In Spain there are mostly combined sewer networks to collect and transport rainwater and wastewater to pumping stations, equalising tanks or sewage treatmen plants. In addition, in many places the sewer networks become silted up, which is why they have to be flushed more frequently. All these media are collected in tankers by the disposal company hired by the region or municipality and - for instance - discharged into a concrete settling pit at the sewage treatment plant. Here, the solids sediment, whereas the highly nitrogen loaded liquid phase is fed in batches to the sewage treatment plant. The solids, a mixture of fibers, fecal sludge, gravel and sand, are removed and stored in containers without further treatment and dewatering, which results in an additional odour nuisance, even some logistic problems to storage certain amount of containers on site, until its dewatering let them be transported. Moreover, some of these solids are also accidentally fed into the sewage treatment plant which causes additional difficulties in operation, e.g. due to clogging of pumps.
Cambrils is a small tourist town, located on the Spanish coast Costa Daurada in Catalonia. The combined sewer networks are linked together in smaller pumping stations, from where the wastewater is pumped to the treatment plant. As a preventive maintenance work, to assure the correct operation of the sewers as well as the pumping stations have to be emptied and cleaned regularly throughout the year by COMAIGUA, as overloading occurs due to sedimentation and increasing loads of dirt caused by increasing tourism. The local sewage treatment plant is operated by COMAIGUA. Aquambiente, a subsidiary of the SUEZ Group, was the company involved in the refurbishment of the plant. In its own interest and on behalf of the water authority and the municipality, it was decided to improve the processes by designing and installing a technically optimal and economically acceptable solution for the faecal sludge and sewer grit receiving. The receiving station is to be built on the local sewage treatment plant. In the end, the company Logistium was commissioned with the planning and purchase of our equipment.