How safe is our drinking water? Threats from chemical spills, pathogens, and terrorism.

How Safe Is Our Drinking Water?

How Safe Is Our Drinking Water?

The state of the universe.
Jan. 16 2014 11:39 PM

How Safe Is Our Drinking Water?

Poisoning the enemy is a long-standing military strategy.

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The last class of threat comes from accidents, as occurred in West Virginia. In many respects these are the most difficult to plan for because there are so many potential contaminants. The MCHM passed directly through the treatment plant into water mains because the plant was not designed to deal with this chemical. It’s not supposed to be in our water. Nor are the thousands of other hazardous chemicals stored and transported around the country. Many tanks are located near a river or lake intentionally, to make transport cheaper. But accidents happen—tanks can leak, trains can derail. Hence the challenge for water suppliers is how to protect against low-probability/high-impact events.

Leaking MCHN tanks at Freedom Industries are being off loaded into tanker trucks on January 10, 2014  in Charleston, West Virginia.
West Virginia American Water customers line up for water after waiting hours for a water truck, only to have it emptied in about 20 minutes, on Jan. 10, 2014, in South Charleston, W.Va.

Photo by Tom Hindman/Getty Images

Because our overall water system from headwaters to tap is simply too large to prevent any contamination, either intentional or accidental, it becomes critical to detect threats quickly, identify the contaminants, and take proper precautions so people don’t drink the water. As a result, improved monitoring is where much of the current action lies.

The town of Loveland, Colo., for example, keeps a tank of drinking water full of trout. When the trout start to die, the water managers know something is wrong with the water and investigate. Bigger systems take multiple measurements at different points in the system every day. Following the Sept. 11 attacks, New York City increased the number of daily water samples. It now tests its tap water more than 330,000 times each year.


The next generation of sensitive monitors will detect a range of contaminants in real time. DNA microchip arrays, immunological techniques, micro-robots, flow cytometry, and molecular probes and other emerging technologies could be placed throughout the water system to provide rapid warning of contaminants early enough to allow quick responses by water authorities.

A utility could harden infrastructure. It may extend distribution pipes or build two treatment plants instead of one, allowing it to draw water from different sources during an emergency. Pipes may be buried instead of elevated. Virtually every construction choice, in fact, might look different if security became a top design priority.

Former New York City Mayor Michael Bloomberg has stated the challenge clearly: “Our drinking water really is the lifeblood of this city, and that, unfortunately, might make it a target for sabotage. We need to be vigilant in protecting our water systems.” This is equally true for accidents. Left unsaid, though, is a vexing challenge.

As with so many policy issues, knowing what to do is only half the battle. You also have to pay for it. System hardening and improved monitoring are expensive. Emerging detection technologies are unlikely to be developed commercially if the market payoff appears small.

Our water systems, though, remain deeply underfunded. A water main bursts somewhere in the country every two minutes. Some cities have pipes that were laid just after the Civil War. In this budget-conscious environment, upgrading plants to treat for every imaginable chemical is not going to happen, nor perhaps should it.

While it’s an obvious question, asking whether our drinking water is vulnerable is not really helpful. It is vulnerable. The question is how vulnerable, and how great the risk of harm compared with other potential threats.

Our water systems are well-designed to prevent natural contaminants from getting into the pipes and coming out of the tap. Poisoning from large-scale attacks remains difficult, given the precautions already in place and the sheer volumes needed to poison a large water supply. Accidents, though, give special cause for concern.

While the recent events in West Virginia—a chemical tank leaking into a river just upstream of a regional water plant’s intake source—may seem like a rare confluence of factors threatening water quality, it would be foolhardy to ignore this as a one-off event. At least two lessons should be clear.

First, we need to pay closer attention to the structural integrity of chemical storage near water bodies. At a time of reduced agency budgets and pressure for deregulation, we need to acknowledge that officials ensuring compliance with health and safety regulations, such as tank safety requirements, keep us safe. Second, water authorities need the resources to ensure effective detection and rapid communication. These are critical in minimizing harm when threats do arise.

Benjamin Franklin wrote that “When the well’s dry, we know the worth of water.” He also observed that “An ounce of prevention is worth a pound of cure.” We would do well to remember both.