Consumers further along the food chain may increase or decrease 

 depending upon the sorts of consumer species available for food. 

 Turbidity that results from chronic erosion decreases the suitabil 

 ity of the standing water as habitat for phytoplankton, aquatic 

 invertebrates, and fishes. 



Disturbance factors should be recognized as an important considera- 

 tion because they extend the effects of the project beyond the 

 boundaries of the immediate site. 



Key attribute alterations 



Key attribute alterations induced by this phase of oil and gas 

 operations involve changes in land elevations. Depressions (canals 

 and marsh buggy tracks) may increase the frequency and area of 

 inundation by salt water. First-order effects include removal of 

 vegetation and creation of a standing-water habitat. If the salt 

 water is not confined by spoil and/or natural topographic features, 

 much larger areas of marsh may be affected. Long-term changes in 

 vegetation and consumer groups would occur. Long-term turbidity 

 increases would also result. 



Canal construction requires spoil placement; in salt marshes this 

 usually results in higher land elevations. Burial of flora is less 

 significant than possible alterations of waterflow regimes. Poorly 

 planned placement of spoil may result in blockage of existing tidal 

 inundation and/or runoff patterns. These blockages will lead to 

 longstanding changes in types and/or amounts of vegetative cover, 

 followed by appropriate changes in consumers. 



Placement and operation of production facilities. 

 1. Activity sequence 



The conversion of a newly drilled well to production status involves 

 the placement of a small amount of equipment at the wellsite. In 

 addition, brine-disposal lines and flowlines are necessary to trans- 

 port the products to a centralized production facility, where numer- 

 ous pieces of equipment handle the products of all wells in the 

 area. The installation and maintenance of lines was discussed in 

 the preceding section. 



Production equipment necessary at the wellhead varies with the type, 

 quality, and quantity of products. Some sort of pump is usually 

 required, especially as an oil well ages. Other units which may be 

 necessary include knockout tanks, heater-treaters, dehydrators, and 



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