sites are maintained to control corrosion. Grounds are maintained by mowing 

 or herbicides. Pipeline rights-of-way are maintained so that shrubs and woody 

 vegetation with roots that might damage underground equipment are controlled. 

 Also, keeping the right-of-way cleared allows efficient monitoring of the 

 pipeline by aerial inspection. 



Cathode stations are checked periodically. After a few years' use, new 

 anodes or additional scrap material may be required to ensure protection from 

 electrolysis. 



Major leaks in pipelines trigger the block valves and stop flow in the 

 pipeline. Thus, only a small portion of the material in the pipe can leak 

 out. Smaller leaks may be detected as noted above. When a leak is detected, 

 immediate steps are taken to repair the faulty area. The steps are similar to 

 those taken when leaks are discovered during testing. However, special precau- 

 tions are required to guard against explosion or fire during the repair phase. 



OIL AND GAS 



ACTIVITIES ON WILDLIFE REFUGES 



The following is an overview of the history, intensity, and scope of oil 

 and gas activities on the Aransas, Brazoria, Delta, Sabine, and San Bernard 

 NWR. 



Aransas National Wildlife Refuge 



The Aransas NWR was purchased in 1937. Previous to the acquisition by 

 the U.S. Department of Agriculture, most of the minerals had been leased to 

 the Continental Oil Company. The first well was drilled in 1940, and well 

 number 64 was completed during the spring of 1977. Because of the reservation 

 of minerals at the time of purchase, the managing agencies have not required 

 permits for activities specifically excluded from their control by the sale 

 agreement and legal precedent. Management of oil and gas activities has been 

 through cooperation and communication between the refuge and the company. In 

 most instances, the company has refrained from major activities during the 

 periods when whooping cranes have been on the refuge. 



Preexploration. The refuge has undergone a significant amount of seismic 

 activity. Most of the activity has been in the upland area, though there have 

 been shot lines in the peripheral marsh and in the bays nearby. On the uplands, 

 several different seismic methods have been used. Explosive methods have been 

 common, though vibroesis and truck-mounted thumpers have been used recently. 

 Since much of the refuge is live-oak brush, some clearing has been necessary. 

 Continental has been the main exploration company on the refuge. Consequently, 

 seismic work has been essentially limited to that required by the company. 



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