11-11-13 Common Council Meeting Minutes

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REGULAR MEETING NOVEMBER 11,2013 waste. So we built some of interceptor sewers that would intercept that flow and take it to the wastewater treatment plant to be treated. But they did not built the treatment plant larger enough to handle all the flow, nor did they build the interceptor sewers larger enough to handle it, and so there are a number of occasions where we are overflowing into the river or even worse people's basements. So here's our motivation,we've got somewhere around 60 to 70 times on a typically year that we've got these overflow events and they could be as many as 36 different locations throughout the city,we've got 36 combined sewer overflows throughout the City of South Bend and somewhere between five hundred million to we had as much as 2 billion gallons a year of overflow from these combined sewer overflows during the year. Here's the other part of the motivation is keeping sewage out of basements. We still have a number of areas where basements are backing up, we simply looked at 3 distinct areas in town just to make sure we were still having issues with basement back-ups and 376 homes surveyed we had response from 225 that they were still having back-ups in their basements. Some of those were multiple times per year. Mr. Horvath referred to his power-point presentation. So here's a diagram showing roughly what combined sewer looks like and operates like on the left you can see under dry weather conditions the downspouts from buildings the storm lines from roads all these go into this combined pipe as does the sanitary sewage from our homes and from our businesses. Under dry conditions our pipes are big enough that they can handle all that flow and so it just continues to flow all the way to the treatment and we treat it there before discharging it back to the river. However, when we have wet weather, it rains our combined sewer starts to raise and at some point we have got bottle necks in our system that they start failing and so we get surcharging in those lines and that's when it backs up and either floods basements or overflows to the river. So our problem is as I mentioned we've got 36 of these along the river our city limits is approximately 40 square miles and our combined system is approximately 20 square miles. So one solution would be separating the entire city storm separate from sanitary and creating a bunch of storm sewers,unfortunately the cost of that program is well in excess of what our term control plan is. So now what I would like to do is maybe just have Becky talk a little bit about long term control plans. Councilmember Oliver Davis: How much rain does there have to be or how much snow does there have to be before it starts surcharging or backing up? Eric Horvath: That totally depends; I know that's not the answer you are looking for. The issue is that's its more about intensity and duration than it is about overall amount. Councilmember Oliver Davis: So the faster that it comes down? Eric Horvath: The faster it comes down the more we are going to have an overflow, so we can have a sprinkle over a couple days and not have an overflow when we get a good rain. You can see 60 to 70 days a year we have overflows. So imagine you know most rainfalls we are getting overflows. Councilmember Oliver Davis: And the same thing after the snow melts? Eric Horvath: Yeah, if you have a big snow melt, you can easily have an overflow as well. Becky Schaefer, Greeley and Hansen Engineers, 7820 Innovation Blvd., Suite 150, Indianapolis, Indiana, (referring to the power point) This slide shows the history of the development of South Bend's long term control plan. I won't get into the details, but it started back in 1989 and the city has invested a significant amount of money to study the system and bring together a bunch on information to develop this plan and they gotten input from several experts along the way and the plan has been through several iterations throughout time over the last twenty years. This table compares South Bend long term control plan to other long term control plans so the costs are listed and then the best way that we have found to compare plans is looking on how much combine sewer area you have in the City and the plan is basically is very dependent on the volume of combined sewage in the area and the land. So South Bend took the cost of the long term control plan per acre, combined acre in South Bend's mid-range. South Bend is in a Federal Consent Decree, a federal enforceable order; it was signed in December 2011. The element of the plan includes eliminating dry weather overflows; reducing wet weather overflows from 60-70 per year to 4 overflows per year and disinfecting those overflows so that water quality standards are met at the state line. There are a couple of ways that we can re-open the