OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00922 | ||
PWS Name: | VERNONIA, CITY OF | ||
Who Was Contacted and Phone: | Jeffery Burch (503) 429-6921 | ||
Contact Date: | 11/07/2012 | ||
Contacted By: | HENRY, ROBERT (DWP) | ||
Contact Method/Location: | Field | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Reasons: | N/A N/A |
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Details: | SUMMARY: CT Tracer Study DETAILS: The City has a surface water treatment plant which pulls water from Rock Cr. The surface water is treated w/rapid sand filters w/flocculation along w/soda ash and chlorine is used to treat the water. The plant is able to produce as much as 700 gpm, with 900 gpm being delivered from the clearwell. Chlorine contact is achieved in an approx. 30,000 gal. clearwell before the water is sent to the distribution system (and first user).HBH was contacted by the City to provide assistance w/a contact tracer study. A previous effort was made at a contact tracer test, but operational changes were needed for a successful test. Completed draft report for flows at 700 in and 910 out. Coordinated w/James Nusrala and City regarding testing at reduced flows. Performed additional tracer testing a reduced treatment plant flow rate.Developed graphs and preliminary results for testing at a reduced treatment plant production flow and altered clearwell operating levels. Reviewed effect of reducing the high level service pump flow rate on both the pump performance and the possible CT results. Coordinated w/James Nusrala and City regarding additional testing scenarios. ACTION NEEDED: Complete data collection at reduced high service pump flow. Work w/water system to ensure compliance w/disinfection requirements. |