ABSTRACT
Water quality means different things to different people, depending on their goals for the water. A chemist in a laboratory will regard high-quality laboratory water as water free from chemical impurities or suspended solids. High-quality environmental water has different criteria. The same chemist on a wilderness backpack trip might identify high-quality water as water in a pristine environment unaltered by human activity. If the chemist is also a sherman, she or he might regard highquality water as a good habitat for sh and other aquatic organisms. A farmer prefers water with low sodium or other dissolved salts that may degrade the soil or be toxic to crops, but may appreciate moderate levels of nutrients such as nitrogen and phosphorus. A drinking water treatment plant manager will dene high-quality water as water with a minimum amount of substances that have to be removed or treated to produce safe and palatable drinking water. A broad view of high-quality water will take into consideration its suitability for particular uses.
