80    DEVELOPMENT AND IMPLEMENTATION OF WATER
QUALITY BASED NPDES PERMITS FOR THE METAL
FINISHING INDUSTRY IN NEW ENGLAND
William R. Beckwith, Environmental Engineer
David O. Lederer, Environmental Engineer
U.S. Environmental Protection Agency
Boston, Massachusetts 02203
INTRODUCTION
Nature of the Toxics Problem in New England
The industrial profile of New England is diverse with a wide variety of raw materials, manufacturing processes, and finished products. One common ground shared by many facilities is that their
wastewater is discharged to one of the region's numerous small streams. Many of these small watercourses do not provide sufficient dilution during low flow periods to adequately assimilate the toxic
effects that can result from industrial discharges.
Facilities that perform metal finishing operations constitute a significant portion of the industrial
base in New England. The wastewater resulting from such activities is generally concentrated with
toxic metals of particular concern because of their potential toxicity to aquatic organisms.
REQUIREMENTS OF PERMITS UNDER THE CLEAN WATER ACT
The Clean Water Act (CWA) [1] requires that the effluent from point source discharges to waters of
the United States satisfy minimum technology and water quality requirements.
Technology Requirements of the CWA
The initial or "first round" National Pollutant Discharge Elimination System (NPDES) permits
issued by the United States Environmental Protection Agency (EPA) concentrated primarily on the
regulation of conventional pollutants (BOD, TSS, pH, oil and grease, and fecal coliform) and other
selected pollutants (ammonia, metals, and phenols) at levels that met the technology requirements
applicable at the time, Best Practicable Control Technology Currently Available (BPT).
National Effluent Guidelines for the Metal Finishing Industry were promulgated on July 15, 1983
[2]. In EPA Region I, which covers the New England states, most of the permit limitations established
in the initial permits to satisfy BPT were stringent enough to satisfy the BAT (Best Available Technology Economically Achievable) requirements that were to be achieved by July 1, 1984.
Water Quality Requirements of the CWA
Water quality standards are required by the CWA to be adopted by each of the states. These
standards must designate uses applicable to each stream segment within the state (fishing, swimming,
for example). The standards must also designate minimum instream criteria sufficient to protect each
stream use (minimum dissolved oxygen concentrations, for example).
Section 301 (b)(1)(C) of the CWA requires that all discharges to waters of the United States meet
limitations necessary to ensure compliance with applicable state water quality standards. All state
water quality standards forbid the discharge of pollutants in amounts that would interfere with the
attainment or maintenance of the most sensitive receiving water uses. In addition, all state standards
include a narrative statement specifically forbidding the discharge of toxic compounds in amounts or
combinations that may cause toxicity in the receiving waters.
The main focus of water quality concerns during first round permit issuance was the control of
conventional pollutants to insure adequate dissolved oxygen levels in the receiving waters and to avoid
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