Relationships Between Dioxins in Soil, Air, Ash, and Emissions from a Municipal Solid Waste Incinerator Emitting Large Amounts of Dioxins
The Columbus Municipal Waste-to-Energy (Columbus WTE) facility in Columbus, Ohio, began operation in June, 1983 and ceased operation in December, 1994. During its operation, it was estimated to have released nearly 1000 grams of dioxin Toxic Equivalents (TEQs) per year. This compares to a 1994 estimate of 9300 g TEQ/yr from all sources emitting dioxins into the air in the United States, and to total releases of dioxins near or below 1000 grams TEQ/yr for England, Belgium, and West Germany. Because of the magnitude of emissions from this single source, the expectation is that there would be a strong potential to detect source impacts to soil and ambient air. This paper presents analysis evaluating dioxin concentrations and profiles in four media: stack gas, ambient air within 2 miles of the incinerator, soil samples up to 6 miles from the incinerator, and incinerator ash. Principal findings include: 1) an "incinerator signature" profile, as defined by stack gas emissions, was found in the ash and in subsets of the other two matrices, 2) soil concentrations declined from directly outside the incinerator property to the city at large, 3) an urban background concentration of dioxin TEQs was estimated at 4 pg/g, respectively, while soil concentrations generally within 2 miles of the incinerator ranged from 4-60 pg TEQ/g, 4) an urban air background concentration is estimated at 0.05 pg TEQ/m3, while air concentrations at a specific location about 1.5 miles in the downwind direction of the incinerator had concentrations of 0.17 and 0.35 pg TEQ/m3 during two sampling dates, 5) analysis of the soil monitoring data in combination with the stack test data suggests that less than 5% of emitted dioxins deposited near the incinerator, and 5) principal component analysis suggests that the fraction of total concentration of OCDD is the single feature explaining most of the variation of all concentration profiles. This paper discusses these and other findings, and their implications.