Field Office Compliance - Assistance

Assistance ID - 101843
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
8/1/2018 On Wednesday, August 1, 2018 after discussing the meeting at Des Moines Water Works on Tuesday, July 31, 2018 with Janet Gastineau I sent an email to Kyle Danley with Des Moines Water Works as follows: Kyle, I wanted to follow up with you after yesterday's (Tuesday, July 31, 2018) meeting at Des Moines Water Works between Des Moines Water Water Works, HACH and DNR Field Office 5. At the conclusion of the meeting you stated Des Moines Water Works wanted to consider these isolated low readings by the CL 17 Units as anomalous and not be used in reporting the daily low residual chlorine measurement. My understanding is these are unusually low readings that occur during regular 2 1/2 minute sampling cycles and the previous and subsequent readings are much higher and in the range of what is expected in the area where the CL 17 Unit is located. I discussed this with Janet Gastineau and we are Ok with Des Moines Water Works proceeding with this premise for the present time until the question as to why these isolated low readings are taking place and what can be done to correct the situation. I also took away from the meeting that HACH is in the beginning stages of evaluating the data provided by Des Moines Water Works regarding the several units in their system where this is happening; also that HACH will come to Des Moines Water Works next week (week of August 6, 2018) and install a CL 17 Unit that was just returned to Des Moines Water Works from HACH (Unit repaired and tested at HACH) in place of one of the units that is having the problem of isolated low readings to see if there are other factors other than the CL 17 Unit that may be causing the low readings. Please keep us informed as to how things progress. Sincerely, Bill Gibbons BILL GIBBONS
8/1/2018 On Tuesday, July 31, 2018 I replied back to Kyle that I would attend the meeting. At the meeting were Kyle Danley, Mike Adams, Leigh Heim and Paul Sanford with Des Moines Water Works. Shelli the sales person for Hach was at the meeting and we called Brian and Mike with HACH (in Ames) on a conference phone. Leigh Heim with Des Moines Water Works had been collecting data on all of the units experiencing the problem and submitting this information to HACH. The main conclusions of the meeting were as follows: HACH is in the beginning stages of evaluating the data provided by Des Moines Water Works regarding the several units in their system where this is happening; also that HACH will come to Des Moines Water Works next week (week of August 6, 2018) and install a CL 17 Unit that was just returned to Des Moines Water Works from HACH (Unit repaired and tested at HACH) in place of one of the units that is having the problem of isolated low readings to see if there are other factors other than the CL 17 Unit that may be causing the low readings. Per Kyle Danley with the Des Moines Water Works they wanted to consider these isolated low readings by the CL 17 Units as anomalous and the readings would not be used in the daily reporting of the low chlorine residual measurement. I told Kyle I would have to discuss this with Janet Gastineau (Environmental Specialist Senior at DNR Field Office 5) and get back with him. BILL GIBBONS
8/1/2018 On Monday, July 30, 2018 I received an email from Kyle Danley with Des Moines Water Works that read as follows: Janet and Bill DMWW is meeting with Hach on Tuesday July 31 at 10:30 at the Fleur WTP (WP Conference Room) to discuss recent issues we are having with the CL17 dropping out for a few minutes. In previous discussions, you mentioned DNR staff may want to participate in this meeting. Please let me know if you or someone from the DNR is available to meet at this time. We are looking forward to discussions on this issue and how we can resolve this in the future. KYLE A. DANLEY, P.E. | Director of Water Production Des Moines Water Works | WATER YOU CAN TRUST FOR LIFE BILL GIBBONS
7/19/2018 On Thursday, July 19, 2018 I talked to Kyle Danley with the Des Moines Water Works. He called to report this is happening more frequently, in fact throughout their system it happened 6 times last night (Wednesday, July 18, 2018). Kyle reached out to the West Des Moines Water System and they are also experiencing this problem. Kyle said they talked to HACH and HACH said they recently changed their reagents but were not sure this was the cause. Kyle said as they change over units to a new batch of reagent this might by why the frequency is picking up. Des Moines Water Works and West Des Moines are going to request HACH come to a meeting so they can further discuss the matter. Kyle does not yet have a date and time for the meeting. I asked if DNR could attend the meeting as well. BILL GIBBONS
7/12/2018 On Thursday, July 12, 2017 I spoke with Mike Adams and Paul Sanford with the Des Moines Water Works. They told me they were able to extract the data from the CL17 units and the low reading was the actual chlorine measurement made by the unit. I asked them if these were all units in the distribution system and they said some of them were however at each plant, Fleur Drive, Maffit reservoir, and the Saylorville Plant there was a monitor at the midpoint and finished water point (source entry point) in the clear wells. They had experienced this problem at several points in the distribution system but had also had this problem with the midpoint monitor at Maffit and at both the midpoint and finished water monitors at Saylorville. They asked what we thought about using one of the other settings for the unit besides the default setting. I told them we only had one other system (Chariton) who had the same problem however they replaced the unit and the problem did not occur again. I told them this was something new and we were not sure yet how this fit into the regulatory framework. I asked if they could send a detailed description of the different monitor settings and Paul said he could copy that page out of the operation manual and email it to me. I asked if they had discussed the situation with HACH. They said they were going to call HACH next (today) to discuss the problem. I told them we would look at the different monitoring settings but we would also like to know what HACH had to say about the situation. I mentioned since they were such a big customer HACH might be willing to send someone out to help them. I also asked if the monitors were purchased at different times (different production batches) or of several of them were purchased at the same time and there might have been a manufacturing problem that occurred with several of the units. They said the units have been purchased separately over a long period of time and they are all doing the same thing. They promised to call me back to let me know what HACH had to say. BILL GIBBONS
7/12/2018 On Tuesday, July 10, 2018 I discussed the situation with Janet Gastineau (Environmental Specialist Sr.). Janet said Chariton had this problem with their CL17 but they replaced the unit and have not experienced the problem since that time. Janet said she was comfortable with them using a data logger to try and determine if it was a unit malfunction or if the SCADA system had a problem. Janet asked if I knew if this was happening at points in the distribution system or at any source entry points (which would have to be reported). I told her I would get back with Kyle and ask that question. We discussed whether they could collect a grab sample to compare with the CL17 result. I told her I talked to Kyle about that but they were not able to get to most of these locations in time to make a comparative analysis before the next sample was obtained. BILL GIBBONS
7/12/2018 On Friday, July 9, 2018 I talked to Kyle Danley with the Des Moines Water Works. He wanted to discuss problems they were having with their HACH CL17 Chlorine monitoring units. There are units placed throughout the system. They take a sample and measure for free chlorine every 2 1/2 minutes. Recently several of the units will suddenly come up with a much lower result than has been obtained in prior samples going from (for example) 1.08 mg/L to 0.5 mg/L. The next sample will be back to what is expected (1.08 mg/L to extend the example). At first they replaced a couple of units but the problem has persisted. They are unsure if it is the CL17 unit or if the SCADA system has some type of problem and is showing a low reading in error. They have purchased a data logger and will put it on different CL17 units to see if the low readings are actual measurements. Kyle said they looked at the manual for the unit and there are different settings for measuring and recording the results. There are 4 settings. The first setting (default) is 1 which is a measurement every 2 1/2 minutes and each measurement is recorded. The second and third settings are an average of 2 or 3 samples. The fourth setting only reports the maximum value between the current reading and the past reading. They were wondering if we have worked with other systems that have incurred this problem and if so have we allowed them to use a setting other than the default setting on the device. I told Kyle I was not aware of other systems having this problem and I would need to consult with Janet Gastineau and get back with them. BILL GIBBONS
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