What is a Contaminant?

A chunk of all natural, no artificial additives
chromite, or chromium ore.

When most people think of contaminants in their water, they think of some nasty chemical that’s polluting the land or water; something that leaked out of a tank somewhere; that was illegally dumped along some lonesome road in the middle of the night; or that is the result of some nefarious industrial process.  And in some instances, any or all of those scenarios may very well lead to contamination of the water supply.  But if you look at the EPA web site where they discuss and list all of the “contaminants” that they currently regulate in drinking water, (http://water.epa.gov/drink/contaminants/basicinformation/index.cfm ), you will also find a lot of compounds that are naturally occurring; no one dumped them, manufactured them, or otherwise “polluted” the environment with them.  They are every bit as much a part of the environment as the water itself.  That doesn’t mean they can’t be harmful – arsenic is naturally occurring, but ingest enough of it and it can still kill you.  Contrary to so many marketing campaigns that make you believe that “natural products” are somehow inherently safe, they can in fact be just as, if not more harmful than anything created by man. 

This issue comes up quite a bit in my interactions with the general public.  They may review their local water companies CCR and see fluoride listed, after which they call, quite upset, wanting to discuss the evils of adding fluoride to the water and how terrible it is that we do so. After I explain to them that there is no fluoride added to the water, but that a low level of fluoride is a natural occurring constituent of the groundwater in their local area, they are often quite surprised.  Just as surprising to me is that when they learn it’s naturally occurring, they don’t seem to think it’s a big a deal any more,  when in fact fluoride is fluoride no matter the source, whether it’s added by Mother Nature or the local water agency.  I guess Mother Nature just has better PR. 

Another good example regarding people’s misconceptions about contaminants is the current issue with hexavalent chromium.  Also known as chrome-6, hexa-chrome, Cr(6), or Cr(VI), this particular oxidative state of the element chromium can, under the right conditions and in sufficient concentration, be quite toxic.  Most people, in California at least, think of chrome-6 in terms of the whole debacle with PG&E contaminating the ground water near Hinkley, CA when they used a chrome-6 containing anti-corrosive chemical in the cooling towers at their natural gas transmission pipeline compressor station nearby.  But by far the greatest source of chrome-6 in the groundwater in California, and elsewhere, is from natural geologic formations containing chromium.  Unfortunately, this misunderstanding is one of many reasons that California may soon be saddled with a chrome-6 maximum contaminant level (MCL) that is excessive and unnecessary.

When I was taking botany in college, someone asked my professor what the definition of a weed was.  His response was that a weed is any plant that is somewhere you don’t want it to be.  Likewise for drinking water, saying something is a contaminant doesn’t mean it’s the result of some toxic spill or other pollution.  It means that, no matter what the source, it’s just something in the water that we don’t want there at more than a certain level, no matter what the source.