Water Domesticated: Measuring the Resource for Better Control

The saga of water in France started later than in England. Paradoxically, this allowed for the deployment of a crucial innovation: the water meter. In addition to resolving equity issues posed by other types of subscriptions, the water meter enabled control over consumption, which was skyrocketing at a time when the network was still too small, especially during periods of drought. Although poorly documented except in a few cities, the history of water service subscriptions has been well studied by researchers such as Konstantinos Chatzis, Bernard Barraqué, and Frédéric Graber, who trace the various issues surrounding subscriptions based on gauges, free taps, and water meters.

Originally, the gauge allowed heavy consumers to have a constant but low flow of water (hence the term “running water”) according to a predetermined volume, while the free tap corresponded to the usage of small consumers. The price of the subscription to the free tap was evaluated based on the most accurate estimate of daily consumption by individuals, regardless of actual consumption. In Angers in 1855, for example, it was estimated that each person in a household would use 20 liters of water, while 75 liters were allocated per horse, 50 liters per car, and 1.5 liters per square meter of irrigable garden. This gives an idea of the urban uses of that time, which were more focused on outdoor spaces (stables, courtyards, gardens, and streets) rather than domestic use.

Jules Dupuit, an engineer from the Ponts et Chaussées, advocated for the “free tap,” which he considered to be the payment solution closest to users’ needs. His Treatise on Water Distribution, published in 1854, prompted many cities, including Paris, to adopt this subscription method in numerous households. However, criticisms quickly arose against this system, with detractors fearing abuses, as the “free tap” sometimes led to donations or resale between neighbors, which was prohibited. In reality, abuses related to this subscription were quite rare, especially since safeguards were put in place in certain municipalities, such as limiting the number of taps, push-button taps (similar to those still found in some public places, now replaced by motion detectors), tap restrictions, absence of sinks (to prevent users from leaving taps open for too long), overestimation of needs in subscriptions, etc.

Abundant Water: Modern Comfort Accessible to All

By 1975, 97 percent of households had running water: the conquest of water was complete, and it brought about a transformation in our way of life. Published within a year of each other, Georges Vigarello's book Le Propre et le sale: L’hygiène du corps depuis le Moyen Age (The Dirty and the Clean: Bodily Hygiene since the Middles Ages, 1985) and Jean-Pierre Goubert's book La Conquête de l'eau : L'avènement de la santé à l'âge industriel (The Conquest of Water: The Advent of Health in the Industrial Age, 1986) illustrate how running water has revolutionized our hygiene habits in only a century. Behind the issue of hygiene, it is, in reality, a bourgeois vision of society that has prevailed over the declining aristocratic elite. The hygienist bourgeoisie opposed the frivolous beautifying practices of the aristocracy with the rigor of nature; they preferred the chaste and pure nudity of the body over cosmetics that enhanced only visible parts of the skin. Previously, it was believed that changing clothes was sufficient for cleanliness, but now doctors recommended washing hands, face, and body with water. However, it took time for bourgeois morality, influenced by Catholicism, to no longer associate intimate hygiene with a form of self-gratification and, instead, conceive personal cleanliness as an unprecedented moral value. In the twentieth century, dirt became the shameful mark of the working classes, who needed to be taught a new physics of the body: fresh air, physical exercise, personal hygiene, as well as the fight against moral and health deviances such as alcoholism.

 This marked a complete reversal of mentality, a true revolution in which the Compagnie Générale des Eaux played a role. As researcher Dominique Lorrain explains, “In the mid-nineteenth century, water at home did not exist, neither technically nor in people's minds.” Initially, both affluent and modest populations saw no need to change their habits, which were based on modest needs. It was only under the influence of hygiene and the Anglo-Saxon elites that behaviors began to change. In the mid-nineteenth century, the average French person consumed an average of twenty liters of water per day and relied on public fountains or water carriers for their supply. In Paris, the commercialization of subscriptions was one of the main reasons why Prefect Haussmann turned to interested management: the teams of the company agreed to convince household staff to connect the homes they were responsible for to the water network and to overcome the resistant competition from water carriers. The pace of change accelerated when French elites compared themselves to their Anglo-Saxon counterparts vacationing on the French coast, for whom access to running water was synonymous with modern comfort.

