In the early 1900s a simple glass of water could quench your thirst—or kill you. The safe drinking water that much of the world takes for granted today did not exist, and deadly waterborne diseases such as cholera, typhoid fever, and dysentery were a constant threat. Thanks to the efforts of scientists and engineers committed to protecting the public health, tap water in most of the world is safe to drink and waterways are guarded against pollution.
| 1900 |
Sanitary and Ship Canal opens in Chicago In Chicago the Main Channel of the Sanitary and Ship Canal opens, reversing the flow of the Chicago River. The 28-mile, 24-foot-deep, 160-foot-wide drainage canal, built between Chicago and the town of Lockport, Illinois, is designed to bring in water from Lake Michigan to dilute sewage dumped into the river from houses, farms, stockyards, and other industries. Directed by Rudolph Hering, chief engineer of the Commission on Drainage and Water Supply, the project is the largest municipal earth-moving project of the time. |
| 1913 |
Los Angeles–Owens River Aqueduct The Los Angeles–Owens River Aqueduct is completed, bringing water 238 miles from the Owens Valley of the Sierra Nevada Mountains into the Los Angeles basin. The project was proposed and designed by William Mulholland, an immigrant from Ireland who taught himself geology, hydraulics, and mathematics and worked his way up from a ditch tender on the Los Angeles River to become the superintendent of the Los Angeles Water Department. Mulholland devised a system to transport the water entirely by gravity flow and supervised 5,000 construction workers over 5 years to deliver the aqueduct within original time and cost estimates. |
| 1913 |
Activated sludge process In Birmingham, England, chemists experiment with the biosolids in sewage sludge by bubbling air through wastewater and then letting the mixture settle; once solids had settled out, the water was purified. Three years later, in 1916, this activated sludge process is put into operation in Worcester, England, and in 1923 construction begins on the world’s first large-scale activated sludge plant, at Jones Island, on the shore of Lake Michigan. |
| 1914 |
Sewerage Practice, Volume I: Design of Sewers Boston engineers Leonard Metcalf and Harrison P. Eddy publish American Sewerage Practice, Volume I: Design of Sewers, which declares that working for "the best interests of the public health" is the key professional obligation of sanitary engineers. The book becomes a standard reference in the field for decades. |
| 1915 |
New Catskill Aqueduct is completed In December the new Catskill Aqueduct is completed. The 92-mile-long aqueduct joins the Old Croton Aqueduct system and brings mountain water from west of the Hudson River to the water distribution system of Manhattan. Flowing at a speed of 4 feet per second, it delivers 500 million gallons of water daily. |
| 1919 |
Formula for the chlorination of urban water Civil engineer Abel Wolman and chemist Linn H. Enslow of the Maryland Department of Health in Baltimore develop a rigorous scientific formula for the chlorination of urban water supplies. (In 1908 Jersey City Water Works, New Jersey, became the first facility to chlorinate, using sodium hypochlorite, but there was uncertainty as to the amount of chlorine to add and no regulation of standards.) To determine the correct dose, Wolman and Enslow analyze the bacteria, acidity, and factors related to taste and purity. Wolman overcomes strong opposition to convince local governments that adding the correct amounts of otherwise poisonous chemicals to the water supply is beneficial—and crucial—to public health. By the 1930s chlorination and filtration of public water supplies eliminates waterborne diseases such as cholera, typhoid, hepatitis A, and dysentery. The formula is still used today by water treatment plants around the world. |
| 1930 |
Hardy Cross method Hardy Cross, civil and structural engineer and educator, develops a method for the analysis and design of water flow in simple pipe distribution systems, ensuring consistent water pressure. Cross employs the same principles for the water system problem that he devised for the "Hardy Cross method" of structural analysis, a technique that enables engineers—without benefit of computers—to make the thousands of mathematical calculations necessary to distribute loads and moments in building complex structures such as multi-bent highway bridges and multistory buildings. |
| 1935 |
Hoover Dam In September, President Franklin D. Roosevelt speaks at the dedication of Hoover Dam, which sits astride the Colorado River in Black Canyon, Nevada. Five years in construction, the dam ends destructive flooding in the lower canyon; provides water for irrigation and municipal water supplies for Nevada, Arizona, and California; and generates electricity for Las Vegas and most of Southern California. |
| 1937 |
