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Bombs in Your Backyard Methodology

The data in this interactive database comes from the Defense Environmental Restoration Program, which is administered by the Department of Defense. The program measures and documents cleanup efforts at current and former military locations. These efforts include the cleanup of sites that contain toxic pollutants and contaminants in the soil or water, as well as sites that contain explosives or discarded military munitions. The data, which ProPublica obtained through a Freedom of Information Request, was last updated in 2015.

Interested in downloading the data? Go to the ProPublica Data Store to be notified when we release it.

Our interactive database contains 4,785 military installations with at least one hazardous site, and 40,688 total hazardous sites. Because not all sites came with location data, only 3,611 installations and 24,809 sites appear on our maps (see “Site Locations” for more information), but all installations and sites in the DOD data appear in our tables.

In some cases, we added descriptions of military installations from the U.S. Army Corps of Engineers, and we added information about the costs associated with each installation from data downloaded from the the DERP website.

Here are more details about the various data components of our interactive database.

LOCATIONS

Site Locations

The data includes a latitude and longitude for 27,329 out of the 40,688 cleanup sites. We programmatically checked whether those coordinates were within the state specified for each site. There were 24,875 sites that matched. We do not display the sites where there was a mismatch on our maps.

We then hand-checked the location of 550 individual sites using Google Maps and online research, including all the sites deemed “high risk” (see “Risk Levels” for more information). Of those, we found six instances where the location was clearly wrong, and removed them from the map. There were another 30 instances where we could not verify the accuracy of the coordinates but they seemed plausible in our judgment. With this very low percentage of error, we are confident in the accuracy of the site locations. If you notice a misplaced installation or site, please contact us.

Installation Locations

The data did not include coordinates for installations. We inferred the location of each installation by using the coordinates of one of its sites, which had passed the initial verification outlined above. To check the accuracy of these locations, we checked the assigned location against the latitude and longitude coordinates listed for former military installations on the U.S. Army Corps of Engineers site. We also used the Google Maps Geocoding API to look up military installation locations and compared them with our assigned locations.

RISK LEVELS

Risk Level for Individual Sites

DERP encompasses several different programs, including the Installation Restoration Program (IRP), which addresses contamination from hazardous substances and pollutants, as well as the Military Munitions Response Program (MMRP),  which address sites that contain unexploded ordnance or discarded military munitions. Depending on which program a site belongs to, it is assigned either a relative risk of High, Medium, Low or a priority level of 1 through 8. We've simplified these different assessments into one risk level based on the following system:  

  • High: Relative Risk = High or Priority = 1 or 2
  • Medium: Relative Risk = Medium or Priority = 3, 4 or 5
  • Low: Relative Risk = Low or Priority = 6, 7 or 8
  • Response Complete: Site has reached Response Complete (DOD cleanup actions are complete)
  • Other: Risk Not Evaluated, Risk Not Required, or missing.

We confirmed this approach with the DOD, which said it was reasonable.

Risk Level for Installations

To assign a risk level to each installation, we use the maximum risk level of all of an installation's sites. So if a military installation has 200 sites and one of them is a high risk (using the method outlined above), we classify the entire installation as high risk.

COST

Costs for Individual Sites For each site we display the money spent on cleanup in 2015, and the expected future cost of cleanup. The data does not indicate money spent on a site prior to 2015. When we don't have a value for this field, we display “Unknown.”

Cost for Installations

For each installation we display the money spent on cleanup so far, as well as the expected future cost of cleanup. For installations at which all sites have already completed cleanup, we display the total cost spent.

DATES

Dates for Individual Sites

For each site we display the date of the final cleanup action (or “final remedy”). Note that this refers to the date the final cleanup action starts, and not the date that cleanup is completed, as sometimes a final cleanup action may last for many years.

We sometimes also display the end date for the last phase of cleanup associated with each site, if that date is after the final cleanup action. Sometimes that date is decades in the future, even for sites that say their cleanup is completed. That's because in many cases a site may be under long-term monitoring and review even after the DOD’s cleanup is complete.

Dates for Installations

For each installation we display the date or expected date for DOD cleanup to be complete at all sites. Long-term monitoring of sites or other restrictions may still be in place after this date.