Sand Creek is a 14.6-mile-long (23.5 km)[2] tributary that flows into the South Platte River near Commerce City, Colorado.

In November 2011, a local fisherman noticed an oily sheen on the surface of Sand Creek.

Testing found the water of Sand Creek to be contaminated with abnormally high levels of the aromatic hydrocarbon, benzene.

In December 2011, the Colorado Department of Health and Environment began to monitor benzene levels at the junction of Sand Creek and the South Platte River.

This is of concern because the South Platte River is drawn on for drinking water by nearby communities and is frequently used for recreational activities such as swimming and fishing.