OHA Drinking Water Services
Contact Report Details |
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| PWS ID: | OR41 00970 | ||
| PWS Name: | NESKOWIN REG WATER DIST | ||
| Who Was Contacted: | Troy Trute | ||
| Contact Phone: | 503-392-3966 (Email address hidden) | ||
| Contact Date: | 12/23/2020 | ||
| Contacted By: | HOFELD, EVAN (DWP) | ||
| Contact Method/Location: | |||
| Assistance Type: | PLAN REVIEW | ||
| Details: | Following elevated disinfection byproduct (DBP) levels in 2020, Troy and I discussed the potential benefit of adding aluminum chlorohydrate (ACH) as a coagulant ahead of the membrane filters to help remove DBP precursors. On 12/23/20, I e-mailed Troy to recommend he contact the membrane manufacturer regarding the correct dose. The addition of ACH was approved as an informal review (no plan review number). I followed up with an e-mail dated 2/19/2021 requesting two 6-month lead and copper demonstration rounds be completed at 10 sites in 2021 following the implementation of ACH dosing in January 2021. The demonstration rounds were completed in June (round 1) and December (round 2) 2021 as requested with no adverse impact to lead and copper 90th percentile levels. As of 8/24/22 (the date this contact report was created), DBP levels have been reduced by roughly 50% after the addition of ACH with a 2nd quarter 2022 TTHM LRAA of 0.034 mg/l and an HAA5 LRAA of 0.016 mg/l. | ||