The “Strategy for Protecting and Restoring the Chesapeake Bay Watershed” was developed under President Obama’s Executive Order 13508 issued in May 2009. The Strategy was released in May 2010 and outlines actions that will be taken by each federal agency to control pollution, restore habitat and wildlife, conserve land, and increase public awareness and accountability in the Chesapeake Bay Watershed. EPA Administrator Jackson stated in her announcement that the EPA will implement broad conservation and restoration efforts and prevents pollution from the urban, suburban and rural areas that feed into the Bay. The new federal strategy for the Chesapeake Bay region of the 64,000-square-mile watershed includes using federal regulations to restore clean water, implement new conservation practices on four-million acres of farms, conserve an additional two-million acres of undeveloped land, and restore the habitat for key species such as oysters, black ducks, and brook trout. The combined agencies and states will be held accountable to achieve specific milestones every two years to ensure measurable progress.
While there is overlap between the recently announced settlement agreement and Strategy, they are not the same. The settlement agreement resolves the lawsuit brought by former Maryland State Senator Bernard Fowler, the Chesapeake Bay Foundation, Maryland and Virginia watermen’s associations, and others filed against the EPA in January 2009 alleging the Agency failed to fulfill its duties under the Clean Water Act (CWA) and the Chesapeake 2000 Agreement. EPA settled the lawsuit with the “settlement agreement,” which requires EPA to:
Establish and implement a Chesapeake Bay total maximum daily load, TMDL, for nutrients and sediments. This will include reviewing watershed implementation plans (WIPs) by the Chesapeake Bay watershed states and the District of Columbia to ensure those jurisdictions achieve the nutrient and sediment allocations under the TMDL.
Review state-issued permits, including proposed construction general permits and NPDES permits for “significant point source discharges of nitrogen, phosphorus, and sediment” in the Chesapeake Bay watershed.
Develop new storm water regulations by 2012 and concentrated animal feeding operation (CAFO) regulations by 2014.
Issue guidance on permitting for municipal separate storm sewer systems.
The Strategy is far more sweeping in its goals as outlined in the full muti-color 173 page text available at: http://executiveorder.chesapeakebay.net/file.axd?file=2010%2f5%2fChesapeake+EO+Strategy%20.pdf .
The Strategy sets four main goals for Bay restoration and identifies “key environmental outcomes” and “supporting strategies” that are intended to help accomplish these goals and complement the multi agency efforts to restore and protect the Chesapeake Bay Watershed. The goals are to: restore clean water; recover habitat; sustain fish and wildlife; and conserve land and increase public access.
Among the federal actions identified in the Strategy, EPA must establish and implement the Chesapeake Bay TMDL and an associated “accountability framework.”
The Executive Order established the Federal Leadership Committee (FLC) for the Chesapeake Bay, which is chaired by the Administrator of the U.S. Environmental Protection Agency and includes senior representatives from the departments of Agriculture, Commerce, Defense, Homeland Security, Interior and Transportation. The Executive Order charged the FLC with developing and implementing a new strategy for protection and restoration of the Chesapeake region. The FLC is intended to support and guide the local efforts. The strategy is intended to support the restoration activities of state and local governments, watershed groups, county conservation districts, landowners and citizens.
The FLC is also charged with developing “key environmental outcomes” that include: Expand Citizen Stewardship. Respond to Climate Change. Develop Environmental Markets and Strengthen Science. Apparently, creating environmental markets is the current darling of the regulatory movement. Selling water release rights and creating a market for these rights is will make non-point source reduction possible and quantifiable.
The Executive Order directs the FLC to expand its role beyond just producing the strategy, to: “Oversee development, coordination and implementation of new federal programs and activities for Chesapeake Bay restoration. Collaborate with state partners to ensure that federal actions are closely coordinated with actions by state and local agencies and resources are used efficiently. Consult with stakeholder groups and the general public. Define milestones for meeting goals. Track and report on restoration activities and spending. Publish an annual Action Plan describing how federal funding will be used. Publish an annual Progress Report on environmental health and restoration efforts. Utilize independent evaluation to strengthen accountability. Make all reports available to the public by posting on a web site. Describe and carry out a process for adaptive management. Federal agencies will join the states in establishing two-year milestones with many federal efforts designed to support the states and District in meeting their current and future water quality milestones.” Buried in this mind numbing list of bureaucratic meetings, spending and report writing is an expansion of federal regulatory control of non-point source pollution.
Showing posts with label non-point source comtamination. Show all posts
Showing posts with label non-point source comtamination. Show all posts
Monday, May 24, 2010
Monday, April 26, 2010
Who is Going to Control Your Water?
