Sewage overload

I have written several letters over the past years concerning Byron Shire Council, including my concerns about the level of infiltration occurring during high rainfall into the gravity sewer mains in Mullumbimby. The previous director of water and recycling and his engineering staff submitted to council in 2011 that the infiltration of the Mullumbimby gravity mains had been resolved. The evidence used to support this was a reduction in sewer-pump run hours. What the director failed to add was that this had been done by replacing the existing pumps with substantially larger pumps. This meant that pump-run hours would be reduced.

There was a consultant’s report supplied to the then Brunswick Waste Water Steering Committee in 2006. That report in part stated that unless the Mullumbimby infiltration was stopped Vallances Road STP would be hydraulically overloaded within four years.

The Vallances Road Sewage Treatment Plant was commissioned in 2011 and the Clause 45 ‘Sewerage Moratorium’ was lifted.

There have been reports of biosolids being dumped on the riverbank from the Vallances Road STP during high rainfall that are extremely offensive in odour. This is a sign that a plant of this design is showing signs of being hydraulically overloaded.

The only way to substantiate that the infiltration had been stopped would be to examine the daily inflow and daily rainfall figures recorded by the operator in charge on the operational sheet at the Vallances Road plant to see if there are larger inflows during rain periods in Mullumbimby. This data recording is required by government authorities.

If the data confirm that infiltration problems exist then the information given to the elected Council by BSC’s sewer management should be re-examined.

Alan Dickens, Brunswick Heads