PART VII. EFFECT OF RAISING RIVER-QUALITY 



STANDARDS IN CENTRAL AND SOUTHERN AREAS 



TO B-CLASSIFICATION LEVEL 



Improving water quality has been a goal of the people of New Hampshire. 

 During the late 1960's, the recommended use classification and quality standard 

 for the central area of the Ashuelot River were raised from class C to class B (see 

 Appendix D). In this analysis, the southern area was assumed to be reclassified 

 B-class also. 



The two water-quality characteristics important to this study were coliform 

 bacteria and dissolved oxygen. The amount of coliform bacteria permissable in 

 class-C water is not specified, and in class-B water the most probable number per 

 100 milliliters must not exceed 240. Not less than five parts per million of 

 dissolved oxygen must be present in class-C waters. Dissolved oxygen must be 

 present in amounts not less than 75 percent of saturation in class-B water. A 

 major determinant of oxygen content in water is the amount of organic and other 

 material whose decomposition uses oxygen. A measure of the amount of material 

 causing drain on dissolved oxygen is termed biochemical oxygen demand (BOD). 

 This BOD in a way is an inverse measure of oxygen presence. 



In terms of river-water use, the reclassification added bathing to the list of 

 recreational activities and use of water as pubhc water supply. There is a rather 

 dubious line dividing water use for pubhc water supply. Good drinking water is 

 obtainable from low-quality water sources with appropriate treatment.^ Use of 

 class-C water from the river was included as an alternative in the southern area. 

 The central area was assumed to obtain its public water supply from portions of 

 the river that were class B. 



Although coliform bacteria count was not specified for class-C water, coliform 

 bacteria counts used in this study were based on water-quality tests made by the 

 new New Hampshire Water Supply and Pollution Control Commissions, in July 

 1967, at various points along the river. 



7.1 Possibility of Attaining B-Class Status 



With existing industrial and other economic activity, the possibility of attaining 

 the B-class level of quaUty is a topic of concern. For the central and southern 

 areas and including the entire basin, the feasible solutions were not obtained for 

 B-class quality during low-flow months (see Table 7.1). The frequency of such 

 low flows becomes most meaningful. In the 36 years from 1934 to 1969, such 

 low river-flow months occurred only six times. 



At the August median-river flow, the basin taken as a whole could carry the 

 economic activity currently found in the basin, with room for economic expan- 

 sion. When areas were analyzed separately, BOD loadings again exceeded per- 

 missible poundage of BOD. It appears that meeting the B classification at median 

 flow is possible but that coordination of water management among the areas 

 and sectors is essential. River-flow level limited the potential level of economic 

 development but not the classification level. Under the three flow levels used in 

 this study, treatment processes were available for meeting industrial expansion 

 potential if the classification level could be met. 



Kneese, A. V., and Bower, B. T. Managing Water Quality: Economics, Technology, 

 Institutions. Baltimore, The John Hopkins Press, 1968. 



49 



