ABSTRACT: As part of a comprehensive evaluation of posttreatment techniques for algal removal from lagoon effluents, intermittent sand filtration was evaluated. The main objective of the study was to delineate the filtration process most feasible for upgrading lagoons and to identify optimum design and operating parameters. Experimental procedures were conducted at the site of Starkville, Mississippi's 6.1‐hectare (15‐acre) lagoon. Studies utilized a full‐scale sonic microstrainer supplied by FMC Corporation and pilot‐sized rapid and intermittent sand filters. Microstraining was characterized by low specific flow rates and poor effluent quality. Rapid sand filters were unable to produce desirable effluent quality in conjunction with a sufficient filter run length. Intermittent sand filters were capable of consistently producing an effluent quality comparable to those expected from more complex advanced waste treatment processes. Optimum media gradation and hydraulic loading for the intermittent sand filters were determined. This paper presents the results of the intermittent sand filter studies.