Field Office Compliance - Assistance

Assistance ID - 35691
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
6/24/2011 I forwarded Jennifer's remarks to Mike. JANET GASTINEAU
6/24/2011 From: Bunton, Jennifer [DNR] Sent: Friday, June 24, 2011 11:40 AM To: Gastineau, Janet [DNR] Subject: RE: DMWW McMullen Plant question Janet~ There is no credit given for river bank filtration unless the system requests it. We only have one system that takes credit for bank filtration, and that’s Sioux City. In the case of the McMullen plant, their credit was determined by the type of treatment they have at the plant (conventional filtration, which provides them with 2.5 log of Giardia credit and 2.0 log for virus). This credit is provided regardless of the source because the system did not ask for bank filtration, so it really means that they could be using water right out of the river and the credit would not change. Of course, it would be much harder and more expensive for them to treat, and that is probably what they need to argue with FEMA. The bank filtration was most likely occurring and allowing them to have much better quality source water, and if what happened with the bank erosion has changed that, then I would assume they have a basis for requesting reimbursement for the stabilization project. If they have turbidity or other water quality data that shows that the river water was of a much lower quality than their raw water, which had undergone “pre-treatment” as a result of bank filtration, and they can show that now these two waters are much closer in water quality, I would think they could probably make their case. So although this event may have impacted their source water quality, it does not change the credits they get at this time or the way they meet the Surface Water Treatment Rule. If they had been taking credit for bank filtration, then it might have been another story. From: Bunton, Jennifer [DNR] Sent: Friday, June 24, 2011 11:40 AM To: Gastineau, Janet [DNR] Subject: RE: DMWW McMullen Plant question Janet~ There is no credit given for river bank filtration unless the system requests it. We only have one system that takes credit for bank filtration, and that’s Sioux City. In the case of the McMullen plant, their credit was determined by the type of treatment they have at the plant (conventional filtration, which provides them with 2.5 log of Giardia credit and 2.0 log for virus). This credit is provided regardless of the source because the system did not ask for bank filtration, so it really means that they could be using water right out of the river and the credit would not change. Of course, it would be much harder and more expensive for them to treat, and that is probably what they need to argue with FEMA. The bank filtration was most likely occurring and allowing them to have much better quality source water, and if what happened with the bank erosion has changed that, then I would assume they have a basis for requesting reimbursement for the stabilization project. If they have turbidity or other water quality data that shows that the river water was of a much lower quality than their raw water, which had undergone “pre-treatment” as a result of bank filtration, and they can show that now these two waters are much closer in water quality, I would think they could probably make their case. So although this event may have impacted their source water quality, it does not change the credits they get at this time or the way they meet the Surface Water Treatment Rule. If they had been taking credit for bank filtration, then it might have been another story. From: Bunton, Jennifer [DNR] Sent: Friday, June 24, 2011 11:40 AM To: Gastineau, Janet [DNR] Subject: RE: DMWW McMullen Plant question Janet~ There is no credit given for river bank filtration unless the system requests it. We only have one system that takes credit for bank filtration, and that’s Sioux City. In the case of the McMullen plant, their credit was determined by the type of treatment they have at the plant (conventional filtration, which provides them with 2.5 log of Giardia credit and 2.0 log for virus). This credit is provided regardless of the source because the system did not ask for bank filtration, so it really means that they could be using water right out of the river and the credit would not change. Of course, it would be much harder and more expensive for them to treat, and that is probably what they need to argue with FEMA. The bank filtration was most likely occurring and allowing them to have much better quality source water, and if what happened with the bank erosion has changed that, then I would assume they have a basis for requesting reimbursement for the stabilization project. If they have turbidity or other water quality data that shows that the river water was of a much lower quality than their raw water, which had undergone “pre-treatment” as a result of bank filtration, and they can show that now these two waters are much closer in water quality, I would think they could probably make their case. So although this event may have impacted their source water quality, it does not change the credits they get at this time or the way they meet the Surface Water Treatment Rule. If they had been taking credit for bank filtration, then it might have been another story. JANET GASTINEAU
6/24/2011 From: Gastineau, Janet [DNR] Sent: Friday, June 24, 2011 10:06 AM To: Bunton, Jennifer [DNR] Subject: DMWW McMullen Plant question Mike McCurnin is wondering if there is any log removal credit given for use of a radial collector well? There interest is....they had significant bank erosion at the McMullen plant last year and FEMA agreed to pay for the stabilization project. Now they say they won't and DMWW is appealing. As part of the appeal process they want to impress upon FEMA that with the loss of the bank they have lost some of the wells' "robustness." He's hoping this can be further documented in the assessment of how the DNR came up with the plant's log removal and if the source was considered. Thoughts? JANET GASTINEAU
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