OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 90416 | ||
| PWS Name: | GEORGIA-PACIFIC, WAUNA MILL | ||
| Who Was Contacted and Phone: | Brittany Park (503) 455-3271 | ||
| Contact Date: | 03/10/2015 | ||
| Contacted By: | HOFELD, EVAN (REGION 1) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
| Reasons: | SWTR Chlorine |
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| Details: | SUMMARY: CT compliance assistance - low CT on 2-10-15 DETAILS: On 2-13-15 I received an e-mail from Brittany Park that they missed meeting required CT by 1 minute on Tuesday, Feb 10, 2015. Based on more detailed analysis of the data, the flow was 105 gpm on 2/10/15, which is included in the 24-hr period reported for 2/11/15 CT determination, therefore, CT had actually been met. The system normally uses flows going into the clearwell for CT determinations, however, this method also captures filter backwash flows, which provides a more conservative CT determination, but overestimates the amount of demand flow used by the distribution system. The system is in the process of procuring and installing a clearwell effluent flow meter to better document system demand flows. ACTION NEEDED: No further action needed at this time. System may continue to use conservative flow rates (including filter backwash rates), but may provide a more detailed analysis of flow data to determine actual CT achieved should the more conservative approach appear to show that they did not meet the required CT. | ||
| Associated Alerts: | N/A - - |
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