Delaware Aqueduct System Construction begins on the 115-mile-long Delaware Aqueduct System. Water for the system is impounded in three upstate reservoir systems, including 19 reservoirs and three controlled lakes with a total storage capacity of approximately 580 billion gallons. The deep, gravityflow construction of the aqueduct allows water to flow from Rondout Reservoir in Sullivan County into New York City’s water system at Hillview Reservoir in Westchester County, supplying more than half the city’s water. Approximately 95 percent of the total water supply is delivered by gravity with about 5 percent pumped to maintain the desired pressure. As a result, operating costs are relatively insensitive to fluctuations in the cost of power. |
| 1938-1957 |
Colorado–Big Thompson Project The Colorado–Big Thompson Project (C-BT), the first trans-mountain diversion of water in Colorado, is undertaken during a period of drought and economic depression. The C-BT brings water through the 13-mile Alva B. Adams Tunnel, under the Continental Divide, from a series of reservoirs on the Western Slope of the Rocky Mountains to the East Slope, delivering 230,000 acre-feet of water annually to help irrigate more than 600,000 acres of farmland in northeastern Colorado and to provide municipal water supplies and generate electricity for Colorado’s Front Range. |
| 1951 |
First hard rock tunnel-boring machine built Mining engineer James S. Robbins builds the first hard rock tunnel-boring machine (TBM). Robbins discovers that if a sharp-edged metal wheel is pressed on a rock surface with the correct amount of pressure, the rock shatters. If the wheel, or an array of wheels, continually rolls around on the rock and the pressure is constant, the machine digs deeper with each turn. The engineering industry is at first reluctant to switch from the commonly used drill-and-blast method because Robbins’s machine has a $10 million price tag. Today, TBMs are used to excavate circular cross-section tunnels through a wide variety of geology, from soils to hard rock. |
| 1955 |
Ductile cast-iron pipe becomes the industry standard Ductile cast-iron pipe, developed in 1948, is used in water distribution systems. It becomes the industry standard for metal due to its superior strength, durability, and reliability over cast iron. The pipe is used to transport potable water, sewage, and fuel, and is also used in fire-fighting systems. |
| 1960s |
Kuwait begins using seawater desalination technology Kuwait is the first state in the Middle East to begin using seawater desalination technology, providing the dual benefits of fresh water and electric power. Kuwait produces fresh water from seawater with the technology known as multistage flash (MSF) evaporation. The MSF process begins with heating saltwater, which occurs as a byproduct of producing steam for generating electricity, and ends with condensing potable water. Between the heater and condenser stages are multiple evaporator-heat exchanger subunits, with heat supplied from the power plant external heat source. During repeated distillation cycles cold seawater is used as a heat sink in the condenser. |
| 1970s |
Aswan High Dam The Aswan High Dam construction is completed, about 5 kilometers upstream from the original Aswan Dam (1902). Known as Saad el Aali in Arabic, it impounds the waters of the Nile to form Lake Nasser, the world’s third-largest reservoir, with a capacity of 5.97 trillion cubic feet. The project requires the relocation of thousands of people and floods some of Egypt’s monuments and temples, which are later raised. But the new dam controls annual floods along the Nile, supplies water for municipalities and irrigation, and provides Egypt with more than 10 billion kilowatt-hours of electric power every year. |
| 1980s |
Bardenpho process James Barnard, a South African engineer, develops a wastewater treatment process that removes nitrates and phosphates from wastewater without the use of chemicals. Known as the Bardenpho process, it converts the nitrates in activated sludge into nitrogen gas, which is released into the air, removing a high percentage of suspended solids and organic material. |
| 1996 |
UV Waterworks Ashok Gadgil, a scientist at the Lawrence Berkeley National Laboratory in California, invents an effective and inexpensive device for purifying water. UV Waterworks, a portable, low-maintenance, energy-efficient water purifier, uses ultraviolet light to render viruses and bacteria harmless. Operating with hand-pumped or hand-poured water, a single unit can disinfect 4 gallons of water a minute, enough to provide safe drinking water for up to 1,500 people, at a cost of only one cent for every 60 gallons of water—making safe drinking water economically feasible for populations in poor and rural areas all over the world. |
Indoor plumbing was rare, especially in the countryside, and in cities it was inadequate at best. Tenements housing as many as 2,000 people typically had not one bathtub. Raw sewage was often dumped directly into streets and open gutters; untreated industrial waste went straight into rivers and lakes, many of which were sources of drinking water; attempts to purify water consistently fell short, and very few municipalities treated wastewater at all.
