Community Modeling and Analysis System


In collaboration with the EPA, we are developing a suite of local-scale air quality screening tools called C-TOOLS (Community Air Quality Tools). These tools predict concentrations of multiple primary pollutants that are directly emitted (CO, SO2, NOx, PM2.5) and select Mobile Source Air Toxics (benzene, formaldehyde, acetaldehyde, and acrolein) at fine spatial scales in the near-source environment. The tools will be accessible 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. C-PORT is a screening level tool and is not intended for regulatory applications, enforcement, or refined analysis intended to meet EPA Guideline on Air Quality Models Appendix W requirements (Appendix W to 40 CFR Part 51).

C-TOOLS are designed to encourage use by non-expert stakeholders through computational efficiency coupled with a default set of emissions and meteorological inputs. The results obtained through the application of these tools are reliable enough to screen for situations that might require further analysis to examine the impact of the source under a range of inputs not included in the default set available through C-TOOLS.


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 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 model for near-PORT applications (C-PORT) is a research grade screening tool for near-port assessments. 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 is available for use in research settings, and should not be used in regulatory applications, enforcement, or refined analysis intended to meet EPA Guideline on Air Quality Models Appendix W requirements (Appendix W to 40 CFR Part 51). C-PORT may be a useful tool as part of a federal agency's review under the National Environmental Policy Act (NEPA). However, C-PORT is not intended for highly refined analyses consistent with EPA Appendix W requirements, so C-PORT is not by itself sufficient for a NEPA analysis intended to satisfy EPA Appendix W requirements.

C-PORT currently includes data from 24 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. More Info