The first step of a WWTP is called the “headworks.” In the headworks, solid objects are removed from the sewage. All sorts of items are removed here: everything from big pieces of wood to little pieces of corn.

After the headworks, we let nature work for us: sewage is sent to basins (sort of like huge bathtubs) where we pump air into the sewage. Bacteria live in these basins. The bacteria use the pumped air to breath, and they literally eat the gross stuff in the sewage. That’s right: you flush your toilet, and we feed the contents to bacteria. These bacteria consume what is in the sewage and convert it to less-harmful substances. In between eating sessions, the bacteria make lots of babies. As these bacteria babies begin to fill up our basins, we must remove a portion to make room for more incoming sewage. The bacteria we remove from the basins is attractively called “sludge.”

Sometimes the sludge, which contains valuable things like nitrogen and phosphorus, is used as fertilizer on farmland. Sometimes the sludge is put into a process called “digestion.” The digestion process is a lot like your stomach: more bacteria go to work “digesting” the contents of the sludge. And just like our stomachs, the bacteria create gas. Unlike our own farts, however, we build special structures to capture these bacteria farts because we can use the gas as a fuel source called “biogas.”

What is left is liquid, and that is sent to a disinfection process. Disinfection kills—or disables—any harmful pathogens and viruses still left in the sewage. If a human or animal were to come into contact with this treated sewage, we don’t want them getting sick, and that is why disinfection is so important! Typically, the disinfected wastewater is then released to a water body, such as a nearby river or stream.
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Now keep in mind, this is a general overview—some sewage requires further, more complex, processing. But you start to get the idea: it is a massive undertaking to properly dispose of the contents of your morning stool. Each part of this system, from the pipes that convey it to the pumps that pump it to the plants that treat it, requires constant attention and maintenance. And our system is not in good shape: the American Society of Civil Engineers (ASCE) report card gives our wastewater treatment system in the US a resounding “D+.” At this point, the EPA estimates that we must spend upwards of $300 billion to meet current and future wastewater treatment demands in this country. Where will that money come from? That’s a good question! The honest answer is that we don’t really know. Some funding comes from the federal government, some from the local government. One federal program called the Water Infrastructure Finance and Innovation Act (WIFIA) will provide approximately $1 billion dollars to local communities which will themselves invest approximately $2 billion. While this is a great start, it is still just a drop in the proverbial wastewater bucket. 

​Our hope is that illustrating exactly how involved and important clean water and wastewater systems are in your own life will increase appreciation and gratitude for the water that you use on a daily basis. What would we do without wastewater infrastructure and treatment? Alarmingly, still more than half of the world's population does not have access to safe sanitation facilities. 

Written by Bethany Yaffe
Environmental Engineer
Well Water Global Board of Directors

October 23 was Imagine a Day Without Water. We discussed what one-third of the global population grapples with on a daily basis: lack of access to clean water. They do not have a faucet that spouts clean water. They do not have showers, toilets, or sinks. These people are helpless as sicknesses spreads through their families and their children die from preventable diseases due to a lack of clean water.

On November 4th we discussed Spring Protection Boxes that allow families to source water from natural artisan springs that are protected from contamination and are ensured to be a clean water source.

Today, we will discuss a topic that is near and dear to my heart. This is something I work on day in and day out, and I never tire of pondering on and problem solving: water infrastructure here in our own home, the United States.

Like you,  most of my daily routines revolve around water: morning, noon, and night. Getting ready for work, enjoying my morning cup of tea or coffee, preparing and enjoying meals, and getting ready for bed, I depend on my faucet to deliver water -  but not just any water - clean, disinfected water that I can use without a second thought. The only time most people think about this resource is when it is not delivered as we expect (my mind immediately goes to Flint, Michigan).

I work as an Environmental Engineer, designing water infrastructure projects and then watching as they are built. Water treatment plants, tanks, pump stations, pipelines - the heart and arteries of American water systems - collect surface and ground water, treat that water, and deliver it to homes ready to be used, at pressures high enough to take showers, flush toilets, and even fight fires.

What goes into this process, and where does your money go when you pay for the water you use? The answer to this question varies greatly across the Unites States, but one thing is consistent: From the desert Southwest, to the rain-soaked temperate rainforests of the Pacific Northwest, to the American Heartland, we depend on water for our livelihoods. Water is essential not only for drinking and daily use, but for our food, computers, paper, clothing, cars, and the energy we use to power our lives. All of these things depend on the availability of clean water.
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I am based in the Denver Metro Area, so I will focus on the water systems I know best. Here, snow melt is collected in mountain reservoirs, which then feeds our water treatment plants and distribution systems. Denver Water (the Utility that serves 1.4 million people in the Denver Metro Area) has put together a series of videos that highlight how water moves from the mountains to our homes (see the first installment below). This is a fun way to learn about how our water makes it to our faucets, as well as the people that make this service possible. 

Once the surface water moves from mountains to the reservoirs and finally to the water treatment plants, the millions of gallons of water undergo treatment. Traditional water treatment typically takes place in three steps that makes the water safe to drink by removing particles in the water and disinfecting it. We add additional treatment steps that can remove tastes and odors as needed (these do not cause health issues but can make the water unpleasant to drink). Finally, the water is delivered to homes through miles of disinfected water lines, tanks, and pump stations. All of this happens seamlessly so we can shower on the third floor of a building, or the local Fire Departments can use water at pressures and volumes high enough to fight fires. These systems take the combined efforts of hundreds and thousands of specially trained personnel and will cost roughly $1 trillion to expand and maintain in the next 25 years across the U.S. 

We encourage you to take a look at these excellent videos put together by Denver Water. What a treasure clean water is to all people, even to those of us that often take it for granted. Also, a fun resource to check out is this interactive map put together by the USGS to see exactly where your water comes from. Clean water is the literal life source of all living things across the world. Isn't it great to hear from Bethany, who is using her education and her life to make clean water available to as many people as possible?