Case Study
Bolivar WWTP
Rehabilitation
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Concrete works (representative)
Project Overview
The Bolivar Wastewater Treatment Plant is Adelaide's largest water recycling facility, processing wastewater from over 600,000 residents across metropolitan Adelaide. The plant's sedimentary tanks, constructed in the 1960s and expanded through subsequent decades, had developed significant concrete deterioration due to decades of exposure to hydrogen sulphide gas, chloride ingress from recycled water chemistry, and carbonation-induced reinforcement corrosion.
Jerome served in a dual role as Project Manager and Structural Engineer within SA Water's AllWater Alliance, leading the structural assessment and concrete rehabilitation of critical sedimentary tank infrastructure. The scope required detailed condition assessment of reinforced concrete walls, floors, and internal baffle structures, followed by design and delivery of repair methodologies tailored to the aggressive chemical environment and operational constraints of a continuously operating treatment plant.
The rehabilitation programme demanded careful coordination with plant operations to maintain treatment capacity throughout the works. Tanks could only be taken offline individually, with dewatering, cleaning, confined space preparation, and reinstatement activities sequenced around the plant's hydraulic loading patterns. Every repair material and methodology had to be compatible with the wastewater environment and approved by SA Water's asset management team for long-term durability.
2014 — Primary Sedimentary Tanks Refurbishment
Specialist Service Subcontractor Coordination
On the Primary Sedimentary Tanks refurbishment for SA Water and AllWater, I managed the specialist service subcontractors who delivered the mechanical and electrical scope inside live tanks.
- Managed WATERNISH and SAGE AUTOMATION across the install and commissioning of pipes, cable, trays, sensors, water-stop gates, activating motors, systems and electro valves
- Most works were delivered in confined-space environments with strict access controls and continuous gas monitoring
- Sequenced rehabilitation works with the live treatment plant operating at full capacity
- Concrete rehabilitation, structural assessment, and reinforcement coordination on the structural side
Scope of Work
JCY delivered the following structural and project management services:
- Detailed structural condition assessment of reinforced concrete sedimentary tanks
- Concrete core sampling, carbonation depth testing, and chloride profiling
- Half-cell potential mapping to identify active reinforcement corrosion zones
- Structural capacity assessment of deteriorated sections against current loading requirements
- Repair methodology development for each deterioration mechanism (sulphide attack, carbonation, chloride-induced corrosion)
- Material specification for concrete repair mortars, protective coatings, and cathodic protection systems
- Reinforcement replacement coordination where section loss exceeded serviceability limits
- Construction programme development sequenced around plant operational constraints
- Confined space work planning and safety documentation for internal tank works
- Project management of the rehabilitation delivery including cost control, progress reporting, and stakeholder communication
Key Challenges & Solutions
Aggressive Chemical Environment
The sedimentary tanks operated in a hydrogen sulphide-rich atmosphere above the water line, with sulphuric acid attack causing severe concrete surface deterioration in the gas zone. Below the water line, chloride ingress from recycled water chemistry had initiated reinforcement corrosion in multiple wall panels. Jerome specified a layered repair approach: sulphate-resistant repair mortars for the gas zone, chloride-extracting treatments in the splash zone, and epoxy-modified cementitious coatings below water level. Each material selection was validated against SA Water's approved materials register and independently tested for compatibility with the specific wastewater chemistry at Bolivar.
Continuous Plant Operations
Bolivar processes approximately 130 megalitres of wastewater per day, and treatment capacity could not be materially reduced during rehabilitation works. Only one tank could be taken offline at a time, and reinstatement had to be completed before the next tank could be dewatered. Jerome developed a rolling rehabilitation programme that aligned tank shutdowns with seasonal hydraulic loading patterns, scheduling the most intensive works during the lower-flow winter months when the plant had greater hydraulic buffer. Each tank turnaround was planned to a daily level of detail, with material procurement lead times built into the programme to eliminate delays during the compressed construction windows.
Confined Space Complexity
All internal tank rehabilitation works constituted confined space entry under SA Water's safety management system, requiring continuous atmospheric monitoring, standby rescue personnel, and strictly controlled entry/exit procedures. The hydrogen sulphide residuals in dewatered tanks required forced ventilation systems running continuously during work periods. Jerome integrated confined space requirements into every construction activity plan, sized ventilation systems for each tank geometry, and established emergency response procedures specific to each work location. This planning enabled an incident-free rehabilitation programme across all tank entries.
Technical Details
Assessment Methods
- Concrete core sampling and compressive strength testing
- Carbonation depth measurement (phenolphthalein indicator)
- Chloride profiling at multiple depths
- Half-cell potential mapping for corrosion detection
- Cover meter surveys for reinforcement location and cover depth
Repair Systems
- Sulphate-resistant cementitious repair mortars (gas zone)
- Chloride-extracting electrochemical treatments (splash zone)
- Epoxy-modified cementitious coatings (submerged zone)
- Supplementary reinforcement where section loss exceeded limits
- Protective coating systems for long-term durability
Project Partners
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JCY delivers structural assessment and concrete rehabilitation for water and wastewater infrastructure, combining structural engineering expertise with practical construction delivery.