You are here:
EFFECTS OF ACIDIC DEPOSITION ON STREAMS IN THE APPALACHIAN MOUNTAINS AND PIEDMONT REGION OF THE MID-ATLANTIC UNITED STATES
Citation:
Herlihy, A., P.R. Kaufmann, M. Church, P. Wigington, R. Webb, AND M. Sale. EFFECTS OF ACIDIC DEPOSITION ON STREAMS IN THE APPALACHIAN MOUNTAINS AND PIEDMONT REGION OF THE MID-ATLANTIC UNITED STATES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-93/475 (NTIS PB94117561).
Description:
Streams in the Appalachian Mountain area of the Mid-Atlantic receive some of the largest acidic deposition loadings of any region of the United States. ompilation of survey data from the Mid-Appalachians yields a consistent picture of the acid-base status of streams. cidic streams, and streams with vary low acid neutralizing capacity (ANC), are almost all located in small (<20 km2), upland, forested catchments in areas of base-poor bedrock. n the subpopulation of upland forested systems, which comprises about half the total stream population in the Mid-Appalachian area, data from various local surveys show the 6-27% of the streams are acidic, and about 25-50% have ANC < 5O ueq/L-1. fter excluding streams with acid mine drainage, National Stream Survey estimates for the whole region show that there are 2,330 km of acidic streams and 7,500 km of streams with ANC <50 ueq/L-1. any of the streams with base flow ANC less than 50 ueq/L-1 become acidic during storm or snowmelt episodes. n these acidic streams, the low pH (median = 4.9) and high levels of inorganic monomeric aluminum (median - 129 ug/L) leached through soils by acidic deposition are causing damage to aquatic biota. uantification of the extent of biological effects, is not possible with available data. ocalized studies have shown that streamwater ANC is closely related to bedrock mineralogy. ttempts to quantify this relationship across the Mid-Appalachians were frustrated by the lack of adequate scale geologic mapping throughout the region. ulfate mass balance analyses indicate that soils and surface waters of the region have not yet realized the full effects of elevated sulfur deposition due to watershed sulfate retention. ulfur retention is likely to decrease in the future, resulting in further losses of stream ANC.
URLs/Downloads:
EFFECTS OF ACIDIC DEPOSITION ON STREAMS IN THE APPALACHIAN MOUNTAINS AND PIEDMONT REGION OF THE MID-ATLANTIC UNITED STATES