Radioactive cat litter from Tilton diverts delivery of waste going to Concord

TILTON — Of all the horror stories that are told as Halloween approaches, one stands out as truly frightening: being billed in excess of $6,500 for the disposal of radioactive cat litter. Is that even a thing?

“I didn’t know radioactive kitty litter was a thing, either,” said Tilton Town Administrator Jeanie Forrester when asked about the invoice the town had received after their solid waste hauler picked up a load that contained the contaminated substance.

Tony Belanger of Pinard Waste Systems said the incident began last November when a truck carrying a load from Tilton pulled up to Wheelabrator Concord’s waste-to-energy facility. Like other waste-disposal sites, the facility employs a radiation detector when a truck enters, and if it detects too high a level, an alarm sounds and the workers have to do a safety check.

“They have to make sure it’s not a bomb or something,” Belanger said.

The procedure is to have the driver pull over to the side of the road and the crew slowly unload the truck and move the material around in order to pinpoint the problem. They then move the contaminant to a storage container and wait for the radiation level to drop.

“With this particular instance, they didn’t have room on the floor to dump the material out and wand it,” Belanger said, referring to the radiation detection wand. “So they asked me to try to find an alternative facility.”

Bow Recycling Center agreed to take the load and have the Department of Environmental Services do the testing on site. The problem was determined to be radioactive cat litter, which was set aside in a storage container to be tested periodically until the radiation level dropped to acceptable levels so it could be disposed of.

“This was Nov. 30 of last year and I think it didn’t get resolved ’til January,” Belanger said. “They kept going back to wand that, but it hadn’t dissipated enough, so there was an extremely strong dose.”

He explained that it is not unusual to find radiation in cat litter, but usually it dissipates quickly.

What makes it radioactive?

Normally, cat litter becomes radioactive because of radioiodine treatment given to cats with hyperthyroidism. The radioiodine rapidly travels through the bloodstream and most of it is absorbed by the cat’s body, with only a small amount remaining to be excreted by the kidneys into the urine. It is the clumps of urine in the cat’s litter box that presents the greatest radiation hazard.

When radioiodine is used as therapy for human patients, the excess radiation is flushed down toilets, where the sanitary sewer system serves as the solution to the problem. The short half-life of radioiodine, combined with the massive dilution effects of the sewer system, make it safe.

Since 1984, when radioiodine therapy for cats was introduced, regulatory agencies required that hyperthyroid cats’ radioactive waste also be flushed into the sanitary sewer system. Many brands of biodegradable and hence flushable cat litters were developed for the purpose.

Alternatively, for cats that reject such litter, empty 5-gallon buckets, available from hardware stores, can be positioned next to the litter boxes, allowing pet owners to collect the clumps of cat litter and seal them in the buckets. To meet the 10 half-life standard for dissipating the radioactivity, the buckets should be held for three months before disposing of the cat litter with the regular garbage.

The covered container can also be turned over to the animal hospital or veterinary facility where the cat received its radiation treatment. The facility stores and monitors the products until the radiation is deemed safe for disposal in the garbage.

Because landfill facilities screen all of the waste passing through their entrance gates using stationary geiger counters, setting off an alarm requires the contents of the truck to be inspected by a qualified representative or physicist. Identification of the source of the radioactive material in the waste has the potential to lead to fines.

The town of Goshen prohibits the placement of cat litter in its trash compactor, requiring that it be put into demolition, because used cat litter and the chemicals it contains have impacted the function of the compactor.

Belanger said the problem with Tilton’s load may have been because the quantity of cat litter had been stored up, or because there had been an extremely strong dose.

“I don’t know, but it didn’t dissipate within a week or so like it normally does,” he said. As a result, the bills from the engineering firm that was preparing reports for the Department of Health and Human Services and the Department of Environmental Services built up. “Of course, they don’t do that work for free,” Belanger said.

“Normally — I’ve been doing this for 37 years — I typically see this once or twice a year at different facilities,” he said, “and it’s normally a very quick and painless process, almost to the point where you don’t even know what happened.”

It’s not just cat litter; nursing homes sometimes dispose of adult diapers in the trash, and patients with radiation treatments can leave traces of that radiation in the disposable undergarments.

Also, because most cat litter is made from clay, it can contain elevated levels of naturally occurring radionuclides, and large amounts of cat litter can be measurably radioactive. Shipments of cat litter have been known to trip radiation monitors.

Sometimes, it is not the cat litter itself that is radioactive. Organic cat litter used to absorb liquids at the Waste Isolation Pilot Plant, an underground nuclear waste dump near Carlsbad, New Mexico, sparked a chemical reaction that led to a radiation leak in 2016. Although no one was inside the plant when the drum burst, the facility's air ventilation system spread some of the gases outside, exposing 21 workers to low doses of radiation.

Weird set of scenarios

Belanger said Tilton’s high bill for the load of radioactive waste was due to “a weird set of scenarios.”

“I’m usually dealing with one party only,” he said. “If I brought the same load to Casella over in Allenstown, who also have radiation detectors, OK. They always have the room. They would never have asked me to send that truck somewhere else.

“The only thing that was different about this time was that Wheelabrator just happened to be full up, with no floor space to work. Otherwise, we wouldn’t be talking right now. It would have been put in a corner, they would have ... tested it a couple of times, Wheelabrator has the on-site people that they don’t charge anything to fill out a report, and no one would have known about this. No one would have gotten a bill for it.”

The night before Pinard took the load down, Wheelabrator had an outage that shut down the facility, but it was too late to notify the trucks that would be arriving in the morning. As a result, the facility quickly reached capacity for holding material.

“It was just the perfect storm of what could go wrong with this type of load,” Belanger said.