The Oronogo-Duenweg Mining Belt covers all of Jasper County and a small part of northwest Newton County, Missouri. Lead and zinc mining and smelting from the mid-1800s through the 1900s left behind heavy contamination in soil, groundwater, and surface water. The EPA added the site to the National Priorities List in 1990, and remedial action began in 1996. Construction is not yet complete, and the site remains on the list.
The main contaminants are lead, cadmium, zinc, and copper. Lead is the top health concern. It can harm brain development in children under seven and cause learning, behavior, and growth problems. Even low blood lead levels carry risk. Pregnant women and nursing mothers can pass lead to babies. Adults face cardiovascular, kidney, and reproductive effects. A 1991 health study found about 14 percent of local children under seven had elevated blood lead levels. Follow-up studies in 2000 and 2002 showed those levels dropped after cleanup efforts began. Despite that progress, human exposure is not under control and groundwater migration is not stabilized.
The EPA has divided the site into five operable units covering mine and mill waste, residential yards, mine waste yard soils, groundwater, and the Spring River Basin. Over the past three decades, cleanup work has removed nearly 25 million cubic yards of mining waste, remediated more than 3,000 residential yards, supplied over 500 homes with clean drinking water, and cleaned about 14 miles of stream tributaries. Active work continues across all operable units. Time-critical removal actions are addressing newly identified contamination at about 30 residences, with that work estimated to run through early 2027. A new remedial action level for residential yards is expected in mid-to-late 2026. Thirteen residences currently receive bottled water or point-of-use filtration for groundwater protection. The most recent five-year review was completed in August 2022, with the next one estimated between August and October 2027.
Some parts of the site have already been remediated and returned to productive use, including a solar farm, a scrap metal recycling facility, a highway bypass, and residential development. As of December 2024, the site supports 356 on-site businesses employing nearly 3,800 people.
Residents can get involved by joining the site contact list, requesting EPA testing of their yard or private well, attending EPA events, and commenting during public comment periods. The Technical Assistance Services for Communities program offers free independent help to understand the science and regulations behind cleanup decisions. To learn more or get connected, contact Community Involvement Coordinator Tanya Young at young.tanya@epa.gov or (816) 799-3251.
