OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00326 | ||
PWS Name: | GLIDE WATER ASSOCIATION | ||
Who Was Contacted and Phone: | John Croll (541) 496-3614 | ||
Contact Date: | 03/29/2007 | ||
Contacted By: | STRASSNER, BOB (DWP) | ||
Contact Method/Location: | Field | ||
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 the North Umpqua River at a rate of 145 gpm. Raw water NTUs over this filter runs previous 10 hrs averaged 4.5 NTUs. Prior to backwash the preparation for the Turbidity Profile included a baseline of the settled water NTUs 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 2.7 NTUs. Sampling was begun at one minute intervals upon initiation of the backwash cycle. The Glides WTP Backwash Process is automated requiring little involvement from the operator. The Multi media filter has 28.26 sq ft of surface area. Typical filtration rates on the filter profiled were 4.06 gpm sq ft. Backwash is normally determined by the operator based on headloss. The plant does have an auto shut down on high NTUs. Once backwash is initiated and the media is fluidized at a single high rate approximately 680 gpm. The plat is equipped with surface wash but is not in use. The Backwash pump times out after the 8 to10 minute cycle and filter flows are reduced to a value to allow restratification of the media layers. The effluent NTU meter has been off line during the Backwash cycle and is now automatically returned to service. Samples from the filter are processed by the online instrument. ACTION NEEDED: Be available for technical assistance if requested. |