Combined Aeration & Biological Treatment Controls Invasive Aquatic Weeds at a QLD School

THE CHALLENGE:

Assisi Catholic College in Coomera faced significant water quality deterioration in their ornamental water body, compromising both the aesthetic appeal and ecological health of this important campus feature.

The approximately 2,800 m² water body with three to four megalitres capacity exhibited multiple interconnected problems:

• Invasive aquatic weed infestations including dense mats of Azolla, Creeping Primrose, and Water Lilies covering substantial portions of the water surface
• Water stagnation with minimal circulation creating dead zones throughout the pond
• Poor dissolved oxygen levels resulting from lack of aeration and excessive plant matter decomposition
• Unpleasant odours emanating from anaerobic conditions caused by organic matter accumulation
• Compromised water clarity affecting the visual appeal of the educational landscape feature
• Ecological imbalance with invasive species dominating over beneficial native aquatic plants

The degraded conditions were particularly problematic for an educational setting, where the water feature serves as aesthetic enhancement and environmental education opportunities for students. Previous treatments had proven inadequate for sustained improvement, with rapid recontamination occurring under Southeast Queensland’s subtropical conditions that favour invasive species proliferation.

OUR SOLUTION:

BioRemedy designed and implemented a comprehensive three-phase combined treatment strategy specifically tailored to restore the water body whilst maintaining environmental sensitivity appropriate for the school setting:

Phase 1: Targeted Herbicide Treatment

• Environmentally sensitive applications: Multiple targeted herbicide treatments conducted by BioRemedy specialists following strict environmental protocols
• Species-specific control: Systematic targeting of Azolla, Creeping Primrose, and Water Lilies without affecting beneficial aquatic plants
• Safety-first approach: All applications timed and dosed to ensure student and wildlife safety whilst achieving effective invasive species control

Phase 2: Mechanical Aeration System

• Sprint 1.5 Fountain Aerator: Installed to provide continuous water circulation and oxygenation throughout the 2,800 m² water body.
• Dual-functionality design: Selected for its ability to improve water quality mixing 1,500l/min whilst serving as an attractive fountain feature enhancing the campus aesthetics, with an attractive 1.5m plume.
• Strategic positioning: Aerator placed to maximise circulation patterns across the entire water body whilst maintaining visual appeal from key campus viewing areas

Phase 3: Biological Restoration

• EcoShock Beneficial Bacteria: Initial shock treatment to establish healthy microbial communities following herbicide breakdown
• EcoTabs Maintenance Programme: Ongoing bacterial dosing to support long-term ecosystem stability and water quality
• Adaptive timing: Bacterial introduction strategically delayed until optimal water conditions were achieved for successful microbial establishment

This combined approach addressed both immediate invasive species problems and underlying water quality issues, creating sustainable conditions that would support long-term ecosystem health appropriate for the educational environment.

THE RESULTS:

This treatment approach delivered remarkable improvements in water quality and ecosystem health at the Assisi Catholic College water body:

Successful Invasive Species Control

• Azolla elimination: Coverage reduced from near-complete surface domination to manageable levels following targeted herbicide applications
• Creeping Primrose reduction: Established plants showed significant decline with new growth substantially reduced
• Water Lily management: Both established plants and new growth effectively controlled whilst maintaining safety for surrounding wildlife
• Enhanced light penetration: Removal of dense surface vegetation allowed improved aerator performance and water quality

Immediate Water Quality Improvements

• Enhanced circulation: Sprint 1.5 aerator eliminated stagnation conditions within the first week of operation
• Increased dissolved oxygen levels: Substantial improvements measured throughout the water column, creating aerobic conditions favourable for beneficial organisms
• Improved water clarity: Visible enhancement in water transparency as circulation patterns distributed oxygen more evenly across the entire 2,800 m² surface

Long-term Ecosystem Restoration

• Odour elimination: Complete removal of unpleasant anaerobic odours through establishment of healthy aerobic microbial processes
• Beneficial bacteria establishment: Successful colonisation of EcoShock and EcoTabs bacterial populations supporting ongoing water quality maintenance
• Native species recovery: Diverse aquatic plants began naturally recolonising areas previously dominated by invasive species
• Wildlife habitat improvement: Enhanced water quality attracted beneficial insects, birds, and other organisms creating educational opportunities for students

Sustained Performance

• Minimal maintenance requirements: System continues operating effectively with routine monitoring and periodic bacterial dosing
• Aesthetic enhancement: Transformation from degraded pond to attractive educational water feature
• Educational value: Restored ecosystem now serves as practical environmental learning resource for students and staff

PROJECT TEAM:

The success of this project reflects the expertise and collaboration of:

BioRemedy Technical Specialists: Led the comprehensive treatment strategy development and implementation with their expertise in water body management. The team’s experience in environmentally sensitive applications proved crucial for achieving effective invasive species control whilst maintaining safety standards appropriate for the school setting. Their systematic approach to combining mechanical aeration with biological treatment delivered the sustainable water quality improvements essential for the educational environment.

Assisi Catholic College Facilities Management: Provided essential on-site coordination and ongoing support throughout all treatment phases. Their commitment to environmental sustainability and willingness to implement innovative water management solutions enabled the successful transformation of the campus water feature into an attractive and ecologically healthy educational resource.

For commercial institutions and facility managers facing similar aquatic weed challenges in urban water bodies, this project offers a proven template for sustainable water quality restoration that maintains both environmental sensitivity and aesthetic appeal. The combined mechanical aeration and biological treatment approach demonstrates how innovative solutions can transform degraded water features into valuable commercial and environmental assets.

Contact our team today to learn how this comprehensive treatment strategy might benefit your water management challenges in commercial settings.