OHA Drinking Water Services
Contact Report Details |
|||
PWS ID: | OR41 00957 | ||
PWS Name: | WINSTON-DILLARD WATER DISTRICT | ||
Who Was Contacted and Phone: | Bob Young (541) 679-8467 | ||
Contact Date: | 03/26/2007 | ||
Contacted By: | STRASSNER, BOB (DWP) | ||
Contact Method/Location: | Office | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Reasons: | N/A N/A |
||
Details: | SUMMARY: Turbidity Profile DETAILS: The plant is treating raw water pumped from the South Umpqua River at a rate of 1450 gpm. Raw water NTUs over this filter runs previous 8.5 hrs averaged 4.0 NTUs. Prior to backwash the preparation for the Turbidity Profile included a baseline of the settled water sample 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 continuous flow was directed to the lab sink where the baseline settled NTU was measured at 1.98 NTUs. Sampling was begun at one minute intervals upon initiation of the backwash cycle. The Winston Dillard Backwash Process is automated requiring little involvement from the operator. The Multi media filter of which there are four with 38.0 sq ft of surface area are backwashed independently. Typical filtration rates on the filter profiled were 3.5 gpm min sq ft. The plant does have an auto shut down on high NTUs. Once backwash is initiated and the media is fluidized the surface water operates for approximately 2 to 3 minutes to dislodge the surface matting of turbidity rate increases for the duration of the 7 minute cycle. The Backwash pump times out and filter flows are reduced to a value to allow restratification of the media layers prior to the filter brought back on line. The effluent NTU meter has been off line during the Backwash cycle and is now automatically returned to service. ACTION NEEDED: Be available for technical assistance if requested. |