Field Office Compliance - Assistance

Assistance ID - 93983
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
5/22/2017 Gastineau, Janet <[email protected]> Attachments1:54 PM (18 minutes ago) to mccurnin If I had been here on Friday, we may well have decided on a Tier 1 public notice requirement because consultation did not take place within 24 hours [567 IAC 42.1(2)"a"(8)]. If Ted had felt it was an public health emergency, I'm sure he would have consulted other DNR staff and assessed a Tier 1 public notice requirement on Friday. However, given the circumstances, I have identified it as a Tier 2 public notice, which is the exceedance is a violation of the treatment technique requirement, but a Tier 1 was not required [567 IAC 42.1(3)"a"(1)] . We have done this with other water systems. The draft treatment technique violation is attached along with the instructions for a Tier 2 PN and the mandatory language. You can adapt the "what happened" and "what was done" sections to fit the event. Please let me know if you have further questions or comments. JANET GASTINEAU
5/22/2017 Gastineau, Janet <[email protected]> 2:12 PM (0 minutes ago) to mccurnin I'm sure I'm preaching to the choir...with any continuous turbidimeter sample collection (raw, settled, IFE, CFE) we encourage water systems to: Consider location, length of sample line, and sample flow rate to turbidimeter (sample detention time). Assess frequency of cleaning sample line and instrumentation. Check locations for chemical feed. Check location for recycle return (if practiced). Check sample line condition and turbidimeter cleaning frequency or replacement frequency. Check for delayed start of sampling. If sample is pumped to the turbidimeter, what controls pump on/off. Is turbidity impacted by pumping sample? Post clear well locations can be problematic (floc due to pH changes and chemical addition, high service pumps turning on and off. Much of this would have been discussed as part of the follow up Jennifer did with DMWW following the data integrity workshop we were allowed to complete at McMullen in 2014. JANET GASTINEAU
5/22/2017 Gastineau, Janet <[email protected]> 10:52 AM (55 minutes ago) to Mike, Ted, Mike, Carter, Jennifer, Jeff, Paul, Tony, George I left Mike a message this morning. I plan to issue a treatment technique violation with Tier 2 public notification requirements. Much like was required following the event in December of 2013. This will include a reporting violation in accordance with 567 IAC 43.3(5)"c"(1) (see below). c. Additional reporting requirement for turbidity combined filter effluent. (1) If at any time the turbidity exceeds 1 NTU in representative samples of filtered water in a system using conventional filtration treatment or direct filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3). JANET GASTINEAU
5/22/2017 From: McCurnin, Mike <[email protected]> Date: Fri, May 19, 2017 at 4:51 PM Subject: SWTP Finished NTU > 1 NTU (May 18, 2017) To: "Petersen, Ted [DNR]" <[email protected]>, "Gastineau, Janet" <[email protected]> Cc: "Adams, Mike" <[email protected]>, "Woodruff, Carter" <[email protected]>, "Puffer, Jennifer" <[email protected]>, "Mitchell, Jeff" <[email protected]>, "Sanford, Paul" <[email protected]>, "Knox, Tony" <[email protected]>, "Lawrence, George" <[email protected]> Janet/Ted: Ted, per our recent discussion please find discussion below in regard to finished NTU greater than 1 ntu on May 18, 2017 at our Saylorville Water Treatment Plant. The event occurred near 11:42 AM on May 18, 2017. The event in question was very narrow in time. FINISHED NTU maxed out at 2.00 ntu; was above 1 ntu for near 6 minutes; was above 0.3 ntu for 12 minutes. Imagery is below (and attached). Some information about this spike: · Does not appear to be a function of maintenance. · Does not appear to be a function of any significant pump change. · The finished instruments are fed via a pump system. Status of those pumps appears to be absent from our trending software. At this time, we cannot comment on the possible toggling/cycling of the feed pumps. · The finished chlorine and finished ntu both had discernable movement at/near the same time. There was no known plant process upset (UF unit turbidity values all very low in the hours preceding the event). · While we cannot explain with absolute certainty the cause of this spike, we remain confident that actual turbidity in the clearwell could not change so drastically over a short span of time. · We intend to report the following May 18, 2017: o Max NTU = 2 ntu o Number of Consecutive Reads > 0.3 ntu = 0 (the event was very narrow) · We are certainly happy to discuss this further. I can be reached at 515-208-1938 and at any time. There are two immediate take-away items here for us: · Alarms for this issue did reach our Control Center, yet went un-noticed and likely acknowledged unknowingly. We will revisit this situation with our staff. · Our logic for MAX NTU needs to be immediately updated. It appears we are still using a collection of “15-minute reads” to extract MAX NTU for the day. · A combination of both of these resulted in our notice to DNR occurring some 29 hours after the event. TED PETERSEN
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