Microfiltration operating costs

In February 1994, the San Jose (Calif.) Water Company began operating a 5-mgd (19 x 10(3)-m(3)/d) microfiltration (MF) plant as part of the Saratoga Water Treatment Plant. The cost of operating the MF plant during 1995 was determined for all noncapitalized expenditures including power, operator labor, chemicals, membrane replacement, maintenance, and repairs. Actual operating costs were $309/mil gal ($82 x 10(3)/m(3)). Production costs for a direct filtration plant treating similar water during the same time period were 20 percent of those for the Saratoga MF plant, largely because of a significant economy of scale and lower power costs. Treatment plant performance, reliability, and operating experience affect the overall cost of treated water. In its fourth year of operation, the MF plant continues to be appropriate for this water supply because it is reliable and easy to operate and provides superior finished water quality.