Industrial Wastewater Coefficients (SIC)
And Water Management
RAE ZIMMERMAN, Assistant Chief
Technical Branch, Enforcement Division
U.S. Environmental Protection Agency
Region II Office
New York, New York
INTRODUCTION
In order to achieve a comprehensive approach to water resource management, land use
planning and water resource management must be coordinated, by evaluating sources of
water pollution and levels of water quality in the same context. An important component is
the determination of the magnitude and spatial distribution of industrial waste generation.
Since a consistent and comprehensive body of data on industrial waste discharges is
generally lacking (1), a more theoretical approaches called for. One method is to construct
industrial waste coefficients expressed in terms of industrial wastes discharged per unit of
production. This paper presents a method of constructing such coefficients for waste
generation before wastewater treatment, as well as presenting a state-of-the-art review of
these coefficients for over forty industries defined at the four digit SIC level. Waste
parameters estimated include volume of wastewater discharged, biological oxygen demand,
chemical oxygen demand, solids, grease, metals and other parameters specific to only a few
industries. These coefficients are based upon literature studies and the field experience of
governmental and private" organizations. The accuracy of the values obtained is evaluated
by comparing them to recent data obtained through the Federal Refuse Act Permit
Program (RAPP). Since the passage of the 1972 Amendments to the Federal Water
Pollution Control Act, the RAPP program has been incorporated into the National
Pollutant Discharge Elimination System (NPDES). Since the trend in legislation
and policy is towards limiting industrial discharges, a conceptual model adapting industrial waste generation coefficients to take into account various waste reductions
options is also presented.
GENERAL CONSIDERATIONS
Estimates of industrial wastewater generation usually only occur in a few inventories
limited in scope by political jurisdiction (2) and in pilot plant studies for the purpose of
establishing design criteria for the construction of wastewater treatment facilities and
determining the unit costs of various treatment methods. Except where industrial waste-
load averages are cited in textbooks (3, 4, 5, 6, 7, and 8) in a few theoretical studies, there
has been little attempt to make systematic across-the-board comparisons of empirical
findings. In those cases in which systematic comparisons have been made, wasteloadings
are expressed in a variety of forms, that are often not comparable. These forms include
concentrations, unitless indices (9), population equivalents (10), wasteload per employee
(11), per day, per unit of output or production (12, 13,14), or per unit of raw material consumed. Since most of these studies emphasize methodology, they often limit wasteload
averages to only one or two parameters or cover only a few industrial categories.
The coefficients presented in Tables II, III, and IV cover forty-one 4-digit industrial
categories that are located in two digit SIC categories that accounted for almost ninety-two
percent of all the wastewater discharged nationally by manufacturing establishments in
1967 (See Table I). The contribution of the four digit categories cited here is, of course,
somewhat less than this, but still significantly large. The industries chosen are also major
contributors of BOD and suspended solids (15). The volume of water discharged criteria, as
well as the noxiousness of wastes discharged and the availability of data, dictated the choice
of industries cited in Tables II and III.
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