Seal of the City of Vandalia, Illinois Vandalia Community Geothermal
Watch the video Express interest

Heating and cooling
for the whole town,
from one shared loop.

A community-scale clean energy study for the City of Vandalia, Illinois. Looking to serve the residential community, three schools, the hospital, and potentially the downtown area.

Express interest See how it works

Participation in any future system would be voluntary.

Pencil elevation drawing of a Vandalia bungalow with its foundation and basement shown below grade.
>100
Residential homes

Individual homes connect to the shared loop with their own heat pump inside.

3
Schools

Elementary, junior high, and high school. 1,460 students.

25beds
SBL Fayette County Hospital

The institutional anchor that lets homes join at their own pace.

15to 20
Commercial buildings

Downtown core, potential. Plus the Vandalia Swimming Pool for waste heat recovery.

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 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 has their own dedicated geothermal heat pump inside their structure. This is the same as any utility that provides potable water, natural gas, and even electricity. The difference is that the heating and cooling is created, retained, and distributed in Vandalia.

Community geothermal is one shared loop under the street, connected to a heat pump in every building. Built once, shared by all.

Line diagram of the Vandalia community geothermal loop. One loop of pipe runs past a row of homes at the top, the borefield and pump house in the middle, and the school, downtown buildings, and hospital along the bottom.

One loop. Homes along the top, the borefield and pump house in the middle, the schools, downtown, and the hospital along the bottom.

How it works

Select a heading to read each part.

The ground loop

Geothermal heat pumps use the stable temperature of the earth just below the surface. A loop of pipe circulates fluid through the ground, where it absorbs heat in the winter and moves it into the building. In the summer the process reverses: heat is pulled out of the building and put back into the ground.

Split illustration of one house in summer and winter, both held at 72 degrees by a vertical ground loop.
The same ground loop heats the home in winter and cools it in summer.

The heat pump

Each building keeps its own geothermal heat pump inside the structure. It can replace the furnace and the air conditioner with one quiet unit, or work alongside them. There is no outdoor equipment. The heat pump is the part you own; the loop under the street is the part you share.

Pencil section of the same bungalow today: a gas furnace and air handler in the basement, a duct along the ceiling, and an outdoor air conditioning unit beside the house.Today: gas furnace and air handler in the basement, AC unit outside.
Pencil section of the same bungalow with community geothermal: heat pump, air handler, and heat exchanger in the basement, two loop pipes through the wall, nothing outside.With community geothermal: heat pump, heat exchanger, and air handler in the basement. Nothing outside.

The shared network

Instead of each home drilling its own well, the community uses one shared network of underground piping, wells, and pumps that keeps an ambient-temperature loop beneath the streets. In winter, heat is drawn from the loop into buildings. In summer, excess heat is returned to the loop. Sharing the loop reduces drilling, lowers upfront cost, and lets more homes take part.

Pencil drawing of a row of Vandalia homes with a blue ambient loop running under the street and vertical boreholes below.
One loop under the street. Every home along it can connect.

The borefield

The borefield is the part of the system you will never see. It would sit beneath open ground at the school complex, holding 300 vertical wells drilled to 300 feet, based on our test well results. Each well holds a closed loop of high-density polyethylene pipe. Once complete, the surface above it can return to ordinary use: athletic fields, parking, or open ground.

Aerial view of the Vandalia school complex with the proposed borefield grid marked north of the schools.
Proposed borefield next to the school complex on Veterans Avenue.
The same ground loop heats the home in winter and cools it in summer, drawing on the earth's steady underground temperature.
Today: gas furnace and air handler in the basement, AC unit outside.
With community geothermal: heat pump, heat exchanger, and air handler in the basement. Nothing outside.
Same house, same basement. The outdoor unit goes away. The heat pump takes the furnace's place, or works alongside it.
One ambient-temperature loop under the street. Every home along it can connect with a small service tap.
Proposed borefield next to the school complex on Veterans Avenue, with a potential secondary location to the south.
Isometric illustration of Vandalia's community geothermal network. Schools, the hospital, downtown buildings, and homes ring a central bore field, all joined by one shared loop.
Vandalia's community geothermal concept: schools, the hospital, and homes connected to a single shared ambient loop with a central well field.
A few things worth knowing

It's efficient.

