Geothermal energy industry workers perform a wide range of duties, such as studying and testing sites for possible geothermal drilling, drilling geothermal wells, designing and building geothermal power plants, and operating and maintaining power plants. The Geothermal Energy Association estimates that 13,100 people are directly employed in the geothermal industry. Many other workers, however, from geologists and biologists to lawyers, surveyors, engineers, architects, site managers, office staff, and others provide support to the industy.