The Lower Sioux Indian Community, near Morton, Minnesota, has made a big bet on hemp to offer a better future for its residents. Construction is nearly complete on a 20,000-sq-ft manufacturing campus that will process hemp into a construction material known as “hempcrete.” The short-term goal is to use the natural building material to construct homes for members of the tribe. Longer term, the Lower Sioux hope to be a leader in the growing “green building” space.
Once the new $6.2 million project is complete, the Lower Sioux are expected to be the largest producer of hemp-infused construction materials in the US. “We’re still not a fully formed, cohesive, vertically integrated system yet, but we’re getting there,” says Earl Pendleton, a former elected member of the Lower Sioux Tribal Council, who led the effort to both grow hemp and build the hempcrete production facility.
When Pendleton first learned about hempcrete, he was drawn to its potential as a non-toxic construction material that also speeds construction times. At the time, the Lower Sioux Community, also known as the Mdewakanton Tribal Reservation, was facing the decline of its main revenue source, the Jackpot Junction Casino. What’s more, the population on the reservation had increased, further depleting the payout of annual casino profits that go to each Lower Sioux family.
About half the residents in the community do not have full-time homes, according to Pendleton. His idea was to create an industry that could house his community, as well as one that could train the young people in construction, agriculture, and the sales aspects of commercial hemp products.
The Lower Sioux began growing hemp in 2016 under a research program run by the University of Minnesota system. They started with just a small acreage, which was actually the first time the community had ever farmed a crop in their 80-plus years on the land. “That was a big endeavor, by itself,” Pendleton says.
Once hemp was decriminalized under the 2018 Farm Bill, the tribe was able to expand and now has hemp growing on anywhere from 100 to 200 acres at any given time. There is potential to expand that area to 300 acres. The tribe has been getting its seeds from New Genetics in Colorado and the Dun Agro Hemp Group, a Dutch company with a processing facility in Indiana. Dun Agro is looking to partner with native communities that have the sovereignty to decide to build production facilities in the US.
Hemp comes from the same species of plant as marijuana but, from a legal standpoint, “marijuana” refers to cannabis that has more than 0.3% THC by dry weight. Any part of the plant lower in THC content is legally considered hemp. Hemp can be cultivated in 90 to 120 days and is able to grow in adverse conditions. A Cambridge study found the plant can absorb around six tons of carbon dioxide per acre during its growth phase, making it a much better option for capturing CO2 than trees.
During processing, the inner woody core of the hemp plant (shives or hurd) is mixed with a lime-based binder, water and sometimes additional materials to make hempcrete or hemp lime. Hempcrete creates a rigid air and water barrier and it’s nontoxic and resists mold, fire and infestation. China is the world’s largest producer of hemp, followed by France.
The U.S. Hemp Building Association is currently working to get hempcrete and other hemp products approved for use in commercial construction. Hempcrete is already a popular construction material in Europe, where it’s also used to renovate older stone or lime building.
Pendleton envisions the hempcrete program manufacturing prefabricated wall panels and blocks that could eventually be sold to outside customers, and perhaps even provide construction services off the reservation. Once open, the processing facility will be the first fully integrated hempcrete facility with its own growing operation nearby in the US. (Sources: Interesting Engineering, LowerSioux, The Guardian)
