Mystery solved!! I have been trying to locate this strange circular feature, it has been on my unidentified list for 2 years. This was located off present day Pheasant Run Drive, at the north end of East Lake Court, Lagrange. The large building in front is The Run Grille and Bar.

UPDATE: The round object was part of Lagrange's new water treatment plant. The land was purchased in 1956 and included a nearby quarry. Water from the quarry was treated in this pond. Prior to this the village used wells for its water supply and they no longer met the needs of the community. A larger treatment plant was built on Rt 303 in 1978 and this facility was no longer needed so it was removed.