“Pond 3 is usually the most reliable, but the concurrent failure of three separate aerators is unexpected,” CDC said.
“Our three ponds rely on a fine balance of biochemistry to stop bad odours from travelling most of the time in waste stabilisation ponds.
“There are two distinct layers within ponds, anaerobic [no oxygen] bottom layer and aerobic [top layer].
The lower layer is made of solids that accumulate over time in the bottom of each pond, where they are slowly consumed by microbes.
“These microbes produce bad odours which are consumed as they pass through the aerobic layer.
“However, if that balance is removed by weather changes, chemicals, or high loads in the network, it will impact the ponds, upsetting the aerobic layer and allowing the bad odours to get to the surface.”
The council said it was looking for replacement aerators.
“One is at the end of its life, and our team has been working on a replacement for the last month to get a replacement.
“A second aerator has a fault, and we are waiting for an electrician to check it.
“The final aerator stopped this week. We are investigating today [Friday] as we suspect it is blocked with rags.”
CDC is dosing twice a day in the interim to increase the oxygen level and divert more of the flow to Pond 1.
The council asked residents to “remember the three Ps”: “If it’s not pee, paper, or poo, it doesn’t go down the loo”.
One of the issues CDC is looking to address in its Long-Term Plan [LTP] is the outdated wastewater treatment plant equipment, which was last upgraded more than 60 years ago.
The potential proposed upgrades will address foul air treatment.
The draft LTP will be available to the public from March 22 as part of the Ordinary Council Meeting agenda for March 27.
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