Officials Urge Caution After SEMASS Rejects Load
CHATHAM — A load of municipal trash from Chatham was rejected by the SEMASS trash-to-energy facility earlier this month after modest levels of radiation were detected from two of the trash bags inside. In response, officials are urging people to be careful when disposing of certain types of medical waste.
On Nov. 1, radiation detectors activated at the West Wareham facility when a trailer of trash from the Chatham transfer station arrived. The load was returned to Chatham where an emergency contractor used radiation detectors to sort through the trash, isolating the radiation to two trash bags which were, fortunately, close to the top of the load, Public Works Director Tom Temple said.
“There were approximately 20 adult diapers,” he said. Apparently, a member of the public had undergone medical treatment or testing utilizing radiation, which was excreted in urine held in the diapers, “and didn’t realize you’re not supposed to throw those in the household trash,” Temple said.
It was the first time in about a dozen years that radiation was detected in a load from Chatham, he said.
Such incidents are rare, said Nicolle Robles, spokesperson for Covanta, the company that operates SEMASS. Of about 45,000 trash loads received by the facility so far this year, only 15 have triggered the radiation alarm, which is extremely sensitive. In almost all cases, the radiation is medical in nature, typically from residents undergoing radiation treatment for cancer, Robles said.
“The radiation could also be from veterinary treatment of family pets such as cats or dogs,” when feces, cat litter or wipes are disposed of in the trash, she said.
Cape Cod Hospital Chief Physicist Gabor Menyhart said radioactive medical waste is handled carefully and methodically in hospitals and medical facilities, which segregate the waste and monitor radiation levels.
“The more difficult items to catch are those which leave the facility inside of the patient,” Menyhart said. While that radiation may be transferred to tissues and bandages or other items that come into contact with excreta and other bodily fluids, “most diagnostically used radioactivity is short-lived, so the material decays away very quickly,” he said.
The most commonly used radioisotopes have half-lives of between 110 minutes and just over 11 days, Menyhart said.
“At CCH, patients are provided instructions to dispose of contaminated items if they are given a procedure where the half-life of the radioactivity administered is greater than one day. The instructions include details for reducing radiation dose to others and reducing the likelihood of contaminated items entering into an unwanted routine solid waste stream,” he said.
The discovery of the radioactive trash bags triggered a complex safety procedure. Following protocol required by the state Department of Public Health’s Nuclear Incident Advisory Team, special provisions were made to allow the contaminated load to be returned to Chatham, Robles said.
“The truck details are loaded into a statewide database to alert first responders (fire/police) in the event the truck has a highway accident on the return trip,” she said. Covanta does not charge the town for the rejected load.
When the discovery was made, Temple consulted with long-time employees at the transfer station and learned that a similar incident had happened in the past. The town was able to contact the contractor, Rockland-based Atlantic Nuclear Corp., which came to the transfer station and sorted through the contaminated trash to find the source of the radiation. Technicians loaded the items in a five-gallon container, which was then put in a lead-lined 55-gallon container, which is being stored on site. Those technicians will return in two or three weeks to test radiation levels again, after the isotopes have had time to degrade.
“Once they take the readings again, they can just throw it in the regular trash,” Temple said.
Temple could not immediately say how much the contractor would be charging the town for its response.