What’s going on with the former Riverton landfill?

    h/t Ingberg Miller Engineers for the featured photo

    STEM students at Riverton Middle School recently kicked-off their year-long project with the University of Wyoming’s Science Initiative, City of Riverton, Ingberg Miller Engineers (IME) and Department of Environmental Quality (DEQ) to work on the former Riverton landfill remediation.

    So what’s going on with the old landfill?


    Landfill history lesson – details provided by IME:

    The landfill operated from 1971-1983. During that period of time, there were fewer regulations (if any) on landfills like a required liner to prevent leaks. It sits in 60 acres between Smith Road and the Wind River with an estimated 650,000 cubic yards of buried waste. It also reportedly generates methane gas.

    Fast forward to 2013 – details provided by Riverton Public Works Director Kyle Butterfield & IME:

    Wyoming legislature created a landfill remediation program to assist communities with landfills that have a high risk to human health and to the environment. DEQ went around to all 82 liner-free landfills in Wyoming and ranked them based on different things like leachate and potential for water quality issues. The Riverton landfill was identified by DEQ as a “high priority landfill” within the remediation program. It was ranked 10th out of the 82 landfills to be exact.


    As Riverton has grown over the years, structures, complexes, etc…have been built over the former landfill. Keep that in mind as we head to the corrective options next.

    The remediation options offered – details provided by Kyle:

    DEQ identified their preferred method as a ‘Pump and Treat‘ system.


    The City of Riverton had IME assess the levels of contamination twice and propose remediation options:

    1. Pump and Treat
    2. Excavate and Line
    3. Excavate and Haul to a Fremont County Solid Waste Disposal District Landfill
    4. Excavate and Haul to a New Riverton Site

    According to Kyle, “Each of these options presented significant variables and costs to consider. The second study was performed in 2018 and detailed the type and level of groundwater contamination in the landfill. It also further honed the location of landfill cells.”

    Fast forward to spring 2019 – details provided by Kyle:


    During a meeting on March 29th, 2019, DEQ, IME and city staff identified another remediation option. Utilizing phytoremediation in conjunction with an open water body hydraulic control and continued groundwater monitoring. DEQ shared the next steps to enter the Landfill Remediation Program under this option a feasibility study detailing the effectiveness of phytoremediation would need to be performed.

    Enter the University of Wyoming’s Science Initiative and RMS STEM students and teachers:

    University of Wyoming Professor Rachel Watson shares, “This collaboration is truly unique because it will allow the 7th grade students to work within their community on a meaningful project and to do so in an interdisciplinary way with community leaders and University of Wyoming student researchers. Not only are the students afforded a rich learning experience, but so too are the instructors and professors who will support their learning. Already I am working with the 7th grade teachers to design curriculum surrounding the old Riverton Landfill remediation. This curriculum will allow students to explore solutions involving phytoremediation, mycoremediation and bioremediation. Thus, they will learn deeply about the chemistry of the landfill leachate, the plant physiology of species that can accumulate these toxins, and metabolism of fungi and bacteria that can also degrade harmful chemicals. They will also learn about all of the future careers that are available in these areas; they will work with the actual researchers, engineers and city planners. This makes things that often seem far off and inaccessible into something tangible. Thus, this will be a truly holistic and life-changing learning experience for all teachers and students involved.”

    Stay tuned as this project develops throughout the year.


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