The arrival of water at home was not enough, and hygiene in the household remained a luxury for a long time, as it required purchasing expensive equipment. Moreover, it required having enough space to dedicate an entire room to personal hygiene. For a large part of the nineteenth century, hygienic practices continued to take place outside the home: laundry was washed in public washhouses, bathing occurred in rivers or public baths, and drinking water was obtained from public fountains.

During this time, the bathtub made its appearance, but it was not fixed in place. Built on legs and not connected to plumbing, it had to be placed in a location convenient for heating water. For those who could not afford a bathtub, the English tub was imported—a sort of basin that could be moved around the dwelling and allowed for standing washing with minimal water usage, embracing the concept of frugality. Bathing scenes were immortalized by Degas in several nude pastel drawings during the 1880s. Other artists, such as painter Pierre Bonnard, made it a subject of study. In the 1920s, he drew multiple nudes of his companion, Marthe, reclining in her bathtub, combining the modern ritual of a woman enjoying time in her bath with the ancient ritual of a body embalmed in a sarcophagus to defy the passage of time.

More trivially, in 1840, the prefect of Nièvre was the only one in the entire department to have a bathtub, and a century later, in 1954, not much had changed: only one in ten households had a bathtub or a shower. However, these new fixtures—the sink, bidet, bathtub, and “water closet” (W.C.)—eventually became more accessible with the post-war economic boom. Historian Jean-Pierre Goubert notes that “gestures performed in public, particularly those related to laundry and defecation, were rejected as belonging to a bygone, even somewhat barbaric past. The landscape of housing evolved. Rooms became specialized, and uses were privatized. Modern comfort settled in, along with an entirely new way of living.” In a 2010 study entitled “Toilet and Bathroom in France at the Turn of the Century,” Monique Eleb analyzed the transformation of the toilet cabinet, which was more focused on beauty and vanity, into the bathroom, a space that “is not defined as masculine or feminine and allows men to access cleanliness in a space less symbolically feminine than the toilet cabinet.”²

The 1950s marked a real turning point. In 1951, Françoise Giroud, then the director of Elle magazine, commissioned a comprehensive study on the cleanliness of the French, but the article's title only focused on women: “Is the French Woman Clean?” The response was “no,” documented by “distressing results” that caused quite a stir even at that time. Toothbrushes, changing or not changing underwear, soap usage—everything was scrutinized. With a touch of sexism that was characteristic of the time, Françoise Giroud took the opportunity to criticize vanity, which continued to overshadow basic hygiene and prevented women from wanting to be clean—the proof being that men, being less concerned with vanity, were supposedly cleaner. A year later, Paris Match presented its ideal home. The magazine stated that “water and order are the true luxuries of modern life.” This conclusion was in line with modernist architects Auguste Perret and Le Corbusier, as they placed hygienic concerns at the center of their work: air circulation, access to water and sanitation, the need for light, space optimization, decluttering rooms, and the importance of outdoor spaces—all concepts that were brought to the forefront during the Covid crisis.

From Invisible Water to Rare Water

Despite its major consequences for our way of life, it is clear that society as a whole seems to have amnesia when it comes to water: whether it is simply about its source (who knows where the water they drink comes from?), its price (who knows the amount of their water bill?), or its quality (who can say what the water flowing from their tap is composed of and what standards define its potability?). While water used to be tangible, organic, and foundational, our relationship with water has evolved in a few decades to a high level of abstraction that “invisibilizes” both the water network (pipes, pumps, and treatment plants) and the territory it manages.

Even the names of French departments, almost all of which are named after a river or stream, are now only described by their number in common language, a sign of a new attachment that is more administrative than geographical. By hiding water, by treating it far from home (upstream or downstream), we have domesticated it. But in the process, we have made the awareness of its fragility less acute. Today, there are many points of ignorance among the general public regarding water management. This can be seen by reading the national water barometer published every year for the past twenty-six years by the Water Information Center (CIEAU). In 2022, for example, 77 percent of people believe that water is drinkable in its natural state. The real function of wastewater treatment is known by less than a third of French people, and two-thirds of French people are unaware of the price of a cubic meter of water. Many of them feel that they spend more on water than on the internet and telephone when, in reality, water is two to three times cheaper.

