|
|
| Introduction :: Data Search Options :: Water System Search :: DWS Home :: DWS Rules |
OHA Drinking Water Services
Contact Report Details |
|||
| PWS ID: | OR41 00276 | ||
| PWS Name: | ELKTON, CITY OF | ||
| Who Was Contacted and Phone: | Gary Trout (541) 584-2103 | ||
| Contact Date: | 03/27/2007 | ||
| Contacted By: | STRASSNER, BOB (DWP) | ||
| Contact Method/Location: | Field | ||
| Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
| Reasons: | N/A N/A |
||
| Details: | SUMMARY: Turbidity Profiles DETAILS: The plant is treating raw water pumped from the South Umpqua River at a rate of 105 gpm. Raw water NTUs over this filter runs previous 10 hrs averaged 16 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 0.98 NTUs. Sampling was begun at one minute intervals upon initiation of the backwash cycle. The City of Elkton’s Backwash Process is automated requiring little involvement from the operator. The Multi media filter of which there are two with 28.26 sq ft of surface area each are backwashed independently. Typical filtration rates on the filter profiled were 1.8 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 low hydraulic rate the surface water operates for approximately 6 minutes to dislodge the surface turbidity the remainder of the cycle is accomplished at a higher hydraulic rate with the surface wash off. The Backwash pump times out after the 10 minute cycle and filter flows are reduced to a value to allow restratification of the media layers prior to the filter being switched into a Filter to Waste Cycle consisting of a 5 minute setting time. 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. | ||