From 2004 through 2006, the U.S. Geological Survey monitored the chemical composition of biosolids, crops, dust, and ground water related to biosolids applications near Deer Trail, Colorado, in cooperation with the Metro Wastewater Reclamation District. This monitoring effort was a continuation of the monitoring program begun in 1999 in cooperation with the Metro Wastewater Reclamation District and the North Kiowa Bijou Groundwater Management District. The monitoring program addresses concerns from the public about the chemical effects from applications of biosolids to farmland in the Deer Trail, Colorado, area. This report presents chemical data from 2004 through 2006 for biosolids, crops, and alluvial and bedrock ground water. The chemical data include the constituents of highest concern to the public (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, zinc, and plutonium) in addition to many other constituents. The ground-water section also includes climate and water-level data.