an area of . Of this area, 46.6% is used for agricultural purposes, while 18.2% is forested. Of the rest of the land, 33.3% is settled (buildings or roads) and the remainder (1.9%) is non-productive (rivers, glaciers or mountains). , 18.19% of the total land area was forested. Of the agricultural land, 44.69% is used for farming or pastures, while 1.92% is used for orchards or vine crops. Of the settled areas, 14.55% is covered with buildings, 5.7% is industrial, 1.62% is classed as special developments, 1.97% is parks or greenbelts and 9.49% is transportation infrastructure. Of the unproductive areas, 0.25% is unproductive standing water (ponds or lakes), and the other 1.62% is unproductive flowing water (rivers). The municipality is part of the metropolitan area of Lucerne. It is located at the confluence of the Kleine Emme into the Reuss. The naturalization law The municipality of Emmen hit international headlines in 2001 when it announced new naturalization law. While there are some fixed requirements for obtaining Swiss citizenship by naturalization set at the federal level, such as the requirement to live and work for 12 years and speak the local language, Swiss cantons and communities are free to introduce more stringent requirements. Until 2001, naturalization was run by a popularly elected committee. But Emmen decided to have the citizens themselves run the nationalization process, requiring that potential citizens pass a series of tests and public interviews and subjecting citizenship applications to the public vote. This process prevented many Yugoslavs-Swiss people, the largest ethnic group among citizenship candidates (Emmen has one of the largest of ex-Yugoslav community in Switzerland), from obtaining citizenship. Human rights campaigners said that the public interviews and voting were degrading. In July 2003, the practice was ruled discriminatory and unconstitutional by the Supreme Court. Emmen has since returned to the previous system of naturalization committees. Population by nationality Emmen has a population () of 27,205, of which 30.7% are foreign nationals. Over the last 10 years the population has grown at a rate of 2.7%. Most of the population () speaks German (81.6%), with Serbo-Croatian being second most common (5.0%) and Italian being third (3.9%). Industry The main industries are steel production, milk processing and arms manufacture. The biggest employers in these areas are Schmolz + Bickenbach, Emmi AG and Ruag respectively. There is the so-called ´golden triangle´ of the sewage plant, the air force base and