These are man-made chemicals, including PCBs, dioxin and triazines , that can cause chronic reproductive and behavioral problems in animals. The molecules of environmental estrogens are chemically similar to natural hormones and trigger subtle hormonal changes, especially in the fetus in early stages of human development. The effects in man are still much disputed by scientists. Some researchers believe these chemicals are responsible for learning disabilities, attention-deficit disorder, breast cancer, and low sperm counts. Flocculation is the process by which chemicals are added to the water, causing tiny clumps of debris to form.
Sedimentation is the process of removing the flocculate matter.
This term refers to water that has been sitting in pipes or plumbing fixtures overnight and is first drawn when taps are opened in the morning. Such samples will usually have the highest levels of lead contamination. See purged line . A meaningless, unregulated word used to describe a source of bottled water, according to Food and Drug Administration rules. One hour later, the goldfish will be dead from chlorine .