Water shortages are nothing new a consistent and clean supply of water has been problematic throughout human history. Climate does change, the Sahara Dessert had adequate surface water only 5,000 to 6,000 years ago. There were lakes and rivers and the Sahara was green. Water supply will not just be a problem in developing countries and does not even require the climate to change. Today the combination of inadequate supply of water in some locations, mismanagement of resources and the pollution of fresh water supplies with endocrine disruptors and trace chemicals from recycled water and runoff will grow into an outcry. Non-point source pollution and water ownership will become the issues in the United States and the developed world. After reducing point source pollution over the past 40 years, we are faced with the more difficult problem of non=point source pollution, Suddenly, everyone will be aware that the fresh water in some locations has annual limits (in truth we have impacted the recharge rate of our fresh water resources) and that the water supplied to their tap by public water companies includes the output stream of the waste treatment plant, urban and agricultural runoff still containing all the trace elements not tested for in our water supplies. There are limits to this renewable resource and it needs to be managed. Political influence is the recipe for mismanagement of water resources. There will be rationing in critical locations and ownership of water rights will become contested. Groundwater and surface water are tied in ways that are not yet fully understood. Changes, diversions, pumping can effect quantity of the water supply.
Non-point source (NPS) pollution is a major factor impacting the quality of the water supply in the United States today. These pollutants are transported to surface water bodies by runoff, which results from precipitation or snow melt (Leeds et al., 1993). Storm water is part of the natural hydrologic process; however, human activities, especially urban development and agriculture, cause significant changes in patterns of storm water flow and infiltration and the type and quantity of contaminants carried from land into receiving waters. The Federal Clean Water Act gives regulatory authority to restrict pollutants discharged into rivers from point sources, such as waste water treatment plants. When the regulations were created 40 years ago, they were intended to address the 85% of pollution believed to be caused by large industrial polluters. Recently William Ruckelshaus (first administrator of the EPA) wrote in the Wall Street Journal “The current generation of (environmental) problems that we are facing, though, is much more subtle, much less visible to the naked eye- and often not nearly as susceptible to a top-down, command-and-control approach.”
Federal authority does not extend to non-point sources, such as farms and septic systems, and in truth Mr. Ruckelshaus is right those problems could not be solved by federal or state regulation. The states need to address these non-point sources using other approaches. Reductions in discharge of contaminants can be achieved through the implementation of “agricultural best management practices” operations and good environmental stewardship practices; however there is building support for direct control of non-point source contaminants and control of water supplies. The suggestions for regulation made by advocacy groups are invasive and far reaching including ownership of the water itself. This will never work. A citizen collaboration between farmers and citizens needs to be created that will encourage and enable prosperous farms, safe drinking water, healthy fish and estuaries and sustainable development. These collaborations are slow to form and function and must begin with knowledge.
Water regulation movements are moving quickly, but they are of the command-and-control variety. Virginia is one of the 40 states with water ownership always assumed to pass with the land. Water is wealth and having the government assume control of water allocations either in a permitting process or direct allocation is frightening, but that is what is happening. The Virginia Ground Water Management Act of 1992 mandates the regulation of large groundwater withdrawals in certain portions of the Commonwealth to prevent adverse impacts due to over utilization of the resource. In the past year there were two proposed changes to the regulations. It was proposed that the Eastern Virginia Ground Water Management Area be expanded to include area beyond the eastern shore and even the confines of the Tidewater, west of the fall zone, into other groundwater basins. The second proposed change was ambiguous and seemingly ambitious in its reach: the Board and DEQ propose “to consider amending the Ground Water Withdrawal Regulation, 9 VAC 25 610 to address the increasing demand on limited groundwater resources, changes to the administrative review process, and regulatory changes necessitated by new information on the coastal plain aquifer system.” Towards that goal the Commonwealth is forming a State Water Plan Advisory Committee without any citizenship/landowner representation. Who is going to control your water?
Non-point source (NPS) pollution is a major factor impacting the quality of the water supply in the United States today. These pollutants are transported to surface water bodies by runoff, which results from precipitation or snow melt (Leeds et al., 1993). Storm water is part of the natural hydrologic process; however, human activities, especially urban development and agriculture, cause significant changes in patterns of storm water flow and infiltration and the type and quantity of contaminants carried from land into receiving waters. The Federal Clean Water Act gives regulatory authority to restrict pollutants discharged into rivers from point sources, such as waste water treatment plants. When the regulations were created 40 years ago, they were intended to address the 85% of pollution believed to be caused by large industrial polluters. Recently William Ruckelshaus (first administrator of the EPA) wrote in the Wall Street Journal “The current generation of (environmental) problems that we are facing, though, is much more subtle, much less visible to the naked eye- and often not nearly as susceptible to a top-down, command-and-control approach.”
