A water-treatment plant is under development on the edge of Thaynes Canyon, one of City Hall’s larger construction projects. The plant is one of the municipal projects and programs officials intend to highlight during an open house planned on Tuesday. Jay Hamburger/Park Record The Park City Ice Arena is expected to temporarily close later in 2021 to allow crews to replace the ice surface and perform other maintenance work, one of a series of projects City Hall plans to outline at an upcoming open house. The ice is replaced every five years as part of the normal maintenance schedule. The process involves melting the ice, touching up lines and logos that are affixed to the floor below the ice and then freezing a new ice surface.