OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00802 | ||
PWS Name: | ARCH CAPE WATER DISTRICT | ||
Who Was Contacted and Phone: | Thomas Merrell (503) 739-2348 | ||
Contact Date: | 07/27/2011 | ||
Contacted By: | HOFELD, EVAN (REGION 1) | ||
Contact Method/Location: | Office | ||
Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
Reasons: | Disinfection Byproducts DBPs |
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Details: | SUMMARY: DBP Alert for High TTHM and HAA5 results DETAILS: I received an alert on 7/27/11 for elevated HAA5 results of 0.0784 mg/l and TTHM results of 0.0971 mg/l from sampling completed 7/20/11. The system has been working on stabilizing new ACH coagulation treatment with membrane filtration, which is anticipated to resolve the elevated DBP levels. The RAA with these new results is still below the MCL. The RAA is 0.06075 mg/l for HAA5 and 0.079875 for TTHM taking into account results from 4th quarter 2010 through 3rd quarter 2011. The system is currently under a Bilateral Compliance Agreeement and has until June 30, 2012 to demonstrate compliance with the DBP MCL. ACTION NEEDED: System to continue optimization of DPB precursor removal mechanisms and is to remain on quarterly monitoring and public notification as indicated when the RAA MCL is exceeded. | ||
Associated Alerts: | CHEM4977 - 07/27/2011 - TOTAL HALOACETIC ACIDS (HAA5) , TTHM CHEM4977 - 07/27/2011 - TOTAL HALOACETIC ACIDS (HAA5) , TTHM |