BY IAN BROWNE, Member PurplePipe & Sandhurst Garden Club

On 15 October approximately 25 Members and guests of PurplePipe met at the Eastern Treatment Plant in Bangholme for a guided tour of the plant.

The weather was cold wet and windy but nevertheless everyone arrived well prepared with the exception of the Tour Guides who didn’t expect that the older generation would want to go out in the wet.

We were treated to a 40-minute video of how the plant works showing the progress of a drop of water falling on Mt Sugarloaf through to its involvement in the sewerage process and finally ending up in the bay.

As our group was a beneficiary of the new recycled Water System, Melbourne Water had a specialist along to talk specifically about that and to answer any questions. He was also there to explain the progress and use of the 3rd stage development.

Points that were discussed were.

1. •The site was selected because it is one of the lowest points in the Metro area and gravity helps the flow.
   

2. •All the pipes meet 45 metres under the plant and the sewerage is pumped up using huge pumps.
   

3. •The overall size of the current operation. Far bigger than anyone realised.
   

4. •This plant processes all the sewerage from the eastern side of Melbourne and it is then discharged into the bay.
   

5. •Currently all sewerage is treated to a Level C category and then 7% is taken and treated to Level A and used as Class A recycled water. The remaining 93 % is discharged into the ocean. It was in order to improve the quality of this waste water that the 3rd stage is being built
   

6. •This would then mean that the water that will be processed to Class A+ level will be better than we are currently getting and will improve in quality and odour.
   

7. •When the plant is completed at the end of 2012 it will have a capacity of approx 60 % of the first stage of the desalinisation plant.
   

8. •Worth noting that the Class A water could be pumped into our dams and mixed with the current supply and then put through normal treatment to make it potable water. It isn’t done as it would be political suicide to try to convince the public to consume recycled sewerage, as is done in most densely populated countries.
   

9. •The plant has a major problem with illegal connections from storm Water to the sewer pipes (to save money) and the consequent is a massive inflow when a storm occurs.
   

We were also taken outside for a tour and shown the pump rooms, all driven by methane gas generated on site.

The filters and the settling ponds where bacteria is used to clean the water, eating the Ammonia and other pollutants.

They have massive Tanks to allow the sediment to settle from the final product and this sediment is then spread across the adjacent paddock to dry in the sun. It is the sold off as fill for certain developments where its’ integrity can be guaranteed. Such as Golf Courses.

A very interesting afternoon and our thanks go to Robert Cullen at PurplePipe who organised it all, and the staff at Melbourne Water who conducted the Tour in poor conditions.

If you get the chance to do the tour, take it, it is well worth it.