Arsenic Removal from Drinking Water by Coagulation/Filtration U.S. EPA Demonstration Project at Conneaut Lake Park in Conneaut Lake, PA. Final Performance Evaluation Report

摘要

This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Conneaut Lake Park (the Park) in Conneaut Lake, PA. The main objective of the project was to evaluate the effectiveness of AdEdge Technologies (AdEdge) coagulation/filtration (C/F) system, using GreensandPlus media (branded as AD-GS+ by AdEdge), in removing arsenic to meet the new arsenic maximum contaminant level (MCL) of 10 ig/L. Additionally, this project evaluated (1) the reliability of the treatment system, (2) the required system operation and maintenance (O&M) and operator skill levels, and (3) the capital and O&M cost of the technology. The project also characterized the water in the distribution system and process residuals produced by the treatment process. The types of data collected included system operation, water quality (both across the treatment train and in the distribution system), process residuals, and capital and O&M cost. The community water system (CWS) was supplied primarily by one groundwater well (i.e., Well No. 2) to meet an average daily and a maximum demand of 124,000 and 231,000 gal/day (gpd), respectively. The daily demand changed seasonally with visitors to the park during the summer months. Total arsenic concentrations in source water ranged from 26.8 to 37.3 ig/L and averaged 29.0 ig/L. Soluble As(III) was the predominating arsenic species, with concentrations ranging from 11.3 to 30.8 ig/L and averaging 26.2 ig/L. Total iron concentrations in source water averaged only 188 ig/L with 78% existing in the soluble form. Therefore, iron addition was necessary to facilitate arsenic removal.