How To Improve Your Air Quality Analysis Report: Part 2- Input Data Graphics

We have all been in the situation of filling out a paper form where the space for entering your phone number spans the width of the 8½ inch form, even though there are only 10 digits, but the space for your email address, which could be almost any length, is about one inch wide. Why did they do that? It takes more time and effort for the person filling the form out to attempt to squeeze all the characters into the tiny space and more time and effort for someone to decipher what was squeezed in than if there was enough space left on the form from the beginning. The most likely reason for the tiny space is when the form was originally developed, it was before there was such a thing as email.

An air quality analysis (AQA) report is required to contain a map that depicts the following items:

  • area within a 1.9 mile (three kilometer) radius of the facility
  • all property lines
  • UTMs to the horizontal and vertical dimensions of the map section
  • the date and title of the map
  • the datum of your coordinates
  • schools within 3,000 feet of the sources nearest to the property line.
  • the nearest non-industrial receptor of any type
  • PSD Class I areas within 10 kilometers (6.2 miles) or 100 kilometers (62 miles)
  • Urban areas
  • non-attainment areas
  • topographic features within 50 kilometers (31 miles)
  • Any on-site or local meteorological stations, both surface and upper air
  • State/local/on-site ambient air monitoring sites used for background concentrations

Though the requirement is to depict all the items above (that apply), the expectation it all fit on an 8½ X 10 sheet of paper. Sounds a lot like the paper form example.

The Problems With Paper

Can you remember the last time you actually used a paper map? You probably upfolded it. It was most likely pretty big; either a very large 2-sided sheet or thick book of maps. Either way, you had to have the whole thing to figure out where you were on it.

If you were to cut a piece out and put it in a report, would anyone else know the location you are pointing to? There is no context. You have the requirement to label the map to address this issue, but how is that verified?  With paper maps, there is a complete disconnect between the information used to make the map and the display of the map to the user.

This data disconnect raises several fundamental issues.

Based on the list items to be depicted on the map for your AQA report, you are required to add “data” your based map. Where do you find this data? Other paper maps? How to you “copy” that information to your base map? How accurate is your copying? How accurate does it need to be?

For the regulator, how do you verify that the base map is authentic? How do you verify that the “data” added and annotated to the base map are accurate? Do you need to verify the sources of the added “data”?

That is why paper maps, in this day in age, are useless compared to what digital maps have to offer.

Trust Your Data Source

Many years ago, there was language in the modeling report instructions that stated an original USGS 7.5 minute quad sheet be used the area map. The reason being this data source, the USGS, was a trusted data source. The original could not be photocopied to make the image larger or smaller. The reason was the scale of the map was a known, standardized value.

Though, this was the case for the base map, the “data” added to the map had no such validation requirements.

With digital maps, there is issue with context does not exist. You can zoom out to where in the world a location is. You can also zoom in and use aerial imagery (usually very recent) as your base map. There are even measuring tools available within the map. There is no need for a bench mark coordinate, north arrow, or scale. These are all build into the map.

With the aerial imagery, you can verify locations with your eyes because you trust the imagery as being accurate. You trust the same information most every day when you navigate in your car or with your smart phone.

The additional data layers to add to the digital map, e.g. schools, Class I areas, nonattainment areas, and ambient air monitors, come with metadata describing the source, accuracy, and age of the data. The data sources, such as the state education agencies, USEPA, and state environmental agencies, are all trusted sources.

Relying on Hand Drawings for Detailed Information?

The area map provides the means to identify where are site is located and other significant features located nearby an industrial site, but the plot plan (a hand drawing) is supposed to represent the details of a dispersion modeling project, such as the emission source, building, and property/fence line locations. It is useful to the reviewing modeler to see the spatial relationship between these items.

As with the paper area map, the plot plan is an out of context representation disconnected from the data used to generate it. The same questions apply. How is this “data” verified? What is the base map or frame of reference for the plot plan?

Since a digital map has a variable scale (you can zoom in and out) and built in coordinate system, why not use the same map for the plot plan? There is no reason to have a separate representation. Wouldn’t that make things easier on the regulator to review only one item rather than many?

The Advantages of Digital Over Paper

We have been mentioning the downside of paper maps, but the two biggest reasons to ditch paper maps are the time and effort involved in generating them and sharing them. To generate a paper map, even if you have digital means to create them (a little ironic), requires special tools and skills. With access to the best of tools and skills, it is still going to take a bit of time (a few hours) to generate these pieces of paper.

With digital maps, no special access or tools are needed. If you have a computer and access to the internet, which you should if you are reading this article, you can create a digital map with all of the requirement information necessary for your AQA report in a matter of minutes.

Also, if you need to share the information with others, rather than going to the copy machine or scanner, you can merely make available the address to the link for the map.


There are many issues with paper maps and plot plans used in AQA reports. It is highly questionable whether any of the information portrayed on paper is verifiable or useful for reviewing and validating a dispersion modeling analysis because the paper map is disconnected from its data sources and depicted out of context. In addition, generating paper maps is a specialized and time consuming process.

Digital maps are connected to their data source and are presented in context because the user can zoom in or out to locate a frame of reference. Additional data layers can be added to provide reference of the necessary data to be displayed.

Digital maps are easily accessible and can be generated in a matter of minutes with readily available tools that require no specialized skills.

Given the evidence in this article of the superiority of digital maps over paper, why are they not used in AQA reports or air quality permit applications? If you were to ask a colleague, the answer would be “I don’t know” or “it’s just done this way because it has always been done this way.”

Sounds like two good reasons to start using digital maps for your next AQ report or air quality permit application.

An example can be found at

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