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OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00248 | ||
| PWS Name: | DALLAS, CITY OF | ||
| Who Was Contacted: | Jake Dyer | ||
| Contact Phone: | 503-623-2175 (Email address hidden) | ||
| Contact Date: | 01/16/2021 | ||
| Contacted By: | SALIS, KARI (DWP) | ||
| Contact Method/Location: | Phone | ||
| Assistance Type: | INCIDENT RESPONSE | ||
| Details: | Saturday 1/16 am: Jake Dyer, WTP operator, contacted Michelle Byrd. The WTP is running, but CFE is 3.5 NTU. After the clearwell it is 0.15 -0.2 NTU, indicating quite a bit of settling is occurring. She let him know the turbidity MCLs and that a boil would be needed if the CFE is over 5.49 NTU, with state discretion between 1.49 and 5.49. Chlorine is 1 ppm. The raw water turbidity is around 35 NTU but the sed basin is increasing turbidity to 45-55 NTU. The solution feed pump and SCM have been repaired. Saturday 1/16 1:15pm: Kari spoke with Jake. CFE is 3.5 NTU since 5 am. Two filters are doing better than the other two. A consultant from Jacobs is helping troubleshoot how to lower the turbidity. The CT actual is around 96, with 43 required. I recommended testing chlorine residual in the distribution system and collecting coliform samples in different parts of the system. They are flushing the sed basin to waste to get rid of some excess polymer. Given the significant polymer overfeed and the settling occurring in the clearwell, I determined that the likely cause of the high turbidity is the excess polymer rather than a treatment failure. Along with more than double the required CT, I did not require a boil advisory at this time. |
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