The $200,000 study, to be completed this year by Louisiana State University scientists, will consider the feasibility and environmental soundness of pumping water from three sewage-treatment plants into wetlands of the Barataria.

The study adds to a growing list of groups that are studying or building similar systems as population growth and tougher environmental requirements push sewage treatment costs higher.

Local officials said using treated wastewater on wetlands also could help mitigate coastal erosion problems and reduce the excessive amount of algae-feeding nutrients in the Mississippi River.

"A lot of people are looking at this because of the cost as well as the environmental benefits," said Marnie Winter, director of environmental development and solid waste.