are given for many states in sources such as Terry ,24 Struzeski 25 Field ,26 Highway 

 Research Board?^ Hanes?^ and Hawkins?^ Unfortunately, most of these sources 

 focus on state highway departments and similar large agencies while giving little, 

 attention to how much road deicing salt is used by county and municipal agencies. 

 Terry SOjoes indicate that in 1969, road salt use by 25 Greater Boston 

 communities was about 47,000 tons. 



New Hampshire was an early user of road deicing salt, and on a highway 

 mileage basis it has also been a fairly heavy user. By 1966-1967 estimated 

 curriulated use was 2,300,000 tons.^^ In the early to mid 1960's, the annual use 

 on state highways was about 85,000 tons, but in the later 1960's and early 

 1970's the figure was 150,000 tons. Then both by decision and by benefit of a 

 mild winter or two the figure has dropped to 100,000 tons of salt in recent 

 years. Based on limited data the present author estimates that towns and cities 

 probably use at least 33,000 tons of sodium chloride per year. 



Miscellaneous 



One possible source of chloride already alluded to is saline water intrusion 

 due to pumpage of ground water or similar activities by man. This is most 

 commonly thought of as occurring near the ocean, but it can occur any place 

 where saline water bodies are present. High chloride values due to this are Ukely 

 to be fairly localized. In New Hampshire, intrusion is occurring around Great 

 Bay and the nearby Atlantic Ocean, and, although important locally, it is of 

 minor importance regionally. 



The fairly common assumption that dissolved natural chlorine gas or chlorine 

 gas used in water treatment or other processes can be a source of chloride is not 

 correct. Without going into detail, the oxidation state of chlorine is so high that 

 dissociation to chloride is not likely under ordinary conditions at the earth's 

 surface ;^^ hence, chlorine is not a likely source of chloride in natural waters. 



^^STRUZESKI 18-19. 



2'^TERRY. 



^^STRUZESKI. 



^^FIELD. 



2'^ ENVIRONMENTAL DEGRADATION BY DE-ICING CHEMICAL AND EFFECTIVE 

 COUNTER-MEASURES (Highway Research Board Record 425, 1973). 



2^R. E. HANES, L. W. ZE1.AZNY, & R. E. BLASER, EFFECTS OF DEICING SALTS ON 

 WATER QUALITY AND BIOTA-LITERATURE REVIEW AND RECOMMENDED 

 RESEARCH (Highway Research Board, National Cooperative Highway Research 

 Program Report 91, 1970). 



^^PROCEEDINGS STREET SALTING - URBAN WATER QUALITY WORKSHOP AT 

 STATE UNIVERSITY COLLEGE OF FORESTRY, SYRACUSE UNIVERSITY (R. H. 

 Hawkins ed., 1971). 



^^ TERRY 81. 



^^TRUZESKI 18. 



^^HEM 170-171. 



