United Utilities were required to build a new spillway on the New Rivers Bridge Dam on Saddleworth Moor. The dam is a Victorian earth fill dam, very long 20-30m piles were needed. Access was an issue such that the only practical solution was driven piles. Bored piles would have been much more expensive when enabling works were considered. The Engineer would have preferred bored piles, despite the cost and contamination risk, and took some convincing to allow driven. We had to carry out extensive vibration monitoring and testing regimes, including setting up a monitor in a tunnel through the dam wall. All the monitors’ recorded minimal vibration and the tests were all good, so the Engineer’s fears were unfounded.