The original IRIS Master Plan was produced in 1992 and recommended an integrated 'all-Island' solution to sewage treatment. The four main objectives were to:

  • cease the discharge of raw sewage to the marine environment
  • transfer foul sewage to a centralised sewage treatment plant for treatment
  • treat the foul sewage flows to a standard designated by Tynwald
  • decommission the proliferation of small sewage treatment works

Since 1995, the following achievements have been noted through implementation of the IRIS Master Plan in the south:

  • sewage from 65% of the Island's population being treated at the new wastewater facility at Meary Veg
  • sludge, the natural sewage by-product, being treated in a new sludge dryer at Meary Veg, thus enabling the resultant pelletised product to be taken to the Energy from Waste Plant 
  • cessation of raw sewage discharges at Port Erin, Port St Mary, Castletown, Derbyhaven, Douglas and Onchan
  • decommissioning of the Union Mills, Braddan Hills, Silverburn, Mount Murray, Croit-y-Caley and Balthane sewage treatment works
  • improvements in bathing water quality