1992 AGN OCT 06 I34 - Laserfiche WebLink

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act .y CITY OF COLTON AGENDA REPORT For Council Meeting of October 6, 1992 TO: Honorable Mayo and Cit cil FROM: Gar a er Public Utilities Y t sties Director SUBJECT: Report on Tertiary Treatment Project for Date: September 28, 1992 the City of Colton BACKGROUND: On September 11, 1992, the Regional Water Quality Control Board (RVVQCB) adopted Order No. 92-50 (Attachment #1). This Order, which amended the previous Cease and Desist Order No. 92-24, requires the City of Colton to begin design of advanced wastewater treatment facilities by October 1, 1992 in compliance with a revised time schedule of the Cease and Desist Order. The RMQCB action is in response to earlier requests by the Cities of Colton and San Bernardino for sufficient time to evaluate the information from the Rapid Infiltration Extraction (RIX) demon- stration to project which was completed in April, 1992. The RIX project has shown that its natural filtration treatment is as effective and reliable as conventional filtration in producing effluent quality that meets Title 22 Pre -disinfection Turbidity requirements of the State of California Depart- ment of Health. Since this has now been established, the R410CB is requiring immediate action to implement advanced wastewater treatment, either utilizing the RIX or conventional filtration. DISCUSSION: Because of our concerns as to which advanced treatment process might be the most cost effective in meeting the City's discharge requirements, the City hired Kennedy - Jenks, Consulting Engineers, to perform an evaluatikon which compared the estimated costs of the RIX and conventional treatment processes. Their evaluation concluded that the RIX would be least cost alternative (Attachment #2). The RIX alternative construction cost was estimated at $22,812,000.00, and the conventional treatment construction cost was estimated at $31,132,000.00. The estimated annual operating costs were similar with the RIX estimated at $2,246,000.00/year, and conventional estimated at $2,402,000.00/year. Furthermore, Kennedy -Jenks suggested that there might be other benefits that could be realized from the RIX process, such as greater nitrogen removal than previously known from the demonstration project. This could result in additional savings from a reduction in nitrogen removal facilities at the existing wastewater treatment plant. Attachments: 2 Page I ofd_— Item No.