EPA Announces Explanation of Significant Differences and Public Availability Meeting, Annapolis Lead Mine Superfund Site, OU-1, Annapolis, Iron County, Missouri
The U.S. Environmental Protection Agency, (EPA) Region 7, has issued an Explanation of Significant Differences (ESD) or New Alternative, for the Annapolis Lead Mine Superfund Site, Operable Unit 1. The selected cleanup plan was described in a Record of Decision (ROD) for the Annapolis Lead Mine Site in September 2005. The purpose of the ESD is to provide an explanation of significant differences between the Record of Decision for the Site, and the Remedial Action for the Site. The ESD describes changes to the remedy, as implemented.
EXPLANATION OF SIGNIFICANT DIFFERENCES (ESD)
The use of phosphate was focused on the south side of Highway 49 and within the Sutton Branch Creek floodplain. EPA has conducted pilot testing of phosphate in other miningareas to determine if it would reduce bioavailability of lead in soils. (Bioavailability of lead means the percent of ingested lead absorbed by the body.) Pilot testing of surface application of phosphate to residential soils did not result in significant reductions in bioavailability. In addition, dense stands of vegetation have already been established in the floodplain areas of the site. Due to the lack of significant reductions in bioavailability and the existing density of vegetation, the phosphate application portion of the remedy is not being implemented. The significant difference under this ESD is the omission of phosphate application as part of the remedy. Phosphate application will not be required as part of the remedy.
PUBLIC AVAILABILITY MEETING
EPA will host a public availability meeting to provide information and answer questions on the Explanation of Significant Differences for the Annapolis Lead Mine Superfund Site, Operable Unit 1. The availability meeting will be held:
Tuesday, September 16, 2008
7:00 p.m. - 8:30 p.m.
South Iron County Community Center
Intersection of Second and Center Streets
Institutional controls will be established at the site. Institutional controls are a legal method to attempt to control or prohibit the drilling, construction, and any other penetration of the soil surface within the boundaries of the area of contamination. The objective of the major institutional controls is to prevent human exposure to soil impacted by lead, and to prevent surface disturbance to the floodplain vegetation which may have a negative impact on the Sutton Branch Creek floodplain.
The Annapolis Lead Mine Site is located approximately one mile east-northeast of Annapolis, Missouri. It is adjacent to, and within the Sutton Branch Creek Flood Plain. The site also includes the mine works. The mine lies on the east side of county road 138. Runoff from the mine area enters Sutton Branch Creek. The area affected by the mining wastes is rural and residential. The dominant feature of the site is a lead chat or tailings residue pile that covers approximately 10 acres in the northern portion of the site. The pile was composed of material that was highly erodible, resulting in an outwash area that fanned westward to Sutton Branch Creek. The creek flows north to south on the west side of Iron County Road 138.
TIME-CRITICAL REMOVAL ACTION
In September 2003, EPA conducted a time-critical removal action for the Site. The goal of the removal action was to identify, consolidate, and stabilize the lead-contaminated waste mine tailings on-site. The time-critical removal action minimized both the potential for human exposure to lead through contact with the soil and the potential for movement of the tailings by surface runoff, wind, or human activity.
The tailings and contaminated soil were formed into a mound in the middle of the ravine where the pile was originally located. All areas in the tailings pile vicinity that had lead surface concentrations greater than 1,000 parts per million (ppm) were defined and excavated. Excavations proceeded until a lead level below 400 ppm in the soil was achieved. All excavated areas were backfilled with clean material and excavated soil was combined into the on-site tailings pile. The tailings pile was graded and compacted, and an engineered protective cover was installed over the tailings. The protective cover consists of uncontaminated clay and topsoil, allowing for the establishment of vegetative cover.
RECORD OF DECISION
EPA issued a Record of Decision (ROD) in 2005 with support from the Missouri Department of Natural Resources (MDNR). The ROD explained cleanup plans for the Annapolis Lead Mine Site that addressed the floodplain soils, mining wastes, sediments in Sutton Branch Creek, stabilization of Sutton Branch Creek, implementation of institutional controls, and annual monitoring to determine remedial effectiveness. EPA implemented the cleanup plans from the ROD in July 2007. EPAand MDNR have conducted regular water quality monitoring and have managed post-removal maintenance of the protective cover consistent with all federal and state laws.
EPA encourages the community to review the Administrative Record, which includes the ESD and supporting documents. The Administrative Record is available during normal business hours at the following locations:
204 School Street
EPA Region 7
901 N. Fifth Street
Kansas City, Kansas
If you have questions or need additional information, please contact: