WATER-QUALITY IN A MIXED LAND-USE WATERSHED - PIEDMONT REGION

Nonpoint source pollution, particularly from agricultural land, has be come a national concern in recent years. It was this concern that lead Maryland to identify Monocacy River Basin as a priority watershed reg arding the potential loadings of sediment and agricultural chemicals t o the Chesapeake Bay. To asses the status, nature and magnitude of the nonpoint source pollution in this basin, a watershed scale monitoring project was established in the Warner watershed located in Frederick County, Maryland. Watershed contains 346 ha land with Piedmont geology and diverse land use. Both paired watershed and upstream-downstream m onitoring design (USEPA's design guidelines) was established to measur e flow, sediment, and nutrient constituents at different stations thro ughout the watershed, Monitoring results obtained for the period of 19 93 until June 1995 was analyzed and is presented in this paper. Data i ndicated that, major cause of pollution was mismanagement of dairy man ure and overall mismanagement of dairy operation. Results showed that lack of fencing around stream channel in a watershed with dairy operat ion resulted in direct deposit of animal waste into the stream, thus c ausing elevated concentrations of nitrogen and phosphorous. Data also indicated that subsurface lateral flow plays a major role in nitrate l oadings to the stream channel in Piedmont physiographic region. This s tudy concludes that implementation of agricultural best management pra ctices (BMP's) related to land use and manure management is a must if water quality improvements are desired.