Requiem for a digester

Billions of microbes, and a $100 million waste-to-energy project, quietly dying

Bob Yost stands beside windrows of finished compost, one of the by-products of the Heartland anaerobic digester facility. The large domed digestion tanks stand in the background.

Neat rows of tanks, each with a capacity of 1.7 million gallons, tower above the plains. Three lagoons border the site to the west and north. Pipes of various sizes interconnect the tanks, along with the intake facility, unseen underground pipes, a tapered smaller tank, compressors and other mechanisms, creating a single organism. An unassuming rectangular building, small beside the tanks, houses the control room that oversees the entire site. To the far northern end is one last pipe, which connects to an interstate gas pipeline.

We’re in LaSalle, 60 miles northeast of Boulder in Weld County, the heart of the state’s oil and gas production. But this isn’t another oil and gas site: it’s an anaerobic digester. With its six “bioreactor” tanks, the facility is capable of turning vast amounts of agricultural and food waste into biomethane, a win for both waste diversion and renewable energy. It’s the only facility of its kind in Colorado, and the largest in North America.

And for about nine months, billions of microbes churning inside the bioreactors — specifically methanogens, microorganisms that live at high temperatures and produce methane in oxygen-deprived environments — turned nearly 1,000 tons of waste into energy every day. Lots of energy: at full capacity, the facility could produce 4,700 dekatherms of energy daily, roughly the capacity of a 20-megawatt power plant, which could service around 20,000 homes. The methane, injected into a gas pipeline and sold to Sacramento to support its clean energy goals, was the highest-value product of this digestion process. But it wasn’t the only one. The digester also produced a superior-quality, pathogen-free compost as well as a liquid soil amendment (LSA), both certified by the Organic Materials Review Institute (OMRI) and suitable for organic use.

Pipes, including a pipe transporting methane away from the biodigester, pass in front of an apparatus that “cleans” the methane and prepares it for injection into the gas pipeline.

In the process, it produced almost no waste. Of the nearly 30,000 tons of material that fed the digester each month, much of which would otherwise go to landfill, it was only trashing about 100 tons — about .003 percent of its intake. Everything else was digested into methane, compost or LSA, or sent to be recycled. The digestion facility also accepted packaged food waste — expired milk, cheese, lettuce or otherwise, still wrapped in plastic, or inside a can or cardboard box, or all of the above. It filtered out the packaging using separator machines called a “Doda” and a “Tiger,” as powerful as their names sound. The digester was eating through the equivalent of 243.1 million pounds of food waste and 546 million pounds of dairy manure annually. 

But all of that ended Jan. 28, when Heartland Biogas, who owns the facility, stopped feeding its anaerobic digester. The billions of microorganisms have died. Rows upon rows of finished compost are still curing in the sun. The lagoons are filled to capacity with LSA with no destination. Sacramento has to source its clean energy elsewhere.

Bob Yost, owner of A1 Organics, which operates the intake portion of the Heartland facility, grows animated as he explains this history.

“I’m using my outside voice again,” says Yost, a Weld County native and respected veteran of the national compost industry. “My wife says, ‘Bob, use your inside voice. Take a deep breath, Bob.’”

Yost has every reason to let the situation get the better of him. He spent nearly a decade helping bring the digester to life, and more than 40 years processing the Front Range’s yard waste and food waste into finished, organic compost at his three A1 facilities. His company invested millions into its portion of the Heartland operation — a $102 million project overall — and spent years negotiating contracts with dozens of large companies to get their food waste sent to the digester, including haulers servicing thousands of smaller businesses. Others in the industry speak of Yost with admiration, and credit much of Colorado’s waste diversion success to his steadfast commitment to composting, or “organics recycling.”

Dan Matsch, another leader in the Front Range recycling scene, manages both the composting program and the Center for Hard-to-Recycle Materials at Eco-Cycle in Boulder. He’s worried about the impact the digester shutdown will have on the City’s newly expanded zero-waste initiative.

