Sequential Batch-Fed Effluent Storage Reservoirs: A New Concept of Wastewater Treatment Prior to Unrestricted Crop Irrigation Available to Purchase

A modification of the Israeli system of holding pond effluents in single storage reservoirs prior to restricted irrigation is presented which enables the treated wastewater to be used for unrestricted irrigation. The modification comprises the use of 3 or 4 sequential batch-fed effluent storage reservoirs, each of which is operated on a cycle of fill, rest, use. The rest period permits the faecal coliform levels to drop below 1000 per 100 ml, in accordance with the current WHO recommendations for unrestricted irrigation. The number of storage reservoirs and the timing of the fill/rest/use cycle depends on the length of the irrigation season; design examples are presented for irrigation seasons of 12, 6 and 4 months, and these are compared with a conventional pond design.