Ek plaas hierdie kort uittreksel uit Wikipedia "Water supply and Sanitation in the United States" sonder kommentaar. Ek wil trouens glad nie weer in 'n debat oor hierdie onderwerpe betrokke raak nie, dis 'n mors van tyd en bring mens nêrens.
With water use in the United States increasing every year, many regions are starting to feel the pressure. At least 36 states are anticipating local, regional, or statewide water shortages by 2013, even under non-drought conditions.[81]
According to the National Academies, climate change affects water supply in the U.S. in the following ways:
- Rising water demands. Hotter summers mean thirstier people and plants. In addition, more evaporation from reservoirs and irrigated farmland will lead to faster depletion of water supplies.
- Increased drought. Scientific evidence suggests that rising temperatures in the southwestern United States will reduce river flows and contribute to an increased severity, frequency, and duration of droughts.
- Seasonal supply reductions. Many utilities depend on winter snowpack to store water and then gradually release it through snowmelt during spring and summer. Warmer temperatures will accelerate snowmelt, causing the bulk of the runoff to occur earlier and potentially increasing water storage needs in these areas.[9]
Pollution
Sewer overflows. Combined sewer overflows (CSO) and sanitary sewer overflows affect the quality of water resources in many parts of the U.S. About 772 communities have combined sewer systems, serving about 40 million people, mostly in the Northeast, the Great Lakes Region and the Pacific Northwest.[28] CSO discharges during heavy storms can cause serious water pollution. A 2004 EPA report to Congress estimated that there are 9,348 CSO outflows in the U.S., discharging about 850 billion US gallons (3.2×109 m3) of untreated wastewater and storm water to the environment.[82] EPA estimates that between 23,000 and 75,000 sanitary sewer overflows occur each year, resulting in releases of between 3 and 10 billion US gallons (38,000,000 m3) of untreated wastewater.[82]
The increased frequency and intensity of rainfall as a result of climate change[8][83] will result in additional water pollution from wastewater treatment, storage, and conveyance systems."[83] For the most part, wastewater treatment plants and combined sewer overflow control programs have been designed on the basis of the historic hydrologic record, taking no account of prospective changes in flow conditions due to climate change.[83]
Main article: Drinking water quality in the United States
Drinking water quality. There are several aspects of drinking water quality that are of some concern in the United States, including Cryptosporidium,[84] disinfection by-products, lead, perchlorates and pharmaceutical substances. However, in almost all cases drinking water quality is in conformity with the norms of the Safe Drinking Water Act, which sets Maximum Contaminant Levels for pollutants. In addition, the EPA's Consumer Confidence Rule of 1998 requires most public water suppliers to provide consumer confidence reports, also known as annual water quality reports, to their customers.[85] According to the EPA, each year by July 1 anyone connected to a public water system should receive in the mail an annual water quality report that tells where water in a specific locality comes from and what's in it. Consumers can find out about these local reports on a map provided by EPA.[86] 29% of Americans are reading their water quality reports. Customers are generally satisfied with the information they are receiving from their water companies and their local or state environmental offices.[55]
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