Standard&Poor's Rating Services assigned its 'AAA' long-term rating to Charleston, S.C.'s series 2016 waterworks and sewer system revenue. Additionally, we affirmed our 'AAA' rating on the system's outstanding revenue bonds. The outlook is stable. The enterprise risk profile is the result of the system's: Service area that continues to grow and diversify with strong income indicators and low unemployment rates; Moderately affordable combined rates representing 2.7% of median household income; Low risk operations characterized by ample system capacity, and Very strong operational management. The financial risk profile reflects the system's: Strong all-in debt service coverage (DSC) levels; Extremely strong system liquidity; Moderate debt to capitalization; and Very strong financial management. The bonds are secured by a pledge of