OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00055 | ||
PWS Name: | ASTORIA, CITY OF | ||
Who Was Contacted and Phone: | Jim Hatcher (503) 325-3524 | ||
Contact Date: | 11/13/2014 | ||
Contacted By: | HOFELD, EVAN (REGION 1) | ||
Contact Method/Location: | Office | ||
Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
Reasons: | Disinfection Byproducts Operations |
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Details: | SUMMARY: OEL Exceedance for HAA5 - 4Q2014 DETAILS: With the November 5, 2014 disinfection byproducts sampling results, the Operational Evaluation Level (OEL) for HAA5 was exceeded for Astoria with an OEL for HAA5 of 0.062 mg/l for the 1st and D and 0.061 mg/l for the Merts sample location. The Locational Running Annual Average for HAA5 at those locations was 0.055 mg/l and 0.053 mg/l, respectively. In response to the OEL exceedance, Astoria submitted an Operational Evaluation to our office, received on December 10, 2014. The OEL report cited low demand and excessive storage capacity leading to high water age as the primary cause. Floating reservoir covers limit operational measures that could keep storage capacity lower in low demand times. The OEL report included a technical memo dated August 10, 2014 from CH2MHill containing data that showed Spur 14 was a source with very low levels of organics when compared to the other sources. The OEL report indicates that since the Spur 14 source has relatively low organics, the plan to address elevated DBP levels is to connect Spur 14 directly to the influent line to the slow sand filters (rather than being diverted first to Middle Lake, which then supplies the filters). This project is anticipated to begin as soon as funding is available in July of 2015. ACTION NEEDED: City to continue to evaluate solutions to mitigate elevated HAA5 levels, including work planned for the Spur 14 source. | ||
Associated Alerts: | CHEM6528 - 11/13/2014 - TOTAL HALOACETIC ACIDS (HAA5) CHEM6528 - 11/13/2014 - TOTAL HALOACETIC ACIDS (HAA5) |