Fats, oils and greases (FOG) discharged from commercial properties combine with other constituents in wastewater and congeal and accumulate in pipelines, service pipes and sewers, resulting in loss of capacity and blockages. Accumulations of FOG in wastewater treatment plants can give rise to pipe, equipment and plant blockages and impede treatment processes such as settlement and clarification, leading to increased maintenance and operational costs. Blockages in combined sewers which collect sewage discharges (including trade effluent containing FOG) and storm water can result in flooding and environmental pollution.
Under the Water Pollution Acts 1977 and 1990, businesses discharging to the public sewer require a valid trade effluent licence. Local authorities grant trade effluent licences and are empowered to insert relevant conditions in such a licence. This includes payment by the licence holders of fees determined by the local authority in relation to the costs of monitoring, treating and disposing of the trade effluents. This is in accordance with the EU Water Framework Directive which requires full cost recovery from non-domestic users of water and wastewater services in accordance with the polluter pays principle. The additional costs to the local authorities of dealing with FOG discharges are therefore levied on those responsible for those discharges.