YEPPOON SEWAGE TREATMENT PLANT AUGMENTATION

YEPPOON

SEWAGE TREATMENT PLANT

AUGMENTATION

PROJECT BACKGROUND

Yeppoon STP Location

Sludge

Dewatering

Blowers

Original BNR Plant

• Existing Yeppoon Sewage Treatment Plant (YSTP) was commissioned in 2006

• Biological Nutrient Removal (BNR) plant designed to treat flow of 21,000 equivalent persons (EP)

• Treated effluent reused for irrigation or discharged to Corduroy Ck

• Waste sludge was dewatered and disposed of at landfill at significant cost

• Plant had performed well to date

Project Background

• Plant Audit and Augmentation Options studies done in 2015 and 2016

• Capacity increased from 21,000 EP to 31,000 EP

• Will accommodate population growth for ~10 years

• Augmentation involved conversion to MBR plant

• Utilises latest membrane technology

• Improved effluent quality (Class A) produced

Augmentation Overview

PROJECT SCOPE

New Inlet Works

New Odour Control Facility

Bioreactor Refurbishment

Membrane Feed Pumping

New Membrane Filtration

New Membrane Filtration

New Chemical Dosing System

Centrifuge

ENGINEERING & DESIGN

Downer MBR ProcessYeppoon STP is Downer’s 21st MBR Process Plant

• Downer has a proven track record of successful delivering 23 MBR process plants over the past 15 years

• First plant constructed in 2005 (Victor Harbor STP)

• Avg Flows between 0.18 – 18.6 ML/day

• Peak Flows between 0.2 – 95 ML/day

Design ParametersParameter ValueInitial Daily Inflow 4 ML/d

46 L/sDesign Average Dry Weather Flow (31,000EP) 6.2 ML/d

71.8 L/sDesign Peak Full Treatment Flow (3 x ADWF) 18.6 ML/d

216 L/sUltimate PFTF 292 L/sMaximum Design MBR net outflow – three trains (12 membrane modules)

256 L/s

Maximum Design MBR net outflow – Ultimate four trains online (4.6 x ADWF)

332 L/s

• MBR design caters well for plants with high rainfall through the addition of more membrane modules.

Design Parameters

• The design was typical domestic wastewater with the provision of septage loading

Parameter Raw Sewage 50%ile Design Load

Raw Sewage 90%ile Design Load

Maximum Septage Load

COD (kg/d) 3,653 4,932 170BOD (kg/d) 1,588 2,144 26.5TSS (kg/d) 1,827 2,467 157VSS (kg/d) 1,553 2,097 103TKN (kg/d) 364 492 14.3Ammonia (kg/d) 291 393 6.4Total P (kg/d) 61 83 3.6Oil and Grease (kg/d) 372 502 3.5

Process Flow Diagram

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3D Modelling

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Final Plant

Planning for Staged Construction

Value in DesignDowner provided a number of key features that added value for Livingstone Shire Council

• Stage 2 upgrade (in 10+ years time) could require an additional bioreactor –Downer provided a connection point on the outlet of the inlet works

• Additional screening capacity provided via ‘oversized’ fine screens

• The membrane tanks were fitted with 3 trains and a fourth spare for a future upgrade

Reduction in Plant Footprint

DELIVERY

Engaging the Local Supply Chain• 6 local delivery partners chosen to perform the main elements of the

project

Contractor Scope

JRT Civil Civil Works

BME Mechanical and piping Installation

NRG Industrial Electrical – Supply & Installation

Intallect

CQ Steel Structural Steel – Supply & Installation

Form2bSure Concrete Structures

Works Staging – integration with existing plantNew facilities integrated into the existing plant in staged process

Stage 1: Enabling Works:

• Demolition & temporary works

Stage 2: New Inlet Works

• New Inlet Works commissioned & cut over

Stage 3: Bioreactor 1 Offline

• Plant operates with new Inlet Works and only 1 Bioreactor while Bioreactor 1 is refurbished

Stage 4: Bioreactor 2 Offline

• Plant operates with new Inlet Works and only 1 Bioreactor while Bioreactor 2 is refurbished

Works Staging – integration with existing plantNew facilities integrated into the existing plant in staged process

Stage 5: MBR Online:

• New MBR process integrated, existing clarifiers & tertiary filters decommissioned

Stage 6: Bioreactor 2 Online

• Refurbishment of Bioreactor 2 complete, plant now operating with new inlet works, MBR, and both bioreactors

Stage 7: Dewatering, Odour Control System and Final Works

• New dewatering system commissioned & cut over

• New Odour control system operational

QLD Building & Construction Training

LSC were successful in securing $5 M funding from Building Our Regions (BOR) State funding program.

Training Hours Achieved:

• Over 4800 hours for workforce apprentices/trainees

How this was Achieved:

• Engagement of local workforce with focus on providing upskilling opportunities

• Tenderers evaluated on their commitment to providing employment to apprentices/trainees for duration of the project

PERFORMANCE

Plant Performance

The final plant performance was assessed against:

• Effluent Quality

• Power Consumption

• Chemical Consumption

• Biosolids Generated

• Operability

Improved Recycled Water Quality

Effluent quality:

• Total Nitrogen <1.5 mg/L

• Total Phosphorus <1 mg/L

• Reliable bacterial results (<2 CFU/100mL)

• Turbidity <1 NTU

Operating CostsNo increase in specific power consumption Reduced Chemical

Biosolids Disposal Costs

Reduced due to increased dryness

• 22%w/w dry solids achieved with decanter centrifuge using membrane pre-thickening of WAS

KEY ACHIEVEMENTS

Key Achievements

• Successful delivery of the treatment plant upgrade on time and on budget

• Successfully integrated the new treatment plant into the existing treatment plant process, without incident

• Improved sustainability and optimised plant operation

• Supporting the community through buying local

• Contributing to the construction industry through training of apprentices