To answer the OP's question, summer internships at local legal services organizations are not usually highly competitive. In contrast, summer internships at major national non-profits, especially impact litigation outfits, are often very competitive. I don't know much about the major environmental non-profits, but if you are interested in environmental law, you might also want to think about local options such as your local government's environmental protection agency and legal services organizations, particularly those that do housing law (which often intersects with concerns about environmental racism). You shouldn't have a problem getting interesting summer work from any of the schools you listed. My advice is to go somewhere near where you want to practice, if you can sort that out, so that you can make connections at clinics and internships throughout your time in school. (Connections to, and experience with, public interest organizations is one of the biggest hiring criteria for most public service jobs.) In addition, I suggest that you look into the kind of support the school provides for students who hope to go into public service, starting with public interest scholarships, guaranteed summer stipends/work-study money, and loan forgiveness (even if most schools are changing their LRAP programs in response to the new federal loan forgiveness legislation). But be sure to look beyond the financial; other things, such as whether there is public interest programming, a dedicated public interest counselor in career services, and a sizable public interest population at the school, will make a huge difference in both your happiness and your career opportunities.Good luck!
All three of the posters have provided you with good insights and sound advice. All I can add is the following: don't rule out a stint at a firm, including a large firm. Public interest outfits (especially the elite, national types alluded to by Miss P) are not in the business of training new law grads to practice law. In a key respect, public interest organizations are similar to in-house law departments at a corporation: they are mainly staffed by lawyers who "got their chops" at either law firms or in the government (or both). At the most competitive/presigious/leading public interest organizations, my guess is that the lawyers (i) did their 1L summer at a public interest organization; (ii) did their 2L summer at a large firm; (iii) took the bar (with the support of that firm) and began practicing at that firm; and (iv) after about 2-5 years or so, left the firm and began their career in public interest. (I work at a large firm, and though at this point I'm in it for the long haul, several of my fellow junior associates plan to go into public interest or government work in 2-3 years.) Good luck!
Re: firm -> nonprofit environmental nonprofitFrom what I heard, it's really tough to get a environmental nonprofit job straight out of law school. But then you're faced with a choice of whether to go to a firm and whether to do environmental work at the firm. I had a memorable with an environmental associate at a firm who answered yes to both questions.She wanted to work for the environment but ended up working for the environmental group at a firm. Five minutes into the interview, she said, "I'm now defending the polluters." And when she tried to do pro bono work for environmental organizations, she frequently was conflicted out by the other clients that her firm represented.I will always remember that interview. Both because she was one of the only people at my law firm interviews who genuinely wanted to hear about my public interest experiences and because she was so candid about the choice she made to hone her environmental skills by "defending the polluters."