There are four main categories of employers in the environmental law area. The nature of the work you do will largely be determined by which category of employer you end up working for. Attorneys at firms cover a wide variety of environmental issues in their daily practice. There is ample opportunity to get a broad feel for the practice. Many firm attorneys advise clients on issues ranging from environmental compliance to land use to permit regulations.
Firms offer nice pay bonuses that are hard to match in the public sector.
Many large corporations hire their own attorneys who work only for that corporation. These companies usually have substantial interaction with environmental law, leading to a variety of experience comparable to that in a firm. Since you have only one client, the corporation, there is not as much client diversity as you would find in a firm, which may have many different clients at the same time. Principally, the environmental lawyers that work for government agencies are interested in enforcing the environmental laws of the federal or state government. They also look over documents and proposed laws to see if they comply with the existing environmental laws.