OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00549 | ||
PWS Name: | TRI-CITY JW&SA | ||
Who Was Contacted and Phone: | Dennis Knebel (541) 863-6856 | ||
Contact Date: | 01/31/2007 | ||
Contacted By: | STRASSNER, BOB (DWP) | ||
Contact Method/Location: | Office | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Reasons: | N/A N/A |
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Details: | SUMMARY: Contact tracer study report, CT study certified results letter and calculations DETAILS: The district has been operating at new clearwell levels and needs to establish contact times at these new elevated storage levels. The work of finalizing the calculations and notes from the onsite visit to the Tri-City water treatment plant required some draft review to verify as-built plant drawings of storage volumes as the plant has both old and new construction. The flow rate requested for the study was significantly higher than the plant typically operates. Plant personnel had modified SCADA systems to allow for a clearwell level higher than normal to accommodate the requested flows. Plant design is specified as at 1800 gpm, although at this rate the plant experiences an overflow condition due to an undersized sedimentation basin. The plant successfully ran at the 1500 gpm rate while producing outstanding water quality. Additional plant modifications are planned in the future in anticipation of achieving the original design rate of 1800 gpm. ACTION NEEDED: The district expects to request testing at additional flow rates after modifications have been completed to plant structures as mentioned in the tracer study. The circuit rider program will follow up as requested with assistance for these studies. |