The effects of acidic deposition on streams in the Appalachian Mountain and Piedmont region of the mid-Atlantic United States

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · Water Resources Research; (United States)

DOI:https://doi.org/10.1029/93WR01072· OSTI ID:5485102

Herlihy, A T; Kaufman, P R ^[1]; Church, M R; Wigington, Jr, P J ^[2]; Webb, J R ^[3]; Sale, M J ^[4]

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1. Oregon State Univ., Corvallis, OR (United States)
2. EPA, Corvallis, OR (United States)
3. Univ. of Virginia, Charlottesville, VA (United States)
4. ORNL, Oak Ridge, TN (United States)

Streams in the Appalachian Mountain area of the mid-Atlantic receive some of the largest acidic deposition loadings of any region of the US. A synthesis of the survey data from the mid-Appalachians yields a consistent picture of the acid base status of streams. Acidic streams, and streams with very low acid neutralizing capacity (ANC), are almost all located in small (<20 km[sup 2]), upland, forested catchments in areas of base-poor bedrock. In the subpopulation in the mid-Appalachian area, data from various local surveys show that 6-27% of the streams are acidic, and about 25-50% have ANC less than 50 [mu]eq L[sup [minus]1]. After excluding streams with acid mine drainage, National Stream Survey estimates for the whole region show that there are 2330 km of acidic streams and 7500 km of streams with ANC less than 50 [mu]eq L[sup [minus]1]. Many of the streams with base flow ANC less than 50 [mu]eq L[sup [minus]1] become acidic during storm or snowmelt episodes. Sulfate from atmospheric deposition is the dominant source of strong acid anions in acid mid-Appalachian streams. Their low pH (median, 4.9) and high levels of inorganic monomeric aluminum (median, 129 [mu]g L[sup [minus]1]) leached through soils by acidic deposition are causing damage to aquatic biota. Quantification of the extent of biological effects, however, is not possible with available data. Localized studies have shown that stream water ANC is closely related to bedrock mineralogy. Attempts to quantify this relationship across the mid-Appalachians, however, were frustrated by the lack of adequate scale geologic mapping throughout the region. Sulfate 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. Sulfur retention is likely to decrease in the future, resulting in further losses of stream ANC. 70 refs., 5 figs., 4 tabs.

• OSTI ID: 5485102
• Journal Information: Water Resources Research; (United States), Journal Name: Water Resources Research; (United States) Vol. 29:8; ISSN WRERAQ; ISSN 0043-1397
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (1990-)
540220 -- Environment
Terrestrial-- Chemicals Monitoring &amp; Transport-- (1990-)
540320 -- Environment
Aquatic-- Chemicals Monitoring &amp; Transport-- (1990-)
560300 -- Chemicals Metabolism &amp; Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID NEUTRALIZING CAPACITY
ACID RAIN
APPALACHIAN MOUNTAINS
AQUATIC ECOSYSTEMS
ATMOSPHERIC PRECIPITATIONS
CHEMISTRY
DEPOSITION
ECOSYSTEMS
ENVIRONMENTAL EFFECTS
MINERALOGY
MOUNTAINS
OXYGEN COMPOUNDS
RAIN
STREAMS
SULFATES
SULFUR COMPOUNDS
SURFACE WATERS
WATER CHEMISTRY