Mapping Superfund Sites in New York State

For the final project, I researched the presence and frequency of Superfund sites across New York state, creating a

dashboard and bar charts, along with a map of the counties in the state with Superfund site(s).

A Superfund site is “any land in the United States that has been contaminated by hazardous waste and identified by the

Environmental Protection Agency (EPA) as a candidate for cleanup because it poses a risk to human health and/or the

environment.” Examples of sites include former chemical or industrial facilities,landfills, and waterways, such as the highly-

contaminated Gowanus Canal, inBrooklyn, New York.

In working on this project, I wanted to become more proficient withvisualization programs, and to see what sort of story

I could tell with the data. Ultimately I wound up using Tableau, for reasons discussed later on.

The subject matter is something with which I had some familiarity, having worked for the Department of Energy, Office of

Environmental Management (DOE-EM). That program office is responsible for cleaning up Manhattan project and other

agency-owned nuclear sites across the country, such as the Hanford complex in eastern Washington state. Working off that

experience, I shifted focus to Superfund sites and began work on the project.

Final Version: https://public.tableau.com/profile/tony.volpe#!/vizhome/MappingSuperfundSitesinNYStateFinal/NYSSuperfundSites

In the dashboard above, the top rectangular section includes a definition of a Superfund site, followed by a map of the

state, with Department of Environmental Conservation (DEC) regions, and a list of the counties in the corresponding DEC

Regions. As noted in the upper-right box, only counties with sites are included in the DEC regions list. Working together, the

items in the upper third provide an introduction and orientation to the material that follows.

The second section shows a concentration of sites by county, using a choropleth map. Using that type of map provides a

ready visual aid that requires minimal text. Additionally, the choropleth mirrors (to some degree) the DEC regions map located

above, potentially reinforcing understanding of the county geography and where sites are located. The map had an unexpected

impact for one user, who mentioned that it was rather concerning, as her sister lives on Long Island, the region with highest

number of Superfund sites in the state.

The third section (Sites by region) uses a bar chart to present a breakdown of sites by DEC region, allowing for quick

analysis. Last, the fourth section (Superfund sites per county) also uses a bar chart, with the bars running horizontally to avoid

duplicating the same layout as the chart next to it. Even though the bars are using a different orientati0n, the fourth chart

presents data in a way that is readily comprehensible for someone viewing it.

As to the creation process, I had started out with a different idea than what I wound up actually building and presenting.

The original idea was to make a map of Superfund sites across the country, but I decided to narrow the focus to New York State,

using Carto for the map portion, and creating bar charts (or other visualizations) in Tableau. I started off creating a map of New

York in Carto, to get an outline of all the counties, and then imported EPA Superfund data into Carto, with decidedly mixed

results. I had wanted the sites to appear on a map as points, with the site name and city displayed when one hovered over it.

While some sites appeared in the appropriate counties, others appeared in entirely different states altogether. The

data from the EPA lacked certain fields that would enable Carto to properly map the sites.

After working with Carto some more, I modified my idea, and switched to Tableau. While working with Tableau 9.3, I ran

into some issues with certain cities not appearing on the map (municipalities under 4,000 were not displaying), so I opted to

revise again, creating a map showing all counties with Superfund sites. The choropleth map was the best option to show the

concentration of sites across the state.

I analyzed the EPA data in different ways (by county, by DEC region) in Excel to provide more context and to present the

material in a way that worked in concert with the map at the upper third of the dashboard. Some users did note that counties

with no sites were greyed out on the map, but that was not necessarily a bad thing. The counties with sites were, in a way, more

visible that way, as they had shading to indicate presence of a site. Once I had the various sheets together in Tableau, I created

an initial version of the dashboard (Version 0), and another (Version 1), with the elements arranged in a different manner.

Images for each are below.

Figure 1 – Version ‘0’ of the dashboard

Figure 2 – Version ‘1’ of the dashboard

To conduct user testing, I emailed five people, with four responding and providing feedback. The user population, while

small, consisted of a former manager of mine (who also worked for DOE-EM), a classmate (filling the novice user role), afriend

with a keen interest in environmental causes and data, and a relative (also another novice user). Requests for feedback went out

on Friday, the 2^nd, with a request to have feedback in by the following Monday so changes could be incorporated into a new

version. I attached a questionnaire, focusing on three areas: subject matter, aesthetics/layout, and comprehension, and asked

that participants provide feedback on those areas. The subject matter asked users to explain the subject of the dashboard in

their own words (i.e., what is this about, and can you explain to someone if needed?), aesthetics/layout focused on determining

which version was more effective and why, and comprehension focused on users’ ability to answer six simple questions, based

on data presented in the dashboard. Questions and feedback are in the appendix of this report.