As a result, waterborne diseases were rampant. Each year typhoid fever alone killed 25 of every 100,000 people (Wilbur Wright among them in 1912). Dysentery and diarrhea, the most common of the waterborne diseases, were the nation's third leading cause of death. Cholera outbreaks were a constant threat.
These challenges of both quantity and quality—to make sure there was enough water conveniently supplied wherever it was wanted and to make sure that it was safe both before and after use—fell to the nation's civil engineers. The results of their efforts speak for themselves: a deadly handful of waterborne diseases virtually eliminated not only in the United States but throughout the developed world; water distribution systems pumping a clean supply into homes, apartments, businesses, and factories and meeting the needs of tens of millions of people in burgeoning new cities and communities; and the rich potential of western lands realized in acre upon acre of irrigated crops. All told, what 20th-century engineers did to improve the water supply wrought a host of stunning transformations—in public health, in living standards, and in both urban and agricultural development.
As the century began, the most pressing task was to find better ways to make water clean. The impetus came from the discovery only a few years before the turn of the century that diseases such as typhoid and cholera were actually traced to microorganisms living in contaminated water. Treatment systems in place before then had focused on removing particulate matter suspended in water, typically by using various techniques that caused smaller particles to coagulate into heavier clumps that would settle out and by filtering the water through sand and other fine materials. Some harmful microorganisms were indeed removed in this way, but it wasn't good enough. One more step was necessary, and it involved the use of a chemical called chlorine. Known at the time for its bleaching power, chlorine also turned out to be a highly effective disinfectant, and it was just perfect for sterilizing water supplies: It killed a wide range of germs, persisted in residual amounts to provide ongoing protection, and left water free of disease and safe to drink.
In 1908, Jersey City, New Jersey, became the first municipality in the United States to institute chlorination of its water supply, followed that same year by the Bubbly Creek plant in Chicago. As had happened in European cities that had also introduced chlorination and other disinfecting techniques, death rates from waterborne diseases—typhoid in particular—began to plummet. By 1918 more than 1,000 American cities were chlorinating 3 billion gallons of water a day, and by 1923 the typhoid death rate had dropped by more than 90 percent from its level of only a decade before. By the beginning of World War II, typhoid, cholera, and dysentery were, for all practical purposes, nonexistent in the United States and the rest of the developed world.
As the benefits of treatment became apparent, the U.S. Public Health Service set standards for water purity that were continually revised as new contaminants were identified—among them industrial and agricultural chemicals as well as certain natural minerals such as lead, copper, and zinc that could be harmful at high levels. In modern systems, computerized detection devices now monitor water throughout the treatment process for traces of dangerous chemical pollutants and microbes; today's devices are so sophisticated that they can detect contaminants on the order of parts per trillion. More recently, the traditional process of coagulation, sedimentation, and filtration followed by chemical disinfection has been complemented by other disinfecting processes, including both ultraviolet radiation and the use of ozone gas (first employed in France in the early 1900s).
One important way to improve water quality, of course, is to reduce the amount of contamination in the first place. As early as 1900, engineers in Chicago accomplished just that with an achievement of biblical proportions: They reversed the flow of the Chicago River. Chicago had suffered more than its fair share of typhoid and cholera outbreaks, a result of the fact that raw sewage and industrial waste were dumped directly into the Chicago River, which flowed into Lake Michigan, the source of the city's drinking water. In a bold move, Rudolph Hering, chief engineer of the city's water supply system, developed a plan to dig a channel from the Chicago River to rivers that drained not into Lake Michigan but into the Mississippi. When the work was finished, the city's wastewater changed course with the river, and drinking water supplies almost immediately became cleaner.
City fathers in Chicago and elsewhere recognized that wastewater also would have to be treated, and soon engineers were developing procedures for handling wastewater that paralleled those being used for drinking water. It wasn't long before sewage treatment plants became an integrated part of what was fast becoming a complex water supply and distribution system, especially in major metropolitan centers. In addition to treatment facilities, dams, reservoirs, and storage tanks were being constructed to ensure supplies; mammoth tunnel-boring machines were leading the way in the building of major supply pipelines for cities such as New York; networks of water mains and smaller local distribution pipes were planned and laid throughout the country; and pumping stations and water towers were built to provide the needed pressure to support indoor plumbing. Seen in its entirety, it was a highly engineered piece of work.
