Table 7.1. Minimum BOD Attainable as Determined by Linear Programming Solution and 

 Allowable BOD Loading of the Ashuelot River for Three Flow Levels and Two 

 River Water-Quality Classifications. 



Constraint on BOD 



Constraint on BOD 



Minimum 



BCC class 



BBB class 



Area 



BOD 



High 



Median 



Low High Median Low 



Pounds BOD 



Northern 3,977 54,025 13,395 4,777 54,025 13,394.8 4,777 



Central 16,694 155,250 32,746 9,216 46,510 9,810 2,760 



Southern 35,520 340,612 112,766 46,432 55,362 18,329 7,547 



Basin 56,080 479,921 158,887 65,422 252,187 83,491 34,378 



^Objective function minimized; data in this column indicate minimum BOD attainable under 

 median river-flow conditions. 



For the basin as a whole, the change in classification did not have as much 

 influence on potential economic activity under median river-flow conditions as 

 did the change in river flow from median to low flow. The imputed price for one 

 pound of biochemical oxygen demand (BOD), at median-flow C-classification was 

 $0.56; at median flow B-classification, $4.15; and for low-flow C-classification, 

 $7.08. 



7.2 Influence of Change in Classification on Cost 



The reclassification of the Ashuelot River to B class obviously would have an 

 effect on cost of providing water supply as well as waste-water treatment. Only a 

 detailed economic engineering study would develop the exact cost of moving 

 from actual conditions now found in the basin to those conditions which result 

 in meeting B classification. Both capital and variable cost must be included, part 

 of which would be borne by state and federal governments. 



The variable cost of operation at the two levels of classification provided 

 interesting insights into relative public and private costs of the two classes. The 

 basic assumption is that current facilities are available for meeting class-C 

 classification under two situations. The first of these assumes optional develop- 

 ment based on optimizing net benefits (REVOWAT) and minimizing public and 

 private cost for providing water supply and waste-water treatment at about the 

 present economic level (SOCCOST). 



The influence on cost, assuming maximized net benefits (REVOWAT), is 

 shown in Table 7.2 for August median- and high-flow levels. At high-river flows, 

 the variable cost would be $25,795 higher for class B than for class C. This is an 

 1 1 percent increase in variable operating costs. The increase is 20 percent at the 

 median-flow level. (Movement from class C to class B with low-flow conditions 

 could not be analyzed because, as previously stated, class B at low flow is 

 infeasible). 



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