Our quality of life and life itself is dependent on our access to water. Mankind cannot survive without water. One of the world’s most critical problems is a lack of quality water. More than a billion people lack access to safe drinking water, and 1.5 million deaths, mostly among children underage five, are attributed to unsafe drinking water each year. People are dying today for lack of clean water. The projections for 2030 are for significant and potentially life threatening water shortages in parts of the world.
Though I tend to distrust all long term modeling efforts for their simplifications and straight line projections; however, water planning ten and twenty years out is a standard practice in the US west and other water critical areas of the world. Water supply projection a decade or two out is a much simpler model than say climate projections, but still are impacted by non correlated variables and limited knowledge of groundwater recharge and reserves that would make it difficult to accurately projects water demand and availability.
In California, the combined demand for irrigated agriculture, expanding suburban footprint, habitat protection, and drought have stressed the water supply. For more than a half a century the Central Valley of California has been one of the most productive agriculture regions of the world. On less than 1% of the total farmland in the U.S. the Central Valley produces 8% of the agricultural output (as measured by value). In 2002 this translated to $17 billion in crop value. This is all made possible by irrigation. Approximately one sixth of the irrigated land in the United States is in the Central Valley of California (Bureau of Reclamation, 1994) and approximately one eighth of all groundwater pumped in the United States is pumped in the Central Valley. According to the US Geological Survey the Central Valley of California was mining groundwater at approximately 1,900 cubic feet per second from 1962 to 2003. As California learned this is an unsustainable practice.
In Virginia, the Water Resource Research Center at Virginia Polytechnic Institute and State University, WRRC, has been studying the projected future demand for water in the Commonwealth and examining the options. From 1999 to 2002 many localities in Virginia experienced a severe drought, but periodic droughts in Virginia are not unusual. In the past, the groundwater had served as the backup resource during critical water shortages. The recent drought was note worthy because the population shifts and growth had caused declining groundwater levels and increased demand in some regions. The WRRC states that there is a high probability that the costal areas and northern Virginia face a sever water shortage in coming decades because of the periodic droughts and increased water demand. Traditionally, building dams and reservoirs and inter-basin transfer of water were used to supply the state. However, these methods would face significant economic, environmental, regulatory and societal challenges in the future.
The WRRC suggests several options to supplement water supplies in these critical areas: water conservation, water reuse, groundwater recharge and desalination. Water conservation is the low lying fruit, but is unlikely to meet the increased demand. Water is the fluid of life and should never be wasted. My years in California make me acutely aware of and careful of my water use. It is important to teach the next generation to use water more wisely than the current generations have. Nonetheless, conservation alone will not be enough. Though we could limit population density by water carrying capacity of the area, the WRRC makes other suggestions.
Desalination techniques are being developed and planned in Florida and California. Their pressing needs will allow others to learn from their experiences, but their ability to supply any significant amount of drinking water is many years in the future. Enhancing groundwater recharge would improve groundwater supplies by an unknown amount. Certainly, elements of long-term water supply planning should be part of all development and growth planning. Groundwater sustainable development would include protection of aquifer recharge zones along with increasing subsurface infiltration and groundwater recharge by implementing low-impact development techniques, such as forestation and bioretention in urban and suburban areas. However, recharging groundwater with reclaimed water and the reuse of the reclaimed water, though practiced in many areas, is of real concern.
When the USGS began looking into a series of fish kills in the southern branch of the Potomac River, they found fish suffering from a variety of lesions. Some fish had bacterial lesions, some fungal lesions, and some fish had parasite. The USGS concluded the fish appeared to be immunosupressed so that any pathogen in the water could attack the fish. A series of studies were performed over a period of years. During the investigation it was discovered the bass suffering from lesions were intersexed. It had previously been demonstrated that estrogen and estrogen mimicking compounds can cause intersex. The occurrence of intersex among the lesioned fish prompted further studies. Since 2004, unexplained fish kills have occurred in the Shenandoah River basin. During 2007 and 2008 similar events took place in the upper James and Cowpasture rivers. Fish kills occur in various parts of the country and seem to occur for a variety of reasons.
The studies of the Potomac fish kill found the problem of endocrine disruption in fish to be widespread within the study area, a portion of the Chesapeake Water Shed, but increased in proximity to and downstream of the waste water treatment plants. Chemical sampling that took place along with the fish sampling found higher concentrations of waste water chemicals near the waste water plants. Pesticides currently used in agriculture were detected at all locations. Hormones were not detected in the samples, but analysis using yeast screening assays found estrogenic endocrine-disrupting chemicals at all locations their specific source is not yet known. Though they cannot identify a single chemical or group of chemicals responsible, the US FW and US GS have embarked on further study.
This reclaimed water implicated in the study is the same reclaimed water the WRRC suggests we all drink and forcibly use to recharge previously pristine groundwater. Due to its protected location underground, most groundwater is naturally clean and free from pollution. Recharging groundwater with reclaimed water may not be the best of ideas until more is known about the causes of the lesions and intersexed fish and the implications to human life. In April of 2009 the US EPA issued the Final List of Initial Pesticide Active Ingredients and Pesticide Inert Ingredients to be Screened under the Federal Food, Drug, and Cosmetic Act as potential endocrine disruptors. Pesticide runoff is a large contributor of known pollutants to the watershed. Water is the fluid of life.
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