The EPA is scrutinizing laboratory practices at the Colorado Division of Wildlife, worried that the infectious agents believed to cause chronic wasting disease could wash into public sewers and underground septic tanks.
Water regulators with the Environmental Protection Agency could require wildlife officials to alter plumbing at division laboratories in Fort Collins, Craig and elsewhere to ensure that the persistent protein – called a prion – doesn’t accumulate in water supplies.
“The concern is that there’s so little known about the prions, that we think we ought to be taking a relatively protective, conservative approach to things,” said Steve Tuber, director of water programs for EPA’s regional office in Denver. “We’re just being careful.”
For the moment, the agencies are exchanging proposals on how to handle the matter. At the root of the problem: How to ensure tiny bits of tissue, or other possibly contaminated fluids or animal hair, don’t make it through floor drains when laboratory areas are washed down.
The EPA hasn’t been a visible player in the CWD problem – a fatal brain malady in deer and elk – until now.
The federal agency’s timing could make things tough for the Division of Wildlife, as it gears up for a fall hunting season in which state workers are prepared to conduct up to 50,000 analyses on deer and elk heads to test for the presence of the disease.
“At this point, we’re still in operation (for testing). We intend to be – we hope to be – all the way through hunting season,” said John Smeltzer, a division supervisor. “If we need to modify our processes, we will do so.”
With archery season under way for nearly a week and some rifle hunting allowed on private lands, about 100 heads – most of them elk – have been submitted to the state for CWD testing, said Division of Wildlife spokesman Todd Malmsbury.
Neither agency could say what the ultimate solution will be. The EPA has recommended a number of possibilities, including the use of absorbent paper on lab benches to soak up blood or other fluids. The division has pledged to come back with some ideas of its own, Tuber said.
Prions pose the same problem as some toxic and radioactive contaminants: They appear to have a long life and survive in the environment for at least a few years. Researchers have found that animals placed in long-empty pens once home to infected animals can acquire the disease, presumably because the prions remain viable in the soil.
In addition, prions are hard to destroy, resistant to extreme heat – up to 1,100 degrees – sunlight and many disinfectants. Agencies responsible for containing the spread of CWD have often incinerated deer and elk carcasses at very high temperature to ensure destruction of the prion.
There are no known cases of a human developing CWD. Nevertheless, scientists urge people to avoid eating meat from infected animals. A related ailment, mad cow disease, which strikes cattle, has made the leap into humans, killing more than 120 people overseas.
Tuber emphasized that the Division of Wildlife isn’t disposing contaminated animal tissue “in any intentional way,” but that the EPA is concerned with residue left behind. “They are taking precautions; we’ve asked them to take additional ones,” Tuber said.
Of most immediate concern is a special EPA permit needed for a Fort Collins laboratory where parts of the brain, tonsils and lymph nodes are removed from deer and elk heads. When the lab is washed down, the rinse water flows to an underground septic tank. Under the law, the lab is considered an industrial discharger and is operating under temporary permission. But the EPA wants more steps taken before issuing a permit.
It will be several more weeks, after more detailed talks between EPA and Division of Wildlife scientists, before the agency will decide whether to grant a permit, Tuber said.
He said the EPA wanted to avoid interfering in the division’s testing program.
“We want to give them an opportunity to keep that protection in place, and at the same time be protective of groundwater,” Tuber said.
Also of concern is the division’s laboratory in Craig, where rinse water is sent to a public wastewater treatment plant. The solution there could involve pre-treatment of some kind before the discharge can be released into the sewers, Tuber said.
Smeltzer said the division will work with the EPA, but believes it takes significant precautions already. He notes that very small amounts of tissue are handled in the labs – the brain samples extracted are about the size of two grains of rice, he said – and that workers frequently spray down work areas with a disinfectant known to be effective in neutralizing prions.
Tuber said the EPA also needs to look at processing plants, where deer and elk are carcasses are prepared. “It’s something that we’re just starting to get to,” he said.