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Plumbing Engineer - Columns: April 2012: Sustainable Design

What have we done to the water?

By Winston Huff, CPD, LEED AP BD+C

If I were a moviemaker, I would make a movie about water. Humans are fascinated with water. We can sit on a beach, in a boat or a bathtub or by a swimming pool or stream for hours, letting the sound, smell and feeling of the water flow around and through us. This is true for most humans from any culture or at any time in history. Could a movie capture that fascination?

I think of this movie while traveling in a plane high over the clouds. The movie begins with a view of a deep blue ocean and the empty blue sky above; then misty clouds roll into the scene. The clouds transform from white to light gray to a menacing dark purple; lightning flashes and thunder rumbles.

The camera angle lowers to the ocean, where huge waves are now pushing large ships like toys in a bathtub. On the nearby shore, trees twist and leaves blow; in the distance, lights suddenly turn on to illuminate city skyscrapers and busy streets. On the ground, umbrellas open, people on the streets and animals outside the city run for shelter.

The rain begins, and nature’s dark mood changes to one of relief. The long-awaited rain works like soothing medicine on a dry, parched landscape. The brown land celebrates the gift of rain from faraway regions. Trees, animals and even the fish in the water dance and enjoy the rain and the life that it sustains. The clean rainwater picks up dust from the air and dirt from the ground, and the muddy water that is not absorbed by the land flows into streams and rivers, becoming clear and clean again.

At the end of the movie, the sun shines on the bodies of water, creating a fog that rises back to the sky. The camera follows the fog as it lifts from the ground, and the view of the blue sky and ocean is the same as when the movie began.


As building professionals, we sometimes forget the cycle of water that flows through us. In addition to sustaining our land and bodies, water sustains those in the plumbing industry financially. From time to time, we all need to stop what we are doing and take a step back to look at the process of water: where it comes from, what we do to it and where it goes. Earth and the biosphere cycle water through a natural process, while human-made systems use another procedure.

Biosphere process

Where does water come from? Much like the movie description, water does not come from a single source; rather, it is a cycle. The cycle begins when water is suspended in clouds as vapor. It is in a relatively pure form, with small traces of chemical elements. In this state, the biosphere has the ability to keep the water clean and pure while moving it hundreds and thousands of miles around the world.

The sun shining over North Africa can create energy that flows west over the Atlantic Ocean, where, in a natural desalination process, water from the oceans is changed into clouds. This energy can increase as it travels thousands of miles across the ocean to the Gulf of Mexico. By this time, hurricane force winds can cause the water from the clouds or in the ocean to flood large portions of North America.

What is in the water? While it is in the clouds, water is free of biological contaminants. Water in this state cannot make you sick. As it falls to the ground, it picks up particles from the air, which can be carried for miles. When rain hits the plants, animals and ground, it picks up minerals, nutrients and biological matter that are carried away to other locations via streams and rivers.

Where is it going? Water is on a journey back to the clouds. It begins to flow, mostly by gravity, underground and over the surface. As it flows, it flushes and moves excess nutrients, solids and minerals from one parcel to another. As water travels on its long journey, its progress slows in areas where the sun’s energy pulls it back up into the clouds.


What did this journey do to the water? Not much. In the natural biosphere cycle, water is constantly moved for thousands of years. The quality of the water in the clouds is not much different now than it was when dinosaurs roamed the earth. This means that a molecule of a dinosaur could be in the water you drink.

Human process

Where does the water come from? In the past two centuries, humans have developed a process very different from the biosphere process to “create” water. The human system is different in that it changes the nature of the water, while the natural water cycle has maintained almost the same level of water quality for thousands of years.

Like the biosphere system, it is a cycle but, in most cases, the human system begins with water from bodies of water on or in the ground. Unlike the water in clouds, the quality of this water may be contaminated with various amounts of biological, mineral and solid materials. Consuming this water untreated could be harmful to people, so it must be taken to a water treatment facility before distribution.

It’s amazing that a typical water treatment facility can treat, filter and distribute this water across an entire region. In some cases, such as in Southern California and New York City, water is transported hundreds of miles for use in other areas. This water is treated, maintained and distributed in drinking water quality seven days a week, 24 hours a day, in all types of weather and drought conditions.

Municipal water treatment facilities filter and distribute high-quality water directly into our buildings. A person can stop in any business and use the toilet, wash their hands and drink water from the tap without worrying about getting sick or making someone else sick. Having this much water constantly available has increased our water usage in the past 100 years. In most communities, approximately 130 gallons of water is processed to drinking water quality for each person using the system per day. This part of the water story is a wonder of our modern society.

Where does the water go? Water supply is only half of the story. The clean drinking-quality water that flows out of the spout is used for less than a second; then it flows into the drain. In this split second, the high-quality water is changed into wastewater. In modern sewer systems, wastewater contains a mix of biological, chemical and solid waste material and is hazardous to plants, people, animals and the soil.

People are in the middle of this process. Water treatment facilities do not make wastewater. In the natural cycle, the term wastewater is not used and the term water quality does not mean very much. These are terms we use to talk about the wastewater people make. We make wastewater every time we flush a toilet, turn on a faucet or use a plumbing fixture.


In some instances, however, humans aren’t even necessary. Sensor-operated plumbing fixtures change drinking water to wastewater without a person touching a thing. We can program systems to use hundreds of gallons of water to irrigate our exotic lawns and landscaping. We do nothing to make it happen except pay the water bill.

The modern waste system carries the same 130 gallons a day per person away from our buildings in a complex system of piping, pumps and filters. The cocktail of contaminants is removed from the waste stream and, in most cases, the water entering the natural biosphere is safe.

Typical water and waste systems are a marvel of modern engineering, and water distribution and treatment are the responsibility of the plumbing industry. It is important to remember that these systems must operate properly for the health and safety of others.

What did we do to the water? The human system is amazing when the quantity and quality of the water are considered. Is our system successful in removing the trace materials that may remain after we use the water? Many studies have shown that there are trace pharmaceuticals in our water supply, due to the disposal of medications.

This automatic system also comes at a great energy cost. A recent study showed that 20 percent of the energy generated by California is used for the state’s water systems.

Is our model a good one for the developing world to use? What if China were to follow our example and supply 130 gallons of drinking-quality water per person every day and then treat the wastewater in the same way we do? China has 20 times as many people as California and would have to generate four times the amount of energy used by the entire state of California just for their water systems. What about other countries with dense populations, such as India and Brazil? Is there enough energy in the world to do this? What would the quality of the water be if these countries copied the United States?

The water distribution system may have started with the intent to supply safe drinking water to people, now it is also a system to carry waste away from people. The system has evolved into a water-based waste system. Have we ever stopped to think whether this is the best way to carry our waste away? Is providing 130 gallons of drinking-quality water per person per day the most efficient way to operate?

What have we done to our water? In the future we need more efficient ways to handle water. Here are some examples:

• Energy-efficient pumping
• Alternate water sources
• Alternate waste systems
• Move away from water-based waste systems
• Mimic the natural biosphere where the words waste and quality have little meaning

In the future, we could design plumbing systems using less water. Imagine that!

Winston Huff, CPD, LEED AP, is a project manager, plumbing fire protection designer and sustainable coordinator with Smith Seckman Reid Consulting Engineers in Nashville, Tennessee. He serves as an ASPE representative on the ICC Green Construction, Energy and Water Code Development Committee and is on the U.S. Green Building Council’s Water Efficiency Technical Advisory Group. He was the founding editor of Life Support and Biosphere Science and has served as its editor-in-chief. He also is editor of Me Green You Green (megreenyougreen.com), a LEED credit databank.

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