Small Meat-Packers Wastes Treatment Systems
JACK L. WITHEROW, Engineer
Industrial Wastes Branch
Pacific Northwest Environmental Research Laboratory
Corvallis, Oregon 97330
INTRODUCTION
The technology reported herein will be helpful to the meat-packing industry, especially
the small plants, in control and treatment of their wastewaters. The number of
establishments processing red meats is about 14,000 of which some 10,000 are considered to
be small plants. A small plant is one with an annual liveweight kill of less than 25,000,000
pounds. Most plants discharge to a municipal treatment system; sewer charges and
pretreatment regulations require treatment of these discharges. Plants discharging directly
to surface waters need treatment to meet national effluent limitations.
To meet treatment requirements that are common in the meat-packing industry, the
biological processes investigated were selected for: 1) reduction of oxygen demanding
material, suspended solids and grease with discharge to a municipal sewer; 2) equivalent
secondary treatment with discharge to a surface water; 3) reduction of nitrogen, especially
in the ammonia form, and phosphorus. Discharge limitations on nitrogen and phosphorus
are becoming common and are expected to be a requirement on discharges in the future.
The facilities used in the project are located at the W.E. Reeves Packinghouse on the
out-skirts of Ada, Oklahoma. The plant is located west of the city on 64 acres of rolling land.
An unnamed creek flows through the property. The prevailing winds are from the south.
North of the plant are cattle ranches with the nearest residence 1V2 miles distant. South and
southwest of the plant the nearest residences are % mile distant. The plant slaughters 500 to
700 cattle per month and 600 to 800 hogs per month, or about 10 million pounds of live
weight annually and produces some 30 items including cut and uncut beef and pork and its
own brand of fresh sausage, bacon, weiners, cold cuts, chili, and other meat items.
OBJECTIVES
The project was divided into a two-phase investigation. In the first phase which is
reported in this paper, the two objectives were: 1) uamonstrate anaerobic + aerobic lagoon
treatment system with greater than 95 percent BOD removal and with an effluent of less
than 50 mg/1 BOD (Sludge recirculation in the anaerobic lagoon was also evaluated); and 2)
develop a spray runoff irrigation process in series with the anaerobic lagoon to obtain 80
percent removal of nitrogen and phosphorus.
In the second phase the two sub-objectives are: 1) develop the spray runoff irrigation
process with both effluent from the aerated lagoon and raw wastewater for nitrogen and
phosphorus removal; and 2) demonstrate the advantage of an aerobic lagoon treatment
system where hydrogen sulfide odors could not be tolerated or where ammonia limits are
imposed.
PLANT DESIGN
To remain functional, the operation of the treatment system should be as foolproof as
possible and mechanical equipment should be minimized and designed to prevent
undetected failure. Small packers do not have personnel trained in the operation of
treatment plants. Simple operation is even more important than minimal costs for
construction. The unit processes demonstrated were designed to simplify the operation of
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