Since 2021, Brooks Construction has been a key player in a renewable energy effort across Eastern South Dakota. With increasing interest and improved technology, dairy farms are now investing in renewable natural gas (RNG) systems to improve their environmental impact and bolster their earnings. Through the use of large, anaerobic manure digesters, technology providers and farms have been working together to change the waste cycle paradigm by capturing the natural byproducts of waste decomposition and transforming them into renewable energy sources.
But RNG digester construction requires experience, knowledge, and manpower to make these large projects come to life. And few concrete companies have the background and resources to commit to RNG digester projects long-term. That’s why investors, farmers, technology vendors, and engineering firms have been coming to Brooks to build these facilities in and around the Sioux Empire.
Benefits of RNG Digesters
Renewable natural gas has become a booming industry over the last decade, and for good reason. RNG facilities carry benefits for every party involved, plus far-reaching positive effects for communities and the environment.
Environmental Benefits
RNG digester construction is carbon-heavy in the initial stages, but its carbon payback is rapid. The smallest of the sites we’ve helped build, for example, is designed to produce enough renewable energy to power more than 11,00 refrigerators for an entire year, all with around one-third of the carbon emissions of conventional natural gas.
Economic Benefits
For dairy farms, the addition of RNG digesters to their operations means adding multiple income streams to their business. Biogas companies lease the land from the farm owner, purchase the manure, and then return the digestate after the methane is collected for either on-site use or reselling as fertilizer.
From end to end, RNG digester construction provides financial gain for the farms, as well as the surrounding communities.
Agricultural Benefits
Waste management on dairy farms requires careful attention. With hundreds of thousands of gallons of manure to move, store, and eliminate each year, having the right solution can change how farms operate. RNG digesters provide an ideal solution for waste management by providing a practical method of disposing of manure while reducing environmental impact. And the byproduct of RNG production, the digestate, acts as a powerful fertilizer.
4 Key Challenges in RNG Digester Construction Projects
To get to a point where these benefits are possible, the contractors for each RNG construction project have a series of challenges to overcome, ranging from geographic to logistic issues. For concrete companies, the solutions take more than just the right tools to achieve.
Curved Concrete Walls
One of the first challenges is efficiently building curved concrete walls. Radial tanks require precision, and hand-built wood forms are extremely difficult to use on large-scale projects like RNG digesters. Pair that challenge with the need for a repeatable and mobile solution to build multiple tanks, and few concrete companies can meet the needs of these immense projects.
Rebar Fabrication
Steel rebar fabrication is a labor-intensive process, even for smaller projects. But when your project calls for 15- to 26-foot curved concrete walls, that fabrication becomes a massive undertaking. Without skilled and experienced teams, RNG digester construction projects simply can’t happen.
Labor Resources
The availability of skilled labor is a major challenge for many concrete companies. But having adequate resources available consistently for longer periods is even more challenging. Manure digester facilities can take anywhere from several months to several years to complete, depending on the scale of the project. Few concrete companies have experienced teams on hand for such extended periods of time.
Contractor Relationships
Digester facilities require special engineering, specialized technologies, and experienced teams to complete. Coordinating all the necessary subcontractors takes extensive relationships with local and regional concrete, electrical, excavation, and technology companies. Without those relationships, initiating a large RNG project could take years of planning and contracting.
Why Choose Brooks for RNG Digester Construction?
RNG projects require highly specialized planning and engineering, and few companies come with all the experience and knowledge necessary to bring these projects to completion. At Brooks, we can confidently say we are in the minority: we have completed multiple projects with several different companies. And with an experienced, year-round workforce on hand, we’re ready to bring renewable energy to more dairy farms.
Proven Partnerships
Since 2021, we’ve been building relationships with tech vendors, contractors, and investment groups to complete multiple RNG digester construction projects in eastern South Dakota. We’ve worked with Stockwell (Sioux Falls, SD), POET (Sioux Falls, SD), Brightmark (San Francisco, CA), and Biogest (Denver, CO) to build large-scale digester facilities that provide new economic opportunities for local farms.
