Tertiary optimisation of an existing WWTP: compact and high-performance solution even in bad weather

Compact, modular and designed to stabilize MES compliance even in rain, this lamella + drum filter solution offers a modern approach to tertiary treatment. Easy to integrate, simple to operate and suitable for constrained sites or combined networks, it secures your water quality without heavy work or oversizing.

Project information

The optimization of tertiary treatment on a STEP 500 EH
Drum filter in underground box 1h2o3
Creation of a drum filter in an underground box 1h2o3
Drum filter in box 1h2o3

500 PE

Nominal

Gravity clarification

Stabilizes dry processing and reduces suspended solids.

Tertiary Polishing

Captures fine particles during rainfall peaks.

Small footprint

Simplified transport, quick installation and optimised operator access.

Project Background

Your station had to meet strict MES standards, including during rainy episodes. The existing installation – screening + primary clarifier – was fed by an old combined network where wastewater and rainwater mix.
During bad weather, the flow rates increased sharply, making the line unstable and compliance difficult to maintain.

Objectives

Implement a compact, reliable and cost-effective solution for:

  • maintain MES compliance during dry and rainy periods,
  • avoid any oversizing of the structures,
  • simplify integration (transport, installation, space),
  • ensure robust and scalable operations.

Technical solution

The solution implemented combines:

  • a lamella clarifier for gravity clarification and solid-state stabilization in the dry regime;
  • a box drum filter for tertiary polishing in the event of rainfall flow peaks.

The box protects the equipment, reduces the footprint and can be completely buried.
The assembly is modular, ready to connect, and allows for quick commissioning.

CNC prefabrication & modularity

  • Separable modules, allowing transport and installation in a small space.
  • Limited connections to reduce installation times.
  • Integration designed for rain variability and handling constraints.
  • Scalable architecture allowing for the addition of equipment or future expansions.

On-site implementation

  • Simplified transport thanks to independent modules.
  • Quick installation in a constrained area.
  • Minimized hydraulic and electrical connections.
  • Hydraulic speed adjustment, drum commissioning, purge plan and operating procedures given to the teams.

Results

  • Stabilised MES, including in rain.
  • Proven efficacy: 5 to 10 mg/L for a flow rate of 11 m³/h.
  • Effective clarification + regular polishing = secure compliance.
  • No need for heavy civil engineering work.
  • Robust, flexible and economical operation.

Operation & Maintenance

  • Simple control: hydraulic speeds / rotation, turbidity monitoring, purge plan.
  • Easy access thanks to the box: cleaning, visual checks, quick maintenance.
  • Compact line suitable for constrained sites or combined networks.
  • Scalable solution if volumes or operating conditions change.

Key figures

  • 500 PE — nominal capacity of the station
  • Lamella + drum — double tertiary treatment stage
  • 5–10 mg/L suspended solids — performance measured at the outlet
  • Compact installation — separable modules & quick installation
  • Optimized costs — no oversizing, no heavy civil engineering

Product focus: Tertiary lamella treatment + drum filter

To secure MES compliance without oversizing the plant, we combine a lamella clarifier for gravity clarification and a box drum filter for tertiary polishing.
In dry conditions, the lamella stabilizes the line; In rainy conditions, the drum takes over and captures residual particles, even at high flows.
Compact, modular and ready to connect, the solution can be easily integrated into existing structures and limits civil engineering work while remaining simple to operate.

Steps to collaborate

  • Diagnosis of the plant — analysis of dry/rainfall flows, suspended solids, combined network constraints.
  • Dimensioning of tertiary treatment — lamella surface, drum mesh, management of peak flows.
  • Preparation & logistics – separable modules, housing, simplified transport and limited connections.
  • Installation & commissioning – hydraulic/rotation adjustments, purge plan, operating procedures.
  • Monitoring & optimization — support at start-up and adjustment of operating instructions.

DO YOU HAVE A PROJECT?

A similar project? Let's talk about it.

Optimization of an existing plant, recycling of industrial effluents, sizing of a new facility… Our teams can adapt our modular solutions to your technical and budgetary constraints.

Shopping Cart
preloader