CHICAGO (Standard&Poor's) March 4, 2013--Standard&Poor's Ratings Services said that it lowered its long-term rating to'A-'from'A'on Will County School District No. 81 (Union), Ill.'s general obligation (GO) bonds. The outlook is stable."The downgrade reflects our view of the district's recent history of deficits in its combined educational and operations and maintenance (O&M) fund,"said Standard&Poor's credit analyst Lin Johnson,"as well as its weak cash liquidity, with the anticipated use of external short-term borrowing."Another factor is the district's negative cash balance in the combined educational and O&M fund in fiscal 2012. Partly offsetting the above credit factors are the district's: Participation in the Chicago metropolitan area economy with access