Looking to serve the residential community, three schools, the hospital, and potentially the downtown area of Vandalia, Illinois.
About the program
The City of Vandalia is progressing with the second phase of engineering, which includes reaching out to residents and business owners in Vandalia to explore the potential for community geothermal to provide resilient heating and cooling for individual homes and businesses.
Community Geothermal connects to the homes, schools, and businesses through a shared underground pipe that uses the Earth's stable temperatures for heating in the winter and cooling in the summer. Each participant will have their own dedicated geothermal heat pump inside their structure, which will connect to the shared loop running underground throughout the city. This is the same as any utility that provides potable water, natural gas, and even electricity. The difference here is that the heating and cooling that this system provides is created, retained, and distributed in Vandalia, making the community more resilient and efficient for all participants. Systems like this reduce dependency on outside energy supplies, strengthening long-term energy stability and keeping more jobs and value within our community for our residents and businesses.
If you live or own a business in Vandalia and want to be part of this study, share your information below. We will keep you posted on town meetings, webinars, and opportunities to participate.
or send us an email at info@vandaliageothermal.com.
Benefits
Community outreach
The City will be performing outreach within the community. Over the next six to eight months, we will be performing community outreach services in the form of:
Project area
To find the strongest fit for community geothermal in Vandalia, the city has been divided into five geographic zones. Each zone is being evaluated for building density, energy use, and resident interest.
Zone 1, anchored around the school complex and the historic core east of downtown, is the leading candidate for the first borefield. It offers the right mix of building types, schools, the hospital, residential homes, and commercial buildings, to support a viable shared loop.
Interest is being gathered from every zone. Depending on how interest is distributed, the project may include more than one site, wherever a sufficient concentration of homes and buildings makes a shared loop feasible. If you live or operate a building anywhere in Vandalia, we want to hear from you.
Express interest for your zone
How it works
Geothermal heat pumps use the stable temperature of the earth just below the surface to heat and cool buildings efficiently. A small underground loop circulates fluid through the ground, where it absorbs heat in the winter and transfers it into the building. In the summer, the process reverses: heat is pulled out of the building and moved back into the ground, keeping indoor spaces comfortable year-round. Because the system works with the earth's consistent underground temperature instead of outside air, it delivers highly efficient heating and cooling in every season.
A Community Geothermal (Thermal Energy Network) system expands this same technology to serve multiple buildings through shared infrastructure. Instead of each home or facility installing its own ground loop, the community uses a shared network of underground piping, wells, and pumps that maintains a stable, ambient-temperature loop beneath the streets.
Each building still has its own geothermal heat pump inside the structure, but all buildings connect to the same underground loop. That loop is what's shared, not the equipment inside the home. In winter, heat is drawn from the shared loop into buildings for heating, and in summer, excess heat is returned back into the loop for cooling. By sharing the underground infrastructure, the system reduces drilling requirements, lowers upfront installation costs, and allows more homes and businesses to access geothermal heating and cooling.
From Gas to GeoHEET · Click to watch on YouTube
For a deeper technical and policy dive, HEET (Home Energy Efficiency Team) maintains a substantial library of community geothermal research at heet.org/what-is-gas-to-geo.
You can also see the U.S. Department of Energy's overview of geothermal heat pumps.
By the numbers
The borefield is the part of the system you'll never see. It would sit beneath open ground at the school complex, holding 152 vertical wells drilled to a depth of 500 feet. Each well contains a closed loop of high-density polyethylene pipe filled with a water-based heat transfer fluid.
Total drilling: 75,947 linear feet. Footprint: 1.43 acres. Once complete, the surface above the borefield can return to ordinary use, athletic fields, parking, or open ground.
A vision for Vandalia
A community-scale system tying the school complex, the hospital, downtown buildings, and surrounding homes into a single underground network. Built once, shared by all.
For homeowners
If your home is in the proposed service area and you choose to participate, the community geothermal system would replace your furnace and air conditioner with a heat pump that connects to the shared loop. You'd get heating in winter, cooling in summer, and hot water (depending on configuration), all from one quieter, more efficient system.
Because the heat pump runs on electricity and uses the ground's stable temperature, the system protects your home from natural gas price volatility and gives you reliable comfort year-round.
Participation in any future system would be voluntary. The City will hold public information sessions before any commitments are made, and the study now under way is what determines whether the project moves forward at all.
Environmental impact
If the proposed system is built, the analysis projects substantial reductions in carbon emissions for Vandalia compared to the conventional natural-gas-and-electric status quo.
Project status
The feasibility study is complete. The City is now sequencing community engagement, geological assessment, and federal incentive work that comes before any construction decision.
Frequently asked questions
No. Participation in any future system would be voluntary. The project is designed around an institutional anchor (schools and hospital) so residential homes can connect at their own pace.
If you participate, you would replace your furnace and AC with a heat pump connected to the shared underground loop. The heat pump handles both heating and cooling, year-round, from the same equipment.
Borefield drilling happens at a single site at the school complex, not in residential yards. The distribution piping runs in public right-of-way under streets. Each connected home needs a small service connection from the street to the building, similar to a water or gas service tap.
Geothermal borefields have an operational life of 50 to 100 years. The Boise, Idaho district geothermal system has been operating continuously since 1892. Heat pumps inside buildings have a service life similar to a furnace, around 20 to 25 years, and are individually replaceable without disturbing the underground loop.
The analysis projects roughly 2,148 tons of CO₂ avoided per year through displaced natural gas use, an 85% reduction compared to the status quo of gas heating and grid-electric cooling.
A single home installs one ground-source heat pump and drills its own well. A community system shares one larger borefield across many buildings. That sharing improves efficiency (cooling demand from one building can offset heating demand from another) and shifts maintenance to professional district operators.
Use the "Express interest" form above to be added to the City's outreach list. You'll get notice of town meetings, webinars, and ways to participate as the study progresses.
Looking for more information?
Community geothermal is a relatively new technology at this scale, and several independent organizations have built up extensive technical and policy resources. If you're researching the topic on your own, these are good places to go deeper.
HEET (Home Energy Efficiency Team) is a Massachusetts non-profit central to the development of community geothermal as a regulated utility service. Their data bank collects technical and policy resources from across the country.
Resources and references
Full technical analysis of the proposed system. Available on request from the City. Link pending
The closest active analog to what Vandalia is studying. Visit framinghamma.gov
Plain-language explainer of how the underlying technology works. Visit energy.gov
Ball State University (Muncie, IN), St. Paul District Energy (St. Paul, MN), Boise Warm Springs Water District (Boise, ID).