OHA Drinking Water Services
Contact Report Details |
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PWS ID: | OR41 01174 | ||
PWS Name: | BUELL-RED PRAIRIE WD | ||
Who Was Contacted: | Scott Cure | ||
Contact Phone: | 503-843-2885 (Email address hidden) | ||
Contact Date: | 08/26/2022 | ||
Contacted By: | BAIRD, GREGG (DWP) | ||
Contact Method/Location: | Phone | ||
Assistance Type: | MONITORING | ||
Reasons: | Cyanotoxins |
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Details: | Raw and finished water samples were collected for cyanotoxins analysis Monday 8/22/22. The finished water sample result was non-detect for cyanotoxins which is good, however the raw water sample showed total microcystins at 0.25 ug/L but had a chlorine residual present of 0.09 ppm so was invalidated by the lab. The operator measured a chlorine residual of 0.11 ppm in the raw water at the time of sample collection, so for some reason the sodium thiosulfate in the sample bottle did not neutralize the chlorine. Requested the operator collect and ship both a raw and finished sample again next week, but this time collect the raw sample from the raw water turbidimeter waste line which may pull water from a location further upstream from the polymer injection point on the raw water line (and test and record chlorine residual prior to sampling). Also reminded operator to take care the sample bottle is not overfilled and overflows to avoid the chance of the sodium thiosulfate pill falling out. Spoke to the circuit rider this date and provided background information to assist with the investigation. Update 9/2/22: raw and finished samples collected 8/29 both non-detect for cyanotoxins. Operator instructed to sample and ship raw & finished again Tues. 9/6 under same protocol (raw sample collected from raw turbidimeter waste line). |