Arsenic and Lead Property Maps

About the project: 


Pueblo, CO has a long industrial past once consisting of five smelters that produced silver and lead from 1883 to 1908. During this time, thousands of residential and commercial properties were exposed to Arsenic and Lead. Over time, these metal toxins can cause a plethora of health issues if people are exposed. The Colorado Department of Public Health and Environment (CDPHE) found elevated lead and arsenic levels in neighborhood soils and slag due to this smelter. The EPA started sampling and cleaning soil in 2015 and is expected to be done by 2029.

More info on background for this massive project can be found here

February of 2022 map of Pueblo, CO when I took over as GIS Analyst

My work

To begin work on this project, I first digitized each property in AutoCAD to classify where any decision units (front, side, or back yards) may be and collect the square footage. Then I sent these maps to the field crews to be sampled and waited to receive the Arsenic and Lead measurements.

The soil in each decision unit was measured to determine if the property required a soil or dust cleanup based on the threshold levels set by the EPA below:

  • Arsenic in soil – 61 ppm 

  • ​Lead in soil – 350 ppm 

  • ​Arsenic in indoor dust – 61 ppm 

  • ​Lead in indoor dust – 275 ppm 

When I received the results from the field unit with the Arsenic and Lead levels, I marked each map with the corresponding values. If there were properties with levels that exceeded what was beyond the threshold, I created a letter to be sent to the property owner that included an informational handout on Arsenic and Lead safety, the map I created, and how to schedule a cleaning.

Micro-scale of a parcel showing arsenic results mailed to a resident

Micro-scale of a parcel showing lead results mailed to a resident

Conclusion

I started this project in 2022, and it remains ongoing. 2,000 properties have received sampling and cleaning when necessary. With so many properties to map and sample, I shared my maps monthly with my team, which helped visualize progress and keep morale high. 

This work ensured safer conditions for current and future residents of Pueblo, CO.

Initial parcel property map from February of 2022 when I took over as GIS Analyst

Most recent parcel property map from April of 2025. This map shows the massive amount of progress that the team has made over the 3 years