Existing plants
Existing water and wastewater plants can drift from their original performance as loads grow, production changes, equipment ages or reuse targets rise.
Unisavour Industries Limited reviews existing plants to understand why they are underperforming, then defines and delivers the improvements worth making — from operational changes to rehabilitation, retrofitting, automation and modernisation.
In short
Existing ETPs and STPs can underperform for many reasons: loads higher than the original design, changes in wastewater characteristics, ageing or failed equipment, unstable biological treatment, inadequate sludge management, manual operation, or a treated-water requirement that has become stricter. The cause is rarely clear from a single symptom, which is why the plant and its data should be evaluated before any upgrade decision.
The challenge
Each of these has several possible causes. They are questions to investigate, not diagnoses.
Treated-water quality no longer meets the requirement.
Flow or organic load now exceeds the original design basis.
Frequent upsets, sludge problems or inconsistent performance.
Breakdowns, worn components or obsolete controls.
Performance depends heavily on manual intervention.
More treated water now needs to be reused, at a higher quality.
New products or processes have changed what reaches the plant.
Engineering approach
Diagnose before deciding. The audit sets the scope of everything that follows.
Review the design basis, records, equipment, operation and treated-water data.
Identify the likely causes from the evidence, including any sampling needed.
Set out practical options, from operational changes to new stages.
Rehabilitation, retrofitting, automation and equipment upgrades.
Confirm performance against the treated-water objective.
Operator training, O&M and servicing to keep performance stable.
Technologies
A named technology is one part of a treatment train. Which of these suits a particular site is confirmed through water analysis, process design and the required outcome.
Wastewater Treatment
Biological treatment combined with membrane separation for applications that require a highly clarified treated-water stream.
Process family · Biological + membrane
Typical use · Advanced biological treatment, high treated-water quality or recycling
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Wastewater Treatment
Attached-growth biological treatment using carrier media that provide surface area for microorganisms while moving within the reactor.
Process family · Attached growth
Typical use · Sewage and industrial wastewater needing robust treatment and operational flexibility
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Wastewater Treatment
A biological process in which treatment stages occur sequentially within the same reactor through controlled operating cycles.
Process family · Activated sludge / batch
Typical use · Variable flows where batch-cycle operation offers process flexibility
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Common questions
What buyers ask about existing plants.
Not always. Some plants can be improved through operational changes or targeted retrofits; others may need significant rebuilding or replacement of specific stages. The audit is what establishes which is realistic for the plant and its objective.
A plant review typically examines the design basis and documentation, current flows and loads, available inlet and outlet analysis, equipment condition, operating practices and records. Where data is missing, sampling may be recommended. The findings are used to identify likely causes and define improvement options.
Retrofitting modifies an existing plant to improve its performance or capacity — for example by adding carrier media to biological tanks, upgrading aeration, adding tertiary filtration or membranes, replacing equipment, or adding automation and instrumentation. The appropriate measures follow from the diagnosis.
Whatever is available. The most useful starting information is:
Existing plants
Share the plant type, capacity, the issues you are seeing and any recent analysis or records. Our team can help define what to investigate first.Don't have complete technical data yet? Share what you know — our team can help identify what is needed for the next step.
