The Five Thousand Pound Gorilla in the Room is Named McKinley

A question came up about the five thousand gorilla in the room.  What is his name? Our crack research team interviewed the water quality heavyweight and found out his name is “McKinley”. 

This makes total sense, because McKinley represents a mountain of material that many people would like to ignore.  Our ETV testing determined that we had 1,600 pounds of material measured coming into the inlet of our device in Griffin, Georgia, while we had 157 pounds coming out of the outlet.  Of that 1,600 pounds at the inlet, a mere 200 pounds of it was silt and clay (less than 62 microns in size), and a whopping gorilla worthy chunk of it (1,400 pounds) was sand over 62 microns in size.  On the other hand, at the outlet, we only had 24 pounds of sand out of the 157 total, and the rest (133 pounds) was silt and clay. 

Even a monkey can understand that with 1,600 pounds coming in, and about 160 pounds coming out, we caught 90% of the solids.  It might require a 5th grader or Jeff Foxworthy to calculate that we caught 67 pounds out of the 200 pounds of silt and clay that came in the inlet, or 33.5%.  If you do not know how big 62 microns is (we caught 98% of everything bigger than that), a human hair is from 40 to 100 microns in width.  A sheet of copy paper is about 100 microns thick.  So, it really stretches the imagination to think that everything above 62 microns is completely clean and does not matter to the environment.  Still, if you make that leap (a big one, even for a gorilla), and throw out everything we caught above 62 microns, we still caught 34% of everything that came into our device. 

We know that McKinley cannot read, but if he could read, he might be confused.  He would read that we only caught 21% of the solids, according to an analysis method that is inaccurate and not reliable.  That method is one developed by the EPA, called EPA 160.2 (TSS).  This analysis method is well documented to underreport sediment concentrations, and has been shown incapable of working well when sand is present.  The ASTM method of analysis, ASTM D-3977-97 (SSC) is the preferred method, and correctly reflected our performance on this site by reporting an 89% removal rate. 

McKinley represents the big, bad pile of nasty material that would go unreported if we started believing that the wrong analysis method is somehow a good thing.  Yet, people do just that.  They look at our testing and say, “Wow, 89% that’s good, but it was SSC analysis.  What did you get using TSS?”  McKinley is not amused.  He hates being ignored.

On March 24, 2011, posted in: Blog by
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