AFTON — Archeologists are scanning the earth in southeast Minnesota to determine whether a proposed $4 million wastewater treatment project might threaten ancient American Indian burial sites.

The St. Paul Pioneer Press reports that two archeologists with Archaeo-Physics, LLC, conducted electrical resistance testing at Steamboat Park in Afton on Monday.

They used a device to test the soil’s electrical resistance in an effort to measure modern disturbances and the presence of archaeological features.

Each reading, roughly six samples per square meter, will be used to produce a map of the site.

The archeologists plan to conduct ground-penetrating radar to clarify the location of the mound.

Another company will conduct shovel testing in the park.