Experts say healthcare facilities are among the largest users of energy and water in their communities. Now hospitals, physician offices and outpatient centers across the country say they're building and buying green in an effort to reduce their environmental footprint. In the St. Louis area alone, every major hospital system is undertaking several environmentally friendly initiatives. Efforts range from changing to energy-saving, low-mercury light bulbs to analyzing which patients can receive medications held in biodegradable paper cups instead of plastic.