Water consumption and wastewater generation from small-scale crude palm oil extraction in Ghana

Abstract

Abstract Crude palm oil extraction is one of the sources of livelihood in Ghana's Central Region. However, the water use and wastewater generation associated with the industry have not been given adequate attention. This study assessed the water consumption and wastewater generation by small-scale crude palm oil extraction mills in the region. Twenty-five (25) mills were selected from four palm oil-processing local government areas in the region. An interview guide was used to obtain information about the operations of the mills and corroborated through structured observations. Water consumption and wastewater generation were measured using a graduated plastic bucket. Water for processing was found to be sourced from hand-dug wells (56%), treated piped water (20%), boreholes with handpumps (16%) and rivers (8%). Water was bought at US$1.93 (boreholes) and US$2.89 (piped water) per cubic metre. The recurrent cost of water was the same as that paid for domestic use. For a litre of palm oil produced, 0.760-2.391 litres of water were consumed and 68-82% returned as wastewater. Sixty-eight percent of the water was used for boiling. The distance to water source influenced the consumption, with higher water consumption recorded for mills with on-plot water sources. Higher recurrent costs of water did not necessarily lead to lower water consumption. There was no significant difference in the water consumption and wastewater production between the wet and dry processing methods. The small-scale palm oil processing industry requires attention to manage a potential competition between commercial and domestic water use in rural and small towns.