FROM NON-COMPLIANCE TO RELIABLE PERFORMANCE: A RESIDENTIAL ESTATE CASE STUDY

Clearedge Projects

Jul 21

2 min read

BEFORE & AFTER

The Challenge

For many residential estates, the wastewater treatment plant is one of those critical assets that nobody thinks about—until it stops working.

More than 15 years ago, Clearedge Projects installed a compact wastewater treatment plant for Rivermead Estate. The system operated successfully for many years, consistently producing compliant effluent and serving the estate without issue.

Over time, service providers changed and modifications were made to the treatment process without a full understanding of how the original system had been designed.

Media was changed and additional treatment reactors were added. The bioreactors ultimately became a hybrid of Clearedge's original Whale Tooth aeration system and coarse bubble diffusers powered by a blower. While the intention was to improve performance, the modified process never achieved the required biological treatment efficiency.

Bioreactor full of sludge & no movement of media
Modified Bioreactors - not working efficiently
Non-original aeration pump - inefficient

A SYSTEM SHOWING SIGNS OF FAILURE

The new reactors showed little to no media movement, resulting in poor oxygen transfer and ineffective biological treatment. As performance declined, the estate began receiving multiple non-compliance notices from the municipality.

Finding a Better Solution

Clearedge was asked to investigate whether the system could be recovered. Having successfully resolved issues on another wastewater treatment plant within the same property portfolio, our team was brought in to assess the situation and recommend a practical solution.

Rather than replacing the entire plant, we looked at how the existing infrastructure could be used more effectively. The treatment plant was housed within a large underground concrete chamber. Instead of installing additional tanks, we removed the existing plastic bioreactors and converted the concrete structure into a permanent treatment facility by constructing internal reinforced walls and waterproofed process compartments.

WORK BEGINS

The Upgrade

The refurbishment included:

A new 7.5 kL balancing tank to stabilise incoming flows.
Two 7 kL Submerged Aerated Fixed Film (SAFF) bioreactors constructed within the existing concrete structure.
Reuse of the existing conical-bottom clarifier and 500L contact tank.
A redesigned aeration system to deliver reliable oxygen transfer and biological treatment.
A fresh coat of paint.

The Result

The rehabilitated plant now provides stable biological treatment, improved process reliability, and a significantly more robust operating platform for the estate. Most importantly, Rivermead Estate once again has a wastewater treatment plant capable of consistently producing compliant effluent.

Why This Matters

Wastewater treatment plants are specialised assets.

While pumps, pipes and electrical components may appear straightforward, the biological treatment process depends on a careful balance of oxygen transfer, hydraulic loading, retention time and process control.

Any modifications to a treatment plant should consider the original process design and the interaction between each component. Even well-intentioned changes can have unintended consequences if the biological process is affected.

For property managers and body corporates, investing in specialist expertise can reduce long-term operating costs, minimise compliance risks and extend the life of existing infrastructure.

If your estate is experiencing recurring compliance issues, odours, poor effluent quality or rising operating costs, Clearedge Projects can assess your existing treatment plant and recommend practical, cost-effective solutions before small problems become major ones.