Water softeners that are charged with sodium chloride may also be a source of 

 chloride particularly in areas of hard water. This is not much of a problem in 

 New Hampshire, but in places where the water is hard a chloride increase of 

 perhaps 100 mg/£. has been suggested. This could be as much as 25 pounds per 

 capita per year in addition to the 20 pounds given above. 



Industrial Effluents 



The widespread variations in the location and concentration of industries 

 such as chemical plants or oil refineries where effluents may be high in chloride 

 makes difficult any form of generalizations as to assignment of rule-of-thumb 

 values. For example, Lakes Huron, Michigan, and Ontario receive several million 

 tons per year from chemical plants and similar industries. 20 New Hampshire 

 appears to have no area where really high concentrations of chloride can be 

 attributed to industries although there are individual point sources. So the 

 combined 20 pounds per capita per year figure is assumed adequate to include 

 all industries on a state-wide basis. 



Road Deicing Salt 



The increasing use of sodium chloride and calcium chloride as road deicing 

 salt has caused serious concern as evidence accumulates for its contamination of 

 water, corrosion of automobiles, and vegetational kills.^^^^The major usage has 

 been since the mid 1940's with sodium chloride being by far the more heavily 

 used compound. However, both chloride salts were used earlier for deicing on 

 roads, and calcium chloride has also been used to hold down dust. Direct 

 contamination of ground and surface waters has occurred due to inadequately 

 designed and maintained storage piles of salt. 



The amount of road salt applied is a function of both climate and philosophy 

 on "bare" highways. State highway departments in the eastern and northeastern 

 United States use between 20 and 40 tons of salt per lane mile per year with 

 most states using 30 tons or less.^^ States in the southern and western parts of 

 the United States use only minor amounts or no road deicing salt. Specific data 



^^E. J. STRUZESKl, JR., ENVIRONMENTAL IMPACT OF HIGHWAY DEICING 47 

 (U.S. Environmental Protection Agency, Water Pollution Control Research Series, 11040 

 GKK 06/71, 1971). (hereinafter cited as STRUZESKl). 



^^O'Conner & Mueller, A water quality model of chlorides in Great Lakes, Proceeding, 

 American Society of Civil Engineers 96, No. SA4, 95 5-975, 1970. 



21 R. FIELD, E. J. STRUZESKl, JR., H.E.M. MASTERS, & A. N. TAFURI, WATER 

 POLLUTION AND ASSOCIATED EFFECTS FROM STREET SALTING 34 (U.S. 

 Environmental Protection Agency, National Environmental Research Center, EPA 

 R2-73-257, 1973). (hereinafter cited as FIELD). 



22 R. c. TERRY, JR., ROAD SALT, DRINKING WATER, AND SAFETY - IMPROVING 

 PUBLIC POLICY AND PRACTICES 64-65 (1974). (hereinafter cited as TERRY). 



