"We need a starting point from which to begin pulling cable," says Pieschl. "The building is basically complete, so the next step is to release it to electrical and mechanical contractors, who will begin constructing piping and cable trays. There's a substantial amount of electrical work required to supply mechanical equipment, motor controls and switchgears."

Construction currently is slightly ahead of schedule, project executives say. Once WP&L suspends plant operations to tie Columbia 1 and 2 to new equipment, project milestones will be measured in hours rather than weeks or months.

Tie-ins to Unit 2 will occur during an annual maintenance outage next January, when workers will have only six weeks to tear out the ductwork feeding the unit's chimney, then route new ductwork to the spray dryer and back. They also will be tying in new electrical equipment and interfacing it with plant controls. Crews will repeat the process on Unit 1 next March.

To accommodate new ductwork, crews already have rerouted and re-activated existing equipment during three weeks of scheduled downtime earlier this year.