Geotube® Municipal Wastewater Applications -  South Eastern Victoria The water authority involved fitted an existing drying bed with a Geotube® dewatering container to contain and dewater sludge produced from their trickling filter STP. No polymer was used initially and as a consequence the sludge dried at quite a slow rate. Nevertheless this process suited the client and they continue to use the same methodology. Another Geotube® container was deployed on a hardpan base under the same operating conditions and produced a dry sludge of >20% when opened 12 weeks after final filling.