OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00055 | ||
PWS Name: | ASTORIA, CITY OF | ||
Who Was Contacted and Phone: | John Wesely (503) 325-3524 | ||
Contact Date: | 10/18/2006 | ||
Contacted By: | SALIS, KARI (DWP) | ||
Contact Method/Location: | Office | ||
Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
Reasons: | Coliform N/A |
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Details: | SUMMARY: TC+ response / possible cause & remedy #1 DETAILS: John Wesely called to let us know that more repeats came back TC+, FC-. They know they violated the MCL and will be doing a public notice. He also told me the suspected source of the problem is a smaller tank at the outlet of Reservoir #3 (an open reservoir). Water loses chlorine residual in Reservoir #3, water flows into this smaller tank (which perhaps serves the purpose of maintaining pressure if they were to ever by-pass Reservoir #3), is then booster chlorinated, and the pipe branches off, one to Reservoir #2, and others to service connections. This tank is below grade, in a dark environment. It was inspected and found to have a thick layer of slime on the inside of the tank. HBH helped determine some possible actions, and suggested installing a light to minimize this type of growth, and to have a diver vaccuum off the slime. A main problem is that this tank cannot be by-passed currently. If it is shut off, half the system loses water service, which of course if undesirable. Since it is not chlorinated, vaccuuming off the slime would potential mix things up, not provide any contact time, and some contamination could flow into the system. ACTION NEEDED: see #2 |