The Joliet Army Ammunition Plant


For most of the last 60 years, the Midewin site has been under the control of the U. S. Army.


The Joliet Army Ammunition Plant (JOAAP) was originally known as the Elwood Ordnance Plant (EOP) and the Kankakee Ordnance Works (KOW) when they were authorized by the federal government in 1940.  The federal government purchased 36,645 acres from local farmers at a cost of $8,175,815. Construction costs totaled over $81 million.  Seventy-seven such plants were built during World War II to  produce ammunition and explosives for the U.S. military. At the time they were built, the Joliet plants were considered the largest, most sophisticated munitions plants in the world. Both the Elwood and Kankakee plants became a training base that supported the Allies' efforts. At peak production during WW II, over 10,425 people were employed at the two plants. The Elwood facility loaded over 926 million bombs, shells, mines, detonators, fuzes, and boosters, and the Kankakee facility set a national record producing over one billion pounds of TNT.


The Elwood and Kankakee Plants were combined and redesignated the Joliet Arsenal in 1945, when operations were placed on standby. The Arsenal was reactivated in 1952-1957 during the Korean War and again during the Vietnam War.  TNT production stopped in 1976 and by the late 1970s, most operations had ceased. The total size of the Joliet Army Ammunition Plant at the time it was declared inactive in 1993 was 23,543 acres.


The JAAP Legacy


Contaminants from the TNT manufacturing process heavily disturbed Grant Creek, which runs through the site, while the plant was still active. The water in the creek at that time flowed red. Now that TNT production has ended, Grant Creek has recovered and exhibits the highest biological diversity on the property. The majority of its watershed is in grasslands, and thus receives very little runoff and silt from crop fields.


The chemicals involved in the manufacture of TNT still contaminate the top few meters of soil in the 4,000 acre area where the process took place. The U.S. Department of Defense is responsible for the clean-up of hazardous waste in this area. When clean-up is complete, the land will be transferred to the USDA Forest Service for inclusion in the Midewin National Tallgrass Prairie.


To complete construction of JOAAP, 45% of the landscape was modified to some degree. JOAAP's buildings are still standing, though most have been idle for 20 years. Over 1,000 of the total 1,462 buildings date back to WW II. Other remnants of the Arsenal's hey-day include 200 miles of roads, 166 miles of railroad, and 392 "igloos" which were used to store ammunition and explosives. The site is also enclosed by 37 miles of 8-foot chain-link fencing with 3 strands of barbed wire. During years of inactivity, the land was leased for agricultural purposes. There are currently 10,700 acres of row crops and 6,000 acres of pasture on the site. The superficial disturbance of land at JOAAP was great. However, subsurface disturbance was minimal.

What will happen to all of this now that the site has been designated for restoration and conservation?

The buildings and railroad lines are being dismantled and salvaged.

Some of the roads will be left and maintained as access roads or trails. Others will be removed.

Some of the fence will be left intact. If bison, elk, or other large animals are reintroduced in the area, the fence will help to keep them within the bounds of protected areas and out of surrounding farmlands. In some areas, the fence will be removed.

The igloos, which were designed to withstand and contain the explosion of their highly-volatile contents in case of accident, would be prohibitively expensive to dismantle. Fortunately, the storage requirements for TNT are very similar to those for storing prairie forbs and seeds. Coming up with other ideas for reusing the igloos has become a favorite past-time of Midewin staff, volunteers, and tour visitors intrigued by the unique challenge of integrating these structures into the Midewin National Tallgrass Prairie.

Existing agricultural uses of the land within the Midewin's boundaries will be phased out over the next 20 years. Thereafter, only those agricultural uses which are compatible with resource management will be allowed.