9.2 Water Infrastructure

WHO? The United States.

WHAT? Drinking Water Infrastructure.

WHEN? Is essential to sustaining life; without it, society would ground to a halt.

WHERE? Just 15% of utilities serve 75% of the population, making them a potential target.

WHY? Although not easy, shutting off the water to a major US city would certainly be catastrophic.

In the last topic we introduced the concept of critical infrastructure protection and told you that DHS works with 16 separately defined infrastructure sectors. Among those 16 infrastructure sectors, four in particular are considered so important they are called “lifeline” infrastructure. Without them, the other sectors could not function. The four lifeline sectors are water, energy, transportation, and communications. In this topic, we will take a close look at the water infrastructure. The US water infrastructure encompasses both drinking water and wastewater systems. There are about 51,000 public waters systems serving more than 300 million people in the US. On the flip side, there are about 16,500 wastewater facilities serving more than 227 million. Both drinking water and wastewater are regulated by the Environmental Protection Agency under authorities given by the 1974 Safe Drinking Water Act and 1972 Clean Water Act. Because 80% of the US population lives in cities, only 15% of utilities serve 75% of the population. This concentration might make water utilities a tempting target for deliberate attack. While you can survive weeks without food, you can only survive days without water. Drinking water systems would be the most likely target of attack. An attack on a wastewater system could result in environmental catastrophe, but would not otherwise pose an immediate threat to human life. This is not meant to minimize the importance of wastewater systems. Indeed, it was not until Dr. John Snow in 1849 linked cholera to wastewater in drinking wells prompting the construction of sewers that allowed London to become the largest city since Rome, which itself had tamed such epidemics with its own sewer system two thousand years before. The Romans were also known for their great aqueducts which delivered about 200 gallons of clean drinking water per person per day, more than twice the average of modern consumption. Aqueducts also carry water in the US. The New York aqueduct is the second largest in the world, delivering 1.5 billion gallons from nearly 60 miles to 8 million residents daily. Water sources vary. About 60% comes from surface sources such as lakes, rivers, and streams. About 25% is groundwater drawn wells. And 12% comes from the ocean and must be desalinated. No matter what the source, most drinking water then undergoes a 4-step treatment process: 1) Flocculation, 2) Sedimentation, 3) Filtration, and 4) Disinfection. Flocculation adds chemicals that bind with small particles to form large particles called floc. Sedimentation allows time for gravity to pull floc to the bottom and separate it from the water. Filtration then passes the water through layers of sand, gravel and charcoal to remove dissolved particles such as dust, parasites, bacteria, viruses and chemicals. Disinfection adds chlorine to kill any remaining parasites, bacteria, viruses and germs. After it is treated, water is directed to storage tanks where it then enters the distribution system. The US has 2 million miles of water pipes. 80% are over 50 years old, and 4% over 90 years old. Attacking a water system would not be easy, but not impossible. Poisoning the water source would be most difficult. It is generally agreed that current treatment methods are capable of removing all but the most insidious forms of biological or chemical toxins. For those of you who remember Flint Michigan in 2015, that crisis was precipitated by a reaction between the water and lead pipes in the distribution system. Those pipes are all being replaced. No, perhaps the most vulnerable points are key pumps within the treatment system. A coordinated attack against those controls over the Internet, could potentially shut down the whole system. And that could be catastrophic.