typically use up to 75,000 m . If, tiowever, airstrips and roads are associ- 

 ated with ttiese sites, quantities can increase to several hundred thousand 

 cubic meters. Based on experience constructing the Yukon River to Prudhoe 

 Bay Haul Road (Haul Road), approximately 31,000 m of gravel are required 

 per kilometer of road construction, and maintenance requirements average 

 about 700 m per kilometer (km) per year for about the first 5 years (Alson 

 personal communication). Alyeska Pipeline Service Company requested about 

 1.5 million m of gravel for maintenance of their project over a 5 year 

 period. The figures presented above for the large pipeline projects repre- 

 sent gravel needs from both upland and floodplain sites. About half of the 

 gravel used on the oil pipeline was from floodplains. 



Alluvial deposits found in broad floodplains offer one of the prime 

 sources of gravel in northern areas. Individual material sites vary consider- 

 ably in size, as indicated by the range of those considered for study in 

 this project: 7,738 to 631,000 m of material removed. Several different 

 sites may be necessary to supply material meeting the required project 

 specifications because one site may not contain all types of material 

 needed. For example, not al I potential sites wi I I have material suitable for 

 topping. Also, since road and pipeline construction projects need materials 

 throughout their lengths, one site or a series of sites in one area will 

 not satisfy the demands of these projects. A haul distance of 6.5 km or 

 less has been estimated to be economically efficient for construction in 

 Alaska, and haul distances of 13 to 16 km or less are planned for mainten- 

 ance of the Trans-Alaska Pipeline System (Alson personal communication). 

 Therefore, material sites for these types of projects necessarily must be 

 located at regular intervals due to economic considerations. 



To protect an environment from unacceptable disturbance, the elements 

 comprising the environment must be known, the various elements of the pro- 

 posed activity must be known, and the effects of the activity on the environ- 

 mental elements separately and as a whole must be known. Where this infor- 

 mation is available, guidelines to conduct the proposed activity with a 

 minimum of environmental perturbation can be developed. Where information on 

 one or more of these elements is lacking or is only partly understood, any 



