there is however no sewerage tariff harmonization for the locations serviced by onep in contrast to tariffs for drinking water consumption table a tariff analysis of wastewater treatment systems operated by onep around showed that the sanitation tariffs allowed recovery of only about per cent of the operating costs excluding depreciation allowances financing costs and costs of maintenance of the infrastructure in other words given the general increase in major cost items for wastewater management there has been an increasing gap between the actual tariffs and the level required for ensuring recovery of operating costs let alone maintenance and depreciation