A RATIONALE FOR PRETREATMENT STANDARDS
FOR INDUSTRIAL DISCHARGES TO
PUBLICLY OWNED TREATMENT WORKS
Jess C. Dietz, Senior Vice-President
Clark, Dietz and Associates-Engineers, Inc.
Sanford, Florida 32771
John D. Dietz, Project Manager
Clark, Dietz and Associates-Engineers, Inc.
Jackson, Mississippi 39206
INTRODUCTION
Pretreatment regulations established pursuant to requirements of Public Law 92-500
are an area of common concern to industry and municipalities as the concept of pretreatment has developed.    Initial pretreatment considerations [ 1 ]  were directed to the
BOD, SS, temperature, pH, and flow characteristics of industrial wastes discharged to
publicly owned treatment works (POTW), probably with a goal to reduce organic loading on municipal facilities.   As more sophisticated treatment processes have been
developed, it has been recognized that protective measures may be warranted to safeguard against adverse effects attributable to various incompatible pollutants.    Three
specific concerns have been noted:    (a) pollutants  that interfere with the treatment
system itself; (b) pollutants that complicate disposal of wastewater sludges generated
by the treatment system; and (c) pollutants that are not modified or removed during
treatment and therefore pass through without reduction.
The potential for cost savings resulting from joint treatment is generally recognized
and accepted, and engineers have encouraged joint treatment for years in selected cases
as advantageous to both industry and municipalities.   Many examples of both successful
and unsuccessful ventures in joint treatment are available in the literature.
It is the objective of this presentation to review historical and emerging concepts
regarding establishment of local pretreatment requirements. A survey of sewer use
ordinances for a number of cities in the United States was conducted to identify the
current range of practice. Particular emphasis is made of regulations governing introduction of heavy metals into municipal systems, owing to prevailing interest in heavy
metal concentration in wastewater sludges. The specific problem of incorporation of
heavy metals in sludge is addressed in terms of criteria for land application in relation
to sewer use regulations for major American cities.
OBJECTIVES OF PRETREATMENT PROGRAM
Section 307, Public Law 92-500, as amended by Public Law 95-217, indicates the
purpose of pretreatment standards is to prevent a discharge of any pollutant into such
treatment works, which pollutant may interfere with, pass through, prevent sludge use
or disposal, or otherwise be incompatible with such works.
One aim of this program is to provide the framework for clean up of industrial discharges to POTWs and to delineate the various responsibilities and deadlines applicable
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