The process involves pressurising sections of each system with a nitrogen-helium mixture and then checking the joints to be satisfied that the system is leak-tight. When the testers are satisfied that a given section is leak-free that section is vented down.

The tests are taking place late in the evening and through the night. Most of the venting will happen at night-time/early morning and at weekends.

The noise levels throughout the testing process will be within the conditions laid down by Mayo County Council.