2011:455 - NEPHIN VALLEY GROUP WATER SCHEME, Mayo

This group water scheme project involved pipe-laying to the north and south of Nephin Mountain in north-west County Mayo, and works across various townlands in the parishes of Addergoole and Crossmolina. The region is dominated by Nephin Mountain (806m OD) to the south and by Lough Conn to the east. The total length of pipe to be laid is c. 42km. This consists of 29km of main pipe and 13km of minor, service pipe. The outside diameter of the main pipe wall varies from 63mm and 90mm to 125mm, while the secondary, service pipe ranges in diameter from 13mm to 38mm. Construction work began in June 2011 and is ongoing at the time of writing.
Substantial areas of pipeline were laid using the directional drilling method. This process involves using a specialised heavy rig to drill a hole (through which the water pipe is subsequently fed) horizontally, c. 1.5m beneath the ground, in horizontal lengths of up to 100m. Pits are excavated every 100m. This construction method limits the amount of open ground visible during monitoring. Where the directional drill could not be used, machine open-cut trenching was employed
Works associated with the scheme took place in road verge, within roads and in fields. A fulacht fiadh was found during monitoring in Massbrook South townland (coordinates 116561.7 304765.3). The site was identified in a directional drilling pit under c. 35m of tar and road fill on the side of a local road. The site (c. 40m OD) was sampled for radiocarbon dating and preserved in situ.

Coosan, Athlone, Co. Westmeath