Evaluation of agricultural reuse practices and relevant guidelines for the Alba Rancho WWTP (primary and secondary facultative ponds) in Cochabamba, Bolivia

Abstract

Many cities in developing countries are experiencing high population growth, which is generating chaotic and unplanned development, reducing land areas available for agriculture, and polluting surface and groundwater. Consequently, the reuse of untreated or partially treated wastewater for agricultural irrigation is increasing in arid and semi-arid regions in developing countries. Cochabamba city in Bolivia also has a high population growth. The climatic characteristics and the lack of clean water sources in this city are forcing the agriculture sector to use treated and untreated wastewater for irrigation. We investigated the effluent quality of the Alba Rancho Wastewater Treatment Plant (WWTP) in Cochabamba, Bolivia, and the existing effluent reuse practices for irrigation of fodder crops in the surrounding agricultural land (La Mayca area). The plant uses primary and secondary facultative ponds, and does not achieve the required effluent quality (according to Bolivian environmental law) for effluent BOD, COD, TDS and faecal coliforms. This paper also includes a brief comparison of guidelines for wastewater reuse in agriculture from several developing and developed countries, comparing the parameters measured as pollution indicators. It appears that for developed countries, the main concern is the health risk that reuse can cause to the farmers and consumers. For developing countries on the other hand, pollution reduction is currently the major aim in their guidelines and standards.