OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00585 | ||
| PWS Name: | OCEANSIDE WATER DISTRICT | ||
| Who Was Contacted: | David Nordman | ||
| Contact Phone: | 503-842-6462 (Email address hidden) | ||
| Contact Date: | 05/30/2019 | ||
| Contacted By: | HOFELD, EVAN (DWP) | ||
| Contact Method/Location: | |||
| Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
| Reasons: | Disinfection Byproducts |
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| Details: | I received an alert on 5-28-19 for a single TTHM result over the MCL. Although the single result was over the 0.080 mg/l TTHM MCL, the locational running annual average (LRAA) was below the MCL and no OEL was exceeded. Since the system was already on quarterly monitoring, no further action was needed. This was communicated via e-mail on 5-31-19 and a spreadsheet showing the compliance calculations was e-mailed to Mr. Nordman on 5-31-19 showing that the 0.0852 mg/l TTHM result from sampling at the "Cape Manager's Home" on 5-14-19 resulted in a TTHM LRAA of 0.0609 mg/l and TTHM OEL of 0.0257 mg/l for the 2nd quarter of 2019. We later spoke on the phone about some elevated TOC levels they observed, the need for TOC removal to address DBP formation, and plans to investigate alternative coagulants such as ACH, which is a coagulant commonly used by coastal membrane plants that appears to work well (e.g. Arch Cape and Warrenton among others). I recommended he work with the membrane manufacturer prior to making any coagulant changes. | ||
| Associated Alerts: | CHEM8335 - 05/28/2019 - TTHM |
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