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OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00670 | ||
| PWS Name: | PORT ORFORD, CITY OF | ||
| Who Was Contacted and Phone: | Dwaine Eckhoff (541) 253-8004 | ||
| Contact Date: | 03/14/2007 | ||
| Contacted By: | STRASSNER, BOB (DWP) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
| Reasons: | N/A N/A |
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| Details: | SUMMARY: Turbidity Profiles DETAILS: The plant is treating raw water pumped from Garrison Lake at a rate of 300 gpm. Raw water NTUs over this filter runs previously 27.5 hrs averaged 0.7 NTUs. Prior to backwash the preparation for the Turbidity Profile included a baseline of the settled water NTUs sampled from the top of the filter, at the location where the profile samples would be drawn. A siphon was started using a garden hose placing the intake just at the point on the surface of the filter where the backwash water would rise and spill into the washwater trough to waste during the backwash cycle. The continous flow was directed to the lab sink where the baseline settled NTU was measured at 0.725 NTUs. Sampling was begun at one minute intervals upon initiation of the backwash cycle. The Port Orford backwash process is automated and requires little involvement from the operator. The multi media filters, which there are two with a 71 sq ft of surface area each are backwash independently. The plant does have an auto shut down on high NTUs. Backwash is normally determined by the operator based on headloss. Once backwash is initiated the media is fluifized at a low hydraulic rate the surface wash operqtion for approximately 4 minutes to dislodge surface turbidity. The remainder of the cycle is accomplished at a higher hydraulic rate. The backwash pump times out after the 15 minutes cycle and the filter flows are reduced to a valve to allow restratification of the media layers prior to the filter being switched into a filter to waste cycle. The Effluent NTU meter has been off line during the Backwash Cycle and is now automatically returned to service. ACTION NEEDED: Be available for assistance if requested. | ||