Exclusive: Secret report suggests fats, oils and grease accumulate in ‘inaccessible dead zone’ at Malabar plant, then dislodge when pumping pressure ‘rapidly increases’

A giant fatberg, potentially the size of four Sydney buses, within Sydney Water’s Malabar deepwater ocean sewer has been identified as the likely source of the debris balls that washed up on Sydney beaches a year ago.

Sydney Water isn’t sure exactly how big the fatberg is because it can’t easily access where it has accumulated.

Fixing the problem would require shutting down the outfall – which reaches 2.3km offshore – for maintenance and diverting sewage to “cliff face discharge”, which would close Sydney’s beaches “for months”, a secret report obtained by Guardian Australia states.

“The working hypothesis is FOG [fats, oils and grease] accumulation in an inaccessible dead zone between the Malabar bulkhead door and the decline tunnel has potentially led to sloughing events, releasing debris balls,” the report concludes.

“This chamber was not designed for routine maintenance and can only be accessed by taking the DOOF offline and diverting effluent to the cliff face for an extended period (months), which would close Sydney beaches.”

  • SwingingTheLamp@piefed.zipEnglish
    11·
    8 hours ago

    That’s not quite it. The wastewater treatment plant is located high up on the cliffs above the ocean. It has a big pipe that they tunneled through bedrock so it discharges at the bottom of the ocean 2.3km from shore. The fatberg is in the junction between the plant and the pipe. To clean it out, they’d have to stop using the big drain pipe, and y’know, just dump sewage off the edge of the cliff into the ocean, pretty much right onto the beach.

    • tomiant@piefed.socialEnglish
      10·
      8 hours ago

      Oh, I got the impression it was just… Floating there right out in the ocean.

      How the fuck is this not an engineering problem they must have foreseen? I mean now what, the pipes just stay clogged? What a literal shitfest.

      • SwingingTheLamp@piefed.zipEnglish
        61·
        7 hours ago

        IKR? The need for maintenance eventually should be foreseen! If they went to all the trouble to put a pipe through bedrock, why not put 2 pipes, so there’s a backup?

        • ryathal@sh.itjust.worksEnglish
          3·
          6 hours ago

          The need for maintenance is forseen, but it’s generally deferred. There was probably a plan to do something every year or two, but they weren’t willing to shut the beach down for a week or so. A second pipe would be absurdly expensive.

        • tomiant@piefed.socialEnglish
          3·
          6 hours ago

          I want to hear FriendlyJordies take on this. I bet it’s going to end up being a case of low bid mafia-connected contractors building the damn thing.