1. Professor Emeritus, Colorado State Univ., 2201 Apache Ct., Fort Collins, CO 80525.
2. Project Engineer, Earth Engineering Consultants, Inc., 4396 Greenfield Dr., Windsor, CO 80550-8010 (corresponding author).
3. Lean Advisor, Encana Oil and Gas Inc., 305 West Magnolia St., # 277 Fort Collins, CO 80521.