EFFECT OF AGRICULTURAL DRAINAGE ON WATER-QUALITY IN MID-ATLANTIC STATES

Agricultural drainage development in the form of drainage alone and co ntrolled drainage-subirrigation (CD-SI) has created environmental conc erns. The primary concern is increased loading of nutrients, pesticide s, and sediments to environmentally sensitive waters. Productive steps to address these concerns are hampered by the lack of research data a nd the lack of public knowledge of the history, development, design, a nd water-quality impacts of these systems. The research activities of the 1970s and 1980s in some states have provided information on the ad verse and beneficial impacts of agricultural drainage and overall wate r-table-management systems. This paper reviews the history, magnitude, institutional and social constraints, and the water-quality impacts o f agricultural drainage in the Mid-Atlantic states (New jersey, Delawa re, Maryland, and Virginia). It also provides examples of the results from selected research activities in these states. Finally, this paper provides some thoughts on research needs. Overall, this study conclud es that the research data on the impact of agricultural drainage on wa ter quality and design guidelines for the specific geologic conditions of the Mid-Atlantic states is limited and in many instances nonexiste nt. Drainage legislation in these states has a history of success in f orming drainage districts and associations, although accurate research data are needed to address the environmental concerns (negative and p ositive) of these systems.