Standard&Poor's Ratings Services it raised to 'AAA' from 'AA+' the rating on Trinity River Authority (TRA or the authority), Texas' Mountain Creek regional wastewater system parity debt. The outlook is stable. We also assigned a 'AAA' rating and stable outlook to the authority's Mountain Creek system series 2011A state revolving fund loan. The upgrade reflects the improved credit quality of the system's customer cities, specifically Grand Prairie, which we view as the strong link in this system despite its position as the smallest participant. The upgrade affects about $1.8 million in outstanding parity revenue bonds. The 'AAA' rating also reflects our opinion of the system's participant cities' general creditworthiness, which includes: Margins that are able to generate appropriate
