You’re welcome Bin! 🙂
A quick update, I found this recent article: Roadtrain® Delivers Safe Environmental Discharge for Saibai STP from Hydrolux, the supplier of the packaged plant which appears to me that their sewage treatment plant system has been upgraded.
Based on our recent chat with a TSIRC staff, we have confirmed that sludge are untreated and sent directly to the landfill.
I hope this helps!
Regards,
Jean