“Because we have such a dedicated partner like Bob, he’ll probably let us keep doing what we do,” Matsch says — meaning, sending high volumes of food waste his way, but to be composted instead of digested. “But if he were to decide no, forget it, then we and every food waste collection effort in the Front Range would be in great jeopardy.”

“To walk away from this project — it’s just crushing,” he adds.

Perhaps more remarkable than the forced shutdown of the digester (more on that shortly) is just how much “waste” this project had quietly been turning into energy for nearly a year. Food waste from Boulder, Denver, Fort Collins and beyond, and manure from two nearby dairies, which sent up to 600 tons of manure per day, entered the Heartland facility in a steady procession of semi-trucks. McDonald Farms, a 50-year-old local environmental services company, was a primary transporter of material to the digester. The highest-volume material they hauled was grease, pumped out of thousands of grease traps in restaurants, hotels and other facilities around the city — eight truckloads of it every day.

“We do 180,000 gallons a day, just of grease, and every bit of that was being used by Heartland to make gas,” says Scott McDonald, owner of McDonald Farms. He’s spent $100,000 outfitting his company to service the digester, and another $60,000 to revert equipment to the pre-digester days. “The cost is going to go up for our customers, which makes it tough on everyone, because a vast majority of that is [now] going to the landfill.”

Six digestion tanks, or bioreactors, were digesting up to 30,000 pounds of food waste and agricultural waste every month and turning it into clean energy at the Heartland Biogas anaerobic digestion facility.

“It’s just a shame,” McDonald adds. “An absolute shame.”

He raises an important point: with the digester, a company’s decision to not send food waste to landfill wasn’t just a responsible one. It was an economical one. Because of the volume and scale of digestion, the high value of its products, especially the methane, and what seemed a stable 18-year contract with Sacramento, sending food waste to somewhere other than the landfill was a cheaper choice for the first time.

“The biggest reason we have a low diversion rate is because the landfill is so cheap, and the economic way to combat that is by bringing down the cost of alternative diversion programs,” says John Griffith, owner of Alpine Waste, Denver’s only commercial compost hauler. Alpine grew its compost services to include a number of large commercial grocers sending tons of packaged food waste that would otherwise be landfilled to the digester in LaSalle. “It costs more to compost than it does to landfill. But with the digester, they’re about equal.”

“Without this digester, composting will never be able to compete,” he says.

The Heartland digester changed that paradigm, briefly. But now, the anaerobic digester is slated to close permanently. That’s according to the most recent civil action filing from Heartland’s lawyers. Heartland, a subsidiary of the multinational energy corporation Electricité de France (EDF), is suing the Weld County Board of County Commissioners, the Colorado Department of Public Health and Environment (CDPHE) and four of its staff, and the Colorado Department of Agriculture (CDA). They’re citing a taking of Heartland’s private property without just compensation, deprivation of due process and misapplication of the law, in eight counts against the defendants.

Here’s why:

In the first half of 2016, nearby residents complained of odor from the digester. According to the lawsuit, 80 percent of complaints came from 10 people. Around that time, Weld County inspectors conducted odor testing, and cited one violation — a type of violation which, according to Jeremy Neustifter, planner at the CDPHE Air Pollution Control Division (APCD), is rare and difficult to document. Nonetheless, when Heartland received a compliance order from the APCD in response to the violation, it immediately took action, spending more than $1 million and committing an additional $3 million to odor mitigation technology. An additional 800 odor tests yielded no further violations.

“They were on time with all of their compliance requirements,” Neustifter says. “The idea is, OK, you’re having odor issues, let’s figure out how to mitigate it first.”

