Expansion sewage treatment plant Beemster

Project’s context & challenges

Municipal sewage treatment plants across Europe are increasingly under pressure due to rapid urbanization and population growth. WWTP Beemster, located in the heart of a protected UNESCO area, faced significant operational challenges as existing infrastructure was pushed to the limits of its design capacity. Conventional solutions such as expanding biological treatment or installing Primary Settling Tanks (PSTs) were impractical due to high costs, long construction timelines, and severe space limitations.

The challenge was to implement a cost-effective, space-efficient, and easy-to-integrate solution that would reduce operational strain, improve compliance with discharge standards, and future-proof the plant for growing loads—all without major civil works.

Customer benefits

Reduced suspended solids, organic and inert load entering biological treatment

Aeration energy savings up to 13%

Surplus sludge reduction of 10–20%, lowering treatment and disposal costs

Increased biological capacity by up to 20% without expanding tanks

Compact, modular design enabling installation in a constrained footprint (~200 m² vs. 2,400–3,200 m² for PSTs)

Energy recovery from sievings with high biomethane potential, supporting biogas production

Improved compliance with stricter discharge regulations

Solution

CirTec implemented Rotating Belt Fine Sieve (RBF) technology as a primary treatment at STP Beemster. Using a 350-micron mesh, RBF units remove suspended solids and associated COD, P and N through a cake filtration process before the sewage enters the biological reactor. The modular and compact design allowed installation with minimal disruption to ongoing operations, making it an ideal solution for a site located in a protected, space-constrained area.

Captured sievings are dewatered using a CellPres to >35%Ds enabling biogas production and contributing to a circular energy approach. Since commissioning, the plant has seen measurable improvements in capacity, operational- and energy efficiency, and sustainability.