The latest public-health worry: Chromium in the water
December 28, 2010
The environmental lobbying organization called the Environmental Working Group has released a report saying that 74 million Americans drink water containing chromium-6
, which EWG argues is a likely carcinogen. The EPA hasn't yet decided to tighten regulations on chromium
, but it may choose to do so, particularly if public pressure is brought upon it to do so. The process for adopting new standards regarding previously-unregulated contaminants can take quite a lot of time, and though the EWG may be correct about the risks, the EPA may also find that the costs of treatment may exceed the potential benefits.
Water-quality treatment inevitably involves a range of trade-offs between the costs of treatment and the expected benefits, and in some cases it is found that some benefit may be gained from an expensive new approach -- but that benefit is less than what might result from spending the same amount of money doing something else. In public water systems
, for instance, it's often easier to obtain funding for new methods of treatment at the source than for the replacement of aging distribution mains, piping, and valves. Yet the costs of unmetered water losses and the potential risks caused by transient pressure drops
in water systems may very well exceed greatly the hazards being mitigated by new approaches to source-water treatment. In other words, people may be willing to spend a lot to have nearly-perfect water at the treatment plant, but they might be better served by spending the same money to ensure that the distribution system itself is sound.
last revised December 2010