, 



ditches, creeks, etc.) that in the opinion of the refuge manager 

 present a significant potential for causing erosion, the pipe- 

 line ditches shall be backfilled to an elevation of 0.6 m (2 ft) 

 above the marsh surface for a distance of 6.2 m (20 ft) on either 

 side of the intercepted drain. 



B-101 All canal crossings by pipelines are to be adequately protected 

 by bulkheaded construction. (Wakefield piling bulkheads are 

 usually required. ) 



357 