The design of the dashboard evolved, but retained common elements among the three versions (two ‘test’ and the final),

including the use of choropleth map, stepped color, and bar charts. Initially, the map had a green color scheme to

show concentration of sites by county. The stepped color scale ultimately used 5 gradations, after trying out scales with more

steps. Additional steps may have been effective if the scale were larger, but since it was smaller (0 to 18), a simpler gradation

scheme worked better for the map. The choropleth map color was changed to match that of the bar charts, to provide a uniform

look.

Ultimately, the final version retained more of the initial design (Version 0) in terms of placement of information on the

dashboard, with some additions to clarify what a Superfund site is, as well as some additional information to clarify what

exactly is being shown. Previous versions did not indicate that all sites were shown, regardless of status. The final version does

make a note of that, in the upper third of the dashboard. Looking back, that note would have been beneficial to include, though

it would not have impacted the layout or comprehension of the subject matter.

User testing (results were generally positive, with recommendations for improvement. More details can be found

below.

In Area I, Subject Matter, all four users were able to state in their own words the purpose of the dashboard, as well as

explain what was being presented. Asked which version was more effective, one user expressed a clear preference for Version 0

over Version 1, saying of the latter:

“While material was clearly labeled, the format and layout created confusion, and the side sweep of the regional interactive map took too much of the page, drowned out the other info in relation to its corresponding info, and also I kept inadvertently dragging the mouse over it, with nauseating zoom effects.”

Two users did not specifically choose a version in the subject matter area, but said that Version 0 presented the material in a

clear and easy to understand manner. The remaining user did not directly choose one over the other, but instead offered

comments on potential improvements for Version 1.

Area II focused on Aesthetics/Layout, with questions focusing on which version (if either) was preferred, and why, as

well as suggestions for improving the preferred version. Findings align with results described above, with Version 0 emerging

as the stronger candidate (with revisions) for use in the final product. Recommendations for improvement of Version 0 focused

mainly around placement of text boxes, and other enhancements to make the visualization clearer. Of version I, one user

indicated the stepped color scheme was less effective because of the lack of differentiation on the map (users had to select a

county to see the color and corresponding number of sites, unlike Version 0). A note about counties without sites was not

initially included, but after user testing, I added it to make it clear why certain areas were not showing up on the choropleth

map.

The last area (Area III) looked at comprehension and application of material presented on the dashboard. All users

were able to correctly answer six questions (such as “Which county has the most Superfund sites?”). The questions were simple

to keep in tune with the relative simplicity of the dashboard. One user noted a concern about not being able to identify counties

that were greyed out on the map, but that did not impact overall comprehension of the material.

Visualization-related findings revealed some unexpected points, including:

Long Island (DEC Region 1 – Nassau and Suffolk Counties) had the highest number of Superfund sites, with 34 total, across a densely populated part of the state.

The next highest was in the Lower Hudson Valley (DEC Region 3 – Dutchess, Orange, Putnam, etc.), with 20 sites. This area tends to be more rural, with a lower population density.

Niagara County (DEC Region 9, in the upper-northwest part of the state) had 7 sites, but is home to the infamous Love Canal (which has been cleaned up). I had thought there would be more sites in the county. Though Love Canal is officially cleaned up, sites nearby are awaiting remediation.

Monroe County (DEC Region 8, and where Rochester is located) had no Superfund sites at all. Companies such as Eastman Kodak and Xerox had a major manufacturing presence in the county. Kodak has had a number of environmental issues over the years, including a 1989 industrial chemical release in a residential area with a school nearby. The company has taken steps to resolve the issues, which may explain the reason for the lack of sites in the county. Xerox has had its own issues, but are less well-known. Like Kodak, Xerox has taken steps to clean up the pollution, avoiding inclusion on the EPA Superfund list.

Sites owned by government agencies such as the Department of Energy (and other agencies) are not a part of the EPA Superfund sites list. The agency that owns the site (such as Brookhaven National Laboratory on Long Island) is responsible for cleanup, but must adhere to state and EPA regulations and standards.

The map, based on EPA data, does not indicate the severity of contamination at a given site, just the presence of a Superfund site. Information about contamination at every Superfund is available from the EPA.

Over time, the design and content of the dashboard evolved based trying out different programs, analyzing data, and user

feedback, resulting in the final Tableau visualization. Revisions included changing the color scheme, including definition of a

Superfund site, and adjusting placement of various items on the dashboard.

While those were easy enough to fix, more can be done with the subject. For example, looking at population density and

location of Superfund sites, or presence of Superfund sites and concentration of health issues (such as cancer, or other

maladies), could yield some results worth exploring.

Though not presented on this dashboard, data can be sliced and diced to show sites by status (deleted, final, proposed),

and presented in individual bar charts to compare and contrast. Expanding the research possibilities, one could look at the

country as a whole, and examine the number and concentration of Superfund sites across the country, to determine any trends

that emerge.

Sources and Resources

Superfund Site definition, and explanation of Superfund site statuses: