Mercury Deposition in the Biscuit Brook Watershed

This project provides weekly wet-only mercury deposition samples at the Mercury Deposition Network (MDN) station in the Biscuit Brook watershed at the Frost Valley YMCA. The station has been in operation since 2004 and is currently funded by New York State Energy Research and Development Authority (NYSERDA). This is the only MDN station located in the Catskill Mountains and one of only 3 stations in New York State. The Catskill Mountains supply 85% of New York City’s drinking water through a system of surface water reservoirs. All of these reservoirs have fish consumption advisories because of the high level of mercury (Hg) in fish in the reservoirs and atmospheric Hg deposition is the main source of Hg to the Catskill Mountains. Changes in Hg deposition must be documented to evaluate its effect on biota and to determine the extent to which changes in Hg emissions relate to changes in Hg deposition. The MDN began in 1996 and provides measurements of Hg deposition across the United States. The network is composed of 101 sites in 41 states in 2007 where Hg concentrations in precipitation are measured weekly. Site operators collect samples with standardized methods and ship those samples to Frontier Geosciences in Seattle, WA where they are analyzed by cold vapor atomic fluorescence. National Atmospheric Deposition Program (NADP) staff use these data to calculate annual Hg loads for each site, develop maps of Hg deposition across the nation, and identify trends in Hg deposition. The public can access the data through the NADP website. This project will produce a final report that will evaluate trends in Hg deposition at Biscuit Brook and patterns of Hg deposition in the region. The Biscuit Brook MDN station is co-located with an NADP National Trends Network (NTN) station that has been in operation since 1983. The NTN station measures major ion chemistry in precipitation with a particular focus on acid deposition. This chemical data will be used to help interpret Hg deposition patterns and trends.