types and community structure within, and sometimes adjacent to, the 

 pipeline corridor, leading to subsequent changes in consumer species 

 composition and population levels; and (3) the creation of gaps or weak 

 spots in the levees which may subsequently alter the existing hydrologic 

 regime in adjacent marsh systems. 



Placement and operation of production facilities . 



1. Activity sequence 



With the exception of the delta marsh system, where large natural levees 

 are common, production facilities are not normally located on levees. 

 Production facilities noted in the delta marsh did include some indivi- 

 dual separator units as well as an entire production complex situated on 

 a natural levee. The complex utilized the levee's entire width (50 m, or 

 165 ft) and approximately 100 m (330 ft) of its length. The complex was 

 relatively compact in order to fit in the limited area. 



Placement of gathering flowlines from the well to the treatment facility 

 requires activities as described for the installation and maintenance of 

 lines; these include line survey, limited vegetation clearing, line 

 installation and burial, and necessary site restoration. Construction of 

 a processing complex and pipeline pumping stations follows the same basic 

 activity sequence as that described for wellsite preparation, except that 

 the placement of treatment, pumping, and storage facilities follows pro- 

 duction foundation completion. Foundations are dug and concrete is poured 

 to anchor or support structures and equipment. Brine disposal lines are 

 installed to the disposal well, although brine-storage pits may occasion- 

 ally be dug, if necessary. Routine operation, maintenance, and repair of 

 treatment, pumping, and storage equipment are conducted within the con- 

 fines of the site. Processing wastes are stored within the complex area, 

 disposed of via flowlines, or transported off site immediately. Typical 

 areal extent of a production facility is approximately 0.4 ha (1 acre). 



2. Primary ecological alterations 



2.1 Creation of an unvegetated production or pumping station site typ- 

 ically 0.4 ha (1 acre) or less in area 



2.2 Remioval of consumer groups within the facility site 



2.3 Loss of soil structure due to movement of heavy machinery and con- 

 struction activities 



308 



