OHA Drinking Water Services
Contact Report Details
|PWS ID:||OR41 00385|
|PWS Name:||HOOD RIVER, CITY OF|
|Who Was Contacted:||Adam Schmid|
|Contact Phone:||503-806-2555 (Email address hidden)|
|Contacted By:||NUSRALA, JAMES (DWP)|
|Assistance Type:||WATER QUALITY ALERT RESPONSE|
|Details:||Cold Springs source sample from 12/3/18 was E. coli +. Nothing out of the ordinary with spring, the City thinks the water level in springbox may have increased due to flap valve installed on overflow a couple of months ago, but that hatch and box appear to be watertight. Distribution samples and Stone 1 and Stone 2 source samples all coliform absent. Central Collection box special sample was total coliform present, E. coli absent. We discussed:
1. Collect five confirmation source samples at the Cold Springs source today, with results due on 12/7/18.
2. If any of the five are E. coli +, corrective action will be required for fecal contaminant source. A boil water notice will be required unless 4-log viral CT can be continually verified.
3. Send all results to DWS right away.
4. Take chlorine residual readings at first customer and at far end of distribution system to verify extent of residual throughout system and to support updated CT calculations.
5. City to review CT calculations in 2018 survey and discuss with DWS as necessary.
6. City will call the two purchasers, Iowa Drive #06249 and Aldridge Ditch #01013, today to notify them of initial E. Coli source sample.
7. I have notified Ice Fountain WD #00387, of initial E. coli + sample, they have an emergency intertie with the City.
12/7/18: City indicated the following for contact time from combined springs: 10,700 feet of 24-inch mainline from chlorine injection to first customer, Zone 1 PRV, with 2,700 gal/min demand, and a 0.33 mg/L free chlorine residual at first customer. This equates to approximately 251,000 gallons of contact volume, and 93 minutes of contact time at peak demand. The achieved CT is then, 93 x 0.33 = 30.73 mg-min/L, which is much greater than the 6 mg-min/L required for 4-log viral CT. Thus a boil water notice would not be required if a confirmed Cold Springs sample is EC+.
12/7/18 4 pm: Mark Lago: all 5 samples at Cold Springs coliform absent. No further action needed.
|Associated Alerts:||COLI18489 - 12/06/2018 - COLIFORM, E. COLI , COLIFORM, TOTAL (TCR)