B757 Captain experiences a LE Slat disagree EICAS message during approach. Checklist procedures are complied with and after declaring an emergency; an abnormal flap landing ensues.

Narrative

On approach Pilot flying (Captain) called for Flaps 1; Pilot not flying moved flap lever to Flaps 1 detent; Pilot not flying called LE SLAT DISAGREE EICAS. Pilot flying confirmed EICAS. Pilot flying asked the Pilot not flying to confirm flap lever in correct detent; Pilot not flying confirmed flap lever in Flaps 1 detent. Pilot flying called for LE SLATS DISAGREE checklist. ATC was notified and aircraft was vectored off the approach and to a safe area. Pilot not flying conducted and Pilot flying confirmed the LE SLAT DISAGREE checklist was completed. Operations and Maintenance Supervisor were contacted via radio to inform of situation and intentions. Pilot not flying confirmed runway distance via NON NORMAL landing performance data in AOM and based on weather and ILS availability crew decided to land ILS 07. Once the aircraft was fully configured and all checklists were complete; ATC was notified to declare the emergency. An uneventful landing ensued and the aircraft taxied to the ramp. Once in the blocks a logbook entry was made and maintenance was briefed. The aircraft was then turned over to maintenance. The Captain then went inside and briefed the on duty Assistant Chief Pilot on the details of the event.