Water screening is indeed an effective method. It saves a lot of
screening time, the recovery is quick and efficient and non abrasive. And a
window screen drawer placed in sliding tray beneath the 1/4 inch mesh makes
for great recovery. It is more time consuming to set up however. And the
pump can be expensive.
    But run off is a problem. If you can build the screen frame into a bank
of heavy plant growth, it filters out most of the sediment before it gets
back to the river or creek. Or if you have to pump your water a long
distance from the water source, run off usually isn't a problem.

   The UofMichigan waterscreen you saw was copied after one I had earlier
used on the Tombigbee. I'll be using a similar one this summer.

N.J.

----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, March 26, 2004 8:51 AM
Subject: Re: Water Screening


> Ron's comments reminded me of one my early experiences working on the
> Tombigbee project in Alabama in the late 70s.  I was working with
UofMichigan on a
> Moundville phase village, but I think everybody else was doing just about
the
> same thing ...  Soils were excavated en masses, literally hundreds of
cubic
> meters, and 100% water-screened with fire hoses, with all sediments simply
being
> dumped back into the river.  I doubt that any of us would get away with
that
> again.
>
> High pressure water screening should still be an incredibly effective way
to
> process large soil recoveries, but it would entail the use of more
formally
> constructed sediment basins ... which, IMHO, shouldn't be that expensive
or
> difficult.  It should be just a question of choosing an appropriate
location for
> the basin ..
>
> Mark C. Branstner
> Great Lakes Research, Inc
> 210 E. Sherwood Road
> Williamston, MI 48895
> 1-517-347-4793 / [log in to unmask]