In 1974, the U.S. Congress enacted the Safe Drinking Water Act to protect the nation’s public drinking water supply. Originally, it addressed treatment of water to make it drinkable, but amendments in 1996 added protection of the sources of drinking water to the legislation.
Protecting the source water is no simple feat. First the feeder systems have to be mapped out. All the rivers, streams and lakes are identified and the aquifers that feed wells. Then an assessment of potential sources of contamination has to be done. Vulnerable areas must address the risk of contamination with methods to assure segregation of wastes and storm water runoff.
Drinking water is most often contaminated by human-related activities such as chemicals spills or improper disposal of wastes. Recently, large animal containment and feeding facilities have been found to be sources of water contamination, bringing fecal matter and bacteria into a high concentration where it is not wanted.
Natural sources of contamination exist. Ground water can pass through mineral formations that contain a toxic substance. A recent case of salmonella in the water supply of a Colorado town was identified as a strain found in local deer and birds, though the mechanism for how it contaminated the water source is still under investigation.
Although water in the United States is generally safe, reports of alerts telling citizens to boil water before drinking are quite common. One of the most frequent causes is water main breaks. The need to repair or replace underground pipe will contaminate the water until the section of pipe is purged.
The U. S. Environmental Protection Agency sets standards for ninety chemical, biological and radiological contaminants, setting maximum levels for their concentration in drinking water. The EPA and others continue to research other substances which may be hazardous to human health if taken internally via the water system.
Substances included in the list of chemical contaminants include carbon-based toxic chemicals such as benzene and toluene. Heavy metals on the list include mercury and lead. Lead is monitored at the tap, meaning samples are taken where a citizen would draw water for a drink. This effectively monitors not just the source, but lead in the pipes which contain and transfer water to the public.
Otherwise healthy people should feel no ill effects from drinking water that meets these standards; however people with serious health problems and allergies to certain chemicals may seek water that has been purified further. For example, a small fraction of the population is allergic to fluoride, which is legally and deliberately added to the supply in some municipalities for increased dental health.
The average American uses over 100 gallons of fresh water every day, so the burden of providing pure water is great and growing every year. Conservation of water is a practice everyone will need to adopt if the system is to meet the needs of a growing population. Even in areas where surface water is plentiful, municipal treatment facilities will be stretched to the limit of capacity requiring bond issues and tax and fee increases to build adequate new facilities.
In recent years, the water use per capita in the U.S. has decreased, but most of the decrease has been at the industrial level. Companies have found that it is cheaper to treat wastewater by avoiding creating so much in the first place. They have modified manufacturing processes to reduce the amount of water added to make food or goods. Agriculture is using less water to irrigate, going from open water irrigation to drip systems. Unfortunately, use of water in American homes is on the rise. Much of the rise is attributed to outdoor uses such as lawn irrigation systems.
Given the demand for water by humans everywhere, water consumption and water quality are high on the list of topics under discussion in many political jurisdictions. Predictions have been made that the fight over water resources will trump all other conflicts in some very volatile parts of the world. It is critical to begin to understand what safe drinking water is and how it is provided efficiently. It is even more important to understand and practice conservation.
Resources:
U. S. Environmental Protection Agency (See link above)
Water Use Is Lower Than It Was 30 Years Ago, National Public Radio, Morning Edition, November 18, 2009
Eilene Toppin Ording - Eilene Toppin Ording comes from a wide industrial and educational background. A farmer's daughter from Minnesota, Eilene is an active ...
