344
K. Takao . B.T. Bower
Table 18.7. Equations comprising the water quality model
Upper COD
=_ac,u,h,_aC,v,h,
C ~[Kh ac,] ~[Kh aC']_KC aDh-kCh I
o
ax
ay +w'+ ax "ax +ay "ay ,,+,
, +~
Lower COD
Lower DIN
where subscripts 1 and 2 indicate upper and lower layers respectively, and the asterisk* indicates
either layer depending on direction of flow; C, 0 = COD and DIN respectively; h = depth; u, v, W = flow
velocity; K = horizontal dispersion coefficient; Kz = vertical dispersion coefficient; K, = sedimentation
velocity; a= rate of promary production; k= rate of decomposition; fO= nitrogen consumption for
COD assimilation; fp = nitrogen release with COD decomposition; Be, Bo = rate of COD and DIN release,
respectively; and Le, Lo = external loads of COD and DIN, respectively.
using data for the 1978-82 period for summer and winter conditions. The resulting model was then used to analyze different cases under different scenario/policy
combinations.
18.3.5
Estimating Costs
Two categories of costs had to be estimated, i.e., liquid waste disposal costs for LW
policies and water-oriented recreation costs for R policies. All costs were estimated
in terms of 1980 yen.
With respect to the liquid waste disposal costs at Sewage Treatment Plants (STPs),
capital costs and operation/maintenance costs were estimated from the cost functions in the "1984 Sewerage System Planning Guide" of the Ministry of Construction, applicable to secondary wastewater treatment plants, and data from Konan
Chubu Sewage Treatment Facility in Shiga Prefecture, applicable for additional treatment with nitrogen removal processes. Because the government has adopted the
requirement that all municipal STPs install secondary treatment, the costs attributable to the LW policy variable consist of costs of increased capacity for secondary treatment beyond the base case and the incremental costs beyond secondary
treatment.
With respect to the costs of liquid waste disposal from industrial activities, reduction of discharges was assumed to be by treatment using the activated sludge
K. Takao . B.T. Bower
Table 18.7. Equations comprising the water quality model
Upper COD
=_ac,u,h,_aC,v,h,
C ~[Kh ac,] ~[Kh aC']_KC aDh-kCh I
o
ax
ay +w'+ ax "ax +ay "ay ,,+,
, +~
Lower COD
Lower DIN
where subscripts 1 and 2 indicate upper and lower layers respectively, and the asterisk* indicates
either layer depending on direction of flow; C, 0 = COD and DIN respectively; h = depth; u, v, W = flow
velocity; K = horizontal dispersion coefficient; Kz = vertical dispersion coefficient; K, = sedimentation
velocity; a= rate of promary production; k= rate of decomposition; fO= nitrogen consumption for
COD assimilation; fp = nitrogen release with COD decomposition; Be, Bo = rate of COD and DIN release,
respectively; and Le, Lo = external loads of COD and DIN, respectively.
using data for the 1978-82 period for summer and winter conditions. The resulting model was then used to analyze different cases under different scenario/policy
combinations.
18.3.5
Estimating Costs
Two categories of costs had to be estimated, i.e., liquid waste disposal costs for LW
policies and water-oriented recreation costs for R policies. All costs were estimated
in terms of 1980 yen.
With respect to the liquid waste disposal costs at Sewage Treatment Plants (STPs),
capital costs and operation/maintenance costs were estimated from the cost functions in the "1984 Sewerage System Planning Guide" of the Ministry of Construction, applicable to secondary wastewater treatment plants, and data from Konan
Chubu Sewage Treatment Facility in Shiga Prefecture, applicable for additional treatment with nitrogen removal processes. Because the government has adopted the
requirement that all municipal STPs install secondary treatment, the costs attributable to the LW policy variable consist of costs of increased capacity for secondary treatment beyond the base case and the incremental costs beyond secondary
treatment.
With respect to the costs of liquid waste disposal from industrial activities, reduction of discharges was assumed to be by treatment using the activated sludge