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SOURCE ASSESSMENT: CRUSHED STONE
Citation:
Blackwood, T., P. Chalekode, AND R. Wachter. SOURCE ASSESSMENT: CRUSHED STONE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-78/004L.
Description:
This report describes a study of air emissions from crushed stone production. The potential environmental effect of the source is evaluated. Crushed stone production in 1972 was 1.07 x 10 to the 8th power metric tons (1.18 x 10 to the 8th power tons), 68% of which was traprock. Contingency forecasts of increased crushed stone demand in the year 2000 range from 300% to 490% of 1968 levels. Atmospheric emissions of respirable particulates (< 7 micrometers) occur in the two areas of operation: mining from the open quarry, and processing at the crushing and screening plant. The emission factor for respirable particulates from the entire facility is 3.25 g/metric ton (0.007 lb/ton) + or - 2.54 g/metric ton (0.005 lb/ton) at the 95% confidence level. Free silica comprises 1.6% of these particulates by weight. The primary crusher and quarrying unit operations account for 73.5% of the respirable particulates. The emission factor for total particulates is 28.4 g/metric ton (0.57 lb/ton) + or - 24.5 g/metric ton (0.049 lb/ton)at the 95% confidence limit. In order to evaluate the potential environmental effect of crushed stone plants, a severity factor was defined as the ratio of the maximum ground level concentration of an emission to the ambient air quality standard for criteria pollutants and to a modified threshold limit value for other pollutants. No emerging technology of specific importance to air pollution control in the crushed stone industry was found in this study.