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.

EPA Contract No. Contract Number: 68-02-1874, Program Element No. 1BB610. "May 1978." Includes bibliographical references (pages 28-31).