TREATMENT OF HIGH-STRENGTH MEATPACKING PLANT
WASTEWATER BY OVERLAND FLOW
Anthony J. Tarquin, Associate Professor
Humberto Bautista, Graduate Student
Civil Engineering Department
University of Texas at El Paso
El Paso, Texas 79968
INTRODUCTION
The pollutional loads placed upon our nation's natural waters by industries and municipalities alike have created public awareness to the water quality problem.   Therefore, the
government has set guidelines whereby the best technology available must be used to
meet the goal of zero discharge of pollutants.   In addition, it has been predicted that by
1980 consumption of water for all uses in the nation will equal or exceed the recoverable
streamflow and ground water supply, thereby making multiple reuse of water necessary.
In evaluating the increased costs of using tertiary treatment to meet these guidelines,
it has been necessary to search for alternatives.   One of the economical alternatives being
considered is land treatment of liquid wastes through irrigation, infiltration-percolation,
and overland flow.   All three provide water reuse:   infiltration-percolation through ground
water recharge, irrigation through plant growth in addition to ground water recharge, and
overland flow through both of the above and through direct reutilization.   Both irrigation
and overland flow provide for reuse of water in addition to treatment.   It has been noted
that some existing systems have been potentially harmful to man and his environment because of failure to employ acceptable technology, monitoring and management.
In order to design an acceptable system, it is necessary to have the proper information
to make the right decisions.   In an effort to provide this type of information, the EPA,
along with the Peyton-Packing Co. and University of Texas, El Paso, undertook a project
in which infiltration and overland flow treatment systems were studied.   In this paper
the effectiveness of the overland flow treatment method is presented.
PROCEDURES AND DESIGN
Wastewater Characterization
At the Peyton packing plant, the effluent flows into a rectangular sedimentation-
skimming tank (catch basin) which has a 30-min detention time at peak flow.   While
the collection and distribution system was being designed and constructed, the wastewater from the catch basin was sampled and characterized.   On six different occasions,
samples were collected at Vi-hr intervals for 24 hr from the effluent pipe of the catch
basin.   On two of these occasions influent samples were also taken.   The depth of flow
was measured in the effluent pipe and, using corresponding velocities as measured in a
separate study, the total flow was calculated.   In addition to analyzing the 48 Vi-hr
samples individually, a flow-proportional composite sample was made and analyzed.
All samples were kept in a polystyrene cooler containing ice until they could be transported back to the laboratory, a storage time of approximately 3 hr.   The samples were
analyzed within 24 hr for pH, Biochemical Oxygen Demand (BOD), Chemical Oxygen
Demand (COD), Grease, Total Solids (TS), Volatile Total Solids (VTS), Suspended Solids
(SS), Volatile Suspended Solids (VSS), and Total Kjeldahl Nitrogen (TKN).   All tests
were conducted according to the procedures specified in Standard Methods [ 1 ].
Overland Flow System Design
The overland flow system was constructed using the cut-and-fill method to achieve a
\-Vi% slope.   The total area was 46 m wide by 62 m long.   The rather shallow slope was
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