Subject: is it possible to curb the ecological destruction from hurricane katrina?

I have a filtration system on my shower head that does not disrupt the flow of 
water.  In a similar vein, would it be possible to set up a system of filters 
down stream IN the mississippi river that wouldn't disrupt much flow, but at 
the same time lessen the havok that this "toxic" water willl wreak in the 
coming years? 
I ask out of curiosity, I have neither the means or the connections to bring 
such a thing into fruition. 

Re: is it possible to curb the ecological destruction from hurricane katrina?