Madison Metropolitan Sewerage District, Pumping Station 8

901 Plaenert Drive, Madison WI 53713

The Molecular Structure mural plays with the visible and hidden beauty of our world. By reflecting the Wisconsin landscape, the mural zooms into microscopic views of nature, and then dives deeper into molecular structures that make up our surroundings.

Through the day and night – we travel the seasons:

The Molecular Structure Mural begins in the day and ends in the night. Our artist, Peter Krsko, created two multilayered stencils to bring our sky to life.

Did you know our Sun is classified as a yellow dwarf star? It is the largest object within our solar system, the sun holds a whopping 99.8% of the system’s mass! If that was not cool enough, our ~4.5 billion year old sun sings… well kind of sings. Stars are in constant symphony as their nuclear power creates vibrations, scientists can translate these vibrations through fluctuations in a star’s brightness so we can hear what a star could sound like. These vibrations can help scientists understand more about the structures of stars. Learn more with NASA’s Solar System Exploration resource. 

And closer to home, we have our Moon. The Sun and Moon work together to create the gravitational pull that creates our tides. We have a lot to be thankful for when it comes to our moon. Although it may be cratered and pitted from impacts – the moon helps stabilize Earth’s wobble … which influences our livable climate!

Cherish our water

Water is made of three atoms: one Oxygen and two Hydrogens. It is shaped at a “bent” angle with oxygen in the center. The uneven sharing of electrons in O-H covalent bonds gives rise to the unique properties of water. There are three distinct phases, or states, that represent the molecular structures of water (Gas/Vapor, Liquid, and Solid.) Can you see the varying degrees of order within each molecular phase? 

Gas state: within the gas state, water’s molecular structure has the most disorder. The water molecules are so far apart they barely interact within on another and are in constant, rapid motion. Within this state, the temperature is the highest of all phases – it can take on the form of room/atmospheric vapor (as seen in our mural), or to being as hot as steam!

Liquid state: in the liquid state, water molecules are close to one another and can interact as they pass buy. It’s like rubbing two weak magnets together, the attractive forces can be felt but the magnets are free to move around.

Solid state: hydrogen bonding of water molecules in the solid state forms 6-membered rings. Can you find this shape in the mural’s snowflakes and ice lake? This is why snowflakes are always hexagonal! The hydrogen bonding between rigidified water molecules leads to “hollow” hexagonal structures within solid ice – which makes ice float!

These states of water reflect all the different types of forms water can take, over and over again. All the water we have now is all the water we will ever have. Water is continually recycled on Earth. This recycling of water happens naturally within our environment, and also with the help of places like the Madison Metropolitan Sewerage District. The water you use everyday has been in many places, in many states, and is as old as the planet. We must protect our water, as only 2.5% of all water on earth is freshwater, and much less is actually usable as fresh drinking water.

Dive into Water Filtration

So how do we protect water, and recycle water well?

Methane is often emitted in wastewater through the decomposition of organic material. The molecule also appears in natural bodies of water through other natural interactions.

Water filtration begins with dividing waste from water. Lighter solids sink to the bottom of bodies of water – cleaning water of any unwanted solids.

The Madison Metropolitan Sewerage district replicates this natural process through their “Primary Settling Tanks”and “Final Clarifiers.”



Microorganisms within the water consume organic matter as a part of the filtration process. The Madison Metropolitan Sewerage district replicates this natural process in what is termed the “Aeration Tank.”

And then finally, Ultraviolet (UV) light passes through water and kills bacteria, represented by the broken DNA. Within nature, the Sun’s UV power works to disinfect our waters.  The Madison Metropolitan Sewerage district replicates this natural process in what is termed the “UV Light Chambers.”

Find wonder in a tree

Water is critical for all life, for example our human bodies are 60% water. And all living organisms need water to survive. For example, take a tree and its roots. Tree roots are designed to grow towards water and nutrient sources. Let’s take a look at the hidden workings of a tree.

Cellulose makes for strong branches and leaves. It is a long-chain polymer of glucose molecules joined together. It is made through photosynthesis. Cellulose is critical for strengthening trunks to hold up even the tallest of trees.

Within the mural, our artists have embedded a cross section of a tree root to get an inside view of tree structures. Trees, like water, are critical for our planet as they provide oxygen, store carbon, enrich and stabilize our soils.

Roots transport water, minerals and nutrients to the whole tree, and anchor trees to the ground. They even store sugar – food for trees – to serve up during the winter months.

The trunk and roots of a tree play important roles for the tree’s health and stability. Now let’s explore tree trunks in more detail.

Just like humans, trees need to have tissue that transfer materials from one location to another. We have arteries and veins. A tree has Xylem and Phloem.

As we zoom deeper into the tree, we see Cambium at a microscopic level. We have got Phloem and Xylem represented in the mural through a microstructure.

Do you know what is sandwiched between Phloem and Xylem? The vascular cambium – which works to produce the two layers.

Phloem is made up of living tubular cells that transports sugar from leaves to all parts of the tree right down to the bottom roots. It is located right under the bark of a tree.

Xylem is what makes the annual rings of a tree, so we can understand the history and age of a tree. It is made up of dead tubular cells that transports water up from the roots to the leaves.



Not only do roots provide and store resources for the tree, they also create rich soil environments, contributing to thriving ecosystems. Our soil can offer solutions to our future.

For example – from soil, we can even unearth new antibiotic-producing microbes that can address a worldwide health threat: antibiotic resistance. Learn more form our collaborators at Tiny Earth.


Check out this fun song by ParrMr about roots, trunks and more!

And finally, we have a tree’s canopy. The beautiful leaves that give us shade, that rustle in the wind and trap light energy for photosynthesis.

