DALLAS (Standard&Poor's) April 2, 2004--Standard&Poor's Ratings Services said that a major raw sewage overflow on March 31 at Trinity River Authority, Texas' central regional wastewater system plant (AA/Stable) would not affect the authority's rating. A malfunction that management attributes to an inadvertent closure of part of the headworks for construction maintenance, and not to any kind of structural problem, at the 162-million-gallons-per-day-capacity plant led to a raw sewage backup, which was initially estimated at up to 50-70 million gallons, and caused the overflow, some of which may have entered the Trinity River. While the contaminated section of the river is not used to supply water to any retail provider in the Dallas-Fort Worth MSA, the Texas