[music] Not only is CTA’s fleet becoming greener, its facilities incorporate green technologies as well. CTA headquarters was designed with Leadership in Energy & Environmental Design (LEED) standards – and includes a green roof. It’s a series of layers that are added to a conventional roofing membrane, of which of course is designed to keep water out of the building There’s first of all a layer of soil or growing medium for the vegetation. Then there’s a separator that separates that soil from a water retention layer. Then there’s insulation, then finally the roofing membrane which is underneath it. CTA's green roof was installed in 2004. Besides the obvious beauty, there are many benefits to installing a green roof. A conventional roof, one of the causes of its deterioration is solar energy. So the green roof layer protects the roof membrane from that kind of deterioration and it can cause the roof to last 2 or 3 times longer than it would otherwise.
Re-roofing a building is a significant capital expense, and if you can postpone that, instead of 10 or 15 years to 30 or 45 years, that’s a significant savings. In addition to it lasting longer, a green roof also: lowers building heating and cooling costs, reduces storm water runoff, keeps rainwater out of the sewer system, filters pollutants out of air and rainwater, and reduces urban heat island effect. There’s that thing called the urban heat island effect, which is a dome of hot air that generally covers urban environments When cities are built up with buildings and pavement, those things capture and retain heat— it’s significantly different at night because these structures hold the heat, and they don’t allow the area to cool down as much. Some studies indicate it could be as much as 25% difference between having a green roof on a building and not. So the CTA takes care of its riding customers every day, and it’s also making every effort to take care of our environment. It's all part of making Chicago the most green city in the world.
CTA is continuing to look for other green initiatives to further reduce the impact of its operations on the environment..