Community geothermal systems are roughly 4 to 5 times more efficient than the most efficient natural gas furnace on the market.

It's not new.

Ground-source heat pumps have been in use since the late 1940s. What's new is utilities and cities deploying them at the community scale.

The wells are shallow, not deep.

The system stays in shallow bedrock, where the ground sits at roughly the average annual air temperature for the area. We are not tapping deep heat.

It fits Vandalia.

The system would replace the natural-gas-and-electric heating and cooling used today in homes, the schools, the hospital, and downtown buildings.

For homeowners

Select a heading to read each part.

Replaces the furnace and AC

If necessary, we will install a heat pump that will replace your current furnace and AC, but only if it's needed. If your home is in the proposed service area and you choose to participate, a heat pump connected to the shared loop can replace your furnace and air conditioner, or it can work in conjunction with those modern HVAC units without having to replace what's already operating well in your home.

Heating

When it's cold, home-heat is extracted off the network
Stored summertime heat is now reused
This efficiency translates into lower heating prices for residents.

Cooling

Cooling in summertime from the same unit
Heat in the house is put into the loop.
the loop then stores the heat in the ground

Hot water

Hot water, depending on configuration, from the same quieter, more efficient system.

Nothing outside

The heat pump is quiet indoor equipment.
No outdoor condenser.
No noise in the yard.
The loop connection is a small service tap from the street, like a water or gas line.

Steady against gas prices

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.

Always voluntary

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.

X-ray style drawing of a Vandalia bungalow on black, showing the heat pump in the basement, ductwork to each room, and the loop connection below grade.
What changes, and what does not. The heat pump and the loop tap are new. The house is the same house.
We are working with the state, government, and utilities to make these home improvements at no cost to initial participants.

The project at a glance.

As this assessment progresses, the engineering shown in this section will be routinely updated.

300
Vertical boreholes, 300 ft deep
5mi
Ambient temperature loop piping
2,005
Tons peak heating capacity
1.057M
Total square feet conditioned
90,000
Linear feet of drilling. Boreholes on 23 ft centers, on a 3.6 acre footprint
2,148
Tons CO₂ avoided per year (gas displacement)
85%
Carbon reduction vs. status quo HVAC
630
Equivalent gasoline cars off the road, per year

Borehole count, depth, drilling length, footprint, and loop length updated September 2026 from test well results. Capacity, conditioned area, and emissions figures from the Vandalia Community Geothermal Feasibility Study (February 2026), available on request from the City of Vandalia.

Five zones, one citywide assessment.

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.

Aerial map of Vandalia divided into five zones with dashed yellow boundaries. Zone 1 sits east of downtown, Zone 2 covers the south-central residential area, Zone 3 is the southeast, Zone 4 is the west, and Zone 5 is the north industrial area.
Vandalia divided into five assessment zones. Zone 1 is the primary focus; interest is being gathered across the entire city.

Zone 1 is the primary focus

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 welcome citywide

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→
Three-dimensional model of the whole City of Vandalia seen from above, every building and street in place.
All of Vandalia, modeled in three dimensions. Every building and street the assessment is looking at.
Cutaway model of a street in black and white. The ambient loop runs as a horizontal pipe in color along the street and ties into a field of vertical geothermal pipes below.
The ambient loop runs as one horizontal pipe along the street and ties into the field of vertical geothermal pipes. Only the pipes are shown in color.
Annotated axonometric drawing of the Vandalia school complex and hospital: elementary, junior high, high school, and hospital in color among the surrounding homes.
The anchor buildings in Zone 1: the three schools and the hospital, with the surrounding neighborhood.
The anchors

Big buildings first, then homes at their own pace.

