73    ZERO DISCHARGE CONSIDERATIONS FOR A
MIDWESTERN INDUSTRIAL FACILITY
Edmund A. Kobylinski, Industrial Wastewater Treatment Specialist
Black & Veatch
Kansas City, Missouri 64114
Amy Shanker, Project Manager
Black & Veatch
Cincinnati, Ohio 45242
Shashi N. Patel, Manager, Safety & Environmental
PDED
General Electric Aircraft Engines
Evendale, Ohio 45215
INTRODUCTION
As part of its overall plan to reduce waste at its Evendale, Ohio, production facilities, the management of General Electric Aircraft Engines (GEAE) has evaluated the treatment processes necessary to
achieve zero discharge of process wastewater to its NPDES-permitted outfall. This evaluation was
precipitated by new NPDES numerical limits that will become enforced in 1995, and make it necessary
for GEAE to dramatically alter its wastewater treatment systems. As part of this engineering analysis,
wastewater treatment methods were evaluated that would produce a water of suitable quality for
recycling to the facility's major water consuming processes.
Wastewater is produced from the injection of quench water into exhaust gases during testing of jet
engines and components, and from cooling tower blowdown. As part of the exhaust quenching, a
portion of the water is evaporated, which increases the total dissolved solids (TDS) concentration in
the wastewater. In addition, hydrocarbons, lubricating oils, and coolants are transferred into the
waste stream. The wastewater characteristics regulated under the NPDES permit (Table I) include
benzene, ethylbenzene, toluene, naphthalene, 1,2,4 trimethylbenzene, oil and grease, pH, and temperature. The present wastewater production rate of 1.7 million gallons per day (MGD) would rise to 2.5
MGD as a result of a planned plant expansion. Wastewater production is highly variable in both
volume and quality, due to variable production and testing schedules.
Table I.    Comparison of Previous and Current NPDES Permit Limits
Previous Limits
Current Limits3
Monthly
Maximum
Monthly
Maximum
Characteristic
Average
Day
Average
Day
Units
Oil and Grease
15
20
10
10
mg/L
Toluene
2.40
mg/L
Benzene
0.972
1.10
mg/L
Ethylbenzene
0.108
1.40
mg/L
Naphthalene
0.076
0.16
mg/L
1,2,4 Trimethylbenzene
0.013
0.18
mg/L
Temperature
32.2
28-summer
18-winter
29-summer
21-winter
C
pH
Between 6.5 and 9.0
s.u.
a Enforceable beginning in
October 1995.
48th Purdue Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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