U plans facility to process animal remains

Geoffrey Ziezulewicz

On any given day in the University’s Veterinary Diagnostic Lab, scientist Ron Joki will dispose of anywhere from hundreds to thousands of pounds of animal carcasses and remains.

Whether from animal research or small tissue samples, the University must dispose of large amounts of animal matter.

The University will take a step forward in disposal techniques when it adds a tissue digester to the vet lab facility on the St. Paul campus this summer.

Currently, the University generates more than 1 million pounds of animal remains annually from health sciences and veterinary research, Facilities Management officials said.

The tissue digester will be the first of its kind in Minnesota, said Jim Collins, a professor of veterinary diagnostic medicine and proponent of the digester.

The digester is a stainless steel vat. The animal remains are lowered into it and chemicals are pumped in, he said.

Aided by high heat and steam pressure, these chemicals liquefy the remains. The process destroys any infectious germs in the animal remains.

Next, water is added to the soupy remains, he said, and the liquid is then safe to flush into the sewage system.

About 10 percent of the original weight of the remains stays solid, but that is also safe to flush into sewage lines, Collins said.

The remaining liquid and solid matter is approved by the U.S. Environmental Protection Agency for

disposal into the sewage system, Facilities Management officials said.

The digester has a 7,000-pound capacity and can digest that amount of animal remains in about six hours, Collins said. That equals almost five 1,500-pound cattle carcasses, he said.

Animals whose remains will be digested include cattle, pigs, sheep, goats, horses, dogs, cats, rodents, chicken and turkeys, he said.

Collins said the decision to construct the digester came from problems with current animal disposal methods.

Currently, the University ships its animal remains to landfills in Minnesota and North Dakota.

The North Dakota landfill recently stopped accepting the remains

because of infection and safety concerns, Collins said. Another company that recycles the University’s animal remains into products such as pet food had similar concerns, he said.

Possible environmental contamination when moving or transporting the remains is another reason for the digester, Collins said.

“It’s not the best handling of this waste to truck it across the state,” he said.

The machine will be built by Waste Reduction by Waste Reduction Inc., or WR2, an Indianapolis-based business that invented and owns the digester patent.

The technology has been around for about 10 years, WR2 President Joe Wilson said. He said digesters have been built at a handful of research and governmental institutions across the country.

Wilson and Collins said the University could potentially generate revenue from the digester because it is the only one of its kind in the state. For example, government agencies can pay to use the digester for dealing with infectious remains such as deer with chronic wasting disease.

Wilson said the liquid remains resemble “a heavy beef broth,” dark as coffee but a bit thicker.

Wilson called the solid byproduct of the digester “bone shadows” because they maintain the form of bones but lack the protein that makes bones hard and heavy.

“It looks like bone, but if you try to grab a horse skull, it will crumble in your hands,” he said.

Wilson said digesters can be used for pet cremations. Cremating a dog typically costs $90.

“One dog going through that will pay for all the chemicals and the cycle,” Wilson said.

Pet remains could be put in and kept separate from other remains, he said.

“We have special cat and dog baskets,” he said of the mechanism that lowers animal remains in to the digester. “When it’s done, you have the bones of your dog or cat. You can take the bones out and crush them and then you can put them in a real nice urn.”