220 Alaskan Science Conference 



and at points where the quantity and temperature of ground 

 water exhibit a heat of fusion sufficient to prevent freezing of 

 the earth. 



The areal extent of permafrost is equal to about one fifth of 

 the land surface of the world. About 60 percent of the land 

 surface of Alaska is underlaid with permafrost. Climatological 

 data presented in Table 1 are characteristic of the low tempera- 

 ture areas discussed in this paper. 



Low temperatures and permafrost present many obstacles to 

 providing a community water supply and distribution system 

 of the type common in continental United States. These ob- 

 stacles are grouped and discussed as follows: 



1. Location of continuous and adequate water sources capable of 

 supplying the demands of industry and communities. 



2. Production of water which is palatable and free from contam- 

 ination. 



3. Continuous distribution of water under pressure. 



4. Construction of stable structures in permanently frozen ground 

 and use of methods, materials and equipment which are suited 

 to use under low temperature conditions. 



5. Development of low temperature area water supply methods 

 which are safe and practical. 



Locating a Community Water Supply in Permafrost 



Melted snow and ice, surface water, rain water, water from 

 the shallow strata of the ground and ground water from deep 

 wells have all been considered as sources of water in the low 

 temperature regions. Examples of all of these sources may be 

 found in the Arctic, but melted ice and snow are by far the most 

 common sources. 



Numberless small lakes and ponds exist throughout the 

 tundra portions of the permafrost regions. The Eskimo depends 

 largely on water dipped from these sources during the warmest 

 months of the year. In the fall he cuts ice from these sources 

 and stores it for his use during the long winter. Ice is either 

 stored in a permafrost cellar or stacked on the ground at a con- 

 venient location. 



