OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 00394 | ||
PWS Name: | IDANHA CITY WATER | ||
Who Was Contacted and Phone: | Bob Bruce (503) 800-1225 | ||
Contact Date: | 02/02/2017 | ||
Contacted By: | PARRY, BETSY (REGION 2) | ||
Contact Method/Location: | Office | ||
Assistance Type: | OTHER REGULATORY - REGULATORY ASSISTANCE | ||
Reasons: | SWTR None |
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Details: | SUMMARY: turbidity rising again, what to do DETAILS: Bob phoned to report that the effluent turbidity began rising again on 1/31/17. It was going to 0.3, even though the influent turbidity was only around 2.0 NTU. It was set up for both an autocall and shut down at 0.3 NTU, but their phone service was out in the area, so each time Bob visited the plant, it was shut down. So he raised the shut down level to 0.5 NTU to keep his reservoir filled. (After the phone service was restored on Feb 1, he felt comfortable lowering that again.) During 1/31-2/1, the turbidity would be 0.1 for 2-3 hrs after BW, then start climbing again. Normally, the finished water is 0.03 NTU. He found water "falling" into the Mud Puppy Crk intake with lots of turbulence, and suspects air entrainment interfered with coagulant function (the PAC dosage seemed correct during this time). He reduced the amt of Mud Puppy water going to the plant so it is now a blend with Rainbow Crk, and the NTU dropped again. We reviewed thresholds for turbidity violations. Cl levels remained fine throughout. Meanwhile, fixing a newly discovered line break along a bridge will help reduce demand on the plant. ACTION NEEDED: Evan Hofeld also spoke to operator, who was open to a technical assistance visit in the coming weeks for review/questions. May want to evaluate the filter media which has not been replaced for 12 years. |