Robin Eisner | Jan 19, 1992 | 8 min read
In Blaenavon, South Wales, on a warm September morning last year, a psychotherapist from Colorado and a computer repairman from northeastern England, both on vacation, sat on a grassy hill slope and measured how water flowed through the layer of topsoil covering the hill. Their readings will help determine the quality of this land, which is currently used for sheep grazing. The next day, on a nearby tract of land, a California elementary school teacher and a New Hampshire accountant, both als