As the nation's thirst continued to grow, even more was required of water managers—and nowhere more so than in California. The land of the gold rush and sunny skies, of rich alluvial soils and seemingly limitless opportunities, had one major problem—it didn't have nearly enough water. The case was the worst in Los Angeles, where a steadily increasing population and years of uneven rainfall were straining the existing supply from the Los Angeles River. To deal with the problem, the city formed its first official water department in 1902 and put just the right man in the job of superintendent and chief engineer. William Mulholland had moved to Los Angeles in the 1870s as a young man and had worked as a ditch tender on one of the city's main supply channels. In his new capacity he turned first to improving the existing water supply, adding reservoirs, enlarging the entire distribution network, and instituting the use of meters to discourage the wasting of water.
But Mulholland's vision soon reached further, and in 1905 citizens approved a $1.5 billion bond issue that brought his revolutionary plan into being. Work soon began on an aqueduct that would bring the city clear, clean water from the Owens River in the eastern Sierra Nevada, more than 230 miles to the north. Under Mulholland's direction, some 5,000 workers toiled on the project, which was deemed one of the most difficult engineering challenges yet undertaken in America. When it was completed, within the original schedule and budget, commentators marveled at how Mulholland had managed to build the thing so that the water flowed all the way by the power of gravity alone. At a lavish dedication ceremony on November 5, 1913, water finally began to flow. Letting his actions speak for him, Mulholland made one of the shortest speeches on record: "There it is. Take it!"
Los Angeles took what Mulholland had provided, but still the thirst grew. Indeed, throughout the 20th century communities in the American West took dramatic steps to get themselves more water. Most notable is undoubtedly the combined building of the Hoover Dam and the Colorado River Aqueduct in the 1930s and early 1940s. The dam was the essence of multipurposefulness. It created a vast reservoir that could help protect against drought, it allowed for better management of the Colorado River's flow and controlled dangerous flooding, and it provided a great new source of hydroelectric power. The aqueduct brought the bountiful supply of the Colorado nearly 250 miles over and through deserts and mountains to more than 130 communities in Southern California, including the burgeoning metropolis of Los Angeles. Other major aqueduct projects in the state included the California Aqueduct, supplying the rich agricultural lands of the Sacramento and San Joaquin valleys. The unparalleled growth of the entire region quite simply would have been impossible without such efforts.
The American West set the model, and around the world it soon became a mark of progress when a nation would turn to large-scale management of its water resources. Egypt is one of the best examples. The building of the Aswan High Dam in the 1960s created the third-largest reservoir in the world, tamed the disastrous annual flooding of the Nile, and provided controlled irrigation for more than a million acres of arid land. Built a few miles upriver from the original Aswan Dam (built by the British between 1898 and 1902), the Aswan High Dam was a gargantuan project involving its share of engineering challenges as well as the relocation of thousands of people and some of Egypt's most famous ancient monuments. Spanning nearly two miles, the dam increased Egypt's cultivable land by 30 percent and raised the water table for the Sahara Desert as far away as Algeria.
Egypt solved many of its water-related problems with this one grand stroke, but most countries in the developing world don't have the economic resources for such an undertaking. And in many cases, they don't have the water to work with in the first place. In such cases, one solution being adopted more and more widely is desalination—the treatment of seawater to make it drinkable. Once a pipe dream, desalination is now a viable process, and more than 7,500 desalination plants are in operation around the world, the vast majority of them in the desert countries of the Middle East.
Two main processes are used to desalinate seawater. One, called reverse osmosis, involves forcing the water through permeable membranes made of special plastics that let pure water through but filter out salts and any other minerals or contaminants. The other method is distillation, in which the water is heated until it evaporates, then condensed, a process that separates out any dissolved minerals. Although these and other desalination techniques do work and have solved water shortage problems, they are too costly for many countries; distillation, for example, requires a good deal of energy input, and fuel costs can be prohibitively high. In some cases, adequate supplies of fuel aren't even available, at any cost.
