Resource Type: Technical Guidance

  • Perchlorate Fact Sheet


    Perchlorate is both a naturally occurring as well as a man-made inorganic chemical. Perchlorate is an oxidizer used in the manufacturing of fireworks, explosives, and other pyrotechnics. In the United States, contamination of soil and water is found predominantly in areas where the manufacture, use, and storage of munitions and rocket propellants took place over…

  • Uranium Fact Sheet


    Uranium is a common naturally occurring and radioactive substance. It is a normal part of rocks, soil, air and water. Uranium occurs in nature in the form of minerals, but never as a metal. Uranium enters water by leaching from soil and rocks, or in releases from processing plants. Uranium has demonstrated toxic effects on human…

  • Taste & Odor Fact Sheet


    There are many causes and sources for taste and odor problems. The chemicals responsible for these problems in drinking water are mostly considered to contribute undesirable aesthetic effects, such as bad tastes, odors and off color or cloudiness. These contaminants and those covered under the USEPA National Secondary Drinking Water Regulations (NSDWRs) at the Secondary…

  • Silver Fact Sheet


    Biologically, silver is a nonessential, non-beneficial element to humans. There are no scientific studies to show adverse health due to its presence in drinking water from natural sources. However, because of its bactericidal abilities, silver is used as a water bacteriostat in carbon containing water filters. The silver is deposited onto the carbon granules to…

  • Selenium Fact Sheet


    Selenium is a metal found in natural deposits as ores containing other elements. The greatest use of selenium compounds is in electronic and photocopier components, but they are widely used in other products as well. Selenium releases to the environment have been primarily from copper smelting industries. The largest releases from 1987 to 1993 occurred…

  • Copper Fact Sheet


    Copper is a metallic element that is essential to human health. Too little is unhealthy and too much can lead to copper poisoning. The body cannot synthesize copper so the human diet must supply regular amounts for absorption. The daily requirement is about 2 mg of copper intake per day to maintain a balance of…

  • Getting Up to Speed on Emerging Contaminants


    Regu P. Regunathan, PhD,discusses different categories of contaminants, their potential for health effects on humans and their relevance. He also covers the EPA’s Unregulated Contaminant Monitoring Rule, occurrence data (where it exists) and treatment process or devices that can be effective in reducing these contaminants.

  • Arsenic Fact Sheet


    The presence of arsenic (As) in nature is due mainly to natural deposits of metalloids in the earth’s crust and usually in ancient rock formations. Arsenic enters ground water through erosion or from manmade sources such as wood preservative, petroleum production, semi-conductor manufacture or due to misuse of animal feed additives and arsenic-containing pesticides (e.g.…

  • Barium Fact Sheet


    Barium is a divalent cation and alkaline earth metal that can be found in naturally occurring mineral deposits. The most common ores are found in Alaska, Arkansas, California, Georgia, Kentucky, Montana, Nevada, and Tennessee. In 2010, 670 thousand tons of barite, a natural barium sulfate ore, were mined in the US, most of it in…

  • Cadmium Fact Sheet


    Cadmium occurs naturally in zinc, in lead and copper ores, in coal and other fossil fuels, in shales and is released during volcanic action. These deposits can serve as sources to ground and surface waters, especially when in contact with low total dissolved solids (TDS) and acidic waters. Major industrial releases of cadmium are due…