What are possible career options associated with a degree in Environmental Engineering?

As others have said, there are many options available in the field of environmental engineering. It sounds like you might be interested in LEED (Leadership in Energy and Environmental Design). This is a program sponsored by the U.S. Green Building Council (http://new.usgbc.org/). I would encourage you to look into this more! There are numerous different certifications that you can achieve within LEED. I'm not sure if colleges offer help with this certification, but it would be a natural progression with anyone with an environmental engineering degree. It is an exciting field, and one that is certainly sustainable within the environmental engineering profession. Best of luck!

I second the opinion express above. Environmental engineering is still a very new field and is a loose terms associated with green buildings, solar, wind, energy storage, energy efficiency, climate modelling etc. Each of these sub-fields have a different focus. For example a solar energy firm would need material science/physics people for basic research and mechanical and electrical engineers for large scale production and packaging of their solar modules. In energy storage research (fuel cells/batteries) research people would mostly be from chemistry, chemical engineering, material science background and the production /system engineering people will be from mechanical and electrical engineering. In green building firms it will be the architects, modelling and civil engineers who will take the lead.
Environmental/ energy engineering degree try to teach you all of the above at the same time thus giving you a very good perspective across the board. This will be very good if you are in an analyst position in a consultancy or in energy venture/ energy investment type of positions. However if you are in a research engineering role then you will have to have primary research skills as good as a civil engineer (in case of green building) or a chemical engineer (in case of battery research). So traditional engineering degrees give you similar opportunities to enter these fields as far as you are able to find the right guide/research group to get some good projects on your resume.
Good luck!

Environmental engineering and energy engineering are newer fields in engineering. The job opportunities out there are often quite interesting, although it's still a niche specialty in the broader engineering field, so there isn't as much of a job market as there are for electrical engineers and mechanical engineers. It's a field that is highly indexed to government funding, so job prospects will depend on budgets, which can sometimes change greatly. That said, the United States BLS says it's a rapidly growing sector, so that might work in your favor. If you go this route, most of your entry-level job titles are going to include the word "engineer", "specialist", "analyst" or something similar. Whether you're called a project manager or not, you'll likely be involved in a lot of project management. You might be working for a contractor, or you might be working for a municipality. There could also be international opportunities further along in your career. NCSU has a nice overview page.

As for Energy Engineering, UC Berkeley just created a new program last year. Here's what they say about career prospects: "There are many job opportunities for students who major in Energy Engineering, especially in green energy. Companies are hiring Energy Engineers, Clean Energy Specialists, Energy Conservation Engineers, Energy Efficiency Engineers, Energy Systems Engineers, Solar Energy Specialists, etc. Employment fields will include Renewable Energy, Photovoltaic Engineering, Waste Management and Recycling, Oil and Gas Production, Fuels Engineering, Energy Systems, Energy Generation, Energy Storage, Energy Transmission, and Energy Consumption, etc. both domestic and global. Some of these jobs may not require a master’s or Ph.D" More.

From what I know, environmental engineering is a really fast growing field that's going to only be in increasing demand as concerns for environmental impact and assessment grow in almost all industries, e.g. http://money.cnn.com/magazines/moneymag/best-jobs/2011/fast-growing-jobs/10.html.

There are a lot of different trajectories from what I can tell. A lot of environmental engineers work as part of the engineering team for large companies that are trying to understand what impacts new projects or manufacturing will have. Another approach is to join environmental engineering consulting companies that specialize in assisting industrial companies in ensuring that they're understanding and meeting environmental protection regulations. This can range from atmospheric modeling of exhaust streams, to taking soil contamination samples out in the field, to making business estimates for carbon pollution allowances or renewable energy credits. Another example of work would involve studying the environmental impacts of new technologies like fracking that are a huge question that will require a lot of engineering to figure out.

From what I can tell, there are also a lot of government positions at all levels for work in developing and enforcing environmental standards. One could also take more of a public policy approach and work to get involved in the writing of regulations either from positions at NGOs (like NRDC) or from government posts.