Specifications include, but are not limited to: Construction services including sewer maintenance and repair, roads and highways and excavation and backfill services, levee and dam construction and digging, ditching, road grading, rock stabilization, equipment rental or lease, and energy conservation; Concrete, cement, plaster, lime, mortars, metal,; Roads and landscape material including asphalts and road and railroad construction materials and soil stabilizers and artificial turf and construction aggregates including rock, gravel, and sand; Public safety and control equipment and supplies and accessories including traffic control (driver feedback signs and traffic signals) and water safety and rescue equipment and accessories and snow and ice melter and snow removal equipment and road salt