WTT designs in-vessel technologies, this means that the composting process takes place in completely closed (concrete) vessels; so called tunnels. Over the past 25 years WTT has built over 1300 tunnels. Throughout this time, WTT has continuously improved the design and identi capital and operating costs. One of the major advantages of composting in tunnels is that it is fast. The tunnels are individually controlled with forced aeration to process organic waste into compost. Each composting tunnel has its own aeration system, water and heating modules and is accompanied with the required instrumentation. Process and odour control is optimal, resulting in homogenic pasteurizations and degradation of organics. The whole configuration is included into a skid for faster installation, easier transport to site and simplified commissioning. The complete tunner system is remotely actuated and controlled by a SCADA visualization system. This allows site operators to set process parameters to be able to adapt to different waste streams and seasonal fluctuations.