This lack of knowledge has been particularly supported by CNRS researcher Agathe Euzen who in 2007 studied perceptions regarding water quality and health risks. She found that the definition of good water evolves with time and sensibilities, but also that ignorance of health standards leads to risky or at least paradoxical behaviors. For example, one condominium refused to change lead pipes because it downplayed the risk involved while “disengaging from any responsibility by adopting individual alternative solutions using filtering pitchers.” Similarly, Parisians, who were the subject of her study, rarely make the connection between limestone and calcium, even though the former contains the latter. One interviewed user said, “In tap water, there is limestone; it is less rich than mineral water.” However, this limestone is composed of calcium carbonate, exactly like some mineral waters, which could also cause scale buildup in household appliances if they were used in kettles or washing machines. From limestone to calcium, there is only a lexical step that consumers dare not take, convinced that one is harmful while the other is beneficial.

It was in the 1990s that consumers began to gather in associations and the media started to take an interest in issues such as water quality or network efficiency (and therefore leaks). The French portmanteau consom'acteur (consumer-actor) appeared to describe the committed forms of consumption that result from ecological awareness.

Géraldine Sénemaud, consumer director of the Water France activity at Veolia, says that, as a result of individualized behaviors and increased consumer demands, customer relations have become paramount in the ecosystem of water distributors. “For a long time, the only contact between the user and the distributor took place when they subscribed and terminated their contract, or when a billing problem arose. Today, the customer does not have a relationship of simple convenience with water; they are aware that it needs to be protected.”

On the customer relations front, the relationship with the user now passes through a permanent link, via call centers modeled on those set up by telecommunications operators in the 1990s. “It has become a know-how,” says Sénemaud. “The customer experience has become paramount.” Water distributors now assert themselves as a local service, with small local agencies in the hearts of cities and permanent offices on market days—and the teams responsible for consumers regain the central role they originally had when it came to contracting the first subscriptions.

On the water quality front, to meet the demand of dissatisfied consumers who see their pipes or domestic appliances damaged, Veolia's expertise, for example, was solicited in the Normandy Vexin to build water decarbonation plants and reduce the limestone content. “These are big investments,” explains Guy Burette, “but it also allows us to protect the groundwater, because limestone encourages people to use more detergent and softeners, which pollute downstream.”

On the equity front, the implementation of the Brottes law in France in 2013 accelerated the deployment of the solidarity water voucher and, more broadly, social tariffing—in addition to ongoing efforts to raise awareness about tap water use, especially among disadvantaged populations who, coming from countries where water is not drinkable, may still prefer to buy bottled water, even for hygiene or cooking purposes, at the expense of their purchasing power.

Finally, on the consumption control front, new personalized services are emerging, based on the introduction of remote meter reading in the early 2000s, well before it was deployed for energy. These new meters allow for almost perfect transparency with the consumer, as well as for real-time billing, capable of alerting the user to their consumption or potential leaks. In 2022, for example, consumers were informed of more than seventy thousand leaks, saving 4.2 million cubic meters of water (equivalent to 1,700 Olympic-sized swimming pools). Xavier Mathieu, CEO of Birdz, a Veolia subsidiary specializing in the digitalization of water professions, believes that data science will make cities smarter, in France and around the world. “Soon, we will even be able to predict tomorrow's consumption volumes or analyze population flows, as water consumption is the best indicator of presence in a territory,” he says. “This information has real value for waste collection. For example, we will be able to determine whether additional trucks need to be dispatched based on the situation.”

As has long been the case, Veolia is developing new services to meet emerging needs—services whose usage is gaining importance over time, with new needs being added to the initial ones: remote reading, initially invented to meet the needs of individualization, shows its usefulness in an era of water scarcity.

Because the era of water scarcity is now: since the late 2010s, episodes of drought and climate disasters have changed mentalities much faster than years of scientific education, and more and more people in France and elsewhere are realizing that water is scarce. As seen in California for several years, customers are now hunting for water waste. They question the irrigation of crops during heatwaves, swimming pool water, golf course irrigation, and the artificial snow at ski resorts. Sandrine Motte, director of Eaux de Marseille, sees attitudes changing in the city: “Just five years ago, the street cleaners would open the hydrants to clean the sidewalks in the middle of summer, letting the water flow into the gutters,” she says. “Today, these hydrants are closed. And when people see practices like street pooling—opening fire hydrants to cool off during heat waves—they send us indignant messages on social media. These are ways of doing things that are no longer acceptable.”

