AWWA MTC61202

The application of membranes in the municipal water market is widely perceived in the industry as a new technology. However, there are ultrafiltration plants that have been successfully operating for many years. One of these plants is located in Littleton, Massachusetts. The ultrafiltration (UF) plant in Littleton was commissioned in 1997 to remove high levels of iron and manganese from the well water, as well as to reduce the risk of contamination by microorganisms. The plant has a capacity of 1.4 MGD. The UF system was supplied by Koch Membrane Systems, and contains four primary skids, with 50 hollow fiber UF cartridges on each skid. All of the reject from the primary skids is sent to a secondary skid with 20 hollow fiber UF cartridges. The original cartridges from all skids (primary and secondary) have been in operation for the last seven years. This paper describes the Littleton plant from design phase to current operation. The specific flux, chemical cleaning frequency, backflush regimen, and backflush recovery system are discussed. The results of recent autopsies that show that the membranes are still in excellent condition are presented. Includes 2 references, figures.