Service tax non-requirement for CETP services: central directive relieves payment for past period due to prevailing practice. The Central Government, satisfied that a generally prevalent practice led to non-levy of service tax on services by operators of Common Effluent Treatment Plants for effluent treatment during the period from 1 July 2012 to 31 March 2015, directs that the service tax payable on those services shall not be required to be paid for that period under the powers conferred by the Central Excise Act and the Finance Act.