In January 2001, a single pipe was installed by the French-Cameroonian team on Lake Nyos, and two more pipes were installed in 2011 with funding support from the United Nations Development Programme. A pipe was installed at Lake Monoun in 2003 and two more were added in 2006. These three pipes are thought to be sufficient to prevent an increase in CO2 levels, removing approximately the same amount of gas that naturally enters at the lake bed. In January 2003, an 18-month project was approved to fully degas Lake Monoun, and the lake has since been rendered safe.