OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00194 | ||
PWS Name: | CLATSKANIE, CITY OF | ||
Who Was Contacted and Phone: | Dan Smith (503) 728-2622 | ||
Contact Date: | 03/30/2015 | ||
Contacted By: | NUSRALA, JAMES (REGION 1) | ||
Contact Method/Location: | Office | ||
Assistance Type: | OTHER REGULATORY - REGULATORY ASSISTANCE | ||
Reasons: | SWTR Operations |
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Details: | SUMMARY: CTs not met on 3/27/15 DETAILS: Diaphragm chlorine feed pump lost prime on 3/27, due to air being introduced as a result of the plant being on, when the 330 gal solution tank was being re-filled. As pump not primed to purge air, residuals at the first user dropped to 0.24 mg/L for a brief period of time, before he was notified of the problem through the low alarm, and able to repair the feed pump. Chlorine residuals back to normal levels (0.6 ppm) within 2 hours. As a result of the low residual, CTs were not met on 3/27. CT required for 1.0-log Giardia inactivation for a pH of 6.6, temperature of 11 deg. C, and residual of .24 is 28. The CT achieved given the 90 minutes of contact time from the tracer study, was 21.6. ACTION NEEDED: Dan to 1.)distribute 30-day public notice to all customers with copy to DWS, 2.) increase low chlorine alarm to 0.4 mg/L instantaneous, and 3.) ensure plant off in future when solution refilled to prevent air and loss of pump prime. DWS to send treatment interruption BMP and after hours phone # to City. |