Awareness of the need to preserve water resources emerged slowly in France, even after the construction of the first water networks. Initially, the theories of miasmatism, which attributed epidemics to foul odors rather than the intrinsic quality of water, persisted. The discoveries made by John Snow in London only date back to 1854—one year after the establishment of the Compagnie Générale des Eaux—and were initially contested by many scientists. It was not until the German researcher Robert Koch identified the Vibrio cholerae bacteria as the cause of cholera in 1883 that Snow's findings were supported. Moreover, urban sanitation initially focused on water supply rather than treatment. Consequently, preserving water quality at its source in its natural environment was not identified as a priority. However, scientific discoveries multiplied, and it was during the Third Republic, under the government of Waldeck-Rousseau in 1902, that one of the first major laws against groundwater pollution was passed in France. This law, known as the Edouard-Alfred Martel Law, prohibited “the disposal of dead animals into natural limestone cavities.” Martel, a pioneer of speleology, demonstrated through his research on spring hygiene that decomposing matter could cause severe epidemics. This legislation can be seen as one of the first movements for the protection of water resources in France, even though its application was limited in scope to freshwater springs.

Edouard-Alfred Martel, Pioneer in the Fight against Water Pollution

The Martel Law was enacted on February 15, 1902. This law, which prohibited the dumping of animal carcasses and putrefying waste in caves, bears the name of Edouard-Alfred Martel, a pioneer in both speleology and the fight against water pollution. Born in 1859, Martel was expected to become a lawyer like other members of his family, but his life took a different turn. After discovering a cave at the age of seven, this future geographer, a fervent admirer of Jules Verne, developed a passion for the depths of the earth.

As a modern adventurer, Martel explored caves, underground spaces, and other cavities with unprecedented scientific rigor. He gained notoriety after discovering the underground river of the Padirac Abyss in Lot, France, in 1889. This abyss, with a depth of 103 meters, is home to a river that runs for over fifty-five kilometers. Martel's wife, Aline de Launay, described his underground adventures as follows: “I accompanied him and waited for him at the cave entrance, admiring the ‘front’ of the landscape while he discovered the ‘back’ in the bowels of the earth [...]. You should have seen the state he was in when he emerged! [...] A true sewer worker!”

Two years later, while exploring the Berrie Abyss in the Vert Valley, Martel spotted a decomposing calf carcass at the bottom of a well. After completing his exploration, the thirsty spelunker drank water from the spring and fell ill with typhoid fever, which lasted for two months. This event inspired him to conduct research on the hygiene of water sources. In 1894, he wrote, “What could be more dangerous and deceptive than these clear waters, seemingly filtered by rocks, but actually carrying an abundance of microbes germinated on carcasses at the bottoms of sinkholes? This is why public nutrition and hygiene are highly concerned by underground studies.”

Edouard-Alfred Martel demonstrated that infiltration waters can carry serious epidemics such as typhoid fever. Hence, the father of modern speleology worked tirelessly to impose new hygiene rules. His work recommended that regions without filtering sandy soils pay extra attention to their water supplies and establish a “protection perimeter” against pollution. Thus, in 1902, the law enacted on February 15 established these protection perimeters and prohibited the dumping of dead animals and waste into natural cavities.

Although he did not directly pursue a political career like the scientists of his time, such as Marcellin Berthelot, Paul Langevin, or Paul Painlevé, who were later honored in the Panthéon, Martel nonetheless gave his name to this law because of his active advocacy on its behalf. With typhoid fever infections decreasing by three-quarters in France, it is no wonder that Martel was recognized as a “benefactor of humanity.” His research and discoveries on water pollution are compiled in a work titled Le nouveau traité des eaux souterraines, published in 1922.

The 1970s: A Turning Point in Environmental Activism, New Solutions to Meet Demands

While the Water Framework Law provides a regulatory framework and financing measures, the economic model for industrial effluent treatment only took shape a little later. In the early 1970s, initiatives in this field were often the work of isolated individuals, such as the director of the water treatment plant in Méry-sur-Oise, who realized that the water was occasionally too polluted to be drawn and treated properly. Jean-François Nogrette, head of the France and Special Waste Europe division at Veolia, recounts this story: “At the time, the Oise River was like a sewer! Along its course, there was a highly developed steel industry that discharged heavy metals and cyanide. The river was on the verge of severe contamination and a water shutdown.” To prevent such a situation, Bertrand Gontard, who was the director of the water treatment plant at the time, proposed that industrial companies treat toxic waste upstream.

