Weldon Spring is former munitions factory and uranium facility outside of St. Louis. Remediation of the site concluded in 2001 with the completion of a 41-acre, onsite disposal cell. The cell provides long-term isolation for 1.48 million cubic yards of low-level radioactive waste and chemical waste.

The Sawyer Seminar visited the Weldon Spring interpretive center with guest lecturer Toby Jones, attended a class on the history of Weldon Spring, and toured the disposal cell.