Provides a thorough presentation of controls on the chemical quality of surface and subsurface waters, both pristine and polluted. Emphasis is placed on inorganic processes and on the chemistry of soil and groundwaters. Unlike most authors, whose civil/sanitary engineering backgrounds promote a more aquatic chemistry and surface water approach Langmuir's geology/geochemistry experience focuses coverage on the chemical interactions between water and geological materials. The text provides valuable training in using the geochemical computer code MINTEQA2 as integral problem-solving tool.