NEW YORK (Standard&Poor's CreditWire) Aug. 11, 1999--Standard&Poor's today assigned its double-'A'-plus rating to Charlotte, N.C.'s $70 million water and sewer system revenue bonds dated Aug. 15, 1999, due June 1, 2024. The bonds are scheduled to sell Aug. 25, 1999. At the same time, Standard&Poor's raised its rating on the city's outstanding water and sewer system revenue bonds to double-'A'-plus from double-'A'. The rating upgrade reflects: -- Very strong financial performance and an expectation of continued coverage of revenue bonds in excess of 2.5 times (x); -- High liquidity; -- Affordable, competitive rates; and -- Strong system growth with comprehensive planning. Also reflected in the rating is a large capital program requiring about $100