AWWA ACE94148

A prefabricated dual-stage filtration system was installed at Freestone, California, as a demonstration project under the US Environmental Protection Agency Small System Technology Initiative. This technology was shown to be a cost-effective compliance option for this community of approximately 70 people which had a long history of microbiological contamination and boil water orders. The dual-stage filtration system consistently produced water with turbidity well below 0.5 NTU from source water averaging monthly turbidities of 4.25-23 NTU. The equipment manufacturer's local independent dealer obtained certification as a California Grade 2 water treatment plant operator and provided O&M services for the system. Using an advanced telemetry device which relayed key operating data to his office 13 miles from the plant site, the operator was able to successfully operate and maintain the equipment with an average of 13 hours per month including travel time and state mandated weekly site visits. Based upon the cost reporting format developed under the Initiative, the overall cost for the dual-stage filtration system at Freestone was $7.56 per 1000 gallons (3.8 m3). This is 42 percent less than the estimated cost for a similarly sized coagulation/filtration system for this site.