Bowen Sewage Treatment Plant Upgrade

Aquatec Maxcon previously worked at the Bowen STP in 1988, however due to increasing population and a highly sensitive environmental location Whitsunday Regional Council engaged Aquatec Maxcon again to design and construct the new Bowen STP in 2018. At the core of our design was to utilise a Membrane Bioreactor (MBR) process to treat the wastewater to the strictest environmental standards. This project continues a long list of MBR projects delivered by Aquatec Maxcon since it delivered the first MBR plant in Australia in 2001 – also in QLD and continues to pioneer the process.

The 14,000EP catchment was predominantly domestic from the local area of Bowen with some industrial contributors. The Brownfield site and constrained project timeline meant programming and cutover methodology would need to be innovative for the success of the project, particularly when considering its environmentally sensitive location.

The full treatment process consists of:

• A package inlet works 
• Bioreactor with dedicated anoxic, aerobic zone with Aquablade fine bubble diffusers and de-aeration zones
• Three membrane tanks with proprietary modules and air-scouring blowers
• Retained chlorine contact tank with gas chlorination for pathogen control
• In-line, pre-validated Trojan ultraviolet system to achieve Class A recycled water
• Conversion of existing bioreactor and clarifier into an MLE-configured Aerobic Digester
• Comprehensive odour modelling to pinpoint emission zones
• BioAir Biological Trickling Filter (BTF) and activated carbon unit treating foul air from the PTA, bioreactor, septage facility and pump station before atmospheric release

The key design parameters were:

• Operational Brownfield site where operation must be maintained
• 3.5MLD ADWF combined influent capacity ( PWWF 5x ADWF)
• Effluent Total Nitrogen (TN) <4.8
• Effluent Total Phosphorus (TP) <1.8 (biological P-removal supplemented by chemical dosing)
• Class B Biosolids Stabilisation from the Aerobic Digester
• <2.5 Odour Units (OU) at the plant boundary

The MBR successfully treats the combined domestic and industrial influent and complies with the environmental license. The recycled water is used in councils greening Bowen initiative and is well received within the community. 

Through innovative design Aquatec Maxcon has utilised new and existing infrastructure on an operational brownfield site successfully to deliver all key project objectives. Aquatec Maxcon has built over 30+ MBR plants across Australia and New Zealand.