Proceedings Abstracts: American Water Resources Association's Symposium on the National Water-Quality Assessment (NAWQA) Program--November 7-9, 1994, Chicago, Illinois

Approximately 418,000 pounds of triazine herbicides are applied annually to control weeds in crops grown in the Albemarle-Pamilico Sound drainage basin, located in North Carolina and Virginia. An enzyme-linked immunosorbent assay was used to detect concentrations of total triazine herbicides in streams draining into Albemarle-Pamlico Sound. Water samples were collected in May and June during the application of triazine herbicides and in early September during low streamflows at approximately 40 sites on streams in the Coastal Plain and Piedmont Physiographic Provinces. Triazine concentrations exceeded 0.2 ?g/L (micrograms per liter) in 67 percent of the water samples collected In June, and 13 percent of the water samples exceeded 0.2 ?g/L in September during low streamflows. The enzyme-linked immunosorbent assay for total triazine herbicides provides a low-cost and rapid analytical method for screening water samples prior to sending them to a laboratory and for semiquantitatively assessing seasonal concentrations of triazine herbicides in streams throughout a large region.