Clean and Dirty

Imagine that you are sitting in Camp Randall stadium, home of the Wisconsin Badger football team, when all of a sudden a gray-colored, smelly water-type substance, with brown hunks floating around starts to be pumped into the stadium. You find yourself running up the stairs to get above the rising level. Somewhere above the halfway point, the pumping ends, and you look below. What you see is the consequence of human action in the wastewater stream. The Madison Metropolitan Sewerage District (MMSD) treats, on average, 40 million gallons of wastewater a day at its Nine Springs Treatment Plant. That amount would fill over one-half of Camp Randall Stadium. Forty million gallons seems like an awful lot of waste water, but this comparison also shows the massive size of Camp Randall. MMSD serves over 340,000 persons and its territory covers about 180 square miles. It runs from Morrisonville near the north boundary of Dane County with Columbia County, south to Verona. We all depend on water and much of the developed world depends on sewage treatment plants to treat wastewater. Clean water is crucial to ourselves, and our way of life. But, as everyone knows from grade school science, all the water on the earth is already here. It recycles itself through the miracle of nature.

MMSD Service Territory
Source:  MMSD

Where ever you are in Dane County, you receive your water from the ground. Groundwater moves slowly. One example illustrates this point. The municipal wells in Fitchburg, WI go deep into what is known as the Mount Simon formation. This thick limestone layer sits right below a shale layer known as the Eau Claire acquitard. Above the Eau Claire layer is the upper aquifer, mainly a sandstone formation. While the shale layer is thought to allow some water penetration, testing of a municipal well shows that the groundwater withdrawn is older than 1950. We know this because the water, at that sampling location anyway, lacks tritium which is a radioactive isotope that is found in the shallow groundwater layer. Tritium resulted due to nuclear testing of the 1950’s and shows that the shallow groundwater is recharged by post 1950 rainwater. One hopes that the Mount Simon has good recharge, but that post-1950 groundwater has yet to reach that municipal well.

Cross-section of Dane County geology
Source:  M Gotkowitz, WI Geologic & Natural History Survey

We tend to treat water as a never ending commodity. One would think that the drought in California and some other western states would end that conception. Even in the Midwest, with our abundant Great Lakes, we take water for granted. What we need to realize is that of all the water on the earth, only about 1% is thought to be available for human use. And of course, wastewater is the back-end of human use and consumption. It results as part of the natural biological process of the human body. Everybody poops, even the Queen of England.  In many societies early treatment of wastewater was, well, limited. Prior to indoor plumbing it was not uncommon to see waste dumped directly into the street. Disease would run rampant through populations. It was one of the first great challenges of the construction of a modern society—the handling of wastewater. Let’s take one example. In 1887 Madison, WI was home to 18 sanitary districts supporting a total population of about 12,000 persons. The districts collected wastewater and piped it—to the lakes! Concern over the use of the lakes as a sanitary settling pond and for recreation raised concerns and the first treatment plant was constructed, using a chemical process. This, process, however, would be abandoned in just a few years and a septic tank with trickling filters would be put in place at what was known as the Burke plant. This would be the first use of a trickling filter in the United States. Growth in the city of Madison would prompt the construction of the Nine Springs Treatment Plant, which opened in 1928. In 1930, MMSD was formed in order to best address wastewater treatment on more of a regional basis. We trust that our water is clean when we use it, but after it is used, it is dirty.

Nine Springs Treatment Plant Construction, late 1920's
Source:  MMSD

People tend to dump whole sorts of objects down the sanitary sewer, and they cause problems. Some of these objects cause problems with the districts 18 pumps stations where they clog the pumps. On average, every week sees a pump needing be lifted out for cleaning and removal of objects that affect the pump. Most pump stations have at least two pumps, and some more than four. First, there is no such thing as flushable wipes. Just because toilet paper can be handled at a treatment plant does not mean baby wipes or other paper objects can be handled in that same manner. Second, floss also gets trapped and causes problems. A shelf in the operations room is full of quaint objects that made there way to the treatment plant—mainly toys. Yes, those objects have been properly cleaned. But, sewage treatment is challenged by other modern day occurrences.

Madison water use
Source:  M Gotkowitz

Our modern way of life affects our water quality. For example, salt use in softeners and as deicing agents have led to high levels of salt, primarily in the streams and lakes. Politicians like to put solutions on to point-source pollution control agencies, like a sewage treatment plant, because it is easier and you are not dealing with a host of private individuals. Chlorides in water is just one example. MMSD receives flow not only from homes, but also through inflow and infiltration. Storm water can make its way into the system and with it, particularly in springs rains so do chlorides. MMSD may treat about 40 mgd on a typical day, but it large rain events it has to be capable of handling over twice that amount. Phosphorus is also an issue. While most phosphorus is a result of agricultural practices (P has been banned in detergents for quite some time), treatment plants have to remove ever increasing amounts in an attempt to make up for poor agricultural practices. The easy methods have already been accomplished to remove about 95% of P, but a coming requirement to remove another 3 to 3.5% will place high costs on the rate payers, particularly if a treatment option has to be chosen. There are also other aspects. Anti-microbial clothing, for example, releases mall specks of sliver when laundered. There is also the use of pharmaceuticals which, when passed through the body, still contain hormones and other parts of drugs that end up in our waterways. For every action there is an opposite and equal reaction, and just because it goes down the drain does not mean there are not consequences involved in having to handle the mess.

MMSD Treatment Plant
Source:  MMSD

Today, the Nine Springs Treatment Plant at MMSD is one of the most advanced in the world. It would cost over one billion dollars to replace. Its leadership and staff are required to look out at least fifty years in an era where most thinking is based on a few months. The treatment plant is one of a handful of plants in the nation to take most of its phosphorous and turn it into pellets for use in agricultural fertilizers. It was the first in the nation to use UV rays to disinfect the effluent. It is looking at partnerships with farmers to reduce more phosphorus, not unlike past work with dentists to separate mercury from the wastewater at the clinic. It is also looking to partner with high chloride users to reduce chloride loading. It realizes that not all solutions can be brick and mortar, but rather individual action can make a difference. Even today it still continues to study new ways of advancing treatment plant technology, often in collaboration with the University of Wisconsin.

MMSD connection to Gulf of Mexico
Source:  MMSD

As you brush your teeth, wash the dishes, or even sit in Camp Randall, think of the other end of the pipes, and the amount of water used, and how perhaps our individual actions can make a difference. Of course, your visit to Camp Randall may never be the same. Through its work with dentists, and its upcoming work with rural landowners, MMSD knows that individual choices can make a difference. It is up to the individual to take action to conserve our water and other valued resources. Progress has been made in regard to water conservation, but it is more than water conservation, it is having a calibrated water softener, it is being judicious with your use of chlorides on your driveway or sidewalk in the winter. As the MMSD executive director has noted, it takes 40 days for water to go from a tap in Dane County to the Gulf of Mexico. Our individual implications have global consequences.  Clean water is vital to our health, let's just try to keep as much as we can clean.