May Gurney waste chief Nicola Peake has left the company.
Peake spent four years as managing director of environmental services for the Norwich-headquartered infrastructure firm.
The company said she had left to pursue other opportunities.
Operations director Steve Jennings and managing director of public sector services John Wilkinson will remain in charge of the Environmental Services business.
A spokesman said: “Nicola made a great contribution to the business during her time with us and we wish her well in the future.
“May Gurney provides environmental services to 20 local authorities and serves 2.2 million households.
“We remain committed to building this area of our business and have recently won a number of contracts, including providing household waste and recycling services for Bristol City Council and for West Oxfordshire District Council.”