Water - not a drop to lose


Water.  Is there anything more fundamental to sustaining life on this planet?  Human survival, our livelihoods, and nearly all modes of economic production depend directly upon water.  However, in spite of the fact that we inhabit a water planet, fresh water is not an abundant resource the world over.  Less than 3% of the water on the planet is fresh water.  Over 80% of this fresh water is locked away in glaciers and ice sheets and therefore not readily available to us.  If you do the math, only 0.5% of all the water on the planet is available for use by man, and nearly all of this water is beneath the surface of the earth in the form of groundwater.  Water scarcity, whether through drought or inadequate distribution can lead to disease, famine, and even armed conflict.   Unfortunately, based on UN population projections, it is estimated that by 2025 more than 2.8 billion people in 48 countries will face water stress or scarcity conditions.

Source: World Business Council for Sustainable Development

According to the United Nations and World Health Organization, there are roughly 1.1 billion people in the world who do not have adequate access to clean drinking water.  Over 2.6 billion people, nearly half the world's population, do not have access to adequate sanitation.  Even where fresh water supplies exist; it is often rendered unsafe through contamination by human waste, untreated industrial waste, and agricultural runoff.  Tragically, again according to the UN, "Polluted water is estimated to affect the health of more than 1.2 billion people, and to contribute to the death of an average 15 million children every year."  Clearly, clean water, free of waste and contaminants, is an absolute necessity for a sustainable, thriving and equitable human society.

Global Drinking Water Coverage

Source : WHO-UNICEF Joint Monitoring Programme

Global Sanitation Coverage

Source : WHO-UNICEF Joint Monitoring Programme


The key to meeting the global demands for clean water is infrastructure - water treatment and distribution systems to deliver clean water and sanitation systems to manage sewerage and storm runoff.  It's no surprise that for many of the non-governmental organizations working in the developing world, such as Engineers Without Borders among many others, a majority of their projects are related to meeting basic water and sanitation needs.  Effective management of fresh water resources as well wastewater contribute directly to two of the fundamental and inseparable elements of global sustainabililty - sustaining human society and sustaining the environment.

Given clean water's fundamental importance to human society and its preciousness as a natural resource, we really don't have a drop to waste.  Yet, the amount of clean water lost from our water distribution systems is astounding.  According to the World Bank, over 32 billion cubic meters of treated water annually is lost from distribution systems due to leakage (that's 8.54 trillion gallons for the metrically challenged).  A further 16 billion cubic meters is unaccounted for each year due to theft, poor metering or corruption.  In the developing world, the amount of treated water lost can approach 60% of the water entering the distribution system.  On a global basis, the estimated cost of the treated water in this way is $14.6 billion annually.  In the developed world, roughly 15% of the water input to their distribution systems is lost.  In the developing world the average is 35% but can be as high as 60%.  A little math results in the conclusion that 26% of all the treated water in the world is lost each year.  What do these numbers mean in terms of real lives?  Well, if we could recover just half of the water lost in this way, we could serve the water needs of an additional 90 million people with no further investment in new water systems or further tapping into increasingly scarce sources of water.  The negative impact of water loss doesn't end with water that doesn't get delivered.  Consider the environmental and cost impacts of constructing the treatment facility capacity and the energy required to produce treated water that, in effect, is simply pumped right back into the ground.  Further consider the broader impact when small leaks go undetected and become catastrophic failures, such as the recent water main break in New York City in May of 2008.  Water loss may sound like a simple maintenance issue but it is far more than that - it is a significant global issue related to one of our most vital natural resources.

Most water utilities have adopted operational strategies to address this problem, such as managing the system pressure to attempt to minimize the amount of water lost through leakage while still maintaining adequate service.  However, these strategies have limited effectiveness and don't address the root problem.  It may be stating the obvious, but plugging the leaks would seem to be the most direct approach to solving the problem of water lost through leakage.  However, that's not as easy as it sounds.  As water distribution systems are largely underground, locating the leaks extremely difficult.  Visual inspection is not possible without digging up the piping.  Many leaks don't manifest themselves in any visible way, such as water bubbling to the surface, and may go undetected indefinitely.  Even when water does the reach the surface, it may be nowhere near the actual leak.  There are a number of technologies available for detecting leaks without digging, such as a variety of acoustic methods and step-wise testing of individual segments of the piping systems.  However, these approaches are not 100% effective in pinpointing the leaks and still require fairly exhaustive examinations of the water systems and are therefore expensive and time-consuming.

According to the American Society of Civil Engineers, in the U.S. alone, investments of an additional $11 billion per year over the next 20 years is required replace water systems near the end of their useful lives and to meet current and future federal water regulations.  Can anyone reasonably expect that these investments can be afforded?  Or, that we have a sufficient pool of qualified professionals to perform the work?  If you believe that the likely answer to these questions is "no," particularly in light of current economic uncertainties, then what is to be done?  Clearly, meeting the demands for infrastructure coverage and quality within limited budgets with limited resources requires innovation.

At Bentley, we are attacking these issues for water systems on multiple fronts - better analytical tools for determining the location of leaks; optimizing the instrumenting of water systems; developing and evaluating effective pressure management strategies; and long-term asset management solutions.  One particularly innovative tool is the Darwin Calibrator which employs genetic algorithms to identify the most likely leakage hot spots in the water system by calibrating the analytical model of the water system to the real-world measurements of pressure and flow within the segments of the distribution system.  A paper presented by Bentley's Applied Research colleague, Dr. Zheng Wu, and Paul Sage of United Utilities in England received the Honor Award for Applied Research in the International Water Association (IWA) Project Innovation Award 2008 competition for the European region. This capability allows utility owners to target their detailed inspection and repair much more effectively than with traditional methods.  Innovative tools such as the Darwin Calibrator increase the return on investments in water system maintenance by reducing the cost to locate problems and investments in capital improvements as well by focusing those investments on the highest priority requirements.

Fixing leaky pipes may sound pretty mundane and routine; it may not sound like the coolest thing for an infrastructure professional to be working on.  But solving the problem will require much more than money - it will require all the creativity and innovation that our infrastructure professionals can muster.  The benefit of fixing a few leaky pipes is immediate and its impact on sustainability is significant.  Eliminating the water loss problem in the next water system will likely have a greater net impact on global sustainability than the next green building or the next wind turbine.  Sounds pretty cool to me.