Provide repairs and upgrades to the existing internal building fixed gas detection systems and provide a 3-year service and calibration contract for the internal building fixed gas detection systems at Derrinumera Landfill, Newport, Co. Mayo F28 TF89 and Rathroeen Landfill, Killala Rd., Ballina, Co. Mayo F26 TF29. The existing systems consist of Crowcon gas detectors and Crowcon vortex control panels. All equipment installed must be compatible with the existing system. Provide a 3-year service and calibration contract to the internal building fixed gas detection systems.