Anaerobic and Aerobic Lagoon
Treatment of Packing Plant Wastes
DONALD R. STANLEY, Consulting Engineer
Stanley Associates Engineering, Ltd.
Edmonton, Alberta, Canada
INTRODUCTION
As population and industrialization increase the complexity and magnitude of
waste treatment problems grow. In the past, the planning for many industrial
plants has not taken into consideration the future requirements for waste treatment.
When many older plants were built the requirements may have been such that
waste discharge required little, if any, treatment. As areas developed these conditions changed and the industry had to build costly facilities to meet the requirements of reasonable water sanitation. In many of these cases consideration of the
problem in the first instance may have resulted in a plant location which would
allow the industry to solve it's problem much more economically.
Waste from most industries located within developed urban areas is usually
discharged to community sewer systems and treated along with domestic sewage.
As the need develops for higher degrees of treatment municipalities have to find
means to finance the capital and operating costs of the treatment facilities required.
In order to do this, many communities have instituted sewer service charges designed to assess the cost of the facilities against the users of the systems on an
equitable basis. Where industrial waste is a problem, a sewer service by-law may
put certain restrictions on the quality of the effluent allowed to be discharged to
the system and in some cases may provide for surcharges based on the concentration of such characteristics as BOD, suspended solids, grease and chlorine demand,
depending upon how these effect the cost of treatment.
In a case where there is a highly concentrated waste and a sewer charge based
on quality, the industry has to analyze the problem to determine whether it is
more economical to pay the community for treating its waste or to construct its
own pretteatment facilities in order to reduce the surcharge. In some cases it may
even be advantageous for the industry to construct treatment and disposal facilities
to the extent necessary for direct discharge into a receiving body of water.
In the case where an industry's location is such that it is almost impossible to
treat and dispose of its waste independently, the cost of treating to meet the municipality's requirements or to pay an equitable share of the cost for the municipality to treat the waste may have a significant effect on the economics of the
plant operation. The type of treatment facility operated by the municipality may
be efficient to handle the community waste as a whole, but very inefficient and
costly for treating particular types of industrial waste.
Such a situation existed in the City of Edmonton, Canada, where the payments by three meat packing plants to the City for waste treatment indicated that
the construction and operation of separate treatment and disposal facilities would
result in substantial savings. After considering several possible solutions to the
problem, the one which appeared to have the best potential involved the use of
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