With an exponentially increasing human population on earth, and a finite amount of dry land, the stress put on both land and sea productivity is increasing accordingly. The use of land to produce agricultural crops uses the best land in terms of its drainage, tilth, and ease of management. There is great competition for this land as a substrate for housing and recreation by that same population for those reasons. This collection of volumes is intended to describe surface water, groundwater, soil, and sediment quality from a chemical point of view. Air quality is another environmental topic, which will not be discussed. This work will describe water quality from the point of view of: natural quality; natural processes that lead to degraded quality; pollutants that degrade quality, both chemical and biological; radioactive elements; organic solutes including dissolved organic carbon, color-producing substances, chemical oxygen demand, biochemical oxygen demand; evaluation of water analyses; evaluation of water and groundwater quality; graphical methods for presenting water-quality data; methods for extrapolating water quality data; and, relationship of water quality to water use. Chemical processes are fundamental to natural phenomena such as crop growth, aqueous and marine animal and plant life, animal life in soil, and ultimately human life. Natural processes are discussed that may result in water having certain chemical and physical characteristics, such as hardness, softness, saltiness, high temperature, or dissolved gases, which require that the water be treated for potable or boiler uses. Man-made pollutants find their way into water from various sources, sewage from leaking public sewers and septic systems, agricultural chemicals, animal feedlot wastes, road deicing salt, landfills, industrial wastes, mine wastes, and brine disposal from petroleum exploration. Most organic chemicals have limited to virtually no solubility in water. However, those that do dissolve can cause water’s quality to suffer or make it totally useless or damaging to health. Organic solvents, polychlorinated biphenyls, phthalic acid esters, herbicides, insecticides, nematocides, and acaricides are among the substances that will be discussed in regard to their effect on water quality.