Costs of the agricultural use of municipal sewage sludge in the agricultural sector

Abstract

This study is based on a survey carried out in 1998 on 71 full scale waste water treatment plants in France (ranging from 400 to 650 000 population equivalents; liquid, pasty, dry, limed and composted sludge). The collected information deals with investment and operating costs of the various stages of the sewage sludge disposal procedures: treatment, storage, handling, transport, application, specific cultural practices, studies and management. The results put forward the relative importance of the cost of sludge treatment (55 % of the total cost, in average). Without sludge treatment, the costs directly related to agricultural use (provisions for depreciation included), with storage and operations of controlled land application, amount to: 1,98 tax free Euros/equivalent-inhabitant, 177,7 tax free Euros/t dry matter, 40,5 tax free Euros/t wet sludge and 0.06 tax free Euros/m3 drinking water. Behind these average values, there is however a great variability in the cost of different types of sludge disposal procedures.