The United States Steel Corporation (USSC) Homestead Works consists of three separate areas. The Carrie Furnace area and the Main Homestead area are on the Monongahela River, about 14.5 km (9 mi) upstream of the confluence of the Ohio, Monongahela and Allegheny Rivers. The Wheel and Axle works is on the Ohio River at McKees Rocks, Pennsylvania, about 4.8 km (3 mi) downstream from the confluence of the three rivers. The McKees Rocks plant consists of the older manufacturing area containing the permitted discharges, and the newer area containing mostly dry operations. Wastewaters are discharged through three outfalls: 018, 019 and 020. All three outfalls discharge to the Graham Street storm sewer which flows into the Ohio River, about 0.8 km (0.5 mi) east of the plant property. On June 12, 1975, NEIC was requested to assist Region III in investigating specific USSC discharges. A reconnaissance of the Homestead Works including the Wheel and Axle plant was conducted on July 23, 1975.