white dome SW of Fitchburg

[Robert F. Sutherland]

Question of "what is it?" --- from my map viewings,
perhaps is something not for the public to know,
but I'm curious.

SW of Fitchburg, area of Oak Hill Country Club, there are 2 towers,
independent of each other.
This is also SES of Waites Corner.

My question is re the more north tower, 3 sided, self-standing, orange &
white  
(Google Earth reads 42:33:43, 71:50:04):
Next to the tower is a white circular low dome, 
the dome being my question.

>From VirtualEarth, the tower shadows on the dome, lead me to suspect
dome center rise is no more then 15 ft off ground.

My guesses are a underground water tank, or 
some sort of radome (there???) ?
Maybe a Coke can switch (excuse me, "Tactile") push button
for the Jolly Green Giant?

Both Google Earth and Virtual Earth (Live Search) show this object.

Please visit my Home page, radio page for images
(I'm including a piece of USGS to help locate)
http://home.netcom.com/~madprof/radmyst.html

Thanks to all who view, or have any information or comments.
Bob Sutherland