Headquarters. Walnut Creek, Calif.

Branch Offices. Brown and Caldwell has 40 offices nationwide.

Roots. Brown and Caldwell has been in business for more than 55 years.

Areas of Expertise. This full-service environmental engineering firm works with municipalities, government agencies, and private industry nationwide.

Key Markets. Business consulting, environmental services, information technology, solid waste, water, wastewater, and water resources.