Federal authority does not extend to non-point sources, such as farms and septic systems, and in truth Mr. Ruckelshaus is right those problems could not be solved by federal or state regulation. The states need to address these non-point sources using other approaches. Reductions in discharge of contaminants can be achieved through the implementation of “agricultural best management practices” operations and good environmental stewardship practices; however there is building support for direct control of non-point source contaminants and control of water supplies. The suggestions for regulation made by advocacy groups are invasive and far reaching including ownership of the water itself. This will never work. A citizen collaboration between farmers and citizens needs to be created that will encourage and enable prosperous farms, safe drinking water, healthy fish and estuaries and sustainable development. These collaborations are slow to form and function and must begin with knowledge.
Water regulation movements are moving quickly, but they are of the command-and-control variety. Virginia is one of the 40 states with water ownership always assumed to pass with the land. Water is wealth and having the government assume control of water allocations either in a permitting process or direct allocation is frightening, but that is what is happening. The Virginia Ground Water Management Act of 1992 mandates the regulation of large groundwater withdrawals in certain portions of the Commonwealth to prevent adverse impacts due to over utilization of the resource. In the past year there were two proposed changes to the regulations. It was proposed that the Eastern Virginia Ground Water Management Area be expanded to include area beyond the eastern shore and even the confines of the Tidewater, west of the fall zone, into other groundwater basins. The second proposed change was ambiguous and seemingly ambitious in its reach: the Board and DEQ propose “to consider amending the Ground Water Withdrawal Regulation, 9 VAC 25 610 to address the increasing demand on limited groundwater resources, changes to the administrative review process, and regulatory changes necessitated by new information on the coastal plain aquifer system.” Towards that goal the Commonwealth is forming a State Water Plan Advisory Committee without any citizenship/landowner representation. Who is going to control your water?
Monday, April 12, 2010
Non-Point Source Pollution and Best Management Practices
Non-point source (NPS) pollution is a major factor impacting the quality of the water supply. The rate at which diffuse sources of pollution are generated and delivered to water resources is greatly affected by human activities and natural processes. These pollutants are transported to surface water bodies by runoff, which results from precipitation or snowmelt (Leeds et al., 1993). Storm water is part of the natural hydrologic process; however, human activities, especially urban development and agriculture, cause significant changes in patterns of storm water flow and infiltration and the type and quantity of contaminants carried from land into receiving waters.
Urban storm water runoff includes all flows discharged from urban land uses into the storm water systems and receiving waters. Urban runoff includes runoff from landscape irrigation, dewatering, and water line and hydrant flushing as well as the wet-weather storm water runoff. Water quality can also be affected when runoff carries sediment and other pollutants such as oil and grease, pesticides, paints, cleaners and other products associated with modern life into streams, wetlands, lakes, estuarine and marine waters, or groundwater.
Agricultural activities that cause NPS pollution include confined animal facilities, grazing, plowing, pesticide spraying, irrigation, fertilizing, planting, and harvesting. The major agricultural NPS pollutants that result from these activities are sediment, nutrients, pathogens, pesticides, and salts. Agricultural activities also can damage habitat and stream channels. Agricultural impacts on surface water and ground water can be minimized by properly managing activities that can cause NPS pollution, by utilizing good environmental stewardship.
Good environmental stewardship means using land and animals in a way that protects and improves the environment. Environmental stewardship begins by evaluating the farm to identify likely pollution sources and their possible effect on the surrounding environment. Overgrazing pastures; applying too much manure; giving animals free access to streams, ponds, wetlands, or marshes; mismanaging manure; and allowing excessive erosion can reduce water quality. The type, size, and numbers of animals affect the amount of management required for your farm. Kate Norris of Prince William Soil and Water Conservation District has put together a series of articles outlining the basic techniques to use to minimize environmental impact from a horse property. Many of these techniques can be used with any small scale livestock farm or hobby horse farm.
Overstocking causes most of the water quality damage on small-scale livestock farms and hobby horsefarms. It occurs when too many animals are kept on too few acres. Overstocking can strip areas of pasture, increasing polluted runoff. On farms where animals are confined and manure is collected, overstocking often leads to large amounts of manure that must be managed. So called Best Management Practices, BMPs, range from making simple changes to building structures that hold manure, but they in total add up to less run-off of pollution. They can be comprehensive and consider how the parts of the farm are related. BMPs are meant to be practical and easy to implement. They are intended to be modified to fit the type of operation, and the environmental and geological factors specific to the site. Unbelievably enough, the Soil and Conservation Districts throughout the nation are there to help you manage your properties for free.
