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Celebrating National Dairy Month by Showcasing How We Power the Dairy and Biogas Industries Behind the Scenes
When people think of Wisconsin dairy farms, they picture rolling farmland, hardworking farmers, and fresh milk turning into world-class cheese. What they rarely picture is the waste. Tons of it, produced daily by hundreds of Holstein dairy cows. But what if that waste could fuel homes, power local businesses, and reduce our reliance on fossil fuels?
That’s exactly what’s happening at Zahn Farms LLC, a forward-thinking dairy farm in Gillett, Wisconsin. Here, cow manure is captured and pumped into an oxygen-free tank called an anaerobic digester, where it’s broken down by microbes that release biogas, a mix of methane and CO2. That gas is upgraded into renewable natural gas (RNG) and sent through a pipeline to heat homes and fuel communities nearby. It’s clean, local energy made from something most people would rather ignore.
From mechanical insulation to plumbing and sheet metal fabrication, every system we installed played a vital role in turning Zahn Farms’ clean energy vision into reality. Our work wasn’t just about installing components, it was about making sure each system functioned seamlessly to support a larger mission. By helping capture and repurpose methane emissions, we reduce greenhouse gases, improving sustainability, and delivering a positive impact for the farm, the surrounding community, and the environment as a whole.
How Anaerobic Digestion and Biogas Systems Create Clean Energy from Manure
So, how does it actually work? At Zahn Farms, the process starts with manure being collected daily from hundreds of Holstein dairy cows. That mauer is moved into a large, sealed tank called an anaerobic digester, where it’s broken down by naturally occurring microbes in the absence of oxygen. As these microbes break down the organic material, they produce biogas, a mix of methane gas (CH4) and carbon dioxide (CO2).
But raw biogas isn’t ready to use. It must be cleaned and upgraded through a series of steps to remove impurities like hydrogen sulfide, moisture, and carbon dioxide. The result is renewable natural gas (RNG), a pipeline-quality fuel that can be used for heating, electricity generation, or as vehicle fuel.
At Zahn Farms, the RNG is injected into a nearby natural gas pipeline, providing clean, renewable energy to homes and businesses in the local community. Not only does this reduce dependence on fossil fuels, but it also cuts greenhouse gas emissions by capturing methane that would otherwise be released into the atmosphere.
Even the byproducts are reused. The leftover material, known as digestate, is repurposed as nutrient-rich bedding or fertilizer, closing the loop on a process that transforms waste into value.
It’s a closed-loop system that turns a major environmental challenge into a sustainable solution, right here in Northeastern Wisconsin.
It’s a powerful example of how dairy farms can embrace sustainability and contribute to a cleaner energy future.
As the industrial mechanical contractor, Hurckman was responsible for the HVAC, process piping, fabrication, plumbing, and pipe insulation that brought this complex system to life.
Mechanical Contractor Services for Biogas and RNG at Zahn Farms
Our role at Zahn Farms was to make the vision of turning cow waste into clean energy a working reality. That meant building the entire mechanical infrastructure that moves material through the anaerobic digestion system and supports the critical upgrades needed to create usable fuel.
We began by installing over 13,000 feet of HDPE (High-Density Polyethylene) piping underground. These pipelines didn’t just carry fluids; they connected each stage of the system, transporting digestate and treated liquids for reuse, and making sure the internal flow of materials remained safe, efficient, and environmentally sound.
Inside the facility, we constructed the biogas piping network. When gas leaves the digester, it’s still low-pressure and needs to be gently moved through a series of dryers, compressors, and purification equipment. We used stainless steel piping for this phase, specifically selected for its ability to resist corrosion and handle the moisture and impurities in biogas.
Once the gas reached pipeline quality, we transitioned to carbon steel piping, which could withstand the higher pressures required to deliver renewable natural gas (RNG) to the local utility grid. In several locations, we also installed blind flanges to close off portions of the piping for future maintenance or expansion.
But piping was only part of the story. Our team also handled ventilation and air quality systems that keep the facility safe and operational. We installed make up air units (MAUs), rooftop ac units (RTUs), exhaust fans, industrial fans, and industrial ductwork, ensuring that air flowed properly and temperatures stayed within range to protect sensitive equipment and create safe working conditions.
From mechanical insulation to plumbing and sheet metal fabrication, every piece we installed served a purpose. We weren’t just building a facility, we were creating a carefully engineered system that turns methane into megawatts, emissions into opportunity, and dairy waste into something the entire community can benefit from.
Overcoming RNG Project Challenges with Field-Ready Mechanical Solutions
Zahn Farms’ renewable natural gas project wasn’t just a large project, it was fast-moving and complex. As construction progressed, real-time decisions had to be made. Designs evolved, schedules shifted with the unforgiving Wisconsin winter. Our crews faced heavy snowfall and subzero temperatures
Rather than slow down, our team leaned in. When early incomplete engineering plans lacked details, we worked closely with P&E Construction and project engineers to find solutions that kept things moving. When frozen ground made some areas inaccessible, we redirected our crews to interior work zones to keep productivity high. As new systems were added, we scaled up staffing and materials to support the added scope without missing key deadlines.
With agile project management, a deep bench of skilled labor, and open communication with our partners, we delivered a system that exceeded expectations and helped make this our most successful biogas project to date.
Mechanical Support for the Dairy Industry: From RNG to Cold Storage
Zahn Farms is just one example of the work we do in the dairy industry. Across Wisconsin, Hurckman supports dairy farms, food producers, and cold storage facilities with mechanical systems that keep operations safe, sustainable, and efficient.
On dairy farms, we install the systems that manage heating, cooling, water flow, and waste management, enabling everything from clean energy production to comfortable, efficient animal care. We’ve supported projects that include plumbing and piping systems, industrial ventilation, mechanical insulation, and equipment installation tailored specifically to agricultural environments.
In food and dairy processing plants, our mechanical work ensures that products move safely from raw milk to finished goods. This includes fabricated piping systems, natural gas piping, sanitary process plumbing, and HVAC systems that support food safety and production efficiency. We also provide service and preventative maintenance to help keep operations running smoothly over the long term.
And in cold storage facilities, Hurckman provides comprehensive refrigeration support. We install and maintain ammonia, Freon, and CO2 refrigeration systems, along with ductwork, pipe insulation, and building envelope services that protect perishable inventory and support regulatory compliance.
From field to factory to refrigerated warehouse, Hurckman provides the technical backbone that keeps Wisconsin dairy operations running strong. Our work may be behind the scenes, but it’s essential to the future of this industry.
The Future of Dairy: Clean Energy, Sustainability, and Mechanical Innovation
At Hurckman, we don’t just build for today—we build for what’s next. Across the country, farms, municipalities, and manufacturers are realizing that RNG isn’t just a niche solution—it’s a serious, scalable energy source that reduces emissions, diverts waste, and builds energy resilience.
Unlike traditional fossil fuels, renewable natural gas captures emissions that would otherwise be released into the atmosphere and turns them into a useful, carbon-neutral fuel. RNG can replace diesel in vehicles, power homes and businesses, and support utility goals for decarbonization. It’s not a future concept, it’s happening now.
At Zahn Farms, it’s happening every day. What began as cow manure is now powering neighborhoods and improving the sustainability footprint of an entire operation. And behind it all is the mechanical infrastructure that makes it possible, built by Hurckman.
We’re proud to stand at the intersection of agriculture, energy, and environmental stewardship—and we’re ready to keep leading as dairy evolves.
Want to learn more about how Hurckman supports the agriculture and biogas industries?
Visit our Biogas Services page or explore the full Zahn Farms project profile.
