The Lincoln Memorial Reflecting Pool has turned green after a $14.2 million renovation intended to make the water an American flag blue.Despite the deployment of ozone nanobubbler technology and chemical treatments, persistent algae growth continues to mar the historic site.Officials face criticism over the no-bid contract and the project's failure to meet aesthetic goals ahead of the 250th anniversary.Maintenance crews are working to vacuum the basin while the Department of the Interior attempts to defend the effectiveness of the new filtration system.