MONTREAL -- It has now been confirmed that REM light-rail construction is to blame for two sinkholes opening up in a wetland near the Pierre Trudeau International Airport in Montreal.

Environmentalists were surprised to find that the St-Laurent Technoparc had partially dried up, but the REM says it's not because of the sinkholes.

The company said the tunnel boring machine hit some soft clay while digging under the wetlands on its way to the airport, which caused the land to cave in essentially causing two sinkholes that appeared during the summer.

However, both the company and the Quebec Environment Ministry, who also investigated the situation, said the drying up of Herons' Marsh is not related to sinkholes.

REM director of communicaitons said the drying up of the marsh was caused by unseasonably dry weather, pointing to Environment Canada trends over the past decade.

In May, the area around the airport got four millimetres of rain compared to the average of 72.

The wetlands dried up in 2012 and 2016.

Environmentalist David Fletcher, however, doesn't buy the argument.

“It’s not a convincing argument," he said. "It has been very dry this summer admittedly, we acknowledge that, but it’s not a coincidence with the appearance of sinkholes that water went out. There still needs to be accountability.”

Fletcher has been going to the wetlands for over a decade and said this year, it didn't just dry up; it drained within a week.

REM workers have filled the sinkholes with soil and is replacing any affected plant life.

It is also filling the marsh with water.

Fletcher will be keeping a close eye on the area hoping the company takes more responsibility.