OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 91511 | ||
PWS Name: | SHADY COVE MIDDLE SD #9 | ||
Who Was Contacted: | John Harding | ||
Contact Phone: | 541-830-6376 | ||
Contact Date: | 04/29/2022 | ||
Contacted By: | CIVIL WEST ENGINEERS, INC (DWP) | ||
Contact Method/Location: | Phone | ||
Assistance Type: | CIRCUIT RIDER ASSISTANCE | ||
Details: | Background/Problem Identification: The circuit rider was contacted by John Harding of Eagle Point School District on 03/15/2022 regarding having a corrosion control method selected and in place if they exceed the MCL for lead again. After several weeks with no response, a new circuit rider support effort was opened when J. Harding reached back out on April 29th, 2022. Assistance Provided: The circuit rider received both requested rounds of WQP from John on 05/09/2022. The results of the WQP tests are summarized and averaged in the table below: Room 10 4/12/22 Staff Sink 4/12/22 Girl's Locker 4/12/22 Boy's RR 4/12/22 Room 10 4/26/22 Staff Sink 4/26/22 Girl's Locker 4/26/22 Boy's RR 4/26/22 AVERAGE Sp. Conductance 386 383 418 422 394 395 429 731 445 ~TDS 257 255 279 281 263 263 286 487 297 Alkalinity - ppm 170 170 184 188 168 168 180 186 177 Calcium - ppm 15.2 14.7 7.6 7.7 14.3 14.6 7.4 5.7 10.9 pH 8.5 8.2 8.1 8.5 8.2 8.6 8.3 8.4 8.4 Temperature - oC 14.7 16.0 16.8 17.5 14.4 15.0 16.3 17.9 16.1 DIC (Appx. B est.) 41 42 45 45 40 39 43 45 43 Target saturation pH = 8.2 Based on the available data and employing the EPA OCCT’s recommendations for corrosion control, Flow chart 1c calls for raising pH with caustic soda in 0.3 increments to a pH of 9.0 – 9.5. The other method is to inject orthophosphate. Using caustic soda to raise the pH may cause scaling. The orthophosphate method would likely need pH adjustment to ~7.5 in order to get in the pH range where orthophosphate works best. We recommend using the caustic soda method first, and only if the scaling is too excessive that the system switch to the pH adjustment/orthophosphate method. Follow-Up Actions Needed: The circuit rider is available to assist further if need be. Technical Reports to be Prepared and Expected Timeframe: N/A |