Did you know that properly managed grass can be an environmental asset?  Grass has significant cooling effects during the summer and traps much of the dust and dirt that is released each year into the atmosphere; absorbs carbon dioxide, ozone, sulfur dioxide, and other gases, while releasing oxygen; reduces water runoff and increases water infiltration compared to most other agriculture and plant systems; slows soil loss from erosion; and efficiently produces organic matter.  You can have a nice lawn and protect the Chesapeake Bay if sound nutrient management practices are followed.  This link will show you how.