Section Three
SITE REMEDIATION
C. GROUNDWATER REMEDIATION
23    ZERO DISCHARGE TREATMENT SYSTEM FOR
GROUNDWATER CONTAINING HEXAVALENT
CHROMIUM
Jerome H. Jacobs, Project Manager
Metcalf & Eddy, Inc.
Beachwood, Ohio 44122
INTRODUCTION
Early in 1990 Metcalf & Eddy was retained by MacAlloy Corporation in Charleston, South Carolina to conduct an Environmental Audit of their Ferroalloy Production Facilities. The plant site had
originally been developed by the Pittsburg Metallurgical Company as a Ferroalloy Production Facility
just prior to World War II and has undergone several changes of ownership. The current owner is the
MacAlloy Corporation.
The plant site is adjacent to the Charleston Navy Yard and comprises about 150 acres. Figure 1
shows a plan view of the site with the major installations. The plant production facilities consist of
two large open electric arc furnaces along with pollution control equipment which includes electrostatic precipitators and baghouses (see Figure 2).
The electrostatic precipitators control the off-gases from the arc furnaces and remove the fine
particulates which previously had been discharged to the atmosphere. As a part of the precipitator
system, a precooler is installed to cool the extremely hot gases from the electric arc furnace and
condition the gases for efficient removal of particulates. The precooler uses a direct water injection
system, which requires about 200 gpm of process water to be injected and evaporated into the gas
stream. At the present time brackish groundwater from the deeper aquifer underlying the plant is used
to supply the spray water system. During the course of the audit it was determined that a plume of
hexavalent chromium was trapped beneath portions of the site. Further exploratory borings installed
during late 1990 and early 1991 determined that the plume existed only in the upper water table
aquifer and occupied an area of about 23 acres surrounding the existing waste impoundment. The
SHIPYARD CREEK
PROPOSEO OUST
IMPOUNDMENT/
SETTLING POND
^OUTFALL 001
EXISTING
DUST
IMPOUNDMENT
FURNACE
MACALLOY SITE MAP
Figure 1.
48th Purdue Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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