Innovative Solutions
When we won the bid for our first project in Baltic, SD, we immediately began researching potential issues, challenges, and solutions that would allow us to complete the project efficiently and within the desired timeframe. At the same time, we wanted to make sure we could embark on new projects in a systematic and repeatable manner.
With innovations like EFCO’s Redi-Radius gang form system, we’ve been able to scale our efforts from a single facility to a dozen different RNG digesters across the eastern half of the state. We continue to innovate with each project, making it easier and more affordable for farms to invest in renewable energy production.
Coordinated Efforts
From the engineering company to the technology providers, we work closely with all involved parties to execute the design efficiently. We work with local groups like Stockwell Engineering, as well as national and multinational companies like Brightmark (partnering with Chevron) and Biogest. Our extensive experience in RNG digester construction makes us a clear choice for circular waste and biogas projects.
Local Green Energy Investment
South Dakota has a long history of agriculture, but renewable energy efforts are just starting to gain traction. These new efforts to build RNG infrastructure bring this booming industry into our communities without displacing our agricultural industries.
RNG Digester Construction Projects
Brooks Construction has been the sole concrete construction contractor for three major RNG digester construction projects in South Dakota, with more digesters currently underway. Here are the stats for these projects:
Mill Valley Dairy (2022-2023, Milbank, SD)
- Working directly with Sioux Falls-based Stockwell Engineering (onsite superintendent)
- 2 technology providers chosen by property owners (Brightmark, Biogest)
- Total digester capacity: 2.4 million gallons
- 2 digester tanks @ 105’ diameter, 26’ height
- 1 receiving tank @ 36’ diameter, 15’ height
- 1 digestate tank @ 36’ diameter, 15’ height
- Designed to convert 178,000 tons of cattle slurry into around 70,000 MMBtu of RNG per year
- Utilized EFCO Redi-Radius gang forms to build steel-reinforced concrete walls for circular tanks
Full Circle Dairy (2022-present, Hurley, SD)
- Working directly with Sioux Falls-based Stockwell Engineering (onsite superintendent)
- 2 technology providers chosen by property owners (Brightmark, Biogest)
- Total digester capacity of 4.8 million gallons
- 4 digester tanks @ 105’ diameter, 26’ height
- 2 receiving tanks @ 36’ diameter, 15’ height
- 1 digestate tank @ 41’ diameter, 20’ height
- Designed to convert 332,000 tons of cattle slurry into around 155,788 MMBtu of RNG per year
- Utilized EFCO Redi-Radius gang forms to build steel-reinforced concrete walls for circular tanks
Athena Digester Facility (2021-2022, Baltic, SD)
- Working with Sioux Falls-based Stockwell Engineering for Martin Energy Group
- 3 separate sites for 3 dairy farms (Mooody County Dairy, Boadwine Farms, Pioneer Dairy)
- NPL (a Centuri Company) selected as the technology provider
- 5 digester tanks @ 120’ diameter, 20’ height
- 1 digester tank @ 100’ diameter, 20’ height
- 1 influent/effluent tank @ 41’ W x 20’ L x 10’ D
- 1 influent/effluent tank @ 41’ W x 20’ L x 12’ D
- Designed to convert 462,448 tons of cattle slurry into around 217,000 MMBtu of RNG per year
- Utilized EFCO Redi-Radius gang forms to build steel-reinforced concrete walls for circular tanks
Read our full in-depth article on the Athena Circularity Center.
Call on Brooks for Your RNG Digester Construction Needs
If you’re seeking innovative ways to dispose of waste, create additional income, and improve the environment with your dairy farm, Brooks Construction is ready to help. We’ll bring our experience, partnerships, and expertise to your project.
Contact us today to get started.
Our Partners
Stockwell Engineering (Sioux Falls, SD)
POET (Sioux Falls, SD)
Brightmark Energy (San Francisco, CA)
Biogest (Denver, CO)
NPL (Phoenix, AZ)
Martin Energy Group (Tipton, MO)
EFCO Forms (Des Moines, IA)
