This study describes the application of organic petrology techniques to quantify the amount of coal and carbonaceous combustion by-products (i.e., coke, coal tar/pitch, cenospheres) in sediments taken from the Kinnickinnic River adjacent to the former site of the Milwaukee Solvay Coke and Gas Company. The site produced metallurgical coke and coal-gasification by-products from 1902-1983 and was assessed in 2001 as a potential Superfund site in part due to high levels of polycyclic aromatic hydrocarbons (PAHs) which readily absorb to coal and combustion by-products.