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OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 01139 | ||
| PWS Name: | MIDLAND WATER ASSOCIATION | ||
| Who Was Contacted and Phone: | Scott MacGregor (503) 201-0050 | ||
| Contact Date: | 10/18/2016 | ||
| Contacted By: | NUSRALA, JAMES (REGION 1) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
| Reasons: | Disinfection Byproducts N/A |
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| Details: | SUMMARY: Follow up on HAA5 sample > MCL DETAILS: I spoke to Scott about the 10/5/16 HAA5 (haloacetic acids) sample of 0.10 mg/L, that exceeded the Maximum Contaminant Level of 0.060 mg/L. Consequently, Midland will begin quarterly sampling in the first quarter of 2017, collecting both a TTHM and HAA5 sample during the second month of each quarter (Feb, May, Aug, Nov), so that the association will sample during the peak month of August. Compliance with the MCL is determined by an annual average of 4 quarters. I also communicated to Scott that an Operation Evaluation Level will be determined after 3 quarters of monitoring as a precursor to the MCL determination. System operating normally, still using Graham Creek. The chlorine residual levels were high in late August, around 3 mg/L, due to the chlorine feed pump not being adjusted properly. That has since been fixed and residual levels are in the normal 1 mg/L range for September. ACTION NEEDED: Midland to collect quarterly samples for both TTHM and HAA5 at 79490 Erickson Dike. DWS to determine OEL and MCL compliance. System may revert to annual DBP monitoring when running annual average for TTHM <= 0.060 mg/L and HAA5 <= 0.045 mg/L. | ||
| Associated Alerts: | CHEM7340 - 10/14/2016 - TOTAL HALOACETIC ACIDS (HAA5) |
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