Section Eight
RESPIROMETRY AND EFFLUENT TOXICITY
42    LONG-TERM WHOLE EFFLUENT TOXICITY
CONTROL: INTERACTION BETWEEN INDUSTRIAL
PRETREATMENT AND TOXICITY REDUCTION
EVALUATION (TRE) PROGRAMS
Douglas J. Fort, Vice President
Enos L. Stover, President
The Stover Group
Stillwater, Oklahoma 74076
INTRODUCTION
Increased regulatory concern over whole effluent toxicity control for National Pollutant Discharge Elimination System (NPDES) permittees has warranted the development of effective
long-term whole effluent toxicity control strategies. At the municipal level, the Industrial Pretreatment program represents one of the best opportunities for long-term whole effluent toxicity
source control and regulation. The Industrial Pretreatment program may be effectively used during three primary stages of NPDES permit toxicity testing: (1) prior to toxicity problems as a
preventative tool, (2) during the TRE program as a means of identifying and controlling sources
of the toxicant(s), and (3) following TRE studies as a means of controlling toxicity through surveying potential problem users, cost-effective aquatic toxicity and microbial inhibition monitoring of users, and public education and outreach programs. Overall, dischargers that have utilized
the benefits of the industrial program have been substantially more successful in controlling
whole effluent toxicity than those who either did not effectively use the program or were not involved in an Industrial Pretreatment program. In this chapter, we describe the successful connection between the TRE program and the Industrial Pretreatment program in the long-term control
of whole effluent toxicity for both industrial and municipal wastewater treatment facilities.
THE TRE PROGRAM
Although no standard approach can be applied to every TRE program, most studies consist of
several critical components (Figure 1). These components, completed in a tiered format, often include a background data review, facility evaluation, toxicity identification evaluation (TIE), toxicity source identification, toxicity treatability studies (if necessary), and toxicity reduction option
selection (Figure 2).
The primary objectives of the background data review are to review the historical chemical-
specific and toxicity data on the effluent and specific point sources (sewer users). Special consideration is typically given to evaluation of records associated with general plant housekeeping,
daily plant operation, selection and use of specific chemicals, and maintenance. Information
gleaned from this review can be used to define the study objectives, provide immediate information as to potential cause(s) and source(s) of toxicity, and provide insight into the efficacy of immediate actions which may be useful in reducing final effluent toxicity.
A detailed facility audit is conducted to evaluate facility housekeeping and operational practices in an effort to identify areas which may be contributing to the observed toxicity. A major
effort is initiated to collect and review all of the information necessary to assess the potential for
reducing toxicity with the existing treatment facilities. An extensive review of operations records
51st Purdue Industrial Waste Conference Proceedings, 1996, Ann Arbor Press. Inc., Chelsea. Michigan 48118.
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