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Wet Weather Challenge

Combined sewer systems carry both sanitary sewage and stormwater. Heavy rainfall can overwhelm treatment capacity, causi

High Organic Loading

Wastewater streams frequently carry organic loads 5-50x higher than domestic sewage, demanding robust biological or physical-chemical treatment capacity.

Variable Conditions

Temperature, pH, flow, and concentration swings between production shifts create treatment instability without proper equalisation and buffering.

Biological Sensitivity

Shock loads, toxins, or pH extremes can kill beneficial biomass. Protection mechanisms like equalisation and pH correction are essential.

Fat, Oil & Grease

High FOG content causes pipe blockage, flotation cell failure, and membrane fouling. Effective pre-treatment prevents downstream operational issues.

Complex Chemistry

Variable chemical composition from cleaning agents, process chemicals, and raw materials requires adaptable treatment chemistry and dosing control.

Regulatory Pressure

Discharge consents are tightening continuously. Treatment must not only meet current limits but accommodate future reductions without major rebuild.

CSO Treatment Solutions

Our CSO treatment systems provide high-rate screening, settling, and disinfection for wet weather flows. These systems t

1. Site Assessment

Comprehensive analysis of wastewater volume, quality, temperature, and variability informs process selection and equipment sizing for optimal performance.

2. Process Design

Treatment train selected from screening, DAF, biological, filtration, and disinfection options based on effluent targets, footprint, and Capital expenditure constraints.

3. Equipment Selection

Materials, pumps, blowers, and instruments specified for the specific duty conditions, chemical environment, and operational maintenance capabilities.

4. Automation & Control

PLC-based control with online monitoring automates chemical dosing, aeration, and sludge withdrawal. Remote access provides 24/7 oversight.

5. Commissioning

Site acceptance testing verifies mechanical, electrical, and process performance. Operator training ensures confident day-to-day management.

6. Performance Guarantee

Contractual effluent targets with financial backing demonstrate our confidence. Monthly reporting proves continuous compliance for regulators and stakeholders.

Green Infrastructure

Green infrastructure including rain gardens, permeable pavement, and detention basins can reduce stormwater volumes ente

Engineered Performance

Every system is designed for your specific wastewater characteristics, flow profile, and effluent targets. No off-the-shelf assumptions — just validated process engineering.

Proven Reliability

Equipment selected from manufacturers with proven field performance in similar applications. Duty/standby arrangements and robust construction minimise unplanned downtime.

Environmental Compliance

Design targets are set at 50-70% of consent limits, providing a safety margin for process variation. Continuous monitoring and automated reporting demonstrate compliance.

Operator Friendly

Intuitive controls, clear instrumentation, and accessible maintenance points reduce training requirements. Standard operating procedures written in plain language.

Technical Support

Direct access to our process engineers for operational advice, troubleshooting, and optimisation. Remote diagnostics and rapid on-site response keep your plant running.

Quality Assurance

Materials certified to EN 10204 3.1, welding procedures qualified to ISO 9606, and pressure testing to 1.5x design pressure. Full traceability from mill to commissioning.

Related Pages

Municipal Centralised

Large-scale centralised wastewater treatment plants for cities and municipalities.

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Municipal Compliance

Ensure municipal wastewater treatment compliance with discharge permits.

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Municipal Decentralised

Decentralised wastewater treatment plants for villages, resorts and remote communities.

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Municipal Environmental

Protect receiving waters with advanced municipal wastewater treatment.

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Municipal Flow Variations

Handle wet weather flow variations in municipal WWTPs.

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Municipal Population

Municipal WWTP design based on population equivalents.

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Municipal Wastewater Treatment Process

Municipal wastewater treatment protects public health and receiving waters by progressively removing solids, organic matter, nutrients, and pathogens from sewage. Our engineered solutions address the unique challenges of municipal flows including diurnal variation, stormwater ingress, seasonal population changes, and increasingly stringent discharge standards.

Preliminary Treatment

Screening, grit removal, and flow equalisation protect downstream processes from damage and overload.

Primary Clarification

Gravity separation of settleable solids achieving 50-70% TSS and 25-40% BOD removal.

Biological Treatment

Activated sludge, MBBR, or SBR processes remove dissolved organics and enable nutrient control.

Tertiary & Disinfection

Filtration, UV, or chemical disinfection guarantees compliance with bathing water and reuse standards.

Plant Design Parameters

Design Flow50 – 500,000 PE (population equivalent)
Dry Weather Flow150 – 250 L/PE/day
BOD Loading50 – 70 g/PE/day
TSS Loading60 – 90 g/PE/day
Nitrogen Loading8 – 12 g/PE/day
Phosphorus Loading1.5 – 3.0 g/PE/day
Hydraulic Retention4 – 12 hours (biological stage)
Sludge Production30 – 50 g DS/PE/day

Discharge Standards & Compliance

Urban Wastewater Directive

EU 91/271/EEC compliance for BOD, COD, TSS, and nutrient removal based on plant size and sensitivity.

Bathing Water Standards

Enhanced disinfection and nutrient removal for coastal and recreational water discharges.

Water Reuse Regulations

Compliance with REGULATION (EU) 2020/741 for agricultural irrigation and industrial reuse.

Need help with stormwater & cso management?

Our experts can design a system tailored to your specific requirements.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.