Placentia is a city in northern Orange County, California. The population was 46,488 at the 2000 census. The 2004 population estimate for Placentia is 49,949. This includes the community of Atwood, which is included in the city of Placentia, and is located in its southernmost quadrants. In recent years Placentia has encountered fiscal difficulties due to its limited tax base and the mismanagement of the OnTrac project, a failed railroad realignment project in its Old Town district. As of January 2007, the city was about $30 million in debt, forcing a reduction of city services.