containers for storage of chemicals. Installation and operation of 

 this equipment requires activities similar to those of wellsite 

 preparation, only on a smaller scale. At dredged location sites the 

 equipment is typically mounted on pile-foundation platforms or 

 barges. Construction of platforms requires a small amount of pile 

 driving and traffic. The extent of the activities depends on the 

 amount and permanence of equipment. All materials are transported 

 by boat or barge. A special slip may be dredged if equipment is to 

 be mounted on a barge. At wellheads on leveed or boarded pads, the 

 placement and operation of equipment is merely an extension of 

 activities necessary for wellsite preparation. Clearing, leveeing, 

 and/or boarding of an additional area is usually not necessary. If 

 it is required, the area involved is quite small. Materials are 

 transported by trucks over the existing roads. 



Flowlines connect wellsite equipment with the centralized production 

 site, which is typically located on more firm soils (upland areas if 

 they are relatively close). If the centralized production facility 

 must be located in the salt marsh, it may be placed on a pile- 

 foundation platform, barges, a leveed site, or a combination of 

 these. The equipment located at this centralized facility usually 

 includes brine treatment apparatus, skimmers, heater-treaters, 

 dehydrators, other separators, chemical tanks, filters, pumps, 

 compressors, and large storage tanks. The area occupied by these 

 units is typically less than 0.4 ha (1 acre). Construction activi- 

 ties vary with the location and are similar to those for site prepa- 

 ration (discussed in an earlier phase of this section). 



Once production has commenced, periodic checking and adjusting 

 occurs to control flows, changes in quality and quantity of products, 

 and transfer of the products to large transportation pipelines. 

 Equipment is maintained and replaced as it deteriorates; corrosion 

 is exacerbated by the climatic conditions of the salt marsh. Vegeta- 

 tion around production facilities may be controlled by cutting, 

 herbicides, or other means. As production continues through the 

 years, additional equipment for treatment becomes necessary due to 

 the increased amount of water mixed with the oil and gas. 



2. Primary ecological alterations 



2.1 Trampling and crushing of vegetation 



2.2 Temporary and permanent displacement of consumers 



2.3 Loss of vegetation and consumers in centralized production 

 facility (0.4 ha, 1 acre) 



197 



