Client:

Citiwater, Business Unit of Townsville City Council

(Water Matters Alliance)

Location:

Horseshoe Bay, Magnetic Island

Service:

Greenfield site, re-use

Value:

-

Completion Date:

2006

After 3 ½ years of successful operation at Picnic Bay, Citiwater in conjunction with the Water Matters Alliance selected a Kubota MBR system as the preferred option for a new wastewater treatment plant at Horseshoe Bay to meet the stringent discharge requirements.

Solution
A MLE Process utilising a Kubota MBR system was installed to meet low nitrogen, phosphate and pathogen limits. Alum was dosed to meet the low Phosphate requirements.
Kubota membranes have a nominal pore size of 0.4µm and an absolute pore size of 0.01µm, which provides an absolute barrier to biomass, and pathogens retaining them within the process tank.

Process Overview
The raw water first passes through a 3mm fine screen into a bioreactor. The bioreactor consists of 3 stages – two denitrification tanks, followed by the MBR tank. Filtration is achieved by drawing effluent through the surface of the flat sheet membranes under a gravity head. No suction pumps are required.

The effluent from the plant is reused to irrigate a dry tropical forest parkland or discharged to the Great Barrier Reef Marine Park.

Client:

Citiwater, Business Unit of Townsville City Council

(Water Matters Alliance)

Location:

Townsville, QLD

Service:

Wastewater treatment

Cleveland Bay which was part of the Water Matters Alliance in Townsville, included mechanical design, equipment and installation including switchboards, PLCs & SCADA and the Kubota flat sheet membranes for the membrane bioreactor at Horseshoe Bay. This plant has received many awards including the Excellence Award for a Major Water Project Greater than $5M and the Alliance Project Team Excellence Award. Also becoming finalists in the 2009 Australian Water Association – Water Environment Merit Award and the 2008 Australasian Alliancing Association Awards.

Delivery of the programme of works included:

• Brownfield capacity and quality upgrade of Cleveland Bay WRP to 126,000 EP Biological Nutrient Removal (BNR);
• Membrane Treatment system retrofitted into the existing clarifiers which we reconfigured to become bioreactors. The plant combines an oxidation ditch with membrane separation. A biosolids handling facility was undertaken also. Effluent from the plant can be treated in a future water reclamation facility which will include reverse osmosis to achieve reuse water suitable for industrial and irrigation applications. The efficient equipment selections have resulted in the operating costs being substantially below the initial projections with savings approaching $1m per annum.
• The Cleveland Bay WTF was, at commissioning, the largest MBR in the Southern Hemisphere and one of the largest MBR plants in the world.
• The scope also included an upgrade of the plants control, SCADA and telemetry systems by MPA Engineering.
• Effluent Achieved: Total N (mg/l – 3.5); Total P (mg/l – 0.5) discharging to Great Barrier Reef Marine Park

Client:

Brisbane Water (BWEA Alliance)

Location:

Sandgate, QLD

Service:

Wastewater treatment

Value:

AUD $130 M

Completion Date:

2006

The Sandgate WWTP is located on Paperbark Drive at Sandgate. It is bordered by residential properties on the northern side of Cabbage Tree Creek in the north Brisbane suburbs of Shorncliffe and Deagon. Sandgate WWTP upgrade was delivered as part of the Brisbane Water Enviro Alliance in which Aquatec Maxcon was a partner. The programme also included upgrades to Oxley Creek, Wynnum and Wacol WWTPs.

The plant discharges treated wastewater into Cabbage Tree Creek. The upgrade to the Sandgate WWTP involved heavily brown fields replacement of out-dated infrastructure and mechanical equipment with new state of the art technology. These works have improved treatment quality, increased plant capacity, reduced odour and improved the quality of water in Cabbage Tree Creek.

Features of the upgrade included:

• Increased capacity from 18mega litres per day to 25 megalitres per day, servicing an ultimate population of 110,000 persons;
• Nitrogen reduced from 30 milligrams per litre to less than 5 milligrams per litre;
• Odour mitigation works between December 2004 and March 2005;
• Replacement of existing trickling filters with bioreactors to improve nitrogen and phosphorus removal using fine bubble aeration oxidation ditch process;
• New final settling tanks;
• New sludge dewatering and handling facilities;
• Installation of ultra violet (UV) disinfection equipment to replace existing chlorine disinfection;
• Decommissioning of primary settling tanks and digesters;
• Upgrade fully constructed inside plant fence line; and
• Effluent quality achieved.