The challenge this represents is a mighty one. For a shockingly high proportion of the world's population, clean water is still the rarest of commodities. By some estimates, more than two billion people on the planet have inadequate supplies of safe drinking water. Most of them still get their water from sources outside their homes-water that is for the most part untreated and rife with disease—carrying organisms. In the developing world, more than 400 children die every hour from those old, deadly scourges—cholera, typhoid, and dysentery. In short, the lack of safe water is a global crisis with a lethal toll.
Today's engineers still struggle with the problem, and some of them are coming up with smaller-scale solutions. A case in point is a relatively simple device invented by Ashok Gadgil, an Indian-born research scientist working at the Lawrence Berkeley National Laboratory in California. When a new strain of cholera killed more than 10,000 people in southeastern India and neighboring countries in 1992 and 1993, Gadgil and a graduate student assistant worked to find an effective method for purifying water that wouldn't require the cost-prohibitive infrastructure of treatment plants.
Their device was simplicity itself: a compact box containing an ultraviolet light suspended above a pan of water. Water enters the pan, is exposed to the light, and then passes to a holding tank. At the rate of 4 gallons a minute, the device kills all microorganisms in the water, with the only operating expense being the 40 watts of power needed for the ultraviolet lamp. Dozens of these devices, which can be run off a car battery if need be, are now in use around the world—from Mexico and the Philippines to India and South Africa, where it provides clean drinking water to a rural health clinic. Regions using the simple treatment have reported dramatic reductions in waterborne diseases and their consequences.
Whatever their scale, from aqueducts and dams to desalination plants and portable ultraviolet devices, the notable successes in water management achieved in the 20th century continue to offer encouragement to a new generation of civil engineers worldwide as they face the challenge of our never-quenched need for clean water.
Samuel C. Florman
Chairman
Kreisler Borg Florman Construction Company
I was born and raised in New York City and have an early memory of a family celebration held at one of Manhattan's more elegant restaurants. I recall the waiter asking my father if he wanted to order a bottle of mineral water with the exotic-sounding name of a European spa. And I recall my father's firm reply: "No thank you, young man. We will all have LaGuardia cocktails." The waiter understood that this reference to our much-beloved mayor meant we wished to be served plain tap water. My father then explained to me that New York City water was the finest, purest beverage one could find anywhere and that it came to us from distant mountains over magnificent aqueducts and through spectacular tunnels carved deep in the earth.
My mother thereupon delivered a lecture on the importance of water to our health and well-being and expressed thanks to providence that many terrible waterborne diseases had recently been conquered, not only because our water came from far away but also because it was filtered and treated with germ-destroying chemicals. After that experience the faucets in our apartment took on for me a fascinating quality they never had before.
A science teacher at school helped nourish my newly awakened interest with a detailed explanation of how the New York City water system was conceived, designed, and built. My father had associated the technological marvel with a popular politician—as did the Romans and many others before and since—and my mother had expressed thanks to providence, surely a benign gesture. But I soon learned that a major part of the credit was due the talented people who had created the marvelous enterprise—the engineers.
I cannot say that this experience, in itself, persuaded me to become an engineer. But I do believe it started me on the way. It prompted me to become an avid sidewalk superintendent, seeking out in our city streets the numerous man-made holes that exposed a fabulous subterranean world of pipes and valves. When, years later, I embarked on my engineering studies, the courses on water supply were among my favorites. The often demanding theoretical work was alleviated by the fun of experimenting with water as it flowed through pipes and channels and poured over weirs. (And the occasional splashing reassured me that engineers are not as totally solemn as they are sometimes said to be.)
Then, as a newly commissioned ensign with the U.S. Navy Seabees, immediately after World War II, I found myself on a small island in the mid-Pacific, assigned to a water supply project. Surrounded by thousands of square miles of salty seas, a supply of fresh water suddenly seemed immensely precious. The elixir we were able to collect from mountain streams, impound behind a small earth-fill dam, then purify and distribute to a military camp reminded me of the water that engineers at home had been able to provide like magic in the midst of large and bustling cities. When work on the island infrastructure was complete and we opened the ceremonial tap, I fleetingly recalled my father's satisfaction in ordering a round of LaGuardia cocktails.
Ultimately, I followed a career in construction engineering and developed a special interest in concrete and steel. Yet each time I see a building rise into the sky, the sight of the plumbing pipes—the final arteries of a marvelous life-sustaining system—evokes a special feeling of wonder and pride.