Technical Abstract: Maintenance and control of liquid levels in anaerobic lagoons and storage ponds require liquid-solid separation as a pretreatment and periodic removal of accumulated sludges. Until local options become available, sludges can be contained, dewatered, and stored using geotextile filtration. We used a geotextile filtration testing method termed a hanging-bag test to treat dairy lagoon sludge, swine lagoon sludge, fresh liquid dairy manure, and fresh liquid swine manure. Hanging-bag performance was evaluated by:(1)determining solids and plant nutrient mass retention efficiencies (MRE);(2)quantifying the overall volume reduction; and (3)characterizing the dewatered manure. When bags underwent multiple fill-dewater cycles, the MRE-values for the various manures or sludges did not vary for many constituents. In fact, after three fill-dewater cycles, the overall MRE-values among the sludges were not significantly different. Geotextile filtration retained 87.8% of total solids (TS), 58.4% of total ammoniacal nitrogen (TAN), 87.0% of organic-N (Org-N), and 86.7% of total phosphorous (TP) and reduced the total influent volume to less than 18.5%. Relatively high MRE-values were calculated for liquid swine manure: 70.2% of TS, 65.1% of TAN, 69.9% of Org-N, and 75.8% of TP. However, the geotextile bag retained 60.3% of the total influent volume making geotextile filtration ineffective for primary liquid-solid separation. For fresh dairy manure (TS=0.71%), geotextile filtration reduced the total influent volume to less than 1%, concentrated the solids and nutrients in the dewatered material 16 to 21 times greater than the influent, and retained 47.3% of TS, 25.8% of TAN, 43.0% of Org-N, and 44.9% of TP making this an effective liquid-solid separation technique.