Photo courtesy of the Milwaukee Metropolitan Sewerage District
Kevin Shafer is the Executive Director of the Milwaukee Metropolitan Sewerage District.
The Milwaukee Metropolitan Sewerage District (MMSD) is a state-chartered agency providing wastewater treatment and flood management to 1.1 million people in 28 communities spread across five counties. The MMSD is scapegoated whenever a flood or sewage overflow occurs and is especially targeted by opportunistic politicians, but it is regarded as a model system nationally and internationally for its ability to keep maintain high standards of health and safety for the people it serves.
The MMSD’s director sat down with the Shepherd Express and explained the work of his agency and some of the new challenges it faces.
What is the mission of the MMSD?
We’re really trying to manage water in a holistic fashion—to do it in a cost-effective manner to reduce pollutants getting in the rivers and into Lake Michigan, which is where our drinking water supply comes from. So, our mission is to improve the environment cost-effectively, but it’s getting harder to do that with the changing climate that we’re currently facing.
Photo courtesy of the Milwaukee Metropolitan Sewerage District
Deep Tunnel construction
Let’s go back 30 years ago, before the Deep Tunnel. There were overflows that were more common than anyone wanted. Then, the tunnel was built—a big storage tank, essentially—which altered the situation. So, how many overflows were happening before the tunnel, and how many are occurring today?
Prior to the Deep Tunnel coming online in August 1993, we had an average of 50 to 60 overflows per year, and unfortunately there are still cities in the U.S. that are still having numbers like that. Since the tunnel was built, we’ve cut that annual number of overflows to just over two.
So, there was real improvement there?
Absolutely, and one of the statistics that we like to talk about is that since the tunnel’s construction, it has captured and cleaned 98.5% of all the water that’s come into the system. The federal requirement is that we have to be above 85%. I don’t know of any other utility in the country that’s had a success rate like we’ve had.
The other issue that’s really come to the fore recently has been climate change. Donald Trump has been trying to pull the U.S. out of the Paris Agreement and so forth. How is climate change affecting Milwaukee and, specifically, MMSD?
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When it rains on our sewer service area, water gets into the system, either directly into the system or through leaks in some of the pipes, so we have to watch the rainfall carefully; just like this past weekend, we were watching the heavy rain in our area. If we get a forecast that says we’re going to be getting more than two inches of rain in our area, that’s when we start getting concerned about the rainfall. We’ll send out an alert to residents not to do their laundry or wash their dishes until after the rain has stopped; it’s the discretionary use of water that we’re trying to avert during these storms.
With the ongoing change in climate, we are seeing more intense storms hit with a higher volume of water in the system, so that puts more water into the tunnel and at our treatment plants. We simply have to try to manage that water and try our best not to have an overflow.
Right now, MMSD is averaging about two overflows per year. Could climate change potentially cause this number to rise?
We’re doing a lot right now to try to be more resilient to the changing climate—trying to address that water where it falls so it doesn’t put pressure on our system. Plus, we’re looking at how much we need to expand our system for these flash storms that we’re getting.
In 2009, I wrote a vision for the district, which said that we’re going to go to 100% renewable energy and try to get to zero overflows. Over the last 20 years, we’ve laid out a program where we have the pipes underground, we have the Deep Tunnel, and we’re trying to manage the water on the surface before it gets into the pipes. We’re doing this through work called Green Infrastructure, where we’re putting rain roofs on buildings, selling rain barrels, using porous pavement on parking lots, putting swales along roads—different ways to manage water in a better fashion.
By doing it this way as opposed to building bigger pipes, we’re putting vegetation back into our urban setting, and we’re adding habitat to the region. It helps the aesthetics of the region and the health of the people who live here, and it makes us more climate-resilient to some of these storms that we’re seeing.
So, it’s a multi-faceted approach to trying to manage storm water where it falls, trying to keep it out of the drains and the tunnel and also bring green areas back to our area to improve public health and some of the air-quality issues that we have.
What specifically are you doing to bring back those green areas you mentioned?
Under our Flood Management Authority, we’re getting concrete out of our river channels. In the 1960s, we lined all the rivers with concrete, so now we’re ripping all that concrete out and putting the natural channels back in. We’re widening the floodplain to bring more green space to the region; there are a lot of trails on it as well, so we’re really linking to city with the rest of the county and the suburbs trying to integrate the water improvement system.
What can an individual do—people who are truly concerned and don’t want to feel helpless?
That’s really the one message we’ve been trying to educate people on since I’ve been at MMSD. Government can do a lot, but it really needs the individual’s help. We’re telling people that they can install a rain barrel on their downspout—which collects the rain water before it drains into our sewer system—and drain that barrel into a rain garden: a deeply tilled area that allows that water to infiltrate into the ground. They can also install efficient water systems inside their homes that utilize less water on a day-to-day basis; there are a lot of little things people can do because, as we say, every drop counts. So, every drop of storm water that you manage on your property and every drop less that you use in your home is one drop less that you’re paying us to treat. That makes for less water that we have to treat, so we’re saving our capacity for those large events.
In terms of “every drop counts,” you can take, process and store only so much water at one time, so anything over that is going to become part of an overflow. If we’re experiencing a heavy rainfall, any water we use could contribute to an overflow because you’re working at the margins.
Right. We have the Deep Tunnel that holds 532 million gallons, and we have two treatment plants that, during a normal day, treat about 75 million gallons each and, during a rainy day, go up to 300 and 390 million gallons. So, we’re treating 690 million gallons of water during a heavy rainstorm. These are really huge numbers that are hard to fathom that we’re either treating or storing. And the water that we’re storing, after the storm passes, is pumped out and treated. We’re seeing larger storms hit that are causing more and more water to go into our system, so we’re trying very hard to manage those storms and hit those margins that you’re talking about.
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