As the building was under construction, in March 2006, Liberty Property Trust ran into trouble with Philadelphia's Plumbers Union Local 690, which had issues with the building's waterless urinals. The waterless urinals were part of the plan to make the Comcast Center an environmentally friendly building because they would save an extra of water a year. The plumbers union opposed the waterless urinals, claiming they were unsanitary and would provide less work for the plumbers. Philadelphia's Plumbing Advisory Board approved the waterless urinals on April 5 after a compromise, which stated that the building's owners and city officials would monitor the performance of the waterless urinals, was reached. Piping that would allow water to flow to the urinals in case they needed to be converted was installed in the Comcast Center, which Liberty Property Trust says was always part of the building's plan.