When residents of a New York City neighborhood saw a tree disappearing down a hole in the summer of 2012, it was obvious something was amiss. Called to investigate, the Department of Environmental Protection determined the cause to be a collapsed 110 year-old sewer line buried 70 feet below the surface of the street.
Amusing as it may sound, such incidents are not uncommon. Most of our water and wastewater systems were built more than 50 years ago and they are aging. The American Society of Civil Engineers says $4.8 trillion in capital investment is needed over the next 20 years for repairs, and while the EPA estimates a more conservative $600bn and 20 years, there should be no doubt that this is a huge problem.