Field Office Compliance - Assistance

Assistance ID - 112077
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
4/9/2020 Gastineau, Janet <[email protected]> 4:49 PM (5 minutes ago) to Ted DMWW would continue to produce water, it would just be a different quality than usual. They will be conducting jar testing to figure it all out. The call yesterday was to focus on chlorine contact time. They wanted to be sure they weren't losing log credit if they weren't softening and would have to make it up somewhere else in the treatment process. Consecutive systems compliance will not be affected. On Thu, Apr 9, 2020 at 7:57 AM Petersen, Ted <[email protected]> wrote: Thanks Janet for keeping me in the loop. A couple questions come to mind...Any talk of DMWW going to a water use conservation mode if CO2 supplies become scarce? Would any change in operations/treatment at DMWW impact consecutive customers? JANET GASTINEAU
4/8/2020 Gastineau, Janet <[email protected]> 4:59 PM (3 minutes ago) to Mark, Corey, Ted, Taroon, Bob DMWW asked to speak with us today about the CO2 situation, so Taroon, Bob, and I shared a conference call with them. They are still not confident the CO2 supply is sustainable for their two lime softening plants and wanted to discuss mostly their options for continuing to comply with chlorine contact time. They reported conversations with Homeland Security and the Governor's office continue, a recent DM Register article acknowledged more of the Poet Ethanol plants are shutting down, and that Lincolnway Energy near Nevada will be starting up "for them." However, they don't know for how long LWE will operate because it will be at a loss due to already having surplus. Should the CO2 supply be a problem then they plan to add just enough lime to bring the pH up to their preferred level of 9.8, which would likely no longer provide the benefits of softening, and TOC removal could be an issue. I looked at their TOC removal ratios and they should still be OK with RAA compliance since most of their ratios are above 3 when they are not using ACC#2. DMWW confirmed they are using the regression equation for CT, so this will continue to be acceptable if CO2 supplies become scarce. They decided to return to injecting the ASR wells now while CO2 supply is good, because if it falls off they would have this source to supplement with. Ankeny finished one ASR injection cycle and the other ASR is finishing. Please let any of us know if you have questions. JANET GASTINEAU
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