and used elsewhere; most (supply lines, flowlines, pilings, super- 

 structure) have usually deteriorated to the extent that they are 

 removed and sold for scrap. Additional trucks, marsh buggies, or 

 barges are necessary for this disassembly and removal. 



The remaining major activity of site restoration consists of return- 

 ing land elevations to prior levels. Basically similar situations 

 exist at marine and road-access locations: depressions (canals, 

 borrow pits/ditches) may or may not be plugged or filled; protrusions 

 (dikes, spoil levees/piles) may or may not be leveled. These activ- 

 ities, if performed, require the major earth-moving equipment listed 

 in the sections that discuss access to site and site preparation. 

 It is unusual for petroleum companies to fill access canals. The 

 canals are used as long as the field is active or the well is produc- 

 tive. During this long period canal banks erode and old spoil 

 compacts and subsides. Thus there is not enough fill from old spoil 

 to refill the canal. In most cases large amounts of fill would have 

 to be barged to the site, which would be economically unfeasible. 

 Therefore many canals are simply abandoned, though in places where 

 canal water movement posed problems, canal plugs have sometimes been 

 constructed. 



Accumulated scrap or residue is buried, hauled away, or burned at 

 the site. Revegetation may be attempted if the owner requires or if 

 large areas of newly exposed soils result. 



If an entire field has ceased production, centralized production 

 facilities are removed as well. This operation is a repetition of 

 disassembly and removal activities as previously discussed. 



2. Primary ecological alterations 



2.1 Trampling and crushing of vegetation at wellsite and along 

 supply lines and flowlines 



2.2 Complete removal or burial of plants and consumers during 

 equipment removal and earth-moving operations 



2.3 Planting of vegetation in newly exposed areas 



2.4 Increases in concentrations of suspended sediments and dis- 

 solved nutrients 



2.5 Introduction of toxic materials to the soil and water systems 

 (spilled or buried) 



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