Document Type

Thesis - University Access Only

Award Date

1996

Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering

First Advisor

Dr. Selim

Abstract

This study was conducted to evaluate an alternative street sanding material called Realite Plus in Rapid City, South Dakota. The results indicated that Realite Plus would be the preferred sanding material in regards to environmental impacts to air quality. The following methods were used to analyze the performance of Realite Plus and the comparison of it against the existing street sanding material which is a river sand material mined from the Cheyenne River near Wasta with rock salt added: • X-ray defractional analysis; • A mass balance receptor model; • A Moh's hardness analysis; • Sieve analysis; • Surface water quality sampling; and • A salt loading comparison between the two sanding materials. X-ray defractional analysis and a mass balance receptor model were used to develop a source apportionment of PM10 between Realite Plus and other dust sources in the area. The results of the study indicated that Realite Plus contributed an average 10 percent of the filter load or an average of 4 micrograms per cubic meter on the filter on the days analyzed. The material hardness analysis indicated that Realite Plus contains a greater percentage of harder mineral compounds than the existing street sanding material. The harder mineral content of the Realite Plus would suggest that it would take a longer period of time for the minerals to be broken down into a fine dust as compared to the existing sanding material. The structural features of the materials were not studied. A sieve analysis comparison between the two sanding materials revealed that the existing street sanding material has a higher percentage of silt content. This means that the existing street sanding material will be crushed to a finer material by vehicular travel than the Realite Plus material because of the smaller size. As a result, it would be reintrained as dust at a faster rate. The low percentage silt content of the Realite Plus sanding material should also mean a lower total suspended particulate loading to Rapid Creek during storm water runoff. Water quality impacts during the Realite plus study were inconclusive due to low storm water runoff during sampling. Sufficient snowfall occurred for street sanding to occur, but there was not enough storm water runoff to adequately sample the impacts of chlorides from the sanding material. After the Realite plus application period, chloride sampling continued. Violations of the chloride standard occurred but the cause of the violation was not determined. A salt application rate comparison was performed between the two sanding materials. Fifty-nine pounds of salt per lane mile was applied with Realite Plus and seventy-eight pounds with the existing sanding material. Although the Realite Plus application rate is lower, this amount may be insignificant in terms of lower chloride rates to the stream.

Library of Congress Subject Headings

Roads -- Snow and ice control -- Environmental aspects -- South Dakota -- Rapid City
Dust control -- South Dakota -- Rapid City
Air -- Pollution -- South Dakota -- Rapid City

Format

application/pdf

Publisher

South Dakota State University

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Rights Statement

In Copyright