The Wisconsin regional Integrated Lake-Watershed Acidification Study (RILWAS): 1981--1983

Technical Report · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6543099

Knauer, D; Brouwer, S A ^[1]

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1. eds.

Round and East Eightmile lakes, small (14--15 ha) seepage lakes in thick (32--190 m) sandy outwash in northwestern Wisconsin, were studied from September 1981 through August 1983. Precipitation was 5 to 15 percent less than normal during the first year and 7 to 15 percent greater than normal during the second year. Snowfall accounted for 24 to 34 percent of the precipitation; however, all snowmelt infiltrated the highly permeable soils, and no spring depression in lake pH was observed. Chemistry of the precipitation was dominated by hydrogen ion, ammonium, and sulfate. Volume-weighted mean pH of bulk precipitation was 4.6 at both sites during the study, with hydrogen ion and ammonium contributing about 60 percent of the cations. Sulfate accounted for approximately 60 percent of the anions, annual sulfate fluxes ranged from 300 to 329 eq/ha. Dry deposition provided 7 to 36 percent of the total (wet plus dry) ion fluxes, except for magnesium (53 percent). Ion fluxes to the two lakes were similar. Volume-weighted mean lake pH's during the study were 6.4 at Round Lake and 6.9 at East Eightmile Lake. The two predominant forest canopies, mixed oak and jack pine, attenuated hydrogen ion; however, hydrogen-ion consumption by silicate hydrolysis exerted primary control on buffering capacity. Mineralogy of the very fine sand (100--50 ..mu..m) showed 46 to 55 percent weatherable minerals--orthoclase feldspar, plagioclase feldspar, mica, hornblende, olivine, and augite. Except for orthoclase, these minerals were depleted in the upper soil horizons, and all were undersaturated in soil solutions and ground water. The lakes contributed to the buffering capacity by producing alkalinity via surface reduction, primarily in epilimnetic lake sediment. 6 refs., 92 figs., 67 tabs.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (USA); Wisconsin Dept. of Natural Resources, Madison (USA)
• OSTI ID: 6543099
• Report Number(s): EPRI-EA-6214; ON: TI89006849
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACID NEUTRALIZING CAPACITY
ACID RAIN
ACID SULFATES
ACIDIFICATION
AIR POLLUTION
ATMOSPHERIC PRECIPITATIONS
CHEMICAL REACTIONS
CHEMISTRY
ENVIRONMENTAL IMPACTS
FEDERAL REGION V
LAKES
MINERALOGY
NORTH AMERICA
OXYGEN COMPOUNDS
PH VALUE
POLLUTION
RAIN
REDUCTION
SAND
SULFATES
SULFUR COMPOUNDS
SURFACE WATERS
USA
WATER CHEMISTRY
WATERSHEDS
WISCONSIN