The project is designed around an institutional anchor, the schools and the hospital, so residential homes can connect when they are ready. Cooling demand from one building can offset heating demand from another, which is part of why a shared loop is more efficient than a single home with its own well.

Community outreach, over the next six to eight months.

The City will be performing outreach within the community. Town meetings, a house-by-house survey, webinars, and educational materials.

01
Town meetings

Open public sessions to walk through the study, answer questions, and hear from residents and business owners.

First town meeting, Kaskaskia CollegeFlyer Watch the recordingYouTube ↗
02
Survey

A house-by-house survey of the 445 homes in the study area, asking who would take part and what heating and cooling they have today.

Campaigner sign-in→
03
Webinars

Online sessions for residents who can't attend in person, recorded and shared afterward.

Kaskaskia College webinar, June 2026YouTube ↗
04
Educational outreach

Materials and conversations with local schools, civic groups, and community organizations.

Presentation to the Town, June 2026PDF June 16 town hall flyerPDF

Two videos. The full story, and the quick version.

Two ways to get to know the project. Watch the full walkthrough, or grab the one-minute version. Both are also on YouTube.

Title frame of the full-length Vandalia Community Geothermal video
The Full StoryWatch on YouTube↗

Long video. Plays here.

Opening frame of the short Vandalia Community Geothermal video
The Quick VersionWatch on YouTube↗

Short. About a minute.

Thumbnail of HEET's 'From Gas to Geo' explainer video.
From Gas to Geo. HEET (Home Energy Efficiency Team). Click to watch on YouTube.
Two construction workers in safety gear next to rows of black HDPE ambient-loop pipe in front of a brick apartment complex.
Workers carrying ambient-temperature pipe in Framingham, Massachusetts. Vandalia's installation would look similar. Photo: HEET.

The HEET video was produced for Massachusetts, where utilities are piloting the first community geothermal networks. The technology and approach would be the same in Vandalia.

Where the study is now, and what's next.

The feasibility study is complete. The City is now sequencing community engagement, geological assessment, and federal incentive work that comes before any construction decision.

Phase 1Months 1–12
Study and design
  • Detailed geological survey and test boring
  • Final engineering design and permitting
  • Community outreach and enrollment
  • Secure financing and federal incentives
Phase 2Months 13–24
Borefield and anchors
  • Borefield installation
  • Central plant
  • Connections at the schools, hospital, and commercial core
Phase 3Months 25–36
Homes
  • Distribution loop build-out
  • Residential connections
  • Individual heat pump installations
  • Commissioning and testing
Phase 4Years 3–5
Operate and grow
  • Performance monitoring and optimization
  • Additional residential connections
  • Tours and community education

Questions Vandalia residents are asking.

Short answers. If yours is not here, write to info@vandaliageothermal.com.

Will I be required to participate?
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.
What happens to my furnace and AC?
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.
Will my yard be torn up?
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.
How long does the system last?
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.
What's the environmental benefit?
The feasibility study (February 2026) 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.
How is this different from a single home with a geothermal heat pump?
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.
How can I follow the study?
Use the "Express interest" form below 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? Independent resources and project documents.

Community geothermal is a relatively new technology at this scale. Several independent organizations have built up extensive technical and policy resources. These are good places to go deeper.

Project documents
  • Vandalia Community Geothermal Feasibility Study (Feb 2026)Full technical analysis of the proposed system. Available on request from the City. Link pending.
  • Presentation to the Town (June 2026)Download the slides (PDF)
  • First town meeting flyerView the advertisement · PDF
  • Comparable systemsBall State University (Muncie, IN), St. Paul District Energy (St. Paul, MN), Boise Warm Springs Water District (Boise, ID).
Independent resources
Express interest

Are you interested? Let us know.

If you live or own a business in Vandalia and want to be part of this study, share your information here. We will keep you posted on town meetings, webinars, and opportunities to participate.

Or send us an email at info@vandaliageothermal.com.

Your information stays with the City of Vandalia project team.