Figure 4. World water reuse capacity forecast
Click here to enlarge imageTaking the definition of reuse as planned beneficial reuse involving secondary wastewater treatment as a minimum, we would estimate the current annual capital expenditure on water reuse projects to be in the region of $1.1 billion per year. This figure is growing at a rate of around 19% per annum, which corresponds to an expansion of capacity from 15.2 million m3/d at the start of 2007 to 28.5 million m3/d at the end of 2011, and 59.7 million m3/d at the end of 2016 (see Figure 4). These are extremely tentative figures, since, unlike desalination, there is currently no systematic record of water reuse projects or system of tracking new projects. Using a ballpark figure of $0.35/m3 for the cost of reuse suggests operating expenditure of $1.9 billion a year, a figure which is experiencing an annual growth rate of around 13%.
The U.S. Reuse Market
Today, the $352 million Orange County Ground Water Replenishment System, which won the 2008 Stockholm Industry Water Award during World Water Week in Stockholm this summer, sets the standard for U.S. water reuse. The first phase of the project has a capacity of 70,000 acre feet per year (237,000 m3/d), representing a capacity cost of $1,485/m3/d. It involves treating wastewater with microfiltration, reverse osmosis and ultraviolet disinfection before pumping it 13 miles to spreading basins where it’s blended with other sources.