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Fact Sheet

March 2012

EPA Announces a Public Availability Session and New Sampling for the Southwest Jefferson County Mining Superfund Site, Jefferson County, Missouri


On September 23, 2009, the U.S. Environmental Protection Agency (EPA) added the Southwest Jefferson County Mining Superfund Site to the National Priorities List (NPL). The NPL is a list of the nation’s hazardous waste sites with the highest priority for cleanup. These sites are eligible for extensive, long-term response action money authorized by Congress under the Superfund Program.

EPA has been working in the Southwest Jefferson County area since November 2007. This Fact Sheet serves as a community notification of EPA’s proposal to further evaluate the extent of contamination in the floodplain.


EPA will host a Public Availability Session to update the community about upcoming site activities. The session will be held from 6:30 p.m. to 8:30 p.m. on Thursday, April 5, 2012 at the following location:

Byrnes Mill City Hall
127 Osage Executive Circle
Byrnes Mill, Missouri


EPA has been conducting time critical removal activities (TCRA) at residential properties where soils exceeded 1,200 parts per million (ppm) and child-care facilities exceeding 400 ppm since November 2007. EPA has also been providing bottled water to residential properties that exceed the maximum contaminant level (MCL) of 15 parts per billion (ppb) in ground water wells, which is the standard for measuring drinking water. To date, EPA has conducted soil sampling at 2,004 residential properties, and ground water sampling at 654 private wells.

EPA representatives will be available to discuss past and upcoming site sampling activities at the availability session.

The current sampling effort allows EPA to continue screening properties in Jefferson County, but focuses along the Big River floodplain throughout the entire county. Evidence from previous studies indicates that the Big River is extensively contaminated within the 100-year floodplain. However, the studies have been river-wide and only provide estimations of contamination. To evaluate the extent of contamination in the floodplain area, EPA needs to perform property screening, which includes sampling for lead in residential soils and ground water in this area.

This screening focuses on residential properties within the 100-year floodplain. However, if you believe that you may have contaminated soils on a property outside of the floodplain, please contact EPA and a representative will schedule a screening of the property based on its scheduling priority.


The Missouri Department of Natural Resources has produced an inventory of sites where mining and smelting operations have occurred throughout Missouri in the past and present. Based on this inventory, EPA identified residential areas in Jefferson County where historical mining and smelting activities may have contributed to elevated levels of lead in soil and ground water. Using this database, EPA started collecting soil and water samples from residences in Jefferson County in 2006.


EPA has compiled the site Administrative Record file. The Administrative Record file is the official record for the site and contains site reports and descriptions of activities and other documents used to determine the appropriate actions to take at the site. The Administrative Record file is available for review during normal business hours at the following locations:

De Soto Public Library
712 South Main Street
De Soto, Missouri


EPA Region 7
Records Center
901 North 5th Street
Kansas City, Kansas


If you have questions about this fact sheet or want additional information about the site, please contact:

Debbie Kring
Community Involvement Coordinator
U.S. EPA Region 7
Office of Public Affairs
901 North 5th Street
Kansas City, KS  66101
Phone: 913-551-7725 or
Toll-free: 1-800-223-0425

Preston Law
Remedial Project Manager
U.S. EPA Region 7
Superfund Division
901 North 5th Street
Kansas City, KS  66101
Phone: 913-551-7097
Toll-free: 1-800-223-0425


EPA Region 7 is committed to providing reasonable accommodations to individuals with disabilities. If you require a reasonable accommodation to participate in one of the public meetings, please notify the EPA Reasonable Accommodations Coordinator, Jonathan Cooper at 1-800-223-0425 or by email at cooper.jonathan@epa.gov at least seven days prior to the meeting. Speech or hearing impaired individuals should email or call using the local relay service.

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