144
6. Water Quality and Pollution
Considerations
resources system as it exists and planning for the expansion of a water
resources system including w
r ater quality. In water pollution control, as in
other areas of public or social investment, there may be important objectives other than strict economic efficiency. In fact in many instances,
social or political factors may be dominant. However, we will be concerned
here with those features that can be quantified. Furthermore, the formulation of the system model will be deterministic rather than stochastic, and,
as expected, the representation of the component subsystems will not be as
detailed as required for the analysis of the operation of an existing system
over a short time period (relative to the planning horizon).
Without the evaluation of water quality control benefits, neither systems
analysis nor comprehensive river basin planning can lead to economic
justification of proposed water quality control measures. An examination of
various sources that have considered the bases for the evaluation of benefits [U.S. Congress, Senate, 1962; Caulfield, 1967; White et al y 1969;
Kalter, et ah, 1969] indicates that four main objectives exist: (1) national
economic efficiency, i.e., how to increase the national income and product;
(2) preserving and improving the national environment for man's use and
enjoyment, which may be referred to as conservation; (3) regional development; (4) intangible benefits related to scientific, historical, and cultural
values. How to quantify these objectives is still a matter for research.
6.2· Concepts Involved in Planning for Water Quality
We need to define a few terms in this section that will be employed in the
formulation of the quality aspect of the model of the water resources system if it is to be compatible with the model in Chapter 2. The major variables of interest in the characterization of water quality are (1) biochemical
oxygen demand, (2) chemical oxygen demand, (3) nutritient materials
other than carbon, (4) temperature, and (5) dissolved oxygen. We shall
ignore temperature effects in what follows.
The biochemical oxygen demand (BOD) is the total oxygen requirement for the oxidation of biodegradable organic material contained in a
waste stream, and is a rough measure of the concentration of the biodegradable waste. Since the constituents corresponding to the BOD consume
dissolved oxygen (DO) in natural streams, the DO is also one of the key
parameters indicating the quality of water. Consequently, the BOD-DO
relationship will be the principal indicator governing the management and
control of stream quality. Chemical oxygen demand (COD) indicates the
6. Water Quality and Pollution
Considerations
resources system as it exists and planning for the expansion of a water
resources system including w
r ater quality. In water pollution control, as in
other areas of public or social investment, there may be important objectives other than strict economic efficiency. In fact in many instances,
social or political factors may be dominant. However, we will be concerned
here with those features that can be quantified. Furthermore, the formulation of the system model will be deterministic rather than stochastic, and,
as expected, the representation of the component subsystems will not be as
detailed as required for the analysis of the operation of an existing system
over a short time period (relative to the planning horizon).
Without the evaluation of water quality control benefits, neither systems
analysis nor comprehensive river basin planning can lead to economic
justification of proposed water quality control measures. An examination of
various sources that have considered the bases for the evaluation of benefits [U.S. Congress, Senate, 1962; Caulfield, 1967; White et al y 1969;
Kalter, et ah, 1969] indicates that four main objectives exist: (1) national
economic efficiency, i.e., how to increase the national income and product;
(2) preserving and improving the national environment for man's use and
enjoyment, which may be referred to as conservation; (3) regional development; (4) intangible benefits related to scientific, historical, and cultural
values. How to quantify these objectives is still a matter for research.
6.2· Concepts Involved in Planning for Water Quality
We need to define a few terms in this section that will be employed in the
formulation of the quality aspect of the model of the water resources system if it is to be compatible with the model in Chapter 2. The major variables of interest in the characterization of water quality are (1) biochemical
oxygen demand, (2) chemical oxygen demand, (3) nutritient materials
other than carbon, (4) temperature, and (5) dissolved oxygen. We shall
ignore temperature effects in what follows.
The biochemical oxygen demand (BOD) is the total oxygen requirement for the oxidation of biodegradable organic material contained in a
waste stream, and is a rough measure of the concentration of the biodegradable waste. Since the constituents corresponding to the BOD consume
dissolved oxygen (DO) in natural streams, the DO is also one of the key
parameters indicating the quality of water. Consequently, the BOD-DO
relationship will be the principal indicator governing the management and
control of stream quality. Chemical oxygen demand (COD) indicates the