In 2010 and 2011, the Burlington WWTF removed approximately 23,000 to 28,000 cubic yards of biosolids from the cells in their lagoon and buried them in trenches in the land next to their facility. Among other things, the Burlington WWTF did not apply for coverage under the EPA Region 8 biosolids general permit and did not sample the biosolids removed from its lagoon as required. On July 21, 2011, CDPHE contacted the Burlington WWTF and asked them if they had removed biosolids from their lagoon. In August 2011, the Burlington WWTF responded and stated that biosolids had not been removed from their lagoon in 2009 and 2010. The EPA sent Burlington a 308 information request on March 7, 2013. A second 308 information request letter was sent to Burlington and Earth Contractors on December 20, 2013.