Here’s a link to what I think is a very good (and brief) article about keeping our drinking water safe, by James Salzman at slate.com. I think a lot of people, including myself, were a bit shaken up by how severely impacted Charleston, WV, was by the discharge of methylcyclohexane methanol (MCHM) into the Elk River, their drinking water supply.
Salzman says there are three broad classes of threat to our water supplies: natural contaminants, intentional attacks, and accidents. I would suggest there are actually four, the fourth being non-point sources of pollution, such as fertilizer or road salt. Salzman considers pathogenic organisms to be a natural source of contamination, but I consider these to be primarily from anthropogenic activities, such as poor sanitation or improper control of livestock waste.
Most of my research on water quality has focused on natural (such as arsenic) or non-point-source contamination of our water resources, which are by far the major threats to safe drinking water. In the months after 9/11, we were approached by the Governor to consider potential terrorist threats to public drinking water systems in Illinois. As Salzman correctly points out, deliberately contaminating a water supply is an extremely difficult thing to do. Poisoning a glass of water is one thing, poisoning a reservoir with millions of gallons of water is another; the dilution effect would require huge amounts of poison. And of course poisoning groundwater would be exponentially more difficult; for most of our aquifers we only have a general idea about where recharge is occurring. There has never been a successful attack on an American drinking water supply, and I doubt there every will be.
Accidents, as happened in Charleston, are rare but still happen too frequently. Preventing accidents should be much easier than preventing non-source pollution. But oftentimes oversight is inadequate, and we’re reminded of this every time one of these accidents occur. I actually don’ like the term “accidents,” which implies they are uncontrollable. Could the Elk River spill have been prevented? With proper oversight and resources, almost certainly. But adequate resources for our aging water infrastructure is a serious issue. I recommend watching “Liquid Assets” to learn more about that.
