The assessment covered air quality, noise, vibration, and odor associated with the facility’s operation. We conducted studies, and made predictions and assessments of each item and prepared a report concluding that the facility will not have an impact on the surrounding living environment. We explained our conclusions to local governments and others, and then applied for permission to install the incinerator.

The area around the project site has a complex topography. Additionally, there are three communities nearby, each lying in a different direction from the facility. In the view of these considerations, we set up survey points to monitor air quality in each of the three communities and conducted a study in each season. As a result of the atmospheric diffusion simulation of stack exhaust gas, the maximum landing concentration of some items exceeded standard values. We therefore presented results (gained from on-site studies made during the existing incinerator’s operation and simulations) showing that exhaust gas landed in nearby mountains before it was diffused in a certain wind direction, that those landing locations were not habitable, and that there were almost no impacts on the nearby communities.

Due to the area’s complex topography, predictions of long-term average occasionally produced irregular results that exceeded predictions of short-term maximums. However, we were able to obtain the prefecture’s understanding with respect to atmospheric diffusion at the planned project area, including the fact that standard values may be exceeded, by explaining variations in atmospheric diffusion and ground-level concentration that come from the topography and stack height and performing some simple diffusion calculations.