City Council Agenda and Packet 1984 06 30

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is 3.2 MGD at present. Until the pre-treatment is completed, our back- wash process utilizes from 0.20 to 0.60 MG seriously reduces our net production for public use. The reason for the wide range on backwash use relates directly to the peaking condition. At flows under 2.5 MGD, the backwash requirement is t 200,000 gallons. However, due to reduced pretreatment detentions under peak loadings, the dirtier filter runs will often require up to 600,000 gallons per day. This represents an 18% backwash consumption versus a more normal 5% to 3%. We can con- clude then, that a gross production of 3.2 MGD will net 2.6 or 2.7 MGD after backwash. Thimmfoare, sustained demands of 3.7 ♦ MGD cannot be wet, and "drafting' of the 3 MG storage tank results. We are hopeful that watering restrictions will "take the edge off' the demand deficit, until the pre-treatment is completed. We hope to have some indication by weeks-end, of the overall effect of the restrictions. Z can only conclude that the plant's limitations were not discovered prior to our investigations, because: (1) A belief that the Pre-Treatment was the major, and sole Problem. (2) A lack of impetus, or no real demand to investigate the total plant hydraulics, since all major components are sized for ultimate capacity. (3) Sketchy recordkespinq and data prior to late 1983, and not having the demands to push the plant to its limit. As is obvious from the attached production/demand chart, the hydraulic improvements significantly double the production from Plant #1. The hydraulic improvements by themselves would not increase our total production without the pretreatment. One is dependent on the other, and they should be view as one project. A. Package #1 (1) New Backwash Pump System, Vault, electrical, etc. (2) Yard Piping modifications to facilitate Plant #1 hydraulics. Total Cost $130,000 B. Package 02 (1) Plant #1 Piping and Metering Improvements. (2) Expanded chemical pacing capabilities. Total Cost $ 35,000 C. Package #3 1. Treated Water Piping, metering and control vault at lower site. 2. Feasibility investigation, and possible 0.40 MG clearwell rehab and piping modifications ($40,000 option) . 3. Overall telemetry and control system improvements. Total Cost $140,000 - $180,000 Packages #1 and #2 are currently being engineered and we hope to request Council approval to advertise for Package #1 at the July l7thmeeting. Package 02 can likely be a negotiated installation package with City purchase of all equipment. We would anticipate completion of these additional improvements, following Reid Burton Const's completion schedule. Package #3 is not essential to the plant hydraulics, but is necessary if we are to accurately measure the effectiveness of our efforts. We recommend that all 3 packages be completed in 1984. Telemetery, metering, and control systems currently exist, however, they require major upgrading and consolidation to provide a truly accurate level of system management. It is very important that we complete these 3 packages, and not "stumble onto" another hidden problem. One solution is to locate, excavate, expose, and map all lower yard piping to verify the hydraulics. Another is to lower our storage tank this fall after demands decrease, and execute a series of simulated peak plant runs, to verify the new pretreatments systems capabilities, to simulate run-off treatment prob- lems, and to "push" the treatment facility to its absolute limit. Staff is confident that Packages #1 and #2 will be successful, and although uncon- ventional, the simulations will provide all parties the proof of capacity requiroi. The following table relates current demand and production capabilities to the various levels of improvements. The Phase I Howard Berry Plant is currently in Engineering, and will be "on-line" for load-season 1986.