OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00205 | ||
| PWS Name: | COOS BAY NORTH BEND WTR BRD | ||
| Who Was Contacted and Phone: | Anna Zaklikowski (503) 423-3822 | ||
| Contact Date: | 04/20/2010 | ||
| Contacted By: | MACPHERSON, JAMES (REGION 2) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | PLAN REVIEW | ||
| Reasons: | SWTR Disinfection Byproducts |
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| Details: | SUMMARY: Pre-Design Plans and Pilot Test Results DETAILS: Discuss planned use of permanganate to oxidize manganese and iron. Chlorine dioxide also evaluated, but concern over potential chlorite and chlorate formation affected decision to deploy. Ozone not tested due to high capital cost. Ferrate also discussed, but no current plan to apply. Alum provided better floc size than ACH and is the preferred coagulant. No other coagulants run in pilot test. Rapid sand flow rate discussed. Data for 7.5 gpm/ft2 reported as more than adequate to reduce turbidity. ACTION NEEDED: Review Pilot Test Report upon receipt. | ||