Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Environmental Water Quality and Hydrochemistry
Water Resources Division Training Center, U.S. Geological Survey
Denver, Colorado
February 26 - March 2, 1973
Public Domain.
