Here are some useful links
Code of Federal Regulations (CFR). This is the official federal government regulations. Title 40 covers environmental regulations.
Electronic Code of Federal Regulations (eCFR)
RCRA Online This is a very useful website where EPA documents its own regulatory interpretations.
EPA's Universal Wastes webpage. This page has information about EPA's Universal Wastes and links to recyclers.
EPA's waste Site.
National Service Center for Environmental Publications. This page contains an index of many EPA publications.
Links to environmental agencies in all 50 states and territories.