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 U.S. Environmental Protection Agency (EPA) is removing coal tar waste 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.
On Wednesday, May 12, 2004, an Action Memorandum Amendment was signed allowing all of the contaminated soil to be sent off-site to a thermal treatment facility.
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.
There have been over 5,000 tons of coal-tar-contaminated soil sent to the thermal desorption facility in Cedar Rapids, Iowa. Due to the Memorial Day holiday, work ended on Thursday morning, May 27, 2004. Work is planned to resume after the holiday on Tuesday, June 1, 2004.
Work hours at the Site have been extended, starting at 6:00 a.m. each day, while the "load out" of contaminated soil continues. Most ending times have generally been around 6:00 p.m. There have been occasions when there have been limited work activities on Sundays during the project. Considerations have been given toward the community when making those decisions, including disruptions to local church traffic.
The structure of the work crews is comprised of an excavation crew and a backfill crew. A portion of the backfill crew is located at a separate location in Le Mars, Iowa, approximately 2 miles away. The backfill is being provided to the EPA by the city of Le Mars at no cost. A "sheep foot" compactor is being utilized to compact the replaced clean fill to meet state compaction regulations. A local engineering firm is being used in a sub-contracting role to perform compaction tests as well as other services including assuring proper grade elevations.
On Wednesday, May 12, 2004, an Action Memorandum Amendment was signed allowing all of the contaminated soil to be thermally treated.
This amendment was needed due to the denial of three Iowa Subtitle D landfills in accepting the coal-tar-contaminated waste. There is one Nebraska Subtitle D landfill located in Jackson that is willing to accept the waste. However, the Nebraska Department of Environmental Quality (NDEQ) requires a public notification period that would result in Site personnel de-mobilizing at a significant cost to the EPA and also would present a hardship to the city of Le Mars Street Department personnel who have re-located during the removal action. Also, due to seasonal fluctuations, the EPA is not encountering the water table at 14 feet below ground surface (bgs). This seasonal fluctuation was not entirely unexpected but was also noted in the amendment.
Excavation of contaminated soils will continue. Approximately 40% of the area has been excavated at this time. Continued replacement of clean backfill will be on-going.
Air monitoring for the workers on-site and the surrounding community continues. Real-time air monitoring of volatile organic compounds (VOCs) and air particulates is performed on a daily basis. In addition, air sampling monitor stations are located at points surrounding the site to track emissions from the site. This is performed to ensure worker safety and the safety of the community.
A water truck on-site is used for dust suppression. Additionally, any piles of soil left on-site overnight are covered before the work ends.
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