Md. taking tentative steps toward clean construction rules: ‘How we buy things matters’s

Diesel-belching trucks are rumbling down Maryland 550 in Woodsboro at high rates of speed. It’s a pretty remote stretch of highway in Frederick County, surrounded mainly by cornfields. Many of the trucks are stopping at Laurel Sand and Gravel, a massive quarry and mining operation off the main road, where 600,000 tons of small stones are ground into powder every year. The powder, known as aggregate, is sold to the concrete industry as a thickening agent.