In the fall of 1960, the General Services Administration (GSA) inspected the Seneca Shipyard property for its sale. The 195 acres of riverfront land was to be advertised and sold by the GSA. Two local business men, William Kasten and William E. Steep met with GSA authorities to determine how the Village of Seneca could purchase, or at least maintain, control of the site. It was recommended that a Regional Port District be created by the state legislature to best serve the interests of Seneca. Kasten and Steep presented this proposal to Mayor James O'Brien and the Village Council.
The Mayor, City Attorney, and select local businessmen met with legislators in Springfield to discuss the possibility of a port bill. On August 9, 1961, Senate Bill 709 was signed by Governor Otto Kerner, creating the Seneca Regional Port District.
In the fall of 1965, the Port District entered into negotiations with E.I. DuPont Company and Central Farmers Fertilizer for the construction of an anhydrous ammonia tank. In order to issue legal and valid bonds for the construction costs involved, a non profit corporation was required.
Under the direction of the Port District, the Seneca Port Operating Company was approved by a Port District resolution on March 19, 1966. Revenue Bonds were issued, and 30 acre tract of land was purchased. An announcement was made on August 3, 1966, that construction of a 30,000 ton refrigerated storage tank for liquid anhydrous ammonia would begin on the South Side of the Illinois River on a 34 acre site. When the bonds were retired in 1996, the Port District acquired outright title to the terminal. C.F. Industries has a truck loading distribution terminal at the site and distributes ammonia to area farmers by truck. The ammonia is used as fertilizer.