Johns Hopkins Howard County General Hospital (Columbia, Md.).The Medical Pavilion at Johns Hopkins Howard County General Hospital is a LEED-Silver certified facility, and it is the largest LEED-certified medical building in the central Maryland area. Some of the environmentally friendly specifics of the pavilion include an irrigation system that feeds the plants using rainwater drainage from the roof, a white roof that reflects heat, priority parking for fuel-efficient cars, recycled construction materials and an HVAC system that will conserve energy and improve indoor air quality. Johns Hopkins Howard County General Hospital also participates in all six HHI Challenges.