Section Nine
APPLICATION OF BIOASSAYS
26    EFFLUENT TOXICITY MONITORING METHODOLOGY
EVALUATED FOR FIVE INDUSTRIAL DISCHARGERS
Elizabeth C. Sullivan, Environmental Engineer
John A. Botts, Environmental Scientist
Jonathan W. Bras well, Project Manager
Engineering-Science, Inc.
Fairfax, Virginia 22030
Dolloff F. Bishop, Project Officer
Water Engineering Research Lab
U.S. Environmental Protection Agency
Cincinnati, Ohio 45768
Gerry H. Slattery, Plant Manager
Bureau of Water and Wastewater
Black River Wastewater Treatment Plant
Baltimore, Maryland 21224
William L. Goodfellow, Jr., Scientist
EA Engineering Science and Technology
Sparks, Maryland
INTRODUCTION AND OBJECTIVES
A major environmental challenge is facing industries today as the Environmental Protection
Agency (EPA) places non-chemical-specific limits on industries discharging to publicly owned treatment works (POTWs). In 1984, EPA and state agencies began to emphasize detecting and reducing
toxic discharges in the National Pollutant Discharge Elimination System (NPDES) program, both for
municipal and industrial discharges.' The General Pretreatment Regulations (40 CFR 403), directed at
industrial discharges to POTWs, were recently amended to define the standards preventing the discharge of any pollutant to POTWs which pass-through, interfere with the operation of, or are
otherwise incompatible with the treatment works.2 As a result, industrial discharges to POTWs are
being evaluated, and potentially surcharged or required to pretreat on the basis of non-chemical-
specific parameters such as potential for pass-through of pollutants or interference with treatment
works, and toxicity. EPA has also recommended that the requirement for a Toxicity Reduction
Evaluation (TRE) be included in those discharge permits which require toxicity monitoring.3
A TRE is being performed by EPA and the City of Baltimore at Baltimore's Patapsco Wastewater
Treatment Plant (PWWTP) to address the problems associated with non-chemical-specific discharges.'* One objective of the TRE is to evaluate monitoring tools to characterize the toxicity of
industrial contributors to the PWWTP. Two different aspects of wastewater toxicity are recognized in
the TRE: inhibition of the biomass and toxicity to the receiving water. This paper presents the
preliminary results of biological toxicity evaluation tests performed on five major industrial contributors to the PWWTP to evaluate the effectiveness of various monitoring tools as indicators of biomass
inhibition and potential toxicity pass-through.
The goal of the batch testing was to characterize those industrial wastewaters which have been
identified as contributing to the pass-through of toxicity at the plant and may be causing deleterious
effects on the biomass, such as reducing the COD removal rate or oxygen uptake. The overall
objective of this testing procedure is to verify the usefulness of the batch test for helping municipali-
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