This activity did not yet exist in France but was made possible by the 1975 law on waste producer responsibility, as well as the contribution of basin agencies, established in 1964, which used the polluter-pays fee to finance treatment plants. As Jean-François Nogrette recalls, “The water agencies understood that to protect the water resource, it was necessary to dispose of this toxic waste, now called ‘hazardous industrial waste,’ upstream, without passing it through any bodies of water.” It is in the context of protecting water as a resource that SARP Industries was founded in 1975, specializing in hazardous waste and related to SARP (Rational Sanitation and Pumping Company).

The 1970s marked a collective awakening around environmental issues. The United Nations Conference on the Human Environment, held in Stockholm in 1972, made the environment a major concern for the first time. Principle 2 of the Stockholm Declaration on the Human Environment states, “The natural resources of the earth, including the air, water, land, flora, and fauna, must be safeguarded in the interests of present and future generations through careful planning or management as appropriate.” In the same year, the Clean Water Act was passed in the United States. The law aimed to reduce pollution in bodies of water, including the Great Lakes, which had become a major health threat. It brought about a radical paradigm shift: moving from a system based on water quality standards to one based on effluent discharge standards, providing a framework to reduce industrial and municipal discharge into water resources. It also initiated a federal program to fund wastewater treatment plants. With this law, the legislature aimed to eliminate “the discharge of pollutants into navigable waters by 1985” and “make waters fishable and swimmable by 1983.” Although these goals were not entirely achieved due to a lack of coercive measures, water quality in the Great Lakes significantly improved during the following decade, with pollutant levels dropping.

The 1970s was also a period of increased associationism, as described by historian Pierre Rosanvallon in his book Le Modèle politique français (The French Political Model)². During this time, “new types of nature and environmental protection associations emerged in France and around the world, from the French Federation of Nature Protection Societies (FFSPN, 1968) to Greenpeace (1971) and Friends of the Earth (1969),” as noted by Alexis Vrignon in the journal Vingtième Siècle.³ The association on the list was established in France under the name “Les Amis de la Terre,” with members including Brice Lalonde and Yves Cochet. It was also a time for the first political ecology magazines, such as La Gueule ouverte, launched by journalist Pierre Fournier in 1972, and Le Sauvage, founded in 1973 by Alain Hervé of Friends of the Earth. Many of these activists and journalists supported the first environmentalist to run for president in the election of 1974, René Dumont. A renowned agronomist and author of influential works like L'Utopie ou la mort! (Utopia or Death!, 1973), Dumont chose to symbolically drink a glass of water during his iconic televised appearance. “I am drinking this precious glass of water before you because before the end of the century, if we continue with such excess, it will be scarce,” he explained to astonished French citizens, who found his words exaggerated, if not downright ludicrous. As the first politician to emphasize not only water quality but also water quantity, René Dumont now appears ahead of his time in trying to convince a population mainly concerned with inflation due to the first oil crisis to pay more attention to ecological issues.

From Water Preservation to Habitat Preservation: Increasingly Ambitious Goals 

The way to characterize water quality itself has become more precise over time. “The construction of water quality has evolved, especially thanks to the exponential development of quality descriptors from 1850 to today,” taking into account criteria that are primarily important for habitats, emphasizes Marie-Christine Huau, the Water and Climate Director at Veolia. Several ages or periods can be distinguished in this history. The first phase is that of pharmacists, who undertook an inventory of hydrothermal sources based on physical variables: the values of mineral ions, temperature, pH, TSS (total suspended solids), and hardness (like the information found on a mineral water bottle). Then, still in the nineteenth century, came the era of analytical chemistry: oxygen, nitrogen, nitrates, and major ions were measured. This period was quickly followed by the time of civil engineers and river chemistry, with the measurement of degradable organic carbon and biological oxygen demand. The focus was mainly on protecting populations against waterborne diseases and problems related to bacteria that could be found in drinking water.

