Water 4.0 : The Past, Present, and Future of the World's Most Vital Resource by David Sedlak

David Sedlak, a civil engineering professor at the University of California and the director of ReNUWit, an engineering research center for Reinventing the Nation's Urban Water Infrastructure, wrote this book to provide a vision of water management in the future by tracking its history. Sedlak contends that water development stems primarily from the development of urbanization--the need to drain streets, remove wastes, and distribute water. Current water issues, "water shortages, flooded streets, and a growing list of water pollutants, and the financing need to implement improvements" just extend the historical issues water managers face. The book also reveals the complexity of modern water management, with the inclusion of chemicals, pharmaceuticals, pollutants, wastes, and trash into our water resources, either intentionally or unintentionally. Additionally, the increased reliance on water reuse and recycling forces the need for citizens, government agencies, and water managers to ensure a safe supply.

The stages of this development, from Water 1.0 to Water 4.0, constitute the subject mater of the book. Water 1.0, occurring during the period of the Roman Empire, saw the first water pipes and sewer systems. Water 2.0 marked the development of water treatment through sand filtration, boiling, and chlorination, among other methods.

Sewage treatment ushered in Water 3.0 to prevent odors and pathogens that caused illnesses. Sewage systems served a twofold purpose: water drainage and the removal of waste thrown into sewer systems, particle removal and disinfection or non-chemical methods such as ozone, activated carbon, ultraviolet light, microfiltration, or reverse osmosis. The term "sewer" derives from the word "seaward" (p. 114). Sedlak explained the balance between disinfection additives to reduce pathogens, such as chlorine, and these additives that at some levels might cause cancer. The introduction of activated carbon treatment or ammonia sought to mitigate this problem. The concern for human exposure to lead, especially in older pipes of many water systems, also gained the attention of water managers. Within fifty years after the initiation of Water 3.0, Water 4.0 followed, with the growth in population and the natural phenomenon of climate change, the first demarcation not tied to a technical advance.

In his chapter "Drains to Bay", Sedlak outlined the history of urban drainage systems, described the consequences of inadequate drainage and the resulting sanitary sewer overflows (SSOs) and their frequency with the United States, and explained current techniques to prevent SSOs in urban areas. Construction of low-impact development, green roofs, rain gardens--a form of low-impact development--and replacing impervious asphalt and concrete with interlocking blocks and permeable pavement also reduces SSOs.

Before delving into the cost and requirements of Water 4.0, Sedlak discussed the chemicals, plastics, and pesticides found in water, especially near sewage treatment plants, that feminized male fish, cause bird deaths, and increase the toxicity of drinking water. The author argued that modern sewage treatment plants can remove from sewage most of the degradable chemicals and "oxygen-demanding organic matter" (p. 154); sunlight and the microbes can remove some toxic elements in rivers. Non-degradable chemicals remain at the same level throughout the process. Disinfection chemicals, such as chlorine, change in some instances the chemical composition of chemicals in water.

To introduce the topic of 4.0, Sedlak disclosed the funding gap that water utilities experience. After federal grants dried up in the 1990s, "the U.S. Conference of Mayors estimates that cities take in only about 80 to 90 percent of the funds needed to repair their water and sewer pipes" (p. 167). Customers face the question of the cost comparison of status quo proactive and reactive maintenance and upkeep in addition to the costs of maintaining for the future.  Labor, material, energy to pump and increase flow of water and sewage, modeling for such phenomenon as climate change and potential regulatory changes, and handling pollution contribute to water management costs.

As indicated previously, Water 4.0 constitutes the only period that does not entail a technological change but a rethinking of our approach to water. Sedlak explains the Three R's of Water 4.0--reduce, water reuse, and water recycling, in short, "closing the loop on water" (p. 188).

President John F. Kennedy in 1961 challenged the U.S. not only to compete in the space race but also to develop desalination technologies that would transform salt water to drinking water. The invention of reverse-osmosis membranes in 1963 and systems in 1965  facilitated this goal to increase drinking water in the arid Middle East, American West, and elsewhere. Energy costs, green house emissions,
the impact on the coastal ecosystems where desalination plants exist, and the brine residue from the plant complicate the acceptance of this technology.

Sedlak believes that water managers' vision for the future projects an extension of past development, resorting to reverse osmosis to expand supplies, when necessary. He concludes, "I am pretty confident that this approach will work in most places--at least in the short term" (p. 239). Water customers, however, should prepare themselves for future costs. Conservation can reduce some of the cost by "changes in plumbing codes, expanded outreach programs, and rebates for purchasing more efficient appliances . . . extensive changes to building codes and investment in some relatively inefficient water saving technologies" (p. 242). He observed that instead of decreasing water consumption, these methods of conservation usually keeps consumption flat. More dramatic methods include Xeriscaping, turf buy-back programs, smart irrigation controllers, and one of the Three Rs, reuse--the separation of black water from gray water--roofwater collections systems, reuse of runoff, and other methods.

Sedlak ends the book by recounting the speed of technological changes and the incremental changes of water management, which results, he stated, in "the failure of urban water systems to more quickly adopt innovative new technologies is a missed opportunity" (p. 275). While acknowledging the 'sunk costs' associated with water infrastructure, the author decried the meager funding by government for developing and promoting technological solutions and government allocation of funds only after highly publicized disasters, such as the fire on the Cuyahoga, high cancer rates in New Orleans, lead contamination in Washington, D.C., and droughts in the West. State governments, facing water shortages, have forced some technological changes--"rapid sand filters, low-flow household appliances, and biological-nutrient-removal waste water treatment plants" (p. 276). Efforts to reduce energy costs have also resulted in more efficient equipment and generator designs. Awareness of innovations in water-stressed areas--Singapore, Southern California, Australia, and Israel, to name a few--can promote emulation and duplication. Sedlak believes that these will guide the development of Water 4.0.