AWWA MTC57595

URS Corporation has completed pilot testing on an integrated membrane system (IMS) utilizing Zenon Ultrafiltration (and later US Filter ACTIFLOC) followed by Nanofiltration (NF) to treat a difficult high turbidity "groundwater" source for the community of Bluffton, Ohio. Sampling, desktop analysis with computer projections, and actual field pilot testing from July 2001 to February 2002 showed that this groundwater would require advanced pretreatment and nanofiltration to meet the US Environmental Protection Agency (USEPA) Secondary Standards for sulfate and TDS and reduce the hardness to an acceptable level. Overpumping of the town's two wellfields by overuse and potentially by a local quarry's dewatering efforts have created a significant drawdown which has resulted in a cascading effect in the uncased wells that promotes the introduction of dissolved oxygen (DO). The introduction of DO to these wells results in immediate and significant oxidation of hydrogen sulfide gas to elemental sulfur (turbidity). The high turbidity has resulted in increased taste and odor complaints, distribution system biological growth, polysulfides, turbidity, discoloration, and corrosion. The Village of Bluffton retained URS Corporation to investigate the necessary treatment options to provide acceptable water quality for its residents. The resultant investigation produced a comprehensive sampling matrix, testing protocol, and pilot testing to confirm the assumptions and provide the necessary data for full-scale design. This paper highlights the significant challenges that this feedwater creates, details some of the findings of the piloting efforts, and describes some of the unique approaches that this project required. Includes tables, figures.