Factors contributing to differences in acid-neutralizing capacity among lakes in the western United States

Technical Report · Tue Sep 01 04:00:00 EDT 1987

OSTI ID:5565285

Eilers, J M; Landers, D H; Brakke, D F; Linthurst, R A

A survey of lakes in mountainous areas of the Western United States was conducted in fall 1985 by the US Environmental Protection Agency (EPA) in cooperation with the USDA - Forest Service. Of the 719 probability sample lakes, only one was acidic; 99% of the lakes were estimated to have pH>6.0. However, acid-neutralizing capacity (ANC) was < or = 50 microeq L-1 for an estimated 16.8% of the lakes in the study area. Of the five subregions in the West, California had the highest proportion of lakes with ANC < or = 50 microeq L-1 (36.7%) and the Southern Rocky Mountains had the lowest proportion (4.6%). The lakes in the West were post-stratified into geomorphic units corresponding to major mountain ranges. Watershed factors, including watershed area, lake area, watershed area: lake area ratio, lake depth, watershed slope, percent exposed bedrock, elevation, and hydraulic residence time, were examined within six geomorphic units in order to evaluate their relationship to lake ANC. These watershed variables had poor predictive capability with respect to ANC. The results suggest that higher-resolution information for factors such as mineralogy and hydrology are required for prediction of lake ANC within a given geomorphic unit.

• Research Organization: Environmental Protection Agency, Corvallis, OR (USA). Environmental Research Lab.
• OSTI ID: 5565285
• Report Number(s): PB-88-112156/XAB; EPA-600/D-87/309
• Country of Publication: United States
• Language: English

Related Subjects

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54 ENVIRONMENTAL SCIENCES
ACID NEUTRALIZING CAPACITY
ACID RAIN
ACIDIFICATION
ATMOSPHERIC PRECIPITATIONS
CHEMISTRY
GEOLOGY
GEOMORPHOLOGY
LAKES
NAPAP
RAIN
SURFACE WATERS
WATER CHEMISTRY
WATERSHEDS