The interviewer is trying to assess your personality and fit for the culture of the company. Before answering this question, take into account how this company is structured in terms of workdays, time spent in the office vs in the field, casual vs formal, small start-up vs. large corporation, etc. Since most environmental projects are organized around teams, highlight your desire to work in a team-oriented workplace. Discuss your work style and try to word your answer so that it blends well with the company's vision. Don't talk about how your ideal workplace is one with lots of vacation time, and don't directly recite the job description or company's 'about us' page. Make it personal to you.