The qualification evolved between the 1950s and 1960s. As water became a resource for aquaculture, industry, and agriculture, biologic variables based on the fauna in the water attracted the attention of geochemists. This was a time of sanitary risk, when people began to ensure that bathing waters did not contain bacteria or pesticides. “We start[ed] to observe aquatic ecosystems from the perspective of their uses,” says Marie-Christine Huau. “From the 1980s, academic research focuses on understanding the functioning of the aquatic system” before entering the era of ecological quality of the natural environment in the early 2000s. “We will look at how this ecosystem works: Is there good oxygen circulation? Do we live well in it? Scientists shift to a hydrobiological approach using biotic indicators on different species of biodiversity. The goal is the preservation of aquatic habitats,” highlights the agronomy engineer. This is particularly important, as ecosystems, sometimes resources and sometimes receiving environments, are essential elements for biodiversity and for the common interest.

The broadening of approaches to water quality, taking into account its effects on humans as well as on the environment, has been accompanied by an increased focus on ecosystems, leading Veolia to invest not only in the sanitary quality of water but also in its environmental quality. The restoration of the underwater ecosystem of Cap-Sicié, near Toulon, is symbolic of this. For decades, sewage wastewater was directly discharged into the sea, causing severe degradation of the environment. In the late 1990s, to address the situation and respond to the first alert raised by a diver in 1980, a wastewater treatment plant was built by Veolia, under the impetus of the authorities. As expected, it quickly restored water quality, but contrary to expectations, it did not lead to the return of life to the environment. To make this possible, the Remora project was initiated in 2011 by the Veolia Foundation, the Rhône-Mediterranean-Corsica Water Agency, and the Paul Ricard Oceanographic Institute. It created artificial reefs composed of lightweight structures made of fiberglass and epoxy resin, capable of adapting to the waves, reefs designed to serve as habitats and protection for microfauna and microflora. The return of life was finally confirmed: in 2016, field research revealed the presence of squid, cuttlefish, and wrasse spawns, as well as juvenile crustaceans, octopuses, and fish.

With over seventy quality criteria, both sanitary and environmental, tap water has become one of the most regulated food products in France. However, the concepts of “potability” and “sanitation” vary depending on the era and scientific knowledge. Originally, “potable” water was directly drawn from rivers or underground aquifers without any further intervention. However, several millennia before Christ, people realized that turbid or odorous water could be unpleasant. “The concept of water quality and treatment has been known for a long time. The Egyptians used aluminum salts, alum, for coagulation, which was used for water treatment,” explains Philippe Hartemann, professor of public health at the University of Nancy.

The Middle Ages marked a period of regression in terms of water treatment. No major innovations in water treatment would appear for nearly a thousand years. On the contrary, wastewater and waste were directly discarded into the streets, contaminating sources of drinking water through runoff and infiltration. According to the National Library of France, the first mention of a sewer that was not open-air in Paris dates to 1325. It was a gallery that passed under the City Hall and drained into the Seine. This dark period, which sometimes receives exaggerated discredit, contributed to shaping the unsanitary conditions of cities. However, it came to an end thanks to the development of science and a major discovery in 1670: the microscope. From that point on, research rapidly advanced, as the microscope allowed scientists to observe tiny particles in water. Throughout the eighteenth century, water filters made of sponge, wool, or charcoal became more common in households. During the same period, wealthy landowners used large burnt wood tanks to store water in better conditions.

Initially, water networks were intended to fetch clear water in large quantities from outside cities, while sanitation networks aimed to dispose of putrefying water far away. In line with miasma theories, they merely created movement to prevent stagnation, ultimately expanding the circle of pollution identified by John Snow. At its inception, “the sanitary movement had no science to guide its efforts,” emphasizes Deaton⁵.

However, a scientific revolution emerged at the end of the nineteenth century, accelerating awareness of the need to treat the resource. Gradually, the miasma theory gave way to the microbial theory. The epidemiological work of the British John Snow was succeeded by the Germans Robert Koch and Karl Joseph Eberth, who laid the foundations of microbiology, and then by the Frenchman Louis Pasteur, who became one of its most famous figures.

Thanks to them, we can now say that “not everything that stinks is deadly, and not everything that is deadly stinks,” says Corbin⁶. The correlation between disease and water contaminated with microbes was scientifically demonstrated. “We drink 90 percent of our illnesses,” Pasteur declared in 1881.

These discoveries helped to understand the lingering health problems associated with the creation of networks and to provide solutions through the implementation of treatment methods. “Science eventually caught up with practice, and the microbial theory of diseases was gradually put into application through more targeted measures based on scientific grounds.” The history of modern treatment begins after the history of networks. However, as Deaton observes, “transitioning from the microbial theory to safe sanitation and water takes time and requires money and authority.” It also requires “engineering and monitoring skills to ensure that the water is truly uncontaminated.”⁷

Louis Pasteur, Father of Microbiology and Pioneer of the Hygienic Movement

Louis Pasteur has left an indelible legacy in various fields of research, including public health and the role of water in hygiene. The chemist and physicist by training contributed to the collective awareness that water could contain microbes and transmit diseases.

