WATERAGRI will further develop the Dewaterability Estimation Test (DET) apparatus, which is a recent invention (concept was experimentally proved) to test how easy it is to dewater mixtures of solids and liquids such as agricultural wastewater. The data will also allow for better management decisions regarding the selection of dewatering technology. Moreover, we will explore if the test can also be used to evaluate the water retention capacity of different soils and sludge within the agricultural industry. The DET is almost as simple as the capillary suction test (CST), but considerably more reliable, faster, flexible and informative in terms of the wealth of visual measurement data collected with modern image analysis software. The standard deviations associated with repeated measurements for the same sludge is lower for the DET than for the CST test. In contrast to the CST device, capillary suction in the DET test is linear and not radial, allowing for a straightforward interpretation of findings.