Not included: Operations sold or closed during 2013, our homebuilding subsidiaries (given the impending sale of WRECO and their relatively minor contribution of environmental impacts compared with our manufacturing facilities, we opted not to collect data from these businesses in 2013), and our wood products distribution centers (insignificant environmental footprint contribution compared with our manufacturing facilities) SOURCES Established internal databases used regularly by our operations Environmental data reported to the EPA and other regulatory agencies Annual companywide internal survey At the facility level, physical measurement, representative and other sampling, application of standard government factors, and recognized industry factors Calculations are performed using measured data as well as commonly recognized engineering standards.