Leaves often have a large surface area in order to capture as much energy from the sun as possible. A leaf has three layers.

The epidermis of the leaf is the outside layer of the leaf – like our skin.

The Palisade layer is right below the Epidermis. The cells of the Palisade layer often have lots of chloroplast to help capture most of the light energy.

And under the Palisade layer is the Spongey layer with lots of air spaces – this layer has veins that transport materials throughout the leaf.



Within our mural, we illustrate microscopic zooms of a Summer leaf and Fall leaf. So why do leaves change colors? Check out this cool video by Reactions.

To fly or fish

Our artist, Ingrid Kallick, has brought to life a Great Blue Heron. Great Blue Herons are the largest and most widespread heron in North America. Feeding on fish, amphibians, reptiles and much more – these birds stand silently along the shore, waiting for their prey, or they will stalk prey slowly with master precision.

From the birds eye view of a bird, we zoom in to the microscopic view of its feather … and then zoom in even further into a molecular structure of keratin, which is a part of a feather’s foundation. Feathers must be light and flexible for precise airborne movements, but also strong enough to withstand the forces of flight. Within a molecular zoom, you see the anatomy of a feather. A feather has a rachis (central shaft) and a vane made of barbs that branch off the rachis. They are made from a protein called beta-keratin, represented in the mural by the molecular structure of keratin.

Find light in the night

Ever wonder where a lighting bug gets its glow from? The answer is Luciferin!

This is the light-emitting compound found in organisms that generate bioluminescence.

If you visit the Molecular Structure mural at night, you may even see a few glowing fireflies hidden during the day.

Can you identify anything else that glows in the mural? Snap a photo and tag us on Instagram.

Meet the curious fox

WELL, HELLO!” said the fox to his reflection. 

Foxes are a part of the Canidae family – like wolves, jackals and dogs. Unlike their distant relatives, they are not pack animals but prefer a solitary life. They often live in burrows. You can find them in every continent except Antarctica, in both suburban and rural settings. They also have commonalities to cats. They are active in the night, have vertically oriented pupils and walk on their toes. They can even climb trees!

Within our mural we have zoomed into the molecule Adenosine Triphosphate, commonly known as ATP. Have you ever wondered how cells do their thing? The answer is: energy. Specifically ATP. ATP is an energy carrying molecule found in cells of all living things. It captures the chemical energy that comes from breaking down food molecules and releases it to fuel other cellular processes. Just like this fox’s cells use ATP, humans do too. ATP connects us all! Can you identify what else in the mural uses ATP?

And don’t forget to say hello to our mural’s many creatures

About our Mural Location, Pumping Station 8:

This station, pumping station 8, is essential to keeping life as we know it going in Madison. Each day, this station pumps about 13 million gallons of wastewater away from homes and businesses to the Nine Springs Wastewater Treatment Plant for treatment and safe return to the environment. The Madison Metropolitan Sewerage District is dedicated to protecting public health & the environment, through innovative engineering and resource recovery. At the treatment plant, chemistry (including molecular structure!) is a key part of bringing water from flush to fresh. Learn more.

Meet the Artist:

Ingrid Kallick
Ingrid Kallick is an artist and writer who has worked in scenic painting, murals, gallery art, children’s illustration, arts administration, and scientific visualization. Her art has appeared on the covers of Science and Cricket Magazine and in Scientific American, Leonardo Magazine, textbooks and picture books.

Peter Krsko
Peter Krsko listens to nature and creates objects and experiences to share his observations. His approach combines science and art; participatory, interactive and community arts; and play with hands-on education.

Meet the Scientists:

Jo Handelsman
Director of the Wisconsin Institute for Discovery
Dr. Jo Handelsman is the Director of the Wisconsin Institute for Discovery at the University of Wisconsin-Madison, a Vilas Research Professor, and Howard Hughes Medical Institute Professor. She previously served as a science advisor to President Barack Obama as the Associate Director for Science at the White House Office of Science and Technology Policy (OSTP) where she served for three years until January 2017, and was on the faculty at the University of Wisconsin and Yale University before that. She received her Ph.D. at the University of Wisconsin-Madison in Molecular Biology and has since authored over 200 scientific research publications, 30 editorials, and 29 essays. She has authored numerous articles about classroom methods and mentoring and she is co-author of six books about teaching – Entering Mentoring and Scientific Teaching. She is responsible for groundbreaking studies in microbial communication and work in the field of metagenomics. She is also widely recognized for her contributions to science education and diversity in science. Notably, she received the Presidential Award for Excellence in Science, Mathematics, and Engineering Mentoring from President Obama in 2011, and in 2012, Nature named her one of “ten people who mattered this year” for her research on gender bias in science.

Zachary K. Wickens
Assistant Professor, Department of Chemistry
Zach started as an assistant professor in the chemistry department at UW–Madison in 2018. His research team focuses on the discovery and development of new strategies to replace wasteful chemical reagents with light and electricity. Ultimately, this work will dramatically reduce the environmental impact associated with the preparation of the organic molecules that underpin modern life–ranging from medicines to solar cells. In the Science To Street Art project, Zach is collaborating with artists on both the molecular structure mural and an activity for all ages wherein participants connect the elements of the periodic table to everyday objects and experiences through art. Zach is thrilled to have a chance to leverage art as a common language to cut through cultural barriers and preconceptions about science. Throughout his efforts in both education and outreach, Zach aims to encourage and empower new voices to join modern scientific conversations.

[su_image_carousel source=”media: 823,824,825,826″ controls_style=”light” align=”center” autoplay=”7″]

The Molecular Structure Mural was completed end of September 2020. Check out our instagram account for more details.