S&P Global Ratings raised its long-term rating to'A'from'A-'on Will County School District No. 81 (Union), Ill.'s general obligation (GO) bonds, based on our view of recent operational surpluses and improvement in the district's general fund reserve levels. The outlook is stable. The district's GO bonds are secured by revenue from its unlimited-tax ad valorem GO pledge. The ratings reflect our view of the district's: Participation in the Chicago metropolitan area economy with access to Joliet; Extremely strong market value per capita; and Rapid amortization. Partly offsetting the above credit factors are the district's concentrated tax base, with the top 10 taxpayers representing 59.1% of the tax base, high overall net debt burden on a per capita
