KWRRI Research Reports

Abstract

Monthly water samples were taken and analyzed to determine the water quality of the Salt River in Anderson and Spencer counties Kentucky prior to the river's impoundment. Sediments from the area watershed were analyzed to total acid digestion, barium chloride extraction, and aqueous extraction methods. Rainwater and runoff water were collected and analyzed for major cations and anions from two sites in the watershed.

The Salt River at Taylorsville is characterized by hard water with high levels of calcium (33.5-74.8 mg/1), bicarbonate (136-236 mg/l), specific conductance (200-535 μmhos/cm), and sulfate (16.5-71.5 mg/l). Nitrates (0.6-5.7 mg/l), phosphates (0.2-2.4 mg/l), sodium (3.2-20.3 mg/l), and potassium (1.3-5.6 mg/l), are moderate. Iron, manganese, copper, and nitrites are less than 0.5 mg/1. Suspended solids in the river (4.0-l ,684.0 mg/l) are highly variable and directly related to fluctuations in discharge. Sediments from the Salt River Basin are high in potassium (12.4-213.3 mg/g) and iron (23.4-135.1 mg/g), with moderate levels of calcium (0.8-45.7 mg/g), sodium (4.5-10.5 mg/g), magnesium (3.2-6.3 mg/g), and phosphate (1.3-15.3 mg/g). Approximately 10% of the total ionic composition of these sediments is exchangeable and may be extracted with barium chloride. Calcium (309-3,292 μg/g), was the most readily adsorbed cation, with lower levels of potassium (17.6-490.5 μg/g), sodium (12.9-458.1 μg/g), and magnesium (89.4-266.2 μg/g). In the aqueous extractions, calcium (18-486 μg/g), potassium (16.6-69.5 μg/g), sodium (11.1-30.8 μg/g), and magnesium (6.6-68.7 μg/g) comprised about 10% of the exchangeable fraction.

Ranges of rainwater ions from the Salt River Basin were: sulfate (8.3-27.8 mg/l), calcium (0.3-10.7 mg/l), potassium (0.4-15.4 mg/l), sodium (0.0-0.7 mg/l), and magnesium (0.1-2.8 mg/l). Ionic composition and sediment yield of runoff water was variable and was related to magnitude of rainfall and runoff sampler placement. Ranges for selected constituents at the two samplers near Taylorsville were: suspended solids (44.0-8,808.0 mg/l), potassium (1.1-84.0 mg/l), magnesium (l.5-7.1 mg/l), calcium (9.5-33.0 mg/l), and sodium (0.6-3.0 mg/l).

Calcium and bicarbonate in the Salt River originate from weathering of calcite, although mole ratios of these two ions greater than 1:2 suggest that weathering of magnesium carbonates also contributes bicarbonate to the water. Carbonate equilibrium calculations using field pH and ionic strength suggest calcium is at saturation in the Salt River. High levels of sulfate in rainwater indicate some of this anion may be introduced into the area watershed by atmospheric precipitation.

Publication Date

10-1977

Report Number

106

Digital Object Identifier (DOI)

https://doi.org/10.13023/kwrri.rr.106

Funding Information

The work on which this report is based was supported in part by funds provided by the Office of Water Research and Technology, United States Department of the Interior, as authorized under the Water Resources Research Act of 1964.

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