BMPs minimize inputs of fertilizers, pesticides, labor, etc. to achieve a desired level of course performance and quality while protecting the environment. BMPs are designed to benefit water quality while maintaining or even enhancing agricultural production.Agricultural BMPs are practical, cost-effective actions that agricultural producers can take to reduce the amount of pesticides, fertilizers, animal waste, and other pollutants entering our water resources. The most recent National Water Quality Inventory reports that agricultural nonpoint source (NPS) pollution is the leading source of water quality impacts to surveyed rivers and lakes, the third largest source of impairments to surveyed estuaries, and also a major contributor to ground water contamination and wetlands degradation. Good environmental stewardship of these properties can go a long way in making agriculture sustainable.
Urban storm water runoff includes all flows discharged from urban land uses into the storm water systems and receiving waters. Urban runoff includes runoff from landscape irrigation, dewatering, and water line and hydrant flushing as well as the wet-weather storm water runoff. Water quality can also be affected when runoff carries sediment and other pollutants such as oil and grease, pesticides, paints, cleaners and other products associated with modern life into streams, wetlands, lakes, estuarine and marine waters, or groundwater.
Agricultural activities that cause NPS pollution include confined animal facilities, grazing, plowing, pesticide spraying, irrigation, fertilizing, planting, and harvesting. The major agricultural NPS pollutants that result from these activities are sediment, nutrients, pathogens, pesticides, and salts. Agricultural activities also can damage habitat and stream channels. Agricultural impacts on surface water and ground water can be minimized by properly managing activities that can cause NPS pollution, by utilizing good environmental stewardship.
Good environmental stewardship means using land and animals in a way that protects and improves the environment. Environmental stewardship begins by evaluating the farm to identify likely pollution sources and their possible effect on the surrounding environment. Overgrazing pastures; applying too much manure; giving animals free access to streams, ponds, wetlands, or marshes; mismanaging manure; and allowing excessive erosion can reduce water quality. The type, size, and numbers of animals affect the amount of management required for your farm. Kate Norris of Prince William Soil and Water Conservation District has put together a series of articles outlining the basic techniques to use to minimize environmental impact from a horse property. Many of these techniques can be used with any small scale livestock farm or hobby horse farm.
Overstocking causes most of the water quality damage on small-scale livestock farms and hobby horsefarms. It occurs when too many animals are kept on too few acres. Overstocking can strip areas of pasture, increasing polluted runoff. On farms where animals are confined and manure is collected, overstocking often leads to large amounts of manure that must be managed. So called Best Management Practices, BMPs, range from making simple changes to building structures that hold manure, but they in total add up to less run-off of pollution. They can be comprehensive and consider how the parts of the farm are related. BMPs are meant to be practical and easy to implement. They are intended to be modified to fit the type of operation, and the environmental and geological factors specific to the site. Unbelievably enough, the Soil and Conservation Districts throughout the nation are there to help you manage your properties for free.
BMPs minimize inputs of fertilizers, pesticides, labor, etc. to achieve a desired level of course performance and quality while protecting the environment. BMPs are designed to benefit water quality while maintaining or even enhancing agricultural production.Agricultural BMPs are practical, cost-effective actions that agricultural producers can take to reduce the amount of pesticides, fertilizers, animal waste, and other pollutants entering our water resources. The most recent National Water Quality Inventory reports that agricultural nonpoint source (NPS) pollution is the leading source of water quality impacts to surveyed rivers and lakes, the third largest source of impairments to surveyed estuaries, and also a major contributor to ground water contamination and wetlands degradation. Good environmental stewardship of these properties can go a long way in making agriculture sustainable.
Thursday, March 4, 2010
Greening Wal-Mart’s Supply Chain
The Environmental Defense Fund is partnering with Wal-Mart to improve the environmental performance of its supply chain. Using Wal-Mart’s leverage to reduce carbon pollution throughout the life cycle of products and the supply chain for those products is a powerful way to change farm practices and other manufacturing behavior. Wal-Mart recently committed to reduce the carbon footprint from the life cycle of Wal-Mart’s products and supply chain by 20 million metric tons of CO2 equivalent from calendar year 2010 to 2015. In part this will be accomplished by having Wal-Mart use their leverage with their supply chain to influence the environmental practices, transportation, and storage of their supplying manufacturer. Part of this reduction will be accomplished by Wal-Mart’s customers who will be educated in more sustainable use of a product. A typical example of customer education is recommending that customers use cold water to wash laundry instead of hot. The Environmental Defense Fund team working on this project has developed a detailed guidance document about what can count towards Wal-Mart's goal, as well as how reductions should be quantified and confirmed if at all possible. That of course is the sticking point with CO2 reductions.