In the collective imagination, Louis Pasteur is known for his intelligent eyes, gazing intently into the camera lens of Félix Nadar. He is also hailed as the father of modern medicine, the inventor of the rabies vaccine, and the namesake of the pasteurization process that extends the shelf life of our food and beverages. However, how many are aware of his pivotal role in ensuring the safety of the water we consume?

Born on December 27, 1822, in Dole, in the Jura region of France, Pasteur was admitted to the École normale (a French elite school) at the age of twenty-one, where he studied physics and physical chemistry. In 1847, he defended his doctoral dissertation in science at the Faculty of Sciences in Paris. Ten years later, he was appointed as the administrator in charge of studies at the École normale supérieure.

From biology to agriculture and medicine to hygiene, Pasteur distinguished himself in numerous fields and pushed the boundaries of scientific knowledge of his time, laying the foundations for our current understanding of germs and their role in disease. He dedicated a significant part of his career to studying waterborne illnesses caused by contaminated water and lack of sanitation, notably cholera.

Pasteur is remembered for his demonstration of the existence of microbes, which develop, among other places, in aquatic environments. After memorable battles against his opponents, particularly Félix Pouchet, a renowned biologist and staunch defender of spontaneous generation, Louis Pasteur published his work refuting this theory in 1861 and 1862. According to him, microorganisms present in atmospheric dust develop and multiply; no living being emerges from nothingness. Furthermore, these microbes can cause diseases and contaminate entire populations. Hence, they should be avoided and combated.
In doing so, Louis Pasteur contributed to the hygienic movement by emphasizing the importance of cleanliness, especially hand hygiene, and the role that water supply plays in combating diseases. Providing the evidence needed for the triumph of the microbial theory over the miasma theory, he also stated that water can carry diseases without being visible or detectable, and may require treatment to eliminate them.

By closely studying the life of microorganisms, he also laid the groundwork for early treatments, highlighting the role that filters or microorganisms themselves can play in self-consumption or annihilation—as seen in the principle of activated sludge, particularly used in wastewater treatment plants.
Pasteur's discoveries, like his predecessors', were not the result of spontaneous generation of ideas in the fertile mind of a genius; they were the fruit of experimentation, not without errors, and built upon a long series of scientific progress.
Pasteur's breakthrough in developing the rabies vaccine in 1885 brought him worldwide acclaim, and he received numerous honors. The Academy of Sciences proposed the creation of an institution dedicated to treating rabies, leading to the establishment of the Pasteur Institute in 1888. Pasteur passed away on September 28 in Villeneuve-l'Étang, in an annex of the Institute that bears his name. He left behind a profound transformation in our relationship with water, summed up in the apocryphal quote, “We drink 90 percent of our illnesses.”

Water Treatment of Discharged Water: From Spreading to Wastewater Treatment Facilities

The link between improving the quality of consumed water and that of the water being discharged was quickly established. In Paris, where Eugène Belgrand designed the system, wastewater was initially evacuated to two sites located in Asnières and Clichy, in the near suburbs of Paris. However, the 400,000 cubic meters of polluted water discharged into the Seine River each day created significant pollution. Eugène Belgrand then opted for an alternative solution: spreading. This idea was inspired by existing practices, as septic tank emptiers often resold the product of their purges as fertilizer.

“We realized that discharging wastewater into watercourses was not the right option, because even though they have a self-purification capacity, they only eliminate contaminants when they are present in a certain quantity. Discharging wastewater outside the cities was not sufficient; it needed to be treated when there was too much of it. In Paris, this began with the discharge of wastewater into fields,” explains Sophie Besnault, research engineer at the National Research Institute for Agriculture, Food, and the Environment (INRAE). The attempt was made to infiltrate wastewater into the soil of the Gennevilliers plain. “This was a preliminary treatment stage because we reused the nutrients in the soil to grow plants. However, we realized that there was not enough land to discharge all the wastewater; it became saturated. That's when we started building the first wastewater treatment plants,” adds Besnault.