International Association of Plumbing and Mechanical Officials
Phone: 909.472.4100
Fax: 909.472.4150
E-mail: iapmo@iapmo.org
http://www.iapmo.org
Select "IAPMO" and browse articles on plumbing codes.

National Association of Plumbing-Heating-Cooling Contractors
Phone: 800.533.7694
Fax: 703.237.7442
http://www.phccweb.org/
Select "Educational Foundation" from side menu bar.