Update on the Duffin Creek Sewage Plant Outfall

February 21 - Joint meeting of Finance & Administration, Health & Social Services, Planning & Economic Development, and Works Committee

  • Regional Environmental Commissioner John Presta gave a PowerPoint presentation to Council about the Phase II report on the Outfall EA which showed a clear preference for 'duckbill diffusers' which would simply spread the effluent a little wider in order to achieve slightly better dilutions. The information presented made tertiary treatment appear very expensive with the highest carbon footprint. The report itself was not presented.
  • DC president Doug Anderson also made a 5 minute presentation dealing with the outfall and sewage in generalities. He indicated the preferred solution would be one which actually removed phosphorus, hence, tertiary treatment.
  • In spite of the sketchy information, the Joint Committee (virtually all members of Council) approved the report.

Subsequently, when the report was released, it became clear that the Powerpoint presentation had left out significant details, most important was the range of tertiary treatment options - including:

  • Travelling Bridge Filters,
  • Deep Bed Filtration,
  • Cloth Filtration,
  • Membrane Filtration, and
  • Ballasted Clarification.

These are all quite different and the only common element among them is that they all remove most of the phosphorus. Click here to view the actual Section 4.5 of the Draft Report. In order to make their preferred option look good, the project team decided that "Membranre filtration will be carried forward as the representative tertiary treatment alternative for evaluation in Phase 2 of this Class EA. It has been selected at this stage as it is the best alternative with respect to performance, which is an important criterion to project stakeholders." In doing so they selected the most expensive of the tertiary treatments. What they neglected to say was that all of the tertiary options have higher prformance than any of the outfall options.

The actual costs and performance of these were compared in a chart using +'s

Note that even the cheapest of these options - ballasted clarification - "can achieve total phosphorus less than 0.15 mjg/L which about 1/4 of the concentration in the current effluent which would not be changed by any of the outfall options.

I have requested that all of these options be properly costed on the grounds that "grouping these 5 tertiary options together as a single option, with the most expensive as representative, makes as much sense as grouping all the outfall options together and using the new 3 km outfall as the representative." Using that logic, tertiary treatment would win. 

February 26 & 27 - Public Information Forums in Pickering and Ajax

  • These meetings were very well attended and the project team were given an earfull. A common topic was phosphorus and it was pointed out the the phosphorus being put into the lake by the outfall was equivalent to 2,000 bags of lawn fertilizer every day.

March 6 - Regional Council Meeting

  • The joint committee report to approve the Outfall Report came to Council was rejected.