To get a good idea of the basic sources for research in environmental law, see Nancy Spyke's article "Making Sense Out of Secondary Sources in Environmental Law: A Research Primer," 25 Environmental Law 93 (1995), which you can supplement with the following Internet resources.
The environmental field is particularly rich with Internet sources. These include home pages by the EPA, the Cornell Legal Information Institute, the Environmental Professionals Homepage and The Environmental Organization Web Directory.
Administrative Decisions: Westlaw has the environmental ALJ decisions for various states in databases using the form xxENV-ADMIN, where the "xx" stands for the states' two-letter postal code abbreviation. To search all states at once, use the MENV-ADMIN database. For U.S. EPA decisions, see "United States Environmental Protection Agency."
Document Delivery: Generally the easiest way to get obscure environment-related pleadings, opinions, regulations or other materials is to find where they are either published or reported in the Daily Environment Report or The Environmental Law Reporter (see News, below). If they're only reported, you can order the document from BNA Plus (800-452-7773) or ELR (800-433-5120), respectively.
Foreign & International: The European Environment Agency posts information on the environmental situation in Europe, with links to national Agencies. The ASIL Guide to Electronic Resources for International Law provides links to international environmental law sites. Databases posted on The Multilaterals Project function as an online catalog for environmental law-related laws, treaties, cases, Instruments of the E.U., reports, etc. For more, see A Basic Guide to International Environmental Legal Research by Heidi Frostestad Kuehl and, if applicable, Researching International Marine Environmental Law by Arundhati Ashok Satkalmi.
See also "Treaties," below.
News: Probably the best sources of environmental law news are the BNA's Daily Environment Report and The Environmental Law Reporter. Both are published as newsletters and kept in looseleaf binders. They are also available - and searchable -- on Lexis (BNA;BNAED, ENVIRN;ALLELR) and Westlaw (BNA-DEN, ELR-xx, depending on the part of the ELR you want to search).
Treaties: Many major environment-related treaties are posted by the Environmental Treaties and Resource Indicators Service (ENTRI) at http://sedac.ciesin.org/entri and The Multilaterals Project.
The ECOLEX treaty database is effectively an online catalog of environment-related treaties. This is particularly useful for finding treaties on a particular subject or environmental problem.
Also look at the ""Foreign & International"" section, above.