The North Carolina Coastal Plain: A Hotspot for Increasing Nutrient Pollution

The North Carolina Coastal Plain is dominated by a series of 2^nd to 5^th order blackwater streams and rivers. These watersheds host over 9 million head of swine and hundreds of millions of chickens and turkeys being raised in CAFOs, or concentrated animal feeding operations. These types of industrial livestock operations dispel animal waste into the environment with no secondary treatment. While swine numbers have stayed steady for the past two decades, poultry abundance has increased dramatically. A 22-year data set collected by the Lower Cape Fear River Program at UNC Wilmington was analyzed for trends at 29 stations. The analysis showed significantly increasing nitrate at 18 stations, increasing total nitrogen at 14 stations, increasing total phosphorus at 20 stations, and increasing fecal coliform bacteria at 17 stations. A separate NCDEQ analysis indicated increasing organic nitrogen at numerous sites in North Carolina. Targeted sampling at a CAFO – rich watershed found chronically high nutrient and fecal bacteria concentrations in receiving streams. Besides the high amounts of waste from swine sprayfields and poultry litterfields entering the land and waterscapes, the soils in this region are porous and water tables high, making movement to the water table rapidly. Thus, streams are subject to both overland runoff and polluted groundwater inputs. Despite the lower Cape Fear River and estuary on the 303(d) list for waters impaired by hypoxia, there are no legal non-point runoff controls in agricultural lands in this large watershed.

Presentation Preference: Oral

Primary Presenter: Michael Mallin, University of North Carolina - Wilmington (mallinm@uncw.edu)

Authors:

Michael Mallin, University of North Carolina Wilmington  (mallinm@uncw.edu)

Lawrence Cahoon, University of North Carolina Wilmington  (cahoon@uncw.edu)

Adam Chaffin, University of North Carolina Wilmington  (achaff24@gmail.com)

Colleen Brown, University of North Carolina Wilmington  (cnb6822@uncw.edu)