DALLAS (Standard&Poor's) Sept. 8, 2008--Standard&Poor's Ratings Services raised its underlying rating (SPUR) on Cedar Hill, Texas' waterworks and sewer bonds to 'AA-' from 'A' based on the system's historically good coverage and healthy customer base expansion. At the same time, Standard&Poor's assigned its 'AA-' standard long-term rating to Cedar Hill's $3 million series 2008 water and sewer system revenue bonds. The outlook on the ratings is stable. A net system revenue pledge secures the bonds. The system's financial operations have historically provided good coverage. Based on fiscal 2007 net system revenues, fiscal 2008 debt service coverage (DSC), which is equal to maximum annual debt service (MADS), is strong at 2.5x annual DSC before transfers.