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Scioto Ordnance Plant


The former Scioto Ordnance Plant, known as SOP, is located one-mile northeast of Marion, Ohio and was originally built on approximately 12,500 acres of farmland. The area is bordered on the west by Pennsylvania Railroad, on the east by State Route 98, on the south by Fairgrounds Road and the Erie Railroad, and on the north by Marseilles-Gallion Road.

Construction of the $5 million Scioto Ordnance Plant began April 14, 1942 and was completed June 20, 1942. The Corps of Engineers, Ohio River Division built the facility. The plant was situated on 12,452 acres of former agricultural land, approximately 5,817 acres of which comprised the manufacturing area. The SOP included administrative, housing, supply, and maintenance areas. There were 177 magazines, five explosive storage igloos, and nine ordnance production lines.

At peak production, the SOP, operated by various government contractors, employed approximately 2,900 people engaged in the manufacture of nearly 15.5 million fuses, 388,000 boosters, 2,336,000 primers, 2.9 million .50-caliber rounds, and at least 100,000 500-pound incendiary munitions along with an undetermined number of 10-pound incendiary cluster munitions. The Cleveland Ordnance District also used some areas of the facility for warehousing. The plant ceased operations on August 14, 1945.

Following World War II, the War Assets Administration, the Federal Farm Mortgage Corporation, and the War Department disposed of the property to various public and private entities. One 1,285-acre tract went to the Atomic Energy Commission for the Scioto Laboratory, which operated from 1949-1953. Currently, the properties comprising the former SOP are occupied by a municipal airport, state correctional facility, various commercial and agricultural enterprises, and a residential development (Grandview Estates).

Major Milestones

Major milestones have been accomplished during the environmental investigation of the former Marion Engineer Depot and Scioto Ordnance Plant in Marion, Ohio. These milestones mark the significant steps achieved during the ongoing 12-year investigation that follows the Comprehensive, Environmental Response Compensation Liability Act (CERCLA).

It is due to the partnership of the U.S. Army Corps of Engineers, U.S. Environmental Protection Agency (EPA), Ohio EPA, Ohio and Marion County Departments of Health, Army Reserve 88th Regional Readiness Command, Army Environmental Command, River Valley Local School District, contractors, Restoration Advisory Board members and other concerned and involved citizens that these milestones were accomplished.

In 1998, a Restoration Advisory Board was formed and co-chaired by the U.S. Army Corps of Engineers. The board consisted of volunteer community members and local, state and federal agency representatives. The U.S. Army Corps of Engineers, Louisville District officially adjourned the Restoration Advisory Board (RAB) for the former Marion Engineer Depot and Scioto Ordnance Plant, formerly used defense sites in Marion, Ohio. The RAB Adjournment Report and other pertinent documents are available below and at the Marion County Library, 455 E. Church Street, Marion, Ohio 43302.

There were approximately 28 areas of concern identified at the former Scioto Ordnance Plant, which resulted in the clean-up of residual contamination from tank removals in three areas of concern. Over the years, 26 groundwater monitoring wells were installed in various areas of concern on the property and 40 reports were generated on the former Scioto Ordnance Plant investigation.

The former Scioto Ordnance Plant had 30 areas of concern that were investigated by the Corps of Engineers. Under the Department of Defense Formerly Used Defense Sites (FUDS) Program, the Army Corps of Engineers developed a Preliminary Assessment in 1992 and Archive Search Report for Hazardous Toxic and Radiological Waste (HTRW) and an Archive Search Report for Ordnance and Explosives Waste (OEW) in October 1994.

In October 1995, the Corps of Engineers, Nashville District produced a report entitled, Final Limited Site Investigation Report for Radiological Contamination at the Former Scioto Ordnance Plant, Marion Ohio. The purpose of this site investigation was to determine if there was evidence of gross radiological contamination within the Monsanto Warehouse and the Likens Chapel basement. The results of radiological survey and analytical sampling indicated that radiation levels at both the Process Research Building and Likens Chapel were well below accepted action levels. From these results, it was concluded that gross radiological contamination was not present at either location. Therefore, no further action was recommended.

Where We Are Now

Although the U.S. Army Corps of Engineers is nearing completion of the investigation and clean-up of the properties formerly used by the military, there are still several areas of concern to be addressed. The Corps expects to complete the investigation of all of the areas of concern at the former Marion Engineer Depot and Scioto Ordnance Plant by June 2013.


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