Chromium in our drinking water?
Monday, December 20th, 2010Ehhhh… not really. The Environmental Working Group published a report on Chromium 6 found in various tap water samples in US cities. Tennessee was a blank. So does that mean no Chromium? Well, not exactly. Apparently, TDEC was asked several times by EWG to fill out a form asking about how they regulate chromium and TDEC never responded. That Tennessee is blank has more to do with TDEC staff than whether or not we have chromium in our drinking water.
So back to the original question. Here’s the long policy explanation. The rules that govern how much pollution gets put in Tennessee’s water has a list of criteria that must be followed. For surface waters, Tennessee has a “domestic supply” criterion of 100 ppb (or 100ug/L - same thing) for total Chromium. That’s the water in rivers that can be used to drink.
There is a criterion for “fish and aquatic life”. The criterion for Chromium 6 is 16 ppb maximum or 11 ppb on the average. This is for rivers that have fish species that you may want to eat and the aquatic bugs that those fish feed on.
Now for the criterion used for what the drinking water plants need to follow - 100 ppb of total Chromium.
Why are fish more protected than humans? My guess? Fish are in a water environment and therefore are more susceptible to the effects of chromium. That’s my guess.
We looked at a couple of sites in Tennessee to see what kinds of chromium we find there. Smokey Mountain Smelters in Knoxville had about 0.001 ppb in testing we did in 2004. That’s very low. We looked at effluent from a landfill. We found no chromium. There was some chromium found from the Kingston disaster, but low levels. In short, some of the nastiest places we’ve looked at don’t seem to be a problem.
That doesn’t mean it won’t be a problem in the future, but for now I’m not worrying about it.
RvH


