Geotechnical engineering deals with earth materials, including soil, rock, and groundwater. As most engineering projects are supported by ground, geotechnical engineering interfaces with most of the other civil sub-disciplines. For example, geotechnical engineers design foundations for structures, sub-grades for roadways, embankments for water storage and flood control, and containment systems for hazardous materials. In addition to participating in the design, construction, and operation of most civil engineering projects, geotechnical engineers also deal with various geologic hazards impacting our society, such as landslides, soil erosion, and earthquakes. Employers of graduates specializing in geotechnical engineering include consulting firms, design firms, contractors, public agencies, utilities, energy companies, and academia.