How many lawsuits?
As far as I understand it, there is currently one lawsuit pending in the 9th circuit court that could put an end to this project. The lawsuit is called Save the Peaks Coalition vs. US Forest Service and has to do with the fact that nobody knows what will happen to someone if the treated sewage is ingested through the mouth, nose or eyes. Additionally, it is unknown what will happen to the animals who drink out of the 10,000,000 gallon storage pond.
There is also currently a lawsuit brought forth by the Hopi Tribe against the City of Flagstaff which could halt the sale of treated sewage effluent to snowbowl, rendering their pipeline useless. Arizona Snowbowl should be forced to see these lawsuits through to resolution before even one tree was cut.
As it stands right now, Eric Borosky (the Mr. Burns of Flagstaff) and Arizona Snowbowl are currently laying the pipeline and cutting down a lot of trees. Even though they could possibly lose one of these lawsuits and have to dig up the pipe.