In collaboration with the EPA, we are developing a new community-scale suite of local-scale air quality modeling systems called C-TOOLS (Community Air Quality Tools). These tools predict concentrations of multiple criteria and toxic air pollutants at fine spatial scales in the near-source environment with access through a web-based platform that requires minimal technical expertise to use. The air dispersion calculations in C-TOOLS are based on scientifically robust formulations similar to those employed in regulatory models, but efficiencies are derived from specification of representative scenarios for the input data. Though functionally, C-TOOLS and regulatory models are similar in that they predict near source air quality, their application and intended purpose are distinctly different. Due to the specificity of a regulatory application, the use of such tools needs to follow strict protocols for data specification and model calculations. However, many community-scale applications require a quick initial assessment of air quality impacts to characterize the scope of the problem and guide more detailed analysis, and often do not require a typical regulatory model application. C-TOOLS attempts to bridge this gap by combining air dispersion models with evolving web-based and visualization technology to provide an easy-to-access tool for community users to undertake such initial air quality impact assessments. For instance, the tool could be used for examining ���what-if��� scenarios related to different planning alternatives, such as changes in traffic volume, speed, fleet mix, and/or port electrification conversions.
The Community LINE Source Model (C-LINE) is a web-based model that predicts concentrations of multiple air pollutants due to traffic emissions near roadways. As has been established in near-road and near-source monitoring studies, busy roadways and large emission sources, respectively, may impact local air quality near the source. Reduced-form air quality modeling is a useful tool for examining what-if scenarios of changes in emissions, such as those due to changes in traffic volume, fleet mix, or vehicle speed. Examining various scenarios of air quality impacts in this way can identify potentially at-risk populations located near roadways and the effects that a change in traffic activity may have on them. C-LINE computes dispersion of primary mobile source pollutants using meteorological conditions for the area of interest and computes air quality concentrations corresponding to these selected conditions. The dispersion routines used are in the analytical version of R-LINE (Snyder, et. al. 2013, also see https://www.cmascenter.org/r-line/). Specific emissions for each road link are calculated by combining national database information on traffic volume (AADT) and fleet mix with emissions factors from the EPA's MOVES modeling system. The user can modify the emissions for each road link by changing the traffic composition, speed, and/or volume. The air quality impact from a change in emissions due to changes in activity, fleet composition, or representative meteorological conditions can be visually quantified for a select set of pollutants and mobile source air toxic (MSAT) species. This web-tool is currently capable of modeling any local area across the United States. C-LINE is a screening-level model and is not intended to replace any regulatory models or be used to make enforcement decisions. Additional information on the overall tool is available in Barzyk et al (Env. Modeling and Software, 2015, 66, pp. 46-56). More Info
C-LINE functionality has been expanded to model emissions from port-related activities (e.g. ships, trucks, cranes, etc.) to support a second, port-specific modeling tool. The Community PORT-Related Modeling System (C-PORT) is designed to be an easy-to-use computer modeling tool for exploring the range of potential impacts that changes to port operations might have on certain components of local air quality.
C-PORT currently includes data from 21 U.S. seaports and features a map-based interface similar to the widely used Google Earth. Data sources include nationally consistent datasets, such as 2011 National Emissions Inventory and the MOVES 2014 emissions model, with emissions allocated to port terminals based on spatial and activity-related allocation methods. C-PORT is a screening level tool, and is not intended for regulatory applications, enforcement, or refined analyses that are based on the latest local data. More Info