How Safe is Our Drinking Water

dreamstime_s_6034467I was interviewed yesterday by Elizabeth Shogren of NPR on the safety of tap water.   Ms. Shogren was troubled by the fact it took nearly two weeks for Freedom Industries to report a second chemical involved in the massive spill in Charleston, West Virginia, and she wanted to know why it wasn’t detected as part of the water company’s rigorous testing.   Fair question, and something the public needs to understand.   Public water systems (both private and public operated) are required by law to routinely test for dozens of potential contaminants – naturally occurring and otherwise – to ensure public health protection.  EPA regulates these contaminants under the Safe Drinking Water Act, and imposes standards and limits called maximum contaminant levels, or MCLs for short. However, with tens of thousands of chemicals being uses in commerce, and potentially upstream from a drinking water intake, it is not practicable, economically or technically, to require a public water system to test for all those chemicals.   My friend, Jim Salzman, author of Drinking Water: A History, has a good article over at Slate, responding to this very question, “How Safe is our Drinking Water.

This question is both timely and timeless, for water providers have constantly defended water sources against contamination. From well before the Romans through today, they have always faced three broad classes of threats.

The first comes from natural contaminants—pathogens we expect to find in water. Despite images of clear, burbling springs and mountain streams, the simple fact is that fresh water is just not very clean. Teeming parasites, viruses, and bacteria live in water. Just a hundred years ago, dying from waterborne typhoid or cholera was commonplace in the United States, and deadly epidemics still break out in some parts of the world today. The addition of chlorine to water supplies a century ago largely eliminated these scourges. We have since become very good at eliminating biological pathogens with chlorination, ozonation, ultraviolet radiation, and filtration as redundant lines of defense. Nonetheless, vigilance remains necessary. Just two decades ago, a treatment plant piped contaminated water to Milwaukee residents, sickening one-quarter of the city’s population. Sixty-nine people died.

So, how safe are our water systems from major attacks?  Truth be told, as a former EPA water regulator, this is something I worried about every day.  Salzman continues:

There have not been any successful major attacks on American water supplies, but the threat and fear remain because our water supplies cannot be fully protected. We could erect more fences, higher fences, locks, security cameras, and hire more guards—and we have—but with more than 75,000 dams and reservoirs, more than 160,000 drinking water facilities, mostly owned and operated by local government and private parties, 2 million miles of pipe and millions more access points, these measures will never make us completely safe. Our water systems present an impossibly big target to protect from intentional acts or accidents.

The good news is that poisoning a water system is hard to do. Putting a few drops of cyanide in someone’s glass will lead to a gruesome death. Putting a few drops, or even a few barrels, in a reservoir is pointless. Reservoirs generally hold anywhere from 3 million to 30 million gallons of water. Even assuming one could back several trucks up to the reservoir and dump their loads without being detected, one would still need to get huge quantities of the poison in the first place. The Department of Homeland Security keeps track of biological and chemical agents that might be used by terrorists, and these substances are not easy to come by in large quantities.

What the public needs to understand, as well documented by Salzman, is that never before in human history has our drinking water been safer.  Having said that, vigilance and contingency planning remain critical to ensuring the public’s water supply remains safe.  In the case of Freedom Industries, it’s difficult for me to fathom why all the details on the chemical released were not immediately provided to first responders, medical professionals, and the water company.  “Spill 101” requires immediate access to details regarding the chemical to assess the extent and scope of the threat.  As I explained to Ms. Shogren, every chemical has a unique fingerprint which can be assessed by very sophisticated analytical techniques, such as mass spectrometry.   But these techniques have their limitations and they can’t always tell you specifically what’s  in the water, only that something is or isn’t present.   You really need to know what chemical you are dealing with, before you can determine whether it’s present and at what concentration.  That’s why the immediate sharing of information in situations like this is so critical.

Can we do better, can we make our water safer?  Absolutely, but at what cost are we willing to increase our level of safety.   Are new laws needed?   Probably, but the devil’s in the details.   Understand, new laws will not eliminate all risks.  And, let’s be clear about something else.  While new regulations may make us all marginally safer, they also will come with a price tag, in terms of higher costs to energy, services, and consumer products.   So, as Congress mulls over changes to our laws, a few priorities to consider.   Communities need to continue to focus on (1) protecting source waters, in particular, by keeping contaminants out of the water to start with, (2) assessing vulnerabilities and threats, (3) planning for emergencies and spill contingencies, (4) maximizing the sharing and accessibility of chemical information, and (5) continuing to improve our understanding of the health effects of chemicals.  Bulk storage of chemicals near waterways should be the obvious focus.   Simple precautions such as effective spill containment and more inspections can go a long way toward greatly reducing the risks of another catastrophic spill.   The passage of regulations, in 1988, bolstering the Clean Water Act’s Spill Prevention, Control and Countermeasures (SPCC) program, in response to the Ashland oil spill on the Monongahela, which impacted over 1 million people, resulted in dramatic reductions of major oil spills.  Personally, I think a similar focus on chemicals in bulk storage with the potential to reach drinking water may be an appropriate starting place.