Handling Waste Disposal at a
Major Food Plant
FRANK T. DUBYNE, Engineer
Campbell Foods, Inc.
Napoleon, Ohio
INTRODUCTION
Waste disposal in any food plant can become a major problem. The lack of
adequate waste disposal facilities obviously has a direct impact on insect and rodent
control, good housekeeping practices and plant sanitation in general. In a major food
processing plant, especially if located in a rural area or small community, an adequate
waste disposal program requires extra attention in order to make it effective.
The Campbell Soup Company Plant located in Napoleon, Ohio, is a major food
plant. Our employee complement varies between 1,500 and 2,000 people on a
year-around basis. Since we produce practically our entire line of heat processed
products at this plant, the volume and variety of ingredients handled generates
tremendous quantities of both liquid and solid wastes.
For the purpose of this discussion, I'll classify our plant wastes in two broad
categories, wet and dry. Wet waste includes liquid waste such as wash water from
preparatory and clean-up operations, grease bearing wastes from digesters, broth
kettles etc., water plant sludge and the waste treatment plant supernatant liquor and
sludge. I'm also including in the wet category ingredients such as milk, cream and the
various vegetable oils. Vegetable trimmings are also classified as a wet type waste
since the moisture content of this material usually runs 80 to 96 per cent plus the
fact that these trimmings are normally removed from the manufacturing plant by
water. Some types of wet waste such as spent bone, vegetable waste and tomato
pomace can be processed to produce a saleable by-product.
In the dry waste category we run the whole gamut of containers such as all
types of paper bags, cardboard boxes, plastic containers of all sizes and description,
cans of all sizes up to 30 lb egg yolk cans plus an assortment of drums both metal
and fiber. A scrap classification would include tinplate, labels, cases, liners,
miscellaneous paper, wood and all types of metal and worn out or obsolete
equipment.
The handling of liquid wastes is pretty straight forward. During our regular
season which runs from October 1 to August 1, all liquid waste is comminuted or
screened to remove solids then delivered to the waste treatment plant. Our system is
a modified secondary type. This includes bar screens, grit removal, roughing tower,
primary sedimentation, aeration, passage through trickling filters, final sedimentation
and chlorination. The BOD of the influent ranges from 600 to 1,000 mg/1 with a
constantly different mix each day depending on the production schedule. The waste
treatment plant is capable of treating a population equivalent of 100,000 people.
During our tomato season the large quantities of tomato wash water create a
handling problem. The re-cycled water plus our normal manufacturing plant waste
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