When operators drill oil and gas wells, they typically remove topsoil from the well site and lay a well pad, where the drilling rig is located. Other equipment on site can include generators and fuel tanks. In addition, reserve pits are often constructed to store or dispose of water, mud, and other materials that are generated during drilling operations, and roads and access ways are often built to move equipment to and from the wells. Generally, these activities can degrade the environment in three ways: • Air quality. Newly graded roads can produce dust, impairing air quality and visibility.