The Le Mars Coal Gas Site (Site), in Le Mars, Plymouth County, Iowa is a non-time critical removal action. The Site is a former manufactured gas plant (FMGP). The Environmental Protection Agency (EPA) is removing coal tar wastes containing benzene, toluene, ethylbenzene, xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAHs) from the Site area. The Action Memorandum for the Site was signed on September 26, 2003. The complete Administrative Record for the site can be found at the record repository located at the Le Mars Public Library.
The Site is located at 331 1st Street Northeast, Le Mars, Plymouth County, Iowa and is a 1.6-acre, right-triangle-shaped property, which is bordered on the northwest by the Union Pacific and Canadian National railroads, on the east by 4th Avenue Northeast and on the south by 1st Street Northeast. The area surrounding the Site is occupied by residential and commercial properties. The Site is in Section 9, Township 92 North, Range 45 West (U. S. Geological Survey [USGS] 1985). The geographic coordinates of the Site are latitude 42°47'40" north and longitude 96°09'37" west.
The Site work crews are spending the first few days setting up the Site to commence work activities. The tar well located below the concrete floor of the main city-owned building was prepared for excavation. A protective vapor barrier was installed to isolate the exclusion zone inside of the building. This was done as a protective measure to city street department personnel who continue to occupy a portion of the building. Late in the week, the location of the subsurface tar well was determined and a portion of the concrete floor was cut. Contaminated soil was then excavated and stockpiled. The brick walled tar well was clearly discernible and etched clean with heavy equipment.
Heavy equipment arrived throughout the week. Some of the equipment and personnel will be staged at the backfill source location at 14th Avenue and 12th Street SE. Other activities include a local professional engineer being awarded a sub-contract to assist in some survey work, soil compaction tests and structural assessments that will be performed during critical phases of the project.
Approximately 14 feet of contaminated soil requires excavation down to the water table. Some de-watering may be necessary. In addition, Gas Holders A and B, the tar well, the 12,000-gallon underground storage tank (UST) and one 2,000-gallon UST will also be removed.
The following listed steps are planned during the removal action to alleviate the human health risk posed by the Site:
a. Air monitoring of removal action construction
b. UST and product removal
c. Excavation of the on-site soil source area
d. Off-site thermal treatment of highly contaminated soil
e. Off-site disposal of non hazardous soil and debris in a Resource Conservation and Recovery Act(RCRA) Subtitle D landfill
f. Backfilling with off-site soil and site restoration
The Iowa Department of Natural Resources (IDNR) has a Site representative, Mr. Michael Leat, who has plans to visit the Site next week to partner with the EPA concerning compliance to state regulations and other technical assistance. Mr. Leat plans on either weekly or biweekly visits to provide that requested assistance.
Also, the Iowa Department of Public Health (IDPH)is sending representatives to the site on May 6-7, 2004 to receive a Site orientation and to assist in any health related questions that local citizens may have.
During the process of removing the various storage tanks that will be removed from the Site, coordination activities will occur with representatives from the IDNR-Underground Storage Tank Section.
Air monitoring stations have been set up in five different locations around the Site and surrounding area(s), including one in the break room of the main street department building. These locations were chosen after close scrutiny of prevailing wind patterns in the area in relationship to sensitive populations. The break room was chosen due to the city street department personnel continuing to occupy the building during segments of the removal action. The EPA regional toxicologist has been notified of the upcoming air monitoring and subsequent analytical results and is ready to assist in the interpretation of those results to assure the well being of the community.
In addition, real time air monitoring equipment is being utilized to assure that the hazardous substances being generated by the Site do not pose a human health risk to either the Site workers or the community.
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