People living near Delhi Airport in India claim that poop—human poop, to be exact—has been pelting them from the sky.
Last Friday, the country’s environmental court, the National Green Tribunal, tasked a committee to investigate whether the feces are of human origin. The order came after Delhiites complained, again, that waste has been raining on their homes.
The court suspects the feces could be bird poop—what makes them think it belongs to avians is unclear. Excrement samples will be collected by the Directorate General of Civil Aviation, Central Avian Research Institute, and Central Pollution Control Board, according to India Times.
But the culprit seems obvious. Last year, residents from the same neighborhood issued several complaints about aircraft seeping sewage mid-air. It’s difficult to say whether Delhi Airport experiences a higher rate of this, but other airports, such as Salt Lake International Airport in Utah have reported similar incidents.
“Satwant Singh Dahiya, a resident near New Delhi’s airport, filed a case in October saying houses in his neighborhood were damaged by feces dumped by airlines at night,” Bloomberg reported in December 2016.
“In another incident, a 60-year-old woman suffered a shoulder injury in December last year probably caused by human excreta falling from the skies,” Bloomberg wrote.
The case involving 60-year-old Rajrani Gaud involved a frozen chunk of ice containing feces and urine. Gaud told the Times of India the football-size chunk ricocheted off a roof, nearly missing her head.
The National Green Tribunal, as a result, ordered India’s Directorate General of Civil Aviation to prohibit planes from releasing human waste containers while in the air. If a plane’s toilet repository is found empty upon landing, the airliner will pay a fine of 50,000 rupees, or $777.
To be clear, planes can’t empty their sewage tanks mid-flight. Crew can only access wastewater tanks from a valve on the outside of the plane, according to the Federal Aviation Administration.
So what’s going on? When a plane has a faulty wastewater system, something called “blue ice”—poop, pee, and a toilet deodorizer called Anotec—can seep onto its exterior. The air temperature freezes it into chunks, and when the plane descends, the icy mixture breaks away.
Dozens of “blue ice” accidents occurred in the US over the last several decades. An especially large chunk tore a hole in a California couple’s roof in 2006. Similar incidents have been reported in England, the Netherlands, and China.
Last year, India’s Central Pollution Control Board again suggested the feces might belong to birds. Alas, a chemical analysis of the waste confirmed that, yes, it was human.