The ways of the Romans are still with us. Oddly enough, our present-day style of managing water has not strayed much from the centralized approach employed by the Romans some 2000 years ago. This was fine when cities first began to modernize, but the 21st century requires something different. This is the conclusion reached by David Sedlak in his book, Water 4.0: The Past, Present, and Future of the World’s Most Vital Resource following an exhaustively researched and riveting history of humankind’s relationship with and management of water. Why is this book important? Although CivilGEO’s primary focus is to create innovative civil engineering software, we would be remiss to ignore other key issues like water supply, quality and conservation. Water is, at its core, one integrated system. What are the component parts and how have we managed them over the years?
How did Cities first put Water to Work?
Glossy promotional pictures of Rome tend to focus on the towering arches, the fountains and viaducts when illustrating the brilliance of Roman engineers. But as Sedlak points out, the system perfected by the Romans over the course of three hundred years or so was even more sophisticated than most imagine. The bulk of the necessary infrastructure needed to transport huge quantities of water up to 50 miles outside the city was underground. This network of aqueducts, consisting of nearly 250 miles of channels, brought water to elaborate public fountains in the city-center and to the homes of the wealthy where it was used for a variety of purposes. There was a network of canals, much like today’s sewer system, to remove wastewater from the inner city. Named the Cloaca Maxima, the system was also designed with settling basins to remove larger solids. The Romans came up with ways to prioritize water use during times of drought as well as to distinguish and assign appropriate uses for potable water and water of inferior quality. A system this elaborate would not appear again until cities entered the modern age.
Challenges of Growth and Industrialization
Sedlak traces with fascinating detail the miserable living conditions of the 19th century that in time led to the earliest versions of today’s water systems. Although early industrialized cities learned to build networks of pipes to move spring water into the city, populations continued to grow and with growth came the problem of waste. Fecal matter inevitably contaminated clean water supplies, which led to water-borne diseases, like cholera and typhoid fever. Sedlak describes this period in history–“the bucket era”–as a time when cities relied on primitive methods to remove human waste, often referred to as “night soil”; it soon became clear that manual removal would not be enough to keep drinking supplies clean. The bigger cities like Paris and London both dumped wastewater into the major rivers running through the cities and experimented with moving waste to “sewage farms” along the riverbanks for crops. None of these methods were long-term solutions, but certain insights into the key microbial activity behind water purification were beginning to be understood.
The Marvels of Water Filtration
The water filtration methods conceived in the late 19th century to rid the water of pathogens marked a milestone in water purification. The basic methodology remains largely unchanged today. Not until 1902 did the addition of chlorine to the water supply become a routine practice. Wide-spread adoption of water treatment plants that used methods of filtration and chlorination to produce drinkable water resulted immediately in noticeable improvements to public health as well as longer life spans. Sedlak refers to the system of water treatment plants that came into being following the 19th century crises in drinking water as Water 2.0.
Byproducts and Bile: Toxic Outputs of the Modern Age
Water management 3.0, in the form of the Clean Water Act and advanced sewage treatment, evolved in response to the obvious contamination of the nation’s waterways. That microbial activity was key to breaking down organic matter which led to the technology behind the first wastewater treatment plants, coming into being in the late 19th century. By 1940 nearly half of the country’s raw sewage was being treated before discharge into a nearby waterway. However, this was only a portion of the problem. The Clean Water Act was passed in response to other sources of contamination like industrial wastes and synthetic chemicals. The technology exists to retrofit older systems to address these issues, but this process is often cost-prohibitive and is not always reliable. Sedlak uses the obvious shortcomings of relying on a built infrastructure to argue for a new water management paradigm called Water 4.0.
Mini Wastewater Treatment Plants, Decentralization and other Opportunities for Reform
In the final chapters of the book, Sedlak outlines the limitations inherent in our existing infrastructure and water treatment systems. Cities have grown up around a centralized infrastructure that imports, treats and distributes water. The massive capital already invested to make this urban water management approach work means that cities may be more likely to expand existing systems through additional tunnels and increased storage capacity and less likely to experiment with alternative strategies. But Sedlak stresses that urgent change is needed to avoid a crisis. Communities can no longer be passive about the issue and homeowners need to take a more active role in the details of water management.
Taking advantage of technologies and methods that help us reuse water is an idea that still needs to gain traction, but Sedlak says it is a critical step. Sedlak envisions Water 4.0 as a “hybrid” system that incorporates both centralized and decentralized components. He advocates the use of methods that encourage water infiltration through rain gardens and permeable surfaces. Technology already exists to retrofit single-family septic systems for some level of wastewater treatment, which would allow water to be reused for limited purposes like lawn care. Other projects to collect and reuse storm-water runoff are gaining traction. For example, with the proper technologies, it is possible for a homeowner to derive drinking water from roof water. These decentralized strategies would be implemented in the suburban areas; urban areas would still be connected via a more centralized water treatment and supply network.
As the earth’s population grows and climate change and other issues loom large, Sedlak makes an excellent argument for a more thoughtful approach to water supply, treatment and management. We have made some inroads into this area, but it would be wise to proactively tackle these issues before we find ourselves in a crisis.