© Des Moines Register

Human remains that could be up to 7,000 years old have been discovered at a construction site in Des Moines.

They were found by a state archaeology team near a site where scientists think people harvested, cooked and ate clams thousands of years ago.

State archaeologist John Doershuk said that it's a unique site to Iowa and the Midwest.

The site's exact location is not being disclosed, lest looters ravage it.

But the discovery and archaeological dig is delaying a $37.8 million sewer project for at least six months. It's estimated the Wastewater Reclamation Authority will have to spend an estimated $1.5 million or more because of the delay.