Economic considerations for wastewater upgrading alternatives: an Israeli test case.
Sewage effluent for land application is becoming an increasingly important source of irrigation water in many semi-arid regions of the world. Two main approaches to the use of sanitation to upgrade effluent for reuse in agriculture were analyzed: (i) sanitizing to the level required for each crop; or (ii) upgrading all effluent to the sanitary level mandated for unrestricted irrigation (<10 fecal coli/100mL). The first approach was authorized by the Israeli health authorities, who consider irrigation with secondary effluent to be complementary to the treatment process. The other approach was conceived mainly by the agricultural and environmental establishments, which debited the additional financial burden to the urban sector and/or the 'general public'. We show that upgrading all effluents in Israel to 'unrestricted irrigation quality' would cost $69 million each year for upgrading alone, in addition to the costs of treatment to the sanitary level required for each individual crop and of observing all the necessary additional precautions and boundaries. This difference in cost stems from the fact that most effluent is used for the irrigation of non-edible crops, for which partial pathogen removal is sufficient. Thus, upgrading to the sanitary level required by the most sensitive crops would be rather wasteful.
Fine
Pinchas
P
Institute of Soil, Water and Environmental Sciences, Volcani Center, ARO, Ministry of Agriculture, POB 6, 50250 Bet Dagan, Israel.
Halperin
Ramy
R
Hadas
Efrat
E
D000383:Agriculture / Q000191:economics* / Q000379:methods; D003247:Conservation of Natural Resources / Q000191:economics*; D003362:Cost-Benefit Analysis; D018556:Crops, Agricultural; D004755:Enterobacteriaceae; D005243:Feces / Q000382:microbiology; D007557:Israel; D012499:Sanitation; D014865:Waste Disposal, Fluid / Q000191:economics* / Q000379:methods*; D014871:Water Microbiology