A plant utilities engineer maintains and operates the mechanical equipment of a utilities plant. The duties you have in this career are dependent upon the plant at which you are working. Generally, a plant utilities engineer calibrates machines for proper output, test machines and troubleshoot issues with the equipment, and repairs any damage that may occur. Some plant utilities engineers perform general work, while others may specialize in an area, such as electrical work, plumbing, or air control systems. A plant engineer may also be required to train new hires on the maintenance of their specific machines.