MSD Project Clear: A Step In What Direction?
Underground sewage tunnels tend to get relegated to the back of our mind—lumped in with all those chase scenes in Marvel movies. But they are very real, and St. Louis is built over a wide swath of them, along with natural caves and artificially filled in caves just waiting to collapse. Owing to Missouri’s karstic limestone landscape, water always manages to find its way underground into these spaces. Ever since we dumped this giant behemoth of litter we call a city on top of it, we have been trying to control our little slice of the Earth’s subsurface in overtly extravagant ways, some good, some bad. The latest installment in this display of extravagance is the Metropolitan St. Louis Sewer District (MSD) Project Clear, a new multi-billion-dollar initiative to divert polluted sewage from entering the Mississippi river. The project has good intentions, but with sewage bills and taxes expected to rise over the next decade to pay for twenty-eight miles of new underground tunnels and thousands of new green landscapes, it is worth an examination.
The River Des Peres that winds through Forest Park is an imposter. The original one was buried a century ago after persistent flooding and a rank stench compelled the city government to bury it underground. This was one of the most highly regarded engineering projects at the time, a tunnel system built under the entirety of the gleaming, advanced, innovative city that was St. Louis. Before then, sewage was thrown directly into the rivers. But “progress” made way for new methods involving steel, concrete, and efficient construction to hide our waste. By the time the city population peaked above 800,000 in the middle of the 20th century this tunnel system worked well, and all our excrement was out of sight, out of mind. The problem was, storm water inevitably made its way into these tunnels, mixing with the waste in a combined sewer system. Now in 2018 the tunnels are reaching maximum filth capacity. Unfortunately, much of this stagnant sewage from the past century has increasingly found its way into the rivers as the tunnels are filled, and it will continue to do so for years to come, unless we do something about it.
For now, “doing something about it” means slowing rising sewage bills across St. Louis county to fund MSD Project Clear and its various initiatives to reduce the amount of storm water entering sewage pipes by drilling separate tunnels for sewage and storm water, cutting off downspouts and other pipes near homes to alleviate leakage into sewage tunnels, and growing green spaces to sponge up storm water where pavement once blocked the way. For many families in high poverty areas, the cost of this project is a heavy burden, so it is important to analyze the costs versus benefits here. How much will this project aid public health versus injure it? First, it is important to distinguish the various approaches to solving the problem.
The one with the highest impact in reducing gallons of storm water mixing with sewage is the tunnel drilling. It turns out this method is most effective in the southwest portion of St. Louis, where the replacement River Des Peres and its tributaries flow. Over the next decade a group of workers will drill through solid rock up to two-hundred thirty feet below the surface, slowly shaping the new tunnels. In a few years time, massive Tunnel Boring Machines (TBMs) will worm their way under our very feet, shredding rock and soil out of the way, without a sound at the surface.
At the same time, contractors will disconnect as many house pipes that lead into sewage tunnels as possible to avoid further choking the already heavily burdened tunnels. Along with the tunneling, this is expected to be one of the most important parts of the project. Workers in brightly colored vests will survey homes over the next decade and block off some of the easiest paths storm water takes to get underground such as ground penetrating downspouts, open yard drains, and other uncapped openings. For all the current wastewater with no place to go, big storage tunnels will be drilled above and below ground. If the wastewater is to ever have a chance at making it to one of MSD’s treatment plants, it needs a place to stay for a while. These seven treatment plants are already overworked, receiving over 350 million gallons a day before pouring out into the Mississippi, Missouri, and various other rivers and watersheds. With increasing overflow, more of these “waiting rooms” need to be built. According to Politico, these tunneling and disconnection methods will cut the amount of storm water entering sewage tunnels by 80 percent.
