Water Treatment and Sanitation

According to a 2007 World Health Organization report, 1.1 billion people lack access to an improved drinking water supply, 88% of the 4 billion annual cases of diarrheal disease are attributed to unsafe water and inadequate sanitation and hygiene, and 1.8 million people die from diarrheal diseases each year.

Water purification is the process of removing undesirable chemical and biological contaminants from raw water. In general the methods used include physical process such as filtration and sedimentation, biological processes such as slow sand filters or activated sludge, chemical process such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi; and a range of dissolved and particulate material derived from the minerals that water may have made contacted after falling as rain.

It is not possible to tell whether water is of an appropriate quality by visual examination. Even natural spring water - considered safe for all practical purposes in the 1800s - must now be tested before determining what kind of treatment, if any, is needed. Chemical analysis, while expensive, is the only way to obtain the information necessary for deciding on the appropriate method of purification.

EPA is the federal governing body over Municipal Water Treatment Facilities, although some states have their own regulatory bodies for water treatment as well. A 2005 study released by the nonprofit Environmental Working Group, a Washington-based research group, found that tap water in 42 states is contaminated with more than 140 unregulated chemicals, including MTBE, perchlorate, and industrial solvents.

To find out more about Water Treatment and Sanitation, use the convenient links on the right hand side of this page.

The Water Treatment Process

Chlorination & Other Additives

Unintended Effects of Treatment