The Stabilization Pond

Juanico M. and Shelef G. (1989). The Stabilization Pond + Reservoir Wastewater Treatment and Storage Unit for Rural Settlements in Israel. Preprints. Small Wastewater Treat. Plants, Norway, pp. 415-422.

ABSTRACT

Israel is utilizing all of its conventional water resources and reclaimed wastewater constitutes the most immediately available additional water for irrigation. As irrigation is carried out during the summer while the need is for the year-long effluent flow, seasonal storage of treated wastewater in reservoirs is necessary. A multiple pond + reservoir unit for the treatment and storage of wastewater from a small rural community is described.
Raw sewage, outflow from the anaerobic ponds, facultative pond and stabilization reservoir, have COD values of 1450, 1200, 370 and 140 mg/l respectively.
The reduction in BOD, MBAS, heavy metals, and other water quality parameters in each step is presented. The quality of the effluent outflowing from the stabilization reservoir at the beginning of the irrigation season is good, but it deteriorates during the second half of the season.
Factor Analysis of effluent quality points out that the percentage of fresh effluent within the reservoir is the main cause of effluent quality deterioration. Two possible alternatives to overcome this problem are an extra treatment of effluent during the critical period, or a reduction in the quantity of fresh effluent entering the reservoir during the critical period by storing it in the stabilization pond.

KEYWORDS

stabilization reservoirs; extra deep ponds; effluent reuse; effluent irrigation.