OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00600 | ||
PWS Name: | CHR DISTRICT IMPROVEMENT CO | ||
Who Was Contacted and Phone: | Wayne Stewart (503) 246-8067 | ||
Contact Date: | 11/16/2010 | ||
Contacted By: | SALIS, KARI (DWP) | ||
Contact Method/Location: | Office | ||
Assistance Type: | PLAN REVIEW | ||
Reasons: | SWTR N/A |
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Details: | SUMMARY: UV light problems DETAILS: Wayned called to discuss the problems they are having with the UV light. The hope was that it could be used for the 0.5 giardia inactivation requirement, but they are having some trouble. There is a 3-minute start up time, where the UV ramps up to 42 mJ/cm2, which seems reasonable, then the membrane plant kicks on, and the UV dose drops to 10. This causes the auto-shut off to shut the membrane and UV plants off. They have since disengaged this alarm, because they have chlorination for giardia inactivation. After 1-2 minutes, the UV system slowly ramps up to 32 mJ/cm2 again, and stays there. We are not sure why this value is not at least 40 mJ/cm2, the value at which is was validated. CHR is working with Trojan to resolve this problem. In the meantime, they are using chlorine to meet CTs, and will probably continue to do so. They intend to get Trojan to either fix it or give their money back if it doesnt meet validated operating standards. ACTION NEEDED: There is a small chance that there is a mix-up with units, and the readings are actually intensity and not dosage. Wayne will let us know if that is the case. We can final the plan review after this has been resolved. |