Water supply industry

Industry Snapshot

GENERAL INDUSTRY: Natural Resources

CAREER CLUSTER: Agriculture, Food, and Natural Resources

SUBCATEGORY INDUSTRIES: Canal Irrigation; Irrigation System Operation; Water Distribution (Except Irrigation); Water Distribution for Irrigation; Water Filtration Plant Operation; Water Supply Systems; Water Treatment Plants

RELATED INDUSTRIES: Beverage and Tobacco Industry; Civil Services: Planning; Electrical Power Industry; Environmental Engineering and Consultation Services; Farming Industry; Local Public Administration; Natural Resources Management; Waste Management Industry

ANNUAL DOMESTIC REVENUES:US$99.9 billion (IBISWorld, 2024)

NAICS NUMBER: 22131

Summary

The water supply industry secures, treats, and distributes fresh water for human consumption and use, as well as for crop irrigation. The overriding function of a water treatment plant is to make sure that all incoming raw water is processed so that the finished product meets all of the regulatory standards for a water supply that is safe to drink. In turn, this means that plant and system operators need to have the training, skills, and tools to run all of the various forms of equipment in the plant, safely control all of the numerous processes that are required under state and federal regulations, and monitor all aspects of the treatment process.

History of the Industry

The earliest known water supply system was a development by the Minoan civilization on the Greek island of Crete in the Mediterranean Sea some five thousand years ago. Aqueducts were used to bring water from nearby streams into the palace and city of Knossus until a huge earthquake, about 1450 B.C.E., destroyed the region. The next major development in water supply technology occurred about 1000 B.C.E., when underground tunnels (called qanats) were used in the Middle East, particularly in what is now Iran, and in North Africa.

One of the renowned engineering triumphs of the Roman Empire, albeit one accomplished with slave labor, was the construction of elevated stone aqueducts beginning about 312 B.C.E. By 300 B.C.E., fourteen major aqueducts were in service, transporting about 151 million liters (40 million gallons) per day to Rome. Similar systems were also constructed at that time in other parts of Europe that were occupied by the Romans, such as the rest of Italy, France, the Netherlands, England, and Spain. One such aqueduct in Segovia, Spain, that was built in the first century by the Romans is still in use today. The Romans also built a system of pipelines in London to convey water from the Thames River and adjacent springs to the people in the city.

The Middle Ages in Europe were noted for filth, disease, and minimal attempts to have personal and public sanitation. Some people bathed only once or twice a year. As cities developed in Europe, North America, and other areas of the world, the easiest way to obtain water was to pipe it in from nearby surface sources or local wells. For example, Paris at the beginning of the sixteenth century had an estimated population of about 300,000 to 400,000 people, who were dependent on water from the Seine River and private wells.

The continued growth in urbanization and the vast array of waste materials that were dumped into the same river systems that were being used for drinking water invariably resulted in the easy spread of waterborne diseases. For example, the cholera epidemic of 1848-1849 caused the deaths of over fifty-three thousand people in London alone. Fortunately, the enterprising physician John Snow of London traced the impure water to one community water pump at Broad Street in Soho in 1854 that was getting its water from a highly polluted portion of the lower Thames River. His solution was simple: He removed the pump’s handle, forcing residents of the area to get their water from other sources.

Bethlehem, Pennsylvania, in 1754 built a municipal water plant, reputedly the first such plant in history. Philadelphia followed in 1801, constructing a pumping plant on the Schuylkill River above the point where it flows into the Delaware River. A treatment plant was built in 1804 in Paisley, Scotland, to serve filtered water to the city. Paris in 1806 built a plant on the Seine River that was designed to treat the water by allowing it to trickle slowly through sand filters. Richmond, Virginia, in 1834 became the first U.S. city to adopt the slow-sand filter system. Poughkeepsie, New York, was far enough upstream on the Hudson River to use fresh water to build its first treatment plant in 1870. Chlorination was first used in 1908 in Jersey City, New Jersey, as a viable means of disinfecting the raw water obtained from surface streams. The immediate result was a sharp reduction in the city’s typhoid rate, and the technique soon spread to other water purveyors.

The Industry Today

The supply sources for many contemporary large water treatment systems have remained the same. For example, Philadelphia; New Orleans; Washington, D.C.; and Chicago still get their water from the Delaware and Schuylkill Rivers, the Mississippi River, the Potomac River, and Lake Michigan, respectively. For those coastal metropolitan areas that border the salty waters of the ocean, large reservoirs in inland watersheds have had to be constructed. A prime example is New York City, which has nineteen reservoirs that collectively serve 9 million people with an average daily consumption of 4.54 million cubic meters (1.2 billion gallons). Another example is central Massachusetts’s Quabbin Reservoir system, which supplies the Boston metropolitan area.

