OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 01479 | ||
PWS Name: | TWILIGHT VIEW ESTATES | ||
Who Was Contacted: | Reggie Boltz | ||
Contact Phone: | 541-218-5555 | ||
Contact Date: | 02/05/2021 | ||
Contacted By: | CIVIL WEST ENGINEERS, INC (DWP) | ||
Contact Method/Location: | Phone | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Details: | Background/Problem Identification: Twilight View Estates water system was tested for copper content and exceeded the copper action level (AL) of 1.3 mg/L. The results were first received by the state on May 3rd, 2002 and subsequently on October 8th, 2010 and September 1st, 2016. Notice of exceeding the AL was sent to the water system on February 1st, 2018. Part of the requirement of this notice was that the water system needed to receive a recommendation from a water system engineer for an optimal corrosion control treatment. Assistance Provided: Based on the EPA OCCT, and the source water quality parameters, we recommend adding caustic soda to increase the pH to 7.5 and to add an orthophosphate product. https://www.epa.gov/sites/production/files/2016-03/documents/occtmarch2016.pdf We recommend injection of the caustic soda immediately downstream of the pressure tanks with chemical metering pump. The same pump that TVE has purchased to inject the orthophosphate (LMI PD041-828SI) may also be employed for the caustic soda injection. We recommend using 25% liquid caustic soda to both avoid freezing issues, and to limit operator exposure. The operator MUST read and follow all SDS recommendations for caustic soda. To push the raw water pH of 6.5 to the target pH of 7.5, the operator should slowly adjust feed quantity from the pump’s minimum setting until a pH of 7.5 is reached. This may take some time to establish. We recommend making changes of no more than 5% and waiting a day or two to test for the resultant pH in distribution. Follow-Up Actions Needed: The circuit rider is available as needed for follow-up assistance. Technical Reports to be Prepared and Expected Timeframe: This technical assistance contact report was sent out on February 5th, 2021. |