The anaerobic digester in LaSalle was taking in thousands of tons of industrial food waste, which would otherwise end up in the landfill, each month. Christi Turner

That’s how the state entity charged with regulating air quality handles such issues. But along the way, the odor issue went before the Weld County Commissioners as well. And there, in what’s described in the civil action as a “kangaroo court,” the hearing about odor transformed into something else entirely: a controversy around the facility’s Certificate of Designation (CD). That’s the all-important document the County must grant for this type of facility to operate in its jurisdiction.

The validity of Heartland’s CD had recently been called into question in a November 2016 letter from First Assistant Attorney General at CDPHE, David Kreutzer. Kreutzer wrote that in his determination, when Heartland Renewable Energy was purchased by EDF in 2013 and took on the new name Heartland Biogas, the CD didn’t transfer to the new entity, although ownership of the facility did. Thus, Kreutzer wrote, he considered the Heartland CD invalid. This was just weeks before the county hearings, and the first Heartland had heard of any issue with its CD, according to the civil action filing. In the nearly four years since the 2013 transfer of ownership, no issue with the validity of the CD had ever been raised.

“When Kreutzer wrote his letter, he did not have and did not review the multiple agreements, approvals, and other historical documents in which the Commissioners and the CDPHE acknowledged again and again that Heartland did in fact have a valid CD,” the civil action reads. “Kreutzer’s conclusion was directly contrary to three years of acknowledgements and commitments made by Weld County and CDPHE.” For this unexpected reversal and the dramatic impact it had on Heartland’s digester operations, Kreutzer is named a defendant in the lawsuit.

While the CD controversy was taking hold, another issue cropped up: in a similar, unexpected reversal, staff of the CDPHE Solid Waste Management division told Heartland that its LSA was suddenly being considered solid waste instead of a soil amendment. That meant that Heartland’s distribution of the LSA — at this point already approved by the Colorado Department of Agriculture and certified organic by OMRI — would be considered illegal. According to the civil filing, this arbitrary change in position unjustly threatened Heartland’s ability to operate, and got three more names — CDPHE Solid Waste Management staff — added to the list of defendants. (In just the past few weeks, however, CDPHE and CDA retreated from their position and once again allowed the LSA to be distributed as a soil amendment.)

The lagoons at the Heartland facility are filled to capacity with LSA with no destination since the digester ceased operations in January. Christi Turner

Over the course of the county hearings, one Commissioner in particular — Barbara Kirkmeyer — seized on the CD issue as a reason to shut down the facility. According to the lawsuit, the County Commissioners looked “for any pretext” to justify a shut-down, and “conducted no less than seven separate compliance inspections of the Facility, most of which were unannounced or conducted with little notice,” with an unprecedented level of scrutiny. (The County declined to comment for this story.)

By Dec. 28, 2016, the County Commissioners demanded that Heartland cease operations.

“We presented, and we still believe, that we have a valid certificate of designation. In the spirit of cooperation we gave (the Commissioners) some options to look back at the documentation we provided, and vote or do whatever they needed to do to get themselves behind the certificate of designation,” says Jason Thomas, plant manager at Heartland Biogas. “We’re just really disappointed in the way that the Commissioners looked at that. They had a lot of options… suspension is a pretty severe one, based on a facility that’s proven compliant.”

But in January, seeing no other recourse, Heartland complied and suspended operations — then sued.

Now it’s June, the methanogens are dead and the lawsuit is ongoing. It’s now up to the courts to determine whether the actions against the Heartland digester facility were irrational, arbitrary and a misuse of authority, as alleged in the lawsuit, or whether a shutdown was truly warranted.

In the lawsuit, EDF/Heartland make clear that their intent is to recoup their losses, not to restart the digester. But once the lawsuit is finished a resale of the facility is possible, and sources confirm that there have been inquiries from potential buyers already. Even if that happens, it will take time.

Despite this possibility, Yost still seems to be in a bit of shock.

“It’s a travesty what’s going on. It’s beyond logic,” he says. “Weld County had the potential to be the fossil fuel and renewable energy capital of Colorado.”

For now, the story of the Heartland anaerobic digester may become an elegy for that potential.

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