8    AN INDUSTRIAL TOXICITY REDUCTION EVALUATION FOR
AN OILY WASTEWATER TREATMENT PLANT
Mujde U. Erten, Project Engineer
Malcolm Pirnie, Inc., Newport News, Virginia 23606
Allen B. Gelderloos, Project Engineer
Malcolm Pirnie, Inc., Newport News, Virginia 23606
Jane S. Hughes, Associate
Malcolm Pirnie, Inc., Chapel Hill, North Carolina 27516
Christine H. Wallace, Environmental Engineer
Naval Facilities Engineering Command
Norfolk, Virginia 23511
INTRODUCTION
The Clean Water Act of 1972 provided the basis for control of toxic substances discharged to waters
of the United States. The Amendments to the Act further mandated the importance of defining and
protecting the beneficial uses of receiving waters and incorporated a combination of chemical specific
and whole effluent toxicity limits into National Pollutant Discharge Elimination System (NPDES)
permits. In 1984, the U.S. Environmental Protection Agency (EPA) recommended that whole effluent toxicity tests be used in toxics management programs, and in September 1988 the Virginia State
Water Control Board (SWCB) adopted the Toxics Management Regulation (Regulation) which governs the control of toxics in treatment plant effluents. The overall goal of the Regulation was to
prevent the discharge of toxic levels of pollutants in to the State's waters. The Regulation also
provided water quality standards for certain pollutants.
Based upon toxicity test results indicating non-compliance with the criteria in the Regulation, a
Toxicity Reduction Evaluation (TRE) was required at a U.S. Naval Fuel Depot's Oily Wastewater-
Treatment Plant (Plant). For compliance with the Regulation, no more than 25 percent of the acute
toxicity tests can exhibit LC50 values of less than 100 percent. The Plant effluent demonstrated a
failure rate of 38 percent (6 out of 16 tests) and consequently the SWCB required the performance of a
Toxicity Reduction Evaluation at the Plant.
A TRE plan was developed by the Navy and consisted of extensive chemical characterization of the
wastewater throughout the treatment process, monitoring of the final effluent for acute toxicity, and
performance of EPA's Phase I Toxicity Identification Evaluation (TIE) procedures to characterize
effluent toxicity. The plan also called for an evaluation of the entire treatment process and the plant
operating procedures. From this evaluation, improvements were made to the treatment system which
produced reductions in acute toxicity below the permitted failure rate. This phase of the project is
referred to as Period I.
In order to verify that the plant improvements reduced the effluent toxicity, additional toxicity
testing was performed. Along with toxicity testing, some of the compounds which were identified in
Period 1 as suspected toxicants were evaluated through additional chemical analyses and laboratory
studies. In addition, more detailed monitoring of plant operations was conducted during this Period
(referred as Period II) to evaluate the effects of different source wastewaters on effluent toxicity. The
results of this Period confirmed Period I results; however, the specific cause(s) of toxicity could not be
identified.
This paper will present the results of the toxicity tests conducted during this project along with the
effects of plant improvements on the toxicity reduction, and the results of special tests performed in
an attempt to focus on suspected toxicants.
47th Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118.
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