Waste Treatment Plants

Determining Water Quality

Government agencies determine and set standards regarding the quality to which water must be purified before it can be consumed by humans. Local, national, and international water standards typically outline a set of minimum and maximum concentrations of harmful contaminants allowed within the water for it to still be considered safe. Since it is nearly impossible to determine water quality simply by its appearance, multiple processes have been developed to test water contamination levels.

Household methods such as boiling water, or utilizing activated carbon filters, such as the popular Brita water filters, have been developed to remove water contaminants, but although these methods are inexpensive and can be widely used, they are insufficient in many cases. Some of these methods are actually misleading to consumers, as they do not address the possibility of more dangerous contaminants. New standards of purification have also caused a reassessment of many traditional sources of water, such as natural spring water. Natural spring water had historically been considered clean for all practical purposes. Natural spring water has come under increased scrutiny recently, however, and is now subject to treatment and batteries of tests much like water from other sources. Chemical analysis that determines the content of water as well as the concentration of contaminants contained therein is the only reliable means of determining which methods of purification are necessary.

The purification of water has taken on new importance according to a 2007 report by the World Health Organization (WHO). According to the WHO report, 1.1 billion people around the globe lack access to a safe and reliable drinking-water supply. “Safe and reliable water,” the standard that is sought, has been defined as water of a quality that can be consumed without immediate or long-term harm from consumption. Safe and reliable water is necessary for human consumption or food preparation. Approximately 88 percent of the four billion annual cases of diarrheal disease reported worldwide have been attributed to a lack of sanitary drinking water. Unsafe water, coupled with inadequate sanitation and hygiene, leads to approximately 1.8 million deaths due to diarrheal diseases each year. These diseases have spurred a growing consensus to provide potable water to as much of the Earth's population as possible.

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