A colossal tide of fertilizer and animal manure that runs off fields in Iowa and other farm states ends up in the Mississippi River. The same agricultural pollution problems are plaguing other iconic U.S. waterways, including Chesapeake Bay and Lake Erie.

Kindra Arnesen is a 46-year-old commercial fishing boat operator who has spent most of her life among the pelicans and bayous of southern Louisiana, near the juncture where the 2,350-mile-long Mississippi River ends at the Gulf of Mexico.

Clark Porter is a 62-year-old farmer who lives in north-central Iowa where he spends part of his day working as an environmental specialist for the state and the other part raising corn and soybeans on hundreds of acres that his family has owned for over a century.

Though they’ve never met, and live 1,100 miles apart, Arnesen and Porter share a troubling kinship — both of their communities are tied to a deepening water pollution crisis that is fouling the environment and putting public health in peril across multiple U.S. states.