PRIORITY POLLUTANT PERSPECTIVES-REGULATORY
ASSESSMENT, ENVIRONMENTAL EVALUATION AND WASTE
TREATMENT
Stacey L. Daniels, Research Specialist
W. Brock Neely, Research Associate
Robert E. Bailey, Senior Research Specialist
Environmental Sciences Research
Dow Chemical USA
Midland, Michigan 48640
INTRODUCTION
The control of toxic and other water-borne pollutants is now approaching new levels of
sophistication and complexity as greater emphasis is being placed by interagency review groups
and criteria/guideline development groups on specific chemical compounds at lower levels of
occurrence.   The many legislative mandates and regulatory actions promulgated in recent
months demand careful and thoughtful integration and implementation to reduce unnecessary
overlap and confusion. Government in all phases must distinguish those enforcement actions
which are reasonable and necessary, and those which demand mid-course corrections or reductions in scope to meet health, environmental, and economical needs.
The regulated community should not blindly accept such regulatory actions at face value as
being scientifically justified in their entirety. It is not simply a question of putting "shoulder
to the wheel" and getting "on with the job" regardless of expenditures of manpower and other
resources. It is industry's right, and indeed legal privilege and social mandate, to challenge any
unreasonable action and demand demonstration of sufficient justification and rationale. To
achieve objective environmental regulation, a sound base of environmental data must be collected, limits of analytical detection determined, realistic hazards must be defined, and levels of
treatment established as necessary.
Certain perspectives for toxic pollutants, which need to be recognized in the logical development and implementation of meaningful and workable regulations, are provided within three
areas:  regulatory assessment, environmental evaluation, and waste treatment.
REGULATORY ASSESSMENT
The first set of perspectives for the toxic pollutants concerns regulatory assessment, i.e.,
the identification of various types of pollutants, the rationale for selection of specific toxic
pollutants, the mechanisms for revision, and the development of appropriate criteria, standards,
and guidelines.
Types of Pollutants
For purposes of regulation [ 1 ], water-borne pollutants are presently divided into three
groups: (a) conventional, (b) nonconventional, and (c) toxic as shown in Table I. The conventional pollutants include many of the so-called traditional parameters of wastewater treatment.
The toxic pollutants have been segregated for special attention, supposedly because of known
or suspected adverse effects upon human health or the environment.   The nonconventional
pollutants have not yet been fully defined but apparently will include certain other pollutants
which are neither conventional nor toxic. Hazardous substances by comparison [2,3] are pollutants which are intermittently "spilled" as opposed to being continually discharged. There
remains some confusion since an intermittent "spill" is not a continuous "discharge," and what
is "toxic" is not necessarily "hazardous" without attendant exposure.
Pursuant to Section 304(a) (4) of the Clean Water Act [ 1 ], the Administrator is required to
publish information identifying "conventional pollutants." This has been done [4] to include
but not limited to: biological oxygen demand (BOD), total suspended solids (TSS), fecal coli-
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