shale

Back in November, I described the background of a project on a sprawling estate in the hills near Hanover, Pa. - a spectacular setting for an enormous swimming pool, an island spa, a cascading waterfeature and big expanses of rockwork and stone decking. As was mentioned, our first task was to remove a brand-new system of retaining walls that had been built adjacent to the planned location for the swimming pool.  We did so because the wall's large footings reached into a space needed to support a  cascade that will appear to tumble into the pool.  To ensure