Gran Sasso National Laboratory sits within a mountain aquifer that feeds water to a local aqueduct.


Chemical spills put Italy’s underground physics lab in jeopardy

Scientists fear for the future of Gran Sasso National Laboratory, a world-leading underground physics lab in central Italy, after prosecutors charged four lab leaders with endangering drinking water supplies. Sparked by a number of accidental spills that released small amounts of toxic chemicals into groundwater feeding a local aqueduct, the 28 September legal action could lead to at least two major Gran Sasso experiments being shut down.

Gianpaolo Bellini, a particle physicist at the University of Milan in Italy and a former spokesperson for Borexino, one of the lab experiments in jeopardy, says fears of contamination are “groundless.” But he says the lab itself is in a “very delicate situation.” He worries that research groups, particularly from abroad, might be put off by the possibility of legal action and delays to their work. “This [investigation] damages the reputation of the lab,” he says. “People will be more cautious about coming and therefore more cautious about investing their money.”

The largest facility of its kind, Gran Sasso consists of three huge experimental halls carved out of a mountain next to a motorway tunnel that connects the cities of L’Aquila and Teramo in Italy’s Abruzzo region. Sheltered from cosmic rays by 1400 meters of rock, the lab draws physicists from around the world to probe neutrinos, search for dark matter, and study other rare subatomic phenomena. But it has also attracted the ire of environmentalists. Some of the experiments rely on large tanks of organic compounds to detect subatomic particles, and critics worry that leaks could contaminate the surrounding mountain aquifer, which provides drinking water to hundreds of thousands of people.

Tensions came to a head in 2002 when researchers working on Borexino, which measures neutrinos from the sun, accidentally released some 50 liters of the hydrocarbon pseudocumene, which ended up in a local river. At the time, a judge in Teramo sealed off the hall containing Borexino, putting that detector out of action for 3 years and forcing another experiment to shut down prematurely. The leak also led the government to appoint a commissioner to improve safety at the lab.

But now the lab, run by Italy’s National Institute for Nuclear Physics (INFN), again finds itself in trouble. Prosecutors from Teramo, backed by a 1000-page investigative report, accuse Gran Sasso Director Stefano Ragazzi, INFN President Fernando Ferroni, and the heads of the lab’s environmental and technical operations of “negligence and imprudence” for having failed to correct safety flaws dating back to the 2002 spill.

The new investigation was triggered after researchers working on the CUPID neutrino experiment in August 2016 accidentally released a dichloromethane solvent, used to clean their detector’s crystals. Small amounts of the solvent somehow ended up in Teramo’s drinking water. The incident only came to light several months later, when the regional government indirectly revealed that the lab’s water had been diverted away from the aqueduct. Augusto De Sanctis, president of the nonprofit environmental group Abruzzo Ornithological Station in Pescara, filed a complaint soon thereafter.

De Sanctis points out that other minor accidents have occurred, including a small air conditioner fire in June 2016 that shut down one experiment for several months, and a minor spill of chloroform in November 2016. But he is most concerned about the potential for a larger spill involving the 1300 tons of pseudocumene in Borexino and some 1000 tons of mineral spirits in the Large Volume Detector (LVD), which also studies neutrinos. De Sanctis argues that the use of the chemicals is illegal under a 2006 law forbidding the presence of dangerous substances within 200 meters of drinking water sources.

The prosecutors agree. They accuse the Gran Sasso management of failing to adopt “measures needed to remove” the lab’s dangerous substances, particularly those in Borexino and the LVD. They also say the safety improvements ordered after the 2002 spill were never completed. Costing €84 million altogether (including improvements to the road tunnels and aqueduct), this work was supposed to include resealing the lab floors and overhauling the drainage system. Eugenio Coccia, who was director of the lab at the time, says he can’t say how much of the work was completed. “I was not responsible for the safety work,” he says.

A spokesperson for INFN says Ferroni and Ragazzi don’t want to speak about the “delicate situation.” They say the lab’s research is carrying on as normal, and the legal action “does not have a direct impact” on research. Spokespeople for Borexino and the LVD declined to comment.

In a 2017 statement, INFN argued that the 200-meter rule doesn’t apply to Gran Sasso because the “underground laboratory infrastructure” predates the 2006 law. But earlier laws imposed the same minimum distance, De Sanctis says, and the 2006 law requires the removal of preexisting substances. In 2013, Italy’s National Institute of Health told the lab that the 2006 law requires a “drastic reduction” in the lab’s activities as long as nearby cities rely on groundwater from the mountain. The lab appears to be moving toward this concession: In January, Ferroni wrote to Ragazzi saying it is “indispensable, although painful” to remove most of the pseudocumene and mineral spirits by the end of 2020.

If lawyers for Ferroni and colleagues cannot persuade the prosecution to drop the case, a judge will then decide whether to put the scientists on trial. To try to avoid that, the lab could decide to disband Borexino and the LVD before 2020, De Sanctis says. “It would be strange if the lab didn’t do something in response,” he says.

Andrew Sonnenschein, a physicist at Fermi National Accelerator Laboratory in Batavia, Illinois, who worked on Borexino as a postdoctoral researcher just before the 2002 spill, says that accident was caused by “chaos in the management” of the plant used to purify Borexino’s pseudocumene. But he insists the incident was “quite overblown” and says critics of Gran Sasso “don’t think quantitatively” about the tiny risk involved. “Gran Sasso is a wonderful facility and it would be a shame if these experiments had to shut down,” he says. “There is no public benefit to doing that.”

De Sanctis sees things differently. “I am a supporter of scientific research,” he says. “But research has to have its limits, particularly when it comes to basic rights such as the right to clean drinking water.”