(Harrisburg) -- A midstate nonprofit warns recent flooding from Tropical Storm Lee could lead to the creation of so-called "dead zones" in a major waterway. Harry Campbell, a senior scientist with the Chesapeake Bay Foundation, says a brown stain from the Susquehanna River has made its way to the bay. He says it's a 100-mile-long plume. "It is a large area of highly turbid and brown water, soiled with large and small particles of dirt that have gotten into the water because of the heavy rains and flooding," he says. Campbell says in the short term, sediment from the plume could smother aquatic life. He adds it's still unclear how severe the flood's long-term effects on the bay will be. The Susquehanna River is the Chesapeake Bay's largest tributary.