US Environmental Protection Agency
Epa: Measuring the P H of Natural Water
How acidic is your water? "In this experiment, you will measure the pH of natural water located near your home or school."
US Environmental Protection Agency
Epa: Gulf of Mexico Program: Woodland Cultures (2000 Bc to 1,000 Bc)
This site presents information on the three periods of Woodland Culture. It briefly describes how the Woodland culture began as small villages depending on subsistence farming and hunting. Also describes the move to the mound building...
Siteseen
Siteseen: American Historama: Clean Air Act of 1963, 1970 and 1990
Discussion of the three sets of federal programs to establish air quality goals and to impose pollution control.
US Environmental Protection Agency
Epa: Radon
Download a copy of the National Radon Results - 1985-1999 and see the "ASTM International "Standard Practice for Radon Mitigation Systems in Existing Low-Rise Residential Buildings."