River channel and harbor dredging activities in the eastern USA generate hundreds of millions of yards of dredge sediments annually, with very little used beneficially. The Woodrow Wilson Bridge dredging project on the Potomac River at Washington D.C. produced in excess of 450,000 square meters of silt loam, high pH, low salt dredge spoils. The materials were barged to Shirley Plantation on the James River in Charles City Co. Virginia, and placed into an upland utilization area atop a previously reclaimed sand and gravel mine. The materials were dewatered, treated with varying rates of yard waste compost and planted to wheat in the fall of 2001 and corn in 2002 and 2003.
Winter wheat yields in 2001 were similar to local agricultural lands despite animal damage and less than ideal establishment conditions. Average corn yields in 2002 were greater than long-term county prime farmland yields in a severe drought year (2002) and equaled county averages in a wet year (2003). Farmer measured yields in 2005 and 2006 remained at or above county averages.
Since 2005 we have also been monitoring an adjacent dredge spoil impoundment that received salt water sediments from the Earle Naval Weapons Station in New Jersey and the Cheatham Annex on the nearby York River. During 2011 we worked with the Virginia DEQ to develop a detailed set of dredge material quality screening criteria to determine which materials are suitable for upland placement and conversion to benefical agricultural uses.
Weanack Annual Monitoring Reports: