Heavy machinery has been seen recently on the highly visible hillside overlooking Old Town from the west.
The Park City Water Department hired a contractor to build a 2.3-mile water pipeline linking the Judge Tunnel water source in Empire Canyon to the Spiro water treatment plant in Thaynes Canyon.
Clint McAffee, the Park City water manager, says the pipeline will carry water from the Judge Tunnel to the treatment plant before it is put into the drinking-water system. The water will be treated to meet drinking-water standards and, eventually, standards that must be met before water is released into a stream.
The Judge Tunnel has not been used as a drinking-water source since mid-2013 based on concerns about the quality of the water.
A section of trail in the vicinity is expected to be closed for another week or so.
The workers installed temporary barriers on the downhill side of the construction zone to ensure rocks do not roll down the hillside.