The Texas Pecan Alliance and scientists with Sierra Club say research shows sulfur dioxide kills vegetation, and is especially harmful to pecan trees. They say production started decreasing in 1980, a year after the Fayette County plant began operating.
Since then, pecan grower Harvey Hayek says thousands of trees along some 100 miles of the Colorado River have died, including two-thirds of the trees on his family's 250-acre ranch.
The Lower Colorado River Authority says it is installing equipment that will remove more than 90 percent of the harmful emissions.
