ECOTOX Code Appendix - Codes and abbreviations used in the ECOTOX database; CAS numbers for many toxicological compounds.
Environmental Contaminants Encyclopedia - on the National Parks Service website
National Environmental Compliance Handbook - PDF of Final 2nd Edition, 2010. Checklist from National Resources Conservation Service for many environmental programs
National Pesticide Information Center, at Oregon State University and the US EPA.
Handbook of environmental protection and enforcement : principles and practice, by Andrew Farmer, 2007
Industrial waste treatment handbook, by Woodard & Curran, Inc., 2006
Handbook of environmental degradation of materials, edited by Myer Kutz
Environmental field testing and analysis ready reference handbook, by Donald A. Drum et al.
Environmental technology handbook, by Sunggyu Lee and James G. Speight
Foodborne disease handbook, editor-in-chief, Y.H. Hui