William de Lumley began his career in 1998 at Lafarge Granulats France, where he successively held the positions of Project Manager and Operations Manager. In 2007, William de Lumley continued his international career, first in India, where he created the new Aggregates and Concrete activity, then in Egypt until 2012 as Quarries Director, and finally in the Philippines until 2017, where he stimulated sustained growth in aggregates, concrete and speciality materials, and supported the integration of the Lafarge and Holcim entities.

After 10 years of multicultural experience, he returned to France in 2017 to lead the ready-mix concrete activity in the Côte
d'Azur region. In 2020, he moved to the Ile-de-France region, where he remained Director of the Seine Aval aggregates operational unit until 2023.

In october 2024, William de Lumley is appointed Keystone (materials activity) and Circular Economy Director at Colas. Reporting to the CEO, Pierre Vanstoflegatte, he joins the Executive Committee.