Monday, December 8, 2014
Water Use In Virginia 2010
As you can see in the chart above, not all water use is fresh water use. Almost 42% of the water used each day and each day is salt water used primarily for thermoelectric power generation. Thermoelectric power generation uses almost 79% of all water in Virginia and over 64% of fresh water. Water for thermoelectric power is used in generating electricity with steam-driven turbine generators. Water is used in more than one way in power generation. Once-through cooling systems circulate water through heat exchangers and then return the water to the source these tend to be older systems. A recirculation system has cooling ponds or towers to cool the water so that it can be constantly reused. Water withdrawals for a recirculating system are used to replace water lost to evaporation, blowdown, drift, and leakage. Newer power plants tend to use less water. It is also to be recalled that Virginia only produces about 64% of the electricity used each day in Virginia. We, like most states are a net importer of electricity.
Of the 664 million gallons of water that is withdrawn from rivers and groundwater each day for public supply, 476 million gallon a day or 72% goes for domestic supply. Domestic water use includes indoor and outdoor use at homes and apartments in Virginia for drinking, food preparation, washing clothes and dishes, bathing and flushing toilets. Common outdoor uses are watering lawns and gardens or maintaining pools or landscape features at your home. Domestic water is either self-supplied or provided by public water companies. In Virginia a total 600 million gallons of water a day is used for domestic supply- 476 million gallons a day is from public water companies and 124 million gallons a day is self-supplied from private wells. According to the USGS 1,650,000 Virginians or 21% of the population of the Commonwealth get their water from private wells. Virginia is still a very rural state with 21% of domestic water coming from private wells which are only in rural or semi-rural locations, nationally only about 14% of domestic water is from private wells. Domestic use, both from private wells and public supplied accounts for less than 14% of all fresh water use in Virginia and less than 8% of total daily water use in the Commonwealth. The typical Virginian uses 75 gallons of water a day for all domestic uses and is the same for public supplies households as well as households supplied by private well. In most states, households on private well use less water than those on public water supplies. On average in the United States a person with a private well uses 81 gallons of water a day and a person on public water supply uses 89 gallons of water a day.
Despite being a very rural state, less than 3% of fresh water withdrawn from rivers, streams, and groundwater is used for agriculture. It rains in Virginia and only 1.4% of fresh water is used for irrigation which includes water for crop irrigation, frost protection, application of chemicals, weed control, field preparation, crop cooling, harvesting, dust suppression, a well as watering of golf courses, parks, nurseries, turf farms, cemeteries, and landscape-watering for businesses and public buildings. Livestock water use which is less than 1.4% is for livestock watering, feedlots, dairy operations, and other on-farm needs.
In mining water is used for the extraction of minerals that may be in the form of solids, such as coal, iron, sand, and gravel; liquids, such as crude petroleum; and gases, such as natural gas. The category includes quarrying, milling of mined materials, injection of water for secondary oil recovery or for unconventional oil and gas recovery (such as hydraulic fracturing), and other operations associated with mining activities. Today, the 35 million gallons a day of water used for mining is primarily for coal mining in the Appalachian plateau.
Water used in aquaculture in Virginia is primarily used in raising shellfish for food, and restoration, conservation of the habitat. Aquaculture production occurs under controlled feeding, sanitation, and harvesting procedures primarily in ponds, flow-through raceways, and, to a lesser extent, cages, net pens, and closed recirculation tanks. Approximately 295 million gallons of water a day are used for aquaculture in Virginia. Much of the water used for aquaculture is maintaining flow for habitat..