HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lawrence, G. B. Articles by Boylen, C. W. Search for Related Content PubMed PubMed Citation Articles by Lawrence, G. B. Articles by Boylen, C. W. Agricola Articles by Lawrence, G. B. Articles by Boylen, C. W. Related Collections Water Quality Watershed and Landscape Processes Surface Water Quality Surface Hydrology

TECHNICAL REPORTS

Surface Water Quality

Chronic and Episodic Acidification of Adirondack Streams from Acid Rain in 2003–2005

^a U.S. Geological Survey, 425 Jordan Road, Troy, NY 12180
^b New York State Dep. of Environmental Conservation, Box 296, Ray Brook, NY 12977
^c U.S. Geological Survey, 425 Jordan Road, Troy, NY 12180
^d New York State Dep. of Environmental Conservation, 8314 Fish Hatchery Road, Rome, NY 13440
^e Adirondack Lakes Survey Cooperation, Box 296, Ray Brook, NY 12977
^f P.O. Box 2641, Nantucket, MA 02584
^g Darrin Fresh Water Inst. and Dep.of Biology, Rensselaer Polytechnic Inst., 110 8th St.Troy, NY 12180

^* Corresponding author (glawrenc{at}usgs.gov).

Received for publication February 4, 2008. Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km² in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANC_G). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 µeq L^–1, whereas 29% were acidified based on an ANC_G value < 0 µeq L^–1. During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 µeq L^–1, whereas 5% were acidified based on ANC_G value < 0 µeq L^–1. The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed.

Abbreviations: ALSC, Adirondack Lakes Survey Corporation • ANC_G, acid-neutralizing capacity by Gran titration • BCS, base-cation surplus • DOC, dissolved organic carbon • USEPA, U.S. Environmental Protection Agency • USGS, U.S. Geological Survey