In an event that seems likely to bring down neighborhood housing prices, a mysterious white foam spewed out of sewage pipes on a road in the city of Xi’an on Tuesday afternoon, covering 200 meters of the street.

Video from the scheme shows the foam flowing out of three manholes on the street, giving the appearance that snow had fallen only on this small section of town. After workers wash the stuff away with water, more arrives to take its place. Eventually, however, they were able to clean the place up by the evening.

The following day, the local environmental department told reporters that the source of the substance was a nearby commercial concrete company, explaining that the foam was an agent used in the construction of metro tunnels. It had leaked into the sewer, flowing down a sewage pipe until finally spewing forth upon an unlucky street.

The substance is said to be not dangerous to humans.