With an average annual precipitation rate of only 381 millimeters (15 inches), Los Angeles during the early twentieth century was quickly exhausting its limited local water supplies. A project was begun in 1907 to import water from the Owens Valley in east-central California, some 375 kilometers (200 miles) distant. The scheme was met with steep resistance from the valley’s residents, who destroyed the aqueduct with dynamite. Nonetheless, Los Angeles was able to secure stable access to Owens Valley water, but the city continued to grow, requiring even greater water supplies. Accordingly, the Colorado River Aqueduct Project was started in 1928 and included thirteen Southern California cities, which together established a metropolitan water district. The modern Metropolitan Water District of Southern California consists of twenty-six water districts and cities that supply drinking water to about 19 million people, with an average delivery of 4,900 acre-feet (6 million cubic meters or 1.59 billion gallons) per day in 2022. However, a severe, decades-long drought in the American Southwest resulted in drastically falling water levels in the Colorado River. The crisis prompted officials to push for cutbacks on water usage from the river as well as looking for possible new sources of water. The crisis was alleviated by a period of heavy rains that hit the region in 2023. However, experts believe the underlying problem of climate change is likely to negatively impact the region in the future.

By the eraly 2020s, the bulk of treated water used domestically was used to flush toilets (24 percent) or for cleaning, including showering and bathing (20 percent), running a faucet (19 percent), and operating a clothes washer (17 percent). Eight percent was used for other purposes, including drinking. Nevertheless, since all such water is supplied through the same pipes, it must all meet the standards for drinking, cooking, and washing. Standards for low-flush toilets introduced in the early 1990s have helped reduce overall water consumption somewhat.

Although there are variations in treatment technologies, most plants start with tried and tested pretreatment processes. The first step in pretreatment usually consists of screens that block large items that are floating in the raw intake water, such as debris, dead animals, and fish. This is followed by the diversion of raw water to large tanks, or holding basins, where suspended sediments, such as silt and clay particles, can settle out. This step is particularly important if the water source contains large quantities of suspended materials. The next step, called flocculation and coagulation, occurs when chemicals such as alum and soda ash are added to the water to encourage the suspension of fine particles. This coagulation process results in the formation of floc, which with time becomes heavy enough to sink to the bottom of the large tanks as sludge. The flocculation and coagulation procedure can remove 90 to 99 percent of the viruses in the water. It does not kill the viruses, but they become part of the floc that settles out and is removed later in the process.

Filtration is next employed by allowing the water to pass through sand and gravel layers that provide more opportunity for the water to be cleansed of finer particles. These filters over time can become clogged with sediments that have to be removed by backwashing or flushing, a process that results in a waste product that must be diverted to a sewer system for further treatment.

The final stages in the drinking-water treatment process generally include fluoridation and disinfection. Sodium fluoride is one of the commonly added compounds and is recommended for the maintenance of healthy teeth. About half of the U.S. population uses water that is fluoridated at an optimum level of concentration. Chlorine gas is also mixed with the water to kill any remaining bacteria and some viruses. Some people contend that chlorinated water has an unpleasant odor and taste, although the use of activated carbon in the treatment process can increase the palatability of the finished water. Residual amounts of chlorine remain in the treated water as it flows through a maze of pipes to reach individual users, so some level of disinfection travels with the flow and further protects consumers.

Given the complaints of some people about chlorine odor and taste in their water, some utilities use ozone gas and ultraviolet radiation systems as disinfectants. Ozone is both a very effective disinfectant and a strong oxidant of odor and taste compounds. However, ozone not only has a higher price than chlorine but also is unable to travel with treated water and continue to disinfect it in a water system’s pipes as chlorine can. Ultraviolet light is particularly effective in killing practically all microbiological organisms that may be in treated water, as the light energy is absorbed in the deoxyribonucleic acid (DNA) of these microbes, thereby eliminating reproduction at the cellular level. Ultraviolet treatment is both costly and slow, however, but it can be very useful in selected situations.

The U.S. water treatment industry has become increasingly privatized in the late twentieth and early twenty-first centuries. Some of the private companies acquiring water treatment systems are domestic and have been around for many years, but many of the larger companies are foreign. In both cases, the companies are well financed and eager to acquire existing firms and facilities. Given the increasing complexity and cost of running a water treatment plant with a variety of state and federal guidelines and regulations that have to be followed, this trend toward privatization is an interesting development in the industry. Although private water treatment systems served only about 12 percent of Americans in 2017, economic circumstances and the growth of the trend toward privatization pushed that figure higher into the 2020s.