The other method, called “rainscaping,” will take effect mainly in the northeast portion of St. Louis, where there are many abandoned, condemned homes. After demolishing these homes, space will be cleared for grass, bushes, and trees to grow and absorb storm water. This method is not as effective as building tunnels as it is only expected to soak up 2 percent of the total overflow storm water, however it is much cheaper than the tunnel, making once desolate areas more aesthetically pleasing, and contributing to carbon sequestration, a win-win-win. The MSD offers grants to the public to grow these gardens so this percentage could rise, but it is not likely to make as significant a dent as the tunnel system.
[su_pullquote]The decisions one city along the Mississippi river literally flow to every other city along the river, so it’s essential that cities collaborate.[/su_pullquote]So is this project worth the costs? In my view, yes it is. Although not all the storm water will be diverted from mixing with sewage, these are positive steps taken by St. Louis policy makers. All across the country, cities are taking similar steps, with different amounts of money proportioned between rainscaping and direct tunnel maintenance. For example, Philadelphia is spending 2.5 billion dollars on creating green spaces all over the city. Chicago is providing its citizens with free rain barrels as well as other rainscaping initiatives. Hundreds of more cities are coming up with measures like this to keep their rivers clean. Just like St. Louis, the majority of these cities have combined sewer systems built in the early 20th century. It is essential that city policy makers turn their focus to this archaic infrastructure and start doling out some money for long-term projects. The decisions one city along the Mississippi river makes literally flow to every other city along the river, so it is crucial that cities collaborate. Just this March, a treatment plant failure in Memphis ended with 200 million gallons of wastewater in the Mississippi. The time is ripe for cities to plan long-term projects like MSD Project Clear. St. Louis is at the front of the pack here, but not without some blots on its record.
[su_pullquote align=”right”]On the project’s website the work is equated “to constructing 11 Busch Stadiums, rebuilding I-64 nine times, or erecting seven new Mississippi River bridges.”[/su_pullquote]The biggest challenge faced by these projects is each city’s inherent unequal distribution of resources. Where the money is, the innovation is. In St. Louis this is stark, as the tunneling will mainly be done in the southwest portion of the city while rainscaping will be predominantly in the northeast. In an ideal world, every downtown building and suburb alike would be lined by lush gardens, roofed with solar panels, and decorated with plants on every window. Unfortunately, the day-to-day lives of most people don’t contain breaks for watering flowers or hours at the local organic farm. The word must get out so people will be inspired to spread the changes equally across the city. The truth is, most St. Louis citizens aren’t aware of MSD Project Clear even though many of them pay those slowly rising sewage bills. The immensity of the project is mind-boggling. On the project’s website the work is equated “to constructing 11 Busch Stadiums, rebuilding I-64 nine times, or erecting seven new Mississippi River bridges.”
But like a lot of environmental projects, the results are difficult to see immediately and the real work is overlooked, or in this case, underground. The rainscaping component of MSD Project Clear is vital to creating awareness of what is going on. So, whoever’s reading this article right now, go ask for money to build a garden! Or at least learn about the cool tunnels. If all else fails, go read about Elon Musk’s vision to create the fastest tunnel boring machines known to man. If Elon Musk doesn’t get you hooked in, I don’t know what will.
[su_pullquote]MSD Project Clear is expensive, but necessary in an age marked by inaction on environmental issues.[/su_pullquote]After the crisis in Flint, Michigan it is easy to see how diabolical of an issue polluted water can be. Along with the increasingly higher amount of precipitation during rainy seasons, rising water levels, and climate change, public health will have to continue to prioritize focusing on how best to maintain clean water supplies. MSD Project Clear is expensive, but necessary in an age marked by inaction on environmental issues. I’m glad you, dear reader, took the time to educate yourself about this project. Now please go out and tell your friend. Although it would best if you went out and sponged up your roof with shrubs and vines, you don’t have to. Learn more about that vast tunnel system right under our feet and how we can make its goal come true.
Christian Fogerty ‘19 studies in the College of Arts & Sciences. He can be reached at c.fogerty@wustl.edu.