OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00025 | ||
PWS Name: | HAFEZ WATER SYSTEM | ||
Who Was Contacted and Phone: | Dan Daugherty, David Alford (541) 967-8633 | ||
Contact Date: | 01/15/2007 | ||
Contacted By: | POTTS, JOHN (DWP) | ||
Contact Method/Location: | Field | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Reasons: | N/A N/A |
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Details: | SUMMARY: Iron and manganese interference DETAILS: High levels of iron (Fe) and manganese (Mn) in test results/numerous associated complaints. In Aug. 2004, Linn Co. HD required continuous chlorination and free chlorine (Cl) residual of 0.2 mg/L maintained at all times and that chlorination was for residual maintenance only. Operator has had difficulty maintaining free Cl residual required. Many service connections to homes replaced due to Mn/Fe build up to the point that inside diameter of water line is about one-quarter inch. All service line meters removed due to excessive clogging from Fe and Mn. SDWIS records over the last 2 years indicate that most monthly Cl residual readings are non-detect (ND)/out of compliance. Visited the system Dec. 15 to evaluate problem. New Stenner Cl injection pump is working, but no free Cl residual maintained in system. I measured 0.0 mg/L free Cl at Dan’s house. Suggested that he raise Cl dosage until he maintains free Cl residual. He probably hasn’t achieved breakpoint chlorination yet. He can adjust the Cl-to-water ratio in solution tank incrementally. Currently ratio is 1 gal. 12.5 per. Cl to 15 gal. H2O. Also recommended sampling for total Cl residual to see how much Cl is combined. One negative side effect of raising Cl dosage to achieve free residual is potential for increased DBP formation. Removal or lowering of the excessive Fe and Mn levels will lower the Cl demand and lessen possibility of DBP formation. System has not collected trihalomethanes or HAA 5 samples yet so those levels are unknown. Reminded Dan and David to collect those 3rd quarter 2007. Prepared technical report on Fe and Mn removal/sent to system. Talked to Dan Jan. 5, he informed me that he raised Cl dosage enough that free Cl residual was very high/he was going to lower it until he maintained minimum of 0.2 mg/L as required. ACTION NEEDED: None |