A major division of the national U.S. water supply infrastructure is the community water system (CWS), which is defined by the U.S. Environmental Protection Agency (EPA) as a facility that delivers water to at least fifteen service connections that are used by year-round residents or twenty-five residents that are year-round users. CWSs vary from privately owned places, such as a very small mobile home park, to very large publicly owned systems, such as New York City. Approximately 152,000 public water systems in the United States serve about 300 million people; of those systems, 52,000 are CWSs, 85,000 are nontransient water systems and 18,000 are transient noncommunity water systems.

Even with the development of more technical and complicated equipment, water treatment operators will always be faced with the increasingly stringent state and federal regulations that the product must meet. To put it another way, there are always new chemicals that get into the rivers and groundwater that could cause harm to the unwary consumer. Thus, both the technology and the regulations driving the delivery of water to consumers and crops are likely to continue increasing over time. Studies by the American Water Works Association (AWWA) indicate that substantial changes are coming to the industry based on new technologies, such as information systems, advances in treatment processes, desalination, and telemetry. The water supply industry must respond to each such change.

Industry Outlook

Overview

The outlook for this industry shows it to be on the decline. According to the U.S. Bureau of Labor Statistics, the number of jobs for water and wastewater treatment plant and system operators is projected to decrease by 7 percent from 2021 to 2031, as compared to the 5 percent growth rate for all occupations combined. As water-utility workers retire, existing positions will need to be filled. Consequently, qualified individuals should be able to find opportunities based on their mix of skills and experience. The need for potable water will continue, as will the growth rate of the U.S. population. These factors continue to drive demand for water treatment facilities and for the labor necessary to operate them. At the same time, however, the use of automation is expected to increase, thus reducing the numbers of workers needed overall.

The largest employers of treatment plant and system operators are local governments. However, jobs are expected to be more plentiful in privately owned plants than in publicly owned plants. An increase in federal certification requirements will encourage the private sector increasingly to specialize in the more complex aspects governing water treatment plant operation and management.

Another factor for job growth is the ongoing nature of regulatory changes in the water industry, based on continually revised and upgraded standards for water quality. Changes in standards may result in the need to have additional workers at each facility, as the complexity of procedures required in the treatment process increases. On-the-job training may increase in order to ensure that personnel acquire the skills necessary to operate new equipment properly.

The EPA's 2000 Community Water System Survey found about 22 percent of plants that handled only surface water had an operator on site twenty-four hours per day. For larger plants that handled customer bases of more than fifty thousand, this percentage increased to 80 percent. Fully 95 percent of systems that served more than 500,000 persons had operators on site at all times. All surface water plants that handled 100 million gallons per day or more had personnel on duty every day, around the clock. Groundwater plants were generally much less likely to have personnel available both day and night, as they generally were smaller systems and did not run at all hours of the night. These smaller systems generally pumped their water into above-ground storage containers (water towers) at high elevations in their service areas so that the morning surge in water use could be handled properly.

Many plants that do not have twenty-four-hour coverage rely on supervisory control and data acquisition (SCADA) to handle either process monitoring or control. This technique allows a plant to monitor or control its systems when an operator is not present. Treatment plants that use groundwater and do not have personnel on site at all times rely on SCADA for process monitoring and process control. These percentages approximately double for surface-water facilities.

Mergers and acquisitions of water purveyors that developed during the 1990s have continued and are expected to continue in the future. The drivers of this trend have been the economies of scale that can be achieved in larger systems, the expanded use and associated development of technical procedures that would not be feasible in smaller plants, and the increasing need to meet new and more stringent environmental regulations. These are some of the very strong pressures that encourage the growth of larger plants and make the operations of smaller plants that much less viable.

Consolidation, or the trend of private investor firms acquiring smaller public water systems, is expected to continue. Rural water-supply systems, in particular, have increasingly formed regional systems. Larger systems are more capable of obtaining capital than smaller systems, and this capital can be used to make the necessary changes to the infrastructure of smaller plants once they are acquired. Larger utilities, either public or private, have the benefit of spreading their overhead expenses over a much larger customer base, allowing them to reduce the per-customer costs of providing service.

Employment Advantages

Water is necessary to life, so employees in the water supply industry need not worry about changes in consumer preferences. They may also gain fulfillment from helping provide consumers with such a fundamental requirement. Jobs in the industry are expected to be relatively plentiful for those with the specific training required to obtain them. Those with interests in chemistry, microbiology, and other experimental sciences who wish their research to have obvious practical effects in the world may find the water supply industry particularly fulfilling. Management positions at large plants may also be good fits for those with a skill for contingency planning and responding quickly to sudden crises.

Annual Earnings

Since the start of the twenty-first century, US water systems earned revenues have increased from $4.3 billion in 2000, to 81 billion in 2019, to $99.9 billion in 2024.

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