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EPA in Missouri

Washington County Lead District - Potosi, Old Mines, and Richwoods Superfund Sites, Washington County, Missouri - Fact Sheet, September 2016

EPA Conducting Remedial Investigation/Feasibility Study and Remedial Action: Operable Units 1, 2, 3 and 4


Washington County Superfund Site site map 2FIGURE 1On March 19, 2008, the U.S. Environmental Protection Agency (EPA) added the Washington County Lead District (WCLD) - Potosi, Old Mines, and Richwoods Superfund Sites 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, as authorized by Congress under the Superfund program.

The WCLD - Potosi, Old Mines, and Richwoods sites are actually three of four Superfund sites located in Washington County, Mo. (see Figure 1 at right. The fourth site, Furnace Creek, is being addressed as a separate investigation and is not included as part of this fact sheet.

The Remedial Action for residential yard cleanups (Operable Unit 1 or OU1) began in 2016 for all three sites addressed here. Residential yard cleanups are set to continue through the end of 2018. EPA is currently conducting the Remedial Investigation/Feasibility Study (RI/FS) for groundwater (OU2), mine waste (OU3), and surface water/sediment (OU4) at these three sites.


Washington County is part of Missouri’s Old Lead Belt, where lead and barite mining, milling and smelting occurred over the span of three centuries.

The Potosi, Old Mines, and Richwoods Superfund sites encompass approximately 180 square miles in northeast Washington County. Historical mining operations at these sites were similar, with remnants of past mining operations such as strip mines, mineshafts, mine dumps, tailings areas, tailings ponds, and associated dams present throughout.

These mining activities have contributed to elevated levels of lead in soil, groundwater, surface water and sediment. Some residents have also unknowingly purchased lead-contaminated gravel for use in landscaping and construction of driveways, parking areas, and playgrounds.


EPA and Missouri state agencies have been addressing lead-contaminated soils in Washington County for more than a decade, providing information, soil assessments, and removal actions.

For the past several years, EPA has conducted residential yard cleanups (time-critical removal actions) at properties with the highest levels of lead contamination – prioritizing properties with children present – due to a potentially greater health risk. Reports for these actions can be found at the site repositories listed at the end of this document.

During the initial cleanup (removal actions), EPA collected soil samples from more than 3,408 residential properties within site boundaries. More than 1,481 of those properties had lead contamination greater than the levels of concern. EPA cleaned up residential soil at more than 355 properties in the three WCLD sites.

During the removal actions, EPA collected water samples from more than 1,866 drinking water wells within site boundaries. Of the drinking water wells tested, 315 were confirmed to have lead levels in the groundwater that exceeded the agency’s health-based level of concern. EPA has continued to address contamination in private drinking water supply wells by providing filtration or alternate sources of drinking water to owners of properties where lead or cadmium has been identified above health-based levels of concern. Removal actions are scheduled to be complete in September 2016.

For the Potosi, Old Mines, and Richwoods sites, the RI/FS reports for residential yards (OU1) were issued in February and July 2010, respectively. After completion of the RI/FSs, EPA submitted proposed plans to the public for review, presented agency findings in a public forum, provided an opportunity for the public to submit comments, and compiled responses to comments into the three Records of Decision (RODs). The RODs for residential yards for all three sites were final on Sept. 29, 2011. The RODs identified the cleanup objectives that were used to evaluate how properties would be addressed. The selected remedy is soil excavation and disposal, health education, and institutional controls.

Remedial Action for Operable Unit 1

The Remedial Action phase is the actual construction or implementation of a Superfund site cleanup that follows the remedial design. The cleanup consists of excavating and removing contaminated soil and gravel from affected properties, and replacing the excavated material with clean fill and vegetative cover, including sod and hydro-seed. The Remedial Action is scheduled to begin in September 2016.


EPA Region 7 staff and contractors have continued to collect soil and groundwater samples from residential properties located within the Potosi, Old Mines, and Richwoods sites. If your property has not been sampled, and you would like to have your soil and groundwater analyzed, please contact EPA. Or, if you have questions about prior testing and/or need information about how to change private drinking water well filters, please contact EPA (see Additional Information section below).


Lead is a toxic metal that is harmful if inhaled or swallowed. Children are more sensitive to lead than adults and can develop lifelong learning disabilities and behavioral problems from lead exposure. Children can get lead into their bodies by putting their hands or toys in their mouths after touching contaminated soil. Pregnant women and nursing mothers should also avoid exposure to lead. Lead poisoning can cause negative health effects in infants and young children, including, but not limited to:

  • Slowed physical growth
  • Hearing problems
  • Nervous system damage
  • Learning disabilities
  • Hyperactivity and other behavioral problems
  • Decreased intelligence

Lead exposure and its effects can be reduced by the following actions:

  • Wash hands after playing outside and before meals.
  • Clean floors, window frames, window sills, and other surfaces weekly. Use a mop or sponge with warm water and general all-purpose cleaner.
  • Thoroughly rinse sponges and mop heads often during cleaning of dirty or dusty areas, and again afterward.
  • Keep play areas clean. Wash bottles, pacifiers, toys and stuffed animals regularly.
  • Clean or remove shoes before entering your home to avoid tracking in lead from soil.
  • Make sure children avoid fatty (or high fat) foods and eat nutritious meals high in iron and calcium. Children with good diets absorb less lead.

Children 6 years old and younger are most at risk from the hazards of lead poisoning. It is important that children in this age range be tested every year, because lead-poisoned children typically do not look or act sick. The only way to know if your child has an elevated blood-lead level is to have his or her blood tested. EPA encourages parents to have their children tested for lead exposure. You can call your local health department or physician to get your child tested. For additional information about lead, please see the EPA contacts under the Additional Information section below. You may also contact the Agency for Toxic Substances & Disease Registry (ATSDR). For more information, visit an online fact sheet about lead.


EPA is committed to providing opportunities for communication between citizens and the agency. Active public involvement is crucial to the success of any public project. EPA will continue to engage the public in various activities designed to inform and involve community members throughout the decision-making process. Prior to any future site cleanup decisions, EPA will continue to present findings of the investigation to the community and solicit public comments about the next steps.


The Administrative Record file serves as the official record for the sites and contains all site documents. It is available for review during normal business hours at:

Washington County Public Library
235 East High Street
Potosi, MO 64664
EPA Region 7 Records Center
11201 Renner Boulevard
Lenexa, KS 66219


To view EPA site profile pages for the WCLD sites, visit the Missouri Cleanups page at, click on “Search for Superfund Site Where You live,” and search for Washington County.


If you have questions about this fact sheet or need additional information, please contact:

Elizabeth Kramer
Community Engagement Specialist
Enforcement Coordination Office
EPA Region 7
11201 Renner Boulevard
Lenexa, KS 66219
Phone: 913-551-7186
Toll-free: 1-800-223-0425
Steve Kemp
Remedial Project Manager
Superfund Division
EPA Region 7
11201 Renner Boulevard
Lenexa, KS 66219
Phone: 913-551-7194
Toll-free: 1-800-223-0425