Researchers Robert Walter and Dorthy Merritts, co-chairs of the Legacy Sediment Workgroup for DEP’s Chesapeake Bay Tributary Strategy are the featured speakers at the next Rachel Carson Forum on Future of the Environment tMay 17.

The Forum will be held from noon to 1 p.m. in the Second Floor Auditorium of the Rachel Carson State Office Building, Harrisburg.

Walter and Merritts, both professors at Franklin & Marshall College, have been researching legacy sediments in southeastern Pennsylvania for four years, and in the past year have been working in central and northeastern Pennsylvania, and northern Maryland.

By examining historic maps from the 19th century, air photos dating back to the 1930s, and outcrops along streams and in backhoe trenches, they have determined that nearly 400 mill dams once existed in Lancaster County, and each dam formed a slackwater pond and associated backwater that trapped sediment over a period of one to three centuries.

Water-powered mills are long gone, and obsolete, derelict dams gradually breach or are removed, releasing legacy sediment to be carried downstream, some of it ultimately reaching the Chesapeake Bay.

Walter and Merritts will talk about legacy sediments as a source of nutrient loads to the Chesapeake Bay from southeastern Pennsylvania, summarize the issues and make recommendations to address the problems and opportunities associated with legacy sediment.

For more information visit the Forum announcement or contact Will Delavan at 717-783-8727 or e-mail wdelavan@state.pa.us .

Link: Documenting Streambank Erosion - Bigger Problem Than Originally Thought

5/11/2007