Field Office Compliance - Assistance

Assistance ID - 108940
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
10/3/2019 RE: Draining presed basin to river Inbox x Adams, Mike Wed, Oct 2, 3:14 PM (16 hours ago) to me, Kyle We would like to drain the basins next week. I will let you know on Monday what day we would like to drain them. DMWW 100-23 Mike Adams | Water Production Supervisor of Operations Des Moines Water Works | WATER YOU CAN TRUST FOR LIFE 2201 George Flagg Parkway | Des Moines, Iowa 50321 | www.dmww.com Phone: (515) 283-8710 | fax: (515) 283-8757 | e-mail: [email protected] From: Gastineau, Janet <[email protected]> Sent: Wednesday, October 02, 2019 2:52 PM To: Adams, Mike <[email protected]> Cc: Danley, Kyle <[email protected]> Subject: Re: Draining presed basin to river Understood. Can you let me know when you plan on discharging so we can make observations if our schedule permits and in case we receive any complaints? It sounds like it could take about half a day to discharge, so it depends on the time of day. Thanks. On Wed, Oct 2, 2019 at 2:44 PM Adams, Mike <[email protected]> wrote: Thanks Janet. We may need to do this several times to complete the valve project. The discharge might be one or both basins. The 4 MG volume would be for both presed basins drained to the first level. This would prevent any solids from leaving the basins. DMWW 100-23 Mike Adams | Water Production Supervisor of Operations Des Moines Water Works | WATER YOU CAN TRUST FOR LIFE 2201 George Flagg Parkway | Des Moines, Iowa 50321 | www.dmww.com Phone: (515) 283-8710 | fax: (515) 283-8757 | e-mail: [email protected] From: Gastineau, Janet <[email protected]> Sent: Wednesday, October 02, 2019 2:23 PM To: Adams, Mike <[email protected]> Subject: Fwd: Draining presed basin to river Since Tom is lead staff in wastewater I asked him for input. His response is below and pretty straight forward based on the data and learning that it would just be river water. He questions whether it's 4 MG because my notes from our call a week ago indicated it would be 2 MG/discharge event (half of one basin). Can you confirm volume per discharge? We don't want to risk loosing solids/sludge. Otherwise, it looks like DMWW is good to go with all the precautions mentioned in Tom's email. ---------- Forwarded message --------- From: Atkinson, Tom <[email protected]> Date: Tue, Oct 1, 2019 at 7:44 AM Subject: Re: Draining presed basin to river To: Gastineau, Janet <[email protected]> Based on that data and the fact that it is Raccoon River water that will be returned to the Raccoon River (through the intake if I remember correctly), I think there is a good case to be made that there is no pollutant being added to the river. Therefore, the draining of the presed basins to the river would be acceptable. Mike's email indicated 4 MG being discharged. Is that indicating that they would be draining the entire basin? If so there would need to be measures in place to ensure the sludge isn't being discharged. If they're planning to discharge 2 MG off the top of the basins, then that shouldn't be an issue. As far as the discharge rate, the proposed 5000-7000 gpm would be fine as long as it doesn't stir up the contents of the presed basin and cause solids to be discharged or create an erosion issue in the river (which I wouldn't anticipate with the discharge through the intake structure). I'm off site today, but feel free to give me a call if you want to discuss further. DNRlogo_gray.jpg Tom Atkinson | Environmental Specialist Sr. Field Office #5 Iowa Department of Natural Resources P 515-725-0371| 502 E 9th Street, Des Moines, IA 50319 www.iowadnr.gov On Tue, Oct 1, 2019 at 7:04 AM Gastineau, Janet <[email protected]> wrote: Let me know what you think. Thanks. ---------- Forwarded message --------- From: Adams, Mike <[email protected]> Date: Tue, Oct 1, 2019 at 1:30 AM Subject: Draining presed basin to river To: Gastineau, Janet <[email protected]> Cc: Danley, Kyle <[email protected]> Janet, Test results for the Fleur presed basin are attached. The water being sent back to the river would be all Raccoon River water. There would be no gallery water in the presed basin. We would like to drain the basins (approximately 4 MG) at a rate of 5000 to 7000 GPM. Let me know if you need more testing results. Gastineau, Janet <[email protected]> Thu, Sep 26, 1:08 PM (7 days ago) to Tom DMWW has a significant valve project on their pre-sed basins planned this fall. They would like to know if it's possible to discharge the contents of the basins back to the Raccoon River. Each basin has 4 MG capacity but it would just be about the top half or 2 MG that would have to be discharged each time. They expect to have to discharge this volume 8-10 times to complete the project. This is because they have someone coming in to look at what is needed and then the parts have to be manufactured and then the parts have to be installed for both basins. No mixing would be done in advance of discharge and they can discharge as fast or slow as we determine (although Kyle wasn't quite as flexible on this as Mike Adams was). The discharge would literally be through the Raccoon River intake as the contents would run through the pump to the suction well to the river intake. Ferric and carbon are normally fed into these basins. No sludge would be discharged. One basin would have to continue to be in use at a time during the project, so there would be no isolation of both simultaneously. Thanks! JANET GASTINEAU
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