WASTEWATER TREATMENT FACILITIES FOR EXXON'S
NEW CORPORATE RESEARCH FACILITIES
Robert W. Powell, Staff Engineer
Francis L. Robertaccio, Engineering Associate
Exxon Research and Engineering Company
Florham Park, New Jersey 08932
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INTRODUCTION
In late 1983, Exxon Research and Engineering relocated its Headquarters and Corporate Research
facilities to Clinton Township, New Jersey, in rural Hunterdon County about 50 miles west of New
York City. The 800 laboratory and pilot plant researchers at Exxon's Clinton site carry out ever-
changing activities as diverse as catalysis, biosciences, metallurgy and laser science. This paper provides an overview of the water conservation and wastewater treatment practices at the site which serve
to bridge the gap between the highly variable wastewaters and the sensitive environmental demands.
In particular, the paper describes innovative facilities to treat two waste streams (sanitary and laboratory) to meet wastewater discharge requirements for a small trout maintenance stream and/or to be
suitable for use as spray irrigation water.
TREATMENT FACILITY OVERVIEW
Figure 1 is a simplified block flow diagram of the treatment and disposal facilities. Treatment and
disposal for sanitary wastewater include flow equalization, extended aeration activated sludge, chlor-
ination, storage, and spray irrigation. The ever-changing laboratory wastewater is treated in a system
which includes: oil and grease removal, flow equalization in two fill-and-draw basins, heavy metals
removal by lime precipitation and recarbonation, soluble organics removal by a combined powdered
carbon/activated sludge (PACT) system, and effluent polishing by dual media filters and carbon columns. Treated effluent is stored in two fill-and-draw quality control basins, and receiving stream flow
and quality are monitored to determine the amount of direct discharge or spray irrigation.
Approximately 90 days storage is provided in lined lagoons for the treated sanitary wastewater to
allow for days when spray irrigation can not be practiced because of frozen or wet ground. Approximately 30 days storage is provided in lined lagoons for the treated laboratory wastewater to allow for
days when the receiving stream flow is too low and spray irrigation cannot be practiced.
The sludge handling and disposal system is shown in Figure 2. Aerobically digested waste sanitary
sludge, thickened chemical sludge, and thickened PACT sludge are all dewatered on-site in a single
gravity belt filter press. Hazardous and non-hazardous sludges are stored separately for contracted
off site disposal.
DISCHARGE REQUIREMENTS
Two permits describe the quality and quantity of treated wastewater that can be discharged. One
permit is for discharge of treated laboratory wastewater to Beaver Brook, a small Class FW-2 trout
maintenance stream. The second permit is for the discharge of treated sanitary and/or laboratory
wastewater to the spray irrigation field. Key provisions of the two permits are shown in Table I. Note
that both the quality and quantity of water that can be discharged are described in each permit. Additionally, the groundwater in the vicinity of the spray field and treatment plant has to be maintained as
drinking water quality. Six wells are sampled and analyzed monthly to provide that assurance.
One of the most difficult permit conditions is a limit on the level of total dissolved solids in Beaver
Brook downstream of the laboratory wastewater discharge. Stream flow is highly variable and generally low. Just upstream of the Clinton discharge, the stream passes beneath Interstate 78 so the stream
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