This is the El Dorado Energy Plant. It burns natural gas, and there's a demonstration solar facility there too. The three black rectangles are ponds of water, I imagine used for cooling.
They are, indeed, cooling water ponds. They appear black because the ponds are lined with dark plastic to prevent water seeping into the ground.
Anonymous
@ 2005-11-04 23:48:15
Why was someone (the person who submitted the map) thinking the buildings were blacked out? Are you reading this? I'm just curious what you were thinking.
Power - Gas 
This is the El Dorado Energy Plant. It burns natural gas, and there's a demonstration solar facility there too. The three black rectangles are ponds of water, I imagine used for cooling.
There's a picture and more details at:
http://www.semprageneration.com/Pages/Projects/El_Dorado/El_Dorado.aspx