OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00473 | ||
PWS Name: | LEBANON, CITY OF | ||
Who Was Contacted and Phone: | Tim Sanders (541) 451-1117 | ||
Contact Date: | 06/17/2008 | ||
Contacted By: | KELLEY, KAREN (REGION 2) | ||
Contact Method/Location: | Office | ||
Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
Reasons: | SWTR Operations |
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Details: | SUMMARY: Turbidity spike on Filter #5 6/16-17/2008. DETAILS: On 6/17/2008, Tim Sanders and Brian Helliwell called to report a high turbidity event involving Filter #5. Turbidity spiked on Filter #5 around 9:50 PM the night of 6/16 to 4.2 NTU. The event lasted through the night until the operator noticed the problem the next morning around 6:50 AM when the filter was shut down until it could be backwashed. The City of Lebanon does not have a combined filter effluent turbidimeter that can measure turbidity of all filtered water prior to storage. Therefore, they are required to report their highest individual filter effluent reading for compliance purposes. As a result, the system exceeded the MCL of 1 NTU. Given the clearwell turbidimeter data showing water going to the customers peaked at only 0.017 NTU, the MCL violation was downgraded from a Tier 1 violation to a Tier 2. I emailed the public notice template to Tim on 7/1/08 to be distributed to customers via the next billing cycle. Tim Sanders emailed filter profiles for all the filters as required. The profiles show a significant increase in headloss at the time of the event. Clarified water measured 2.43 NTU and the other two filters were not affected. Alarms were not triggered during the event due to the fact that the operator forgot to turn them back on after leaving the plant for the day. I am referring the profiles to our Area-Wide Optimization Team for further review and recommendations. It appears as though this filter should have been backwashed after the first increase in headloss (around 9PM) and filter run time should be shortened to no more than 72 hours. ACTION NEEDED: Gather recommendations from AWOP Team. Await copy of public notice from the City. |