Urban runoff is a main source of pollution at beaches across the United States. But solutions, known collectively as "green infrastructure" can reduce the amount of polluted water flowing into our oceans, rivers and lakes. These techniques, which are available today, range from green roofs to permeable pavement and roadside plantings. It's a green wave of urban planning that's making for cleaner blue waters. To find if your beaches are clean, see  www.nrdc.org/beaches to explore NRDC's 20th Testing the Waters beachwater quality guide.