Field Office Compliance - Assistance

Assistance ID - 90127
Des Moines Water Works - 310338211
9966 Maffitt Lake Dr Cumming, IA 50061
Dallas County

FO 5

Report
File Name File Type File Date Note
Comments
11/10/2016 From: McCurnin, Mike [mailto:[email protected]] Sent: Wednesday, November 09, 2016 6:26 PM To: Gastineau, Janet [DNR] Cc: Water Production Supervisors; Corrigan, Ted Subject: FW: High NTU filter reading at Fleur Janet: The October MOR has been submitted for Fleur Drive. I wanted to add some additional comments in regard to our response to the event associated with Filter #4 here at FDWTP. 1. Control Room personnel began recording IFE values on an hourly basis as a back-up to the instruments and controls that we have struggled with in the past. This began on Monday of this week. Should this occur again we won’t catch it w/in 15 minutes, but we should be able to limit the duration to less than a few hours. 2. Interrogation into the apparent failure of localized logic has also been ongoing. We have been unable, thus far, to duplicate the problem. Initial testing indicated shut down logic to be functional. By all appearances, the turbidimeter provided a signal to plant controls that corresponds to 20 NTU, yet no alarms were activated and the shutdown logic that is present at Fleur Drive did not trip. 3. With no detectable influence on our CFE values, we filled out the MOR for 10/28/2016 to show a max NTU of 0.04 ntu for Filter #4 and included a brief note. If you or others at DNR have concerns with this approach, please let me know and Mr. Adams and I will endeavor to submit a revised MOR. 4. Also this week, we will be testing all 28 IFE turbidimeters at all DMWW plants to test for proper operation of applicable alarms and shutdowns. Filters w/out proper function will be placed out of service until common function is achieved. If additional discussions are needed here, please just let us know. JANET GASTINEAU
11/10/2016 From: Gastineau, Janet [DNR] [mailto:[email protected]] Sent: Friday, November 04, 2016 3:20 PM To: Adams, Mike <[email protected]> Subject: RE: High NTU filter reading at Fleur Thanks, Mike. Can you include some narrative no later than with the submittal of the monthly operation report about what is being done to keep this from being a problem in the future. Seems to me there was a similar event when we conducted the workshop at McMullen two years ago. What would the control room staff have seen as they reviewed control screens during this 12 hour period? There must have been some shift change that would have had to document conditions or is there anything operators have to log in at a given frequency to document control/observations? Wouldn’t they have kept seeing the reading of 20 NTU? Did the controller impact any other filters? Provide as much detail in this regard as possible. Thanks. From: Adams, Mike [mailto:[email protected]] Sent: Friday, November 04, 2016 2:42 PM To: Gastineau, Janet [DNR] Cc: McCurnin, Mike; Woodruff, Carter; Puffer, Jennifer Subject: High NTU filter reading at Fleur Janet: On October 28th at 12:01am we had a Hach SC100 turbidimeter controller malfunction at our Fleur plant. The controller on filter # 4 locked in test mode with a turbidity reading of 20 NTU’s. The filter was on line for 12 hours with a 20 NTU reading. The controller did not issue an alarm or shut down the filter. Maintenance personnel have corrected the problem with the instrument. The event did not have an impact on finished water turbidity. I have attached filer # 4 and finished water trends. Let us know if you need additional information on this matter. JANET GASTINEAU
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