Recovered diesel in sight tube of vapor-liquid separator tank at remediation treatment building. The Mandan Remediation Trust reports that on June 21 the first free-phase diesel fuel was recovered from the subsurface of the downtown area using the new extraction system installed south of Main Street. The diesel was recovered during initial phases of the start-up of the multi-phase extraction portion of the remedial system that also removes water and vapors from the soil’s subsurface through a vacuum system. There are about 75 wells and 5 miles of pipe in the area south of Main Street that all hook up to a treatment building located between the John Iverson building and the Movie Gallery.

The remediation system began operating in mid-April in soil vapor extraction mode, with more wells being added to the vacuum system as methane levels would allow. Methane is produced when naturally occurring microbes attack diesel-contaminated soil. The large methane build-up beneath the soil’s subsurface needed to be reduced before diesel could be extracted.

The next step in the remediation process is to get the extraction system installed in the area north of Main Street. Earthmovers of Minot has been awarded the contract for excavating the area to lay 11 to 12 miles of pipe that will connect about 200 wells in an approximate four-block area. Excavation is tentatively scheduled to begin July 17. Businesses will receive notification of when work is planned in their area after July 4.

The Mandan Remediation Trust is overseeing the diesel fuel clean-up effort and expenditure of funds with environmental engineering firm Leggette, Brashears and Graham of Sioux Falls, S.D., hired to coordinate installation and operation of the remedial system. The MRT meets every Tuesday at 1:30 p.m. at Mandan City Hall at 205 2nd Avenue NW. The public is welcome to attend. The MRT will not meet on July 4.

The MRT consists of Jim Neubauer as an appointee of the City of Mandan, Dave Glatt as an appointee of the North Dakota Department of Health, and Francis Schwindt, a retired North Dakota Health Department official selected to assist with the project because of his experience.

A goal of the remedial process is to restore all areas disrupted by the installation process to a condition equal to or better than what previously existed. Reconstruction of the south side of Main Street between the Depot and the John Iverson building is expected to begin July 5.

The south-side reconstruction plan includes hard surfacing for parking lots, sod for an extended park area to the east of the Depot, utilities, greenery, pedestrian street lights, park benches and an area preserved east of the Movie Gallery building for an additional 6,800 square feet of future commercial space. As part of the project, MDU is putting the electrical lines in the area underground. The south-side reconstruction project is to be substantially complete by September 30. Future ideas for the new park area include adding a fountain in the form of a creek-bed with natural stones and a sculpture of a cowboy watering his horse to tie in with Mandan’s theme, “Where the West Begins.”