ARA Winznau; from flow measurement to dynamic sewer network control

Complete renovation of the exterior structures as general contractor
  • Complete conversion of the control technology and new control system (ARAbella online)
  • Control technology with variable flow rate in the stormwater tanks
  • Several partially filled pneumatic outflow regulators

Inventory 2013

The special-purpose association of the Olten wastewater region (ZAO) includes 13 communities that treat their wastewater in the Winznau WWTP. The WWTP itself was and is already the subject of rehabilitation measures, but other structures in the sewer network were also in considerable need of rehabilitation, including pumping stations and stormwater tanks. Their automation was outdated, but also the work safety and comfort no longer met today’s requirements. The control technology also allowed little leeway, because the outflows were controlled purely mechanically, and the outflow quantities could neither be precisely set nor recorded. Furthermore, the flush valves were not equipped with a monitoring system, which would have resulted in very high drinking water consumption in the event of a defect.

Terms of reference

Requirements

  • Everything from a single source (general contractor mandate)
  • No burden on the sewage treatment plant staff due to reconstruction work: Renovate external structures at the same time as the sewage treatment plant
  • Increased occupational safety
  • Integral sewer network control (INKA) for water protection optimisation
  • Completely rehabilitated structures

Implementation

The defects are repaired step by step and the upcoming modernisations and optimisations with regard to occupational safety and comfort as well as explosion protection are carried out.
and comfort as well as explosion protection are carried out. In addition, STEBATEC AG is equipping the entire sewer network with dynamic, volume-precise flow controllers, which are integrated into the ARAbella process control system via STEBAnet and can thus be operated centrally. Everything is thus being prepared so that ZAO’s entire wastewater system can be integrally controlled in 2016. By then, the preparatory work on the INKA project, which will project, which will optimise the utilisation of sewer networks and storage volumes during rain events, should be completed by then. The web-based ARAbella coordinates the individual components, which also all have on-site intelligence. With the INKA controller it will even be possible to control the flow rates on the basis of the pollution loads and not only on the basis of the volumes.

Products in use