Operation of Three Waste Stabilization Ponds
in Series
ADNAN SHINDALA, Associate Professor
JEROME L. M AH LOCH, Assistant Professor
Mississippi State University
State College, Mississippi
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THOMAS WALKER, Bio-Environmental Engineer
USAF Biomedical Science Corps.,
Whiteman, Missouri
INTRODUCTION
Nature of the Problem
Waste stabilization ponds have been used extensively to treat municipal as well as
industrial wastewaters throughout the United States. Their low costs of construction and
operation have resulted in their wide adoption as a means of wastewater treatment.
Depending on depth and mode of operation, oxidation ponds are generally classified
as aerobic, facultative, and anerobic. Facultative ponds are the most widely used. The
treatment process in the aerobic and facultative ponds involves the use of aerobic bacteria
to oxid ize the organic matter while algae, through the process of photosynthesis, supply the
oxygen needed for the aerobic bacterial action. The facultative ponds also maintain a
bottom anaerobic sludge layer where deposited solid matter undergo anaerobic
decomposition. The degradable substances in the anaerobic ponds are stabilized by
anaerobic microbial population.
Until recently, waste stabilization ponds have been accepted by the pollution control
agencies as a means of wastewater treatment. However, due to the growing awareness ofthe
pollutional aspects of wastewater and in order to preserve the natural values of streams for
fish, wildlife, recreation, water supply, and for general aesthetic considerations, more
stringent water quality criteria have been adopted for all surface waters. To meet these
standards, a high degree of wastewater treatment that will produce high quality effluents
must be provided. Unfortunately, single cell ponds do not provide the desired level of
wastewater treatment to satisfy the water quality standards promulgated for the receiving
streams. The low degree of treatment during the winter months and the high accumulation
of algae in the hot summer days are two main characteristics associated with the operation
of single cell ponds. Algae will eventually die away in the receiving streams thereby
imparting an additional BOD load, producing odors and creating undesirable aesthetic
conditions.
In order to obtain a higher degree of treatment from oxidation ponds, the use of ponds
in series has been suggested. It has been reasoned that the longer detention time and the
availability of a second and third pond will result in the reduction of the algal and coliform
population, reduction of suspended solids concentration and an increased BOD removal
with a concommitant reduction in the odor problem. Unfortunately, there is neither enough
field data available which can verify such claims nor is there a satisfactory theory for the
proper design of a multicell pond system.
Background Information on Multi-Cell Ponds
As reported earlier, field studies of multi-cell ponds are extremely scarce. One of the
first reported studies was conducted on the pond system serving the city of Esparto,
California (1). The system at the time of the survev consisted of three ponds in series with a
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