AWWA MTC93059

Iron removal utilizing manganese greensand filtration has been successfully proven for many years. However, the use of these filters prior to R/O membranes is relatively new. The use of greensand filters has high potential to make R/O more cost-effective and applicable to raw waters not heretofore considered treatable by membranes due to concerns of fouling. As with any newly constructed facility, some problems have been experienced during start-up. These problems have been relatively minor and the City remains very optimistic regarding the long term cost/benefit attributes of greensand filtration. It is expected that reductions in cost will be seen as the plant staff gains knowledge through "hands-on" experience and minor modifications are implemented to improve the ease of operation. Much information has yet to be derived from this facility. As data is gathered and analyzed over time, the true cost savings derived from the use of greensand filtration can be more accurately defined. Dunedin's facility is believed to be in the forefront of water technology. Not only is this facility one of very few of its kind, it is the largest municipal greensand filtration system in the United States. The very low capital and operating cost of this pretreatment system indicates that this technology should be considered for numerous applications where the quality of raw water is very low.