NASHVILLE, Tenn. (AP) — The Tennessee Advisory Commission on Intergovernmental Relations voted Wednesday to begin a comprehensive study of litter pollution in the state.

The Tennessee Wildlife Federation, which advocated for the study, said in a news release that $15 million in taxpayer money is spent to clean up litter each year. In spite of that effort, the Tennessee River contains more microplastics per gallon than any other studied river in the world, according to the group.

Other impacts to the economy include negative tourist perception and $60 million a year in agricultural damage, according to the group.

The new study will include the sources and composition of litter, financial and environmental costs, and the economic opportunities of recovering waste.

“If we want to see reductions in litter pollution, we need a comprehensive and statewide approach,” Wildlife Federation CEO Michael Butler said in a news release. “Our water, wildlife and wild places are drowning in litter.”