Part of all of this is bureaucracy and public image, but if somehow out of this study comes a set of tools to quickly help business people and consumers make good and informed decisions about their environmental behavior it would be great. The environmental Defense Fund is not just focusing on carbon contained in the supply chain and life cycle of the products. They say that they are looking to identify the most serious environmental and social "hot spots" in the life cycle of Wal-Mart’s private brand food and grocery categories and working with designers and suppliers to improve overall product sustainability including water and pesticide usage. Encouraging and educating farmers and even the industrial farm complex on farming “best practices” is a proven way to reduce pesticide runoff and environmental impact at very little dollar cost.
In a pilot study performed on dairy suppliers, the Environmental Defense Fund analyzed the costs and emissions associated with a gallon of milk, from dairy farm to distribution center. By gathering and looking at the data, the Environmental Defense Fund identified the easily achieved improvements that “best practices” farm management can have in energy used to produce milk. Simple changes in fertilizer and manure management, at dairy processing facilities can achieve significant improvements in energy efficiency and even in the product itself, such as making milk shelf-stable. Soil and Conservation Districts nationwide have been aware of the improvements in environmental stewardship that can be achieved though simple improvements in farm practices; however, these organizations have not had any leverage to encourage farmers and dairy operations to implement these practices or adequate budget to develop farm plans. Wal-Mart’s involvement in this area could really encourage the adoption of these programs. It is important that these efforts be couched in more than CO2 reduction, because carbon reduction is such a limited concept and this is truly environmental stewardship and sustainability improvement project.
Part of all of this is bureaucracy and public image, but if somehow out of this study comes a set of tools to quickly help business people and consumers make good and informed decisions about their environmental behavior it would be great. The environmental Defense Fund is not just focusing on carbon contained in the supply chain and life cycle of the products. They say that they are looking to identify the most serious environmental and social "hot spots" in the life cycle of Wal-Mart’s private brand food and grocery categories and working with designers and suppliers to improve overall product sustainability including water and pesticide usage. Encouraging and educating farmers and even the industrial farm complex on farming “best practices” is a proven way to reduce pesticide runoff and environmental impact at very little dollar cost.
In a pilot study performed on dairy suppliers, the Environmental Defense Fund analyzed the costs and emissions associated with a gallon of milk, from dairy farm to distribution center. By gathering and looking at the data, the Environmental Defense Fund identified the easily achieved improvements that “best practices” farm management can have in energy used to produce milk. Simple changes in fertilizer and manure management, at dairy processing facilities can achieve significant improvements in energy efficiency and even in the product itself, such as making milk shelf-stable. Soil and Conservation Districts nationwide have been aware of the improvements in environmental stewardship that can be achieved though simple improvements in farm practices; however, these organizations have not had any leverage to encourage farmers and dairy operations to implement these practices or adequate budget to develop farm plans. Wal-Mart’s involvement in this area could really encourage the adoption of these programs. It is important that these efforts be couched in more than CO2 reduction, because carbon reduction is such a limited concept and this is truly environmental stewardship and sustainability improvement project.
Monday, February 15, 2010
Agriculture a Source of Pollution and Environmental Impact
Non-point source pollution is cumulative in nature. While any single contributor of non-point source contamination may be insignificant, the cumulative effect of many such sources is measurable and leads to significant pollution of ground and/or surface waters. Surface and groundwaters are interrelated. Groundwater is surface water (lakes, rivers, streams, or overland flow from precipitation) that has percolated into and then through the ground to an aquifer. Groundwater may move back into surface water bodies through seepage, springs, or base flow into a river or lake depending on the geology of an area. Contaminated groundwater can move into uncontaminated aquifers or return to surface water, depending on the geology. Section 319 of the Federal Clean Water Act mandates development of programs for control and reduction of non-point source pollution of both surface and ground water.
Non-point source contamination comes from run off both agricultural and urban as well as other small sources such as septic and AOSS. Agriculture is reported to be one or the main non-point sources of water pollution and in studies done in the Chesapeake Bay Watershed and Sacramento River Delta and other locations the contamination from agriculture runoff has been the major source of contamination. Pesticide runoff is a large contributor of known pollutants to the watersheds and may be a significant contributor of endocrine disruptors to the freshwater supply. Both rain feed and irrigated agriculture are sources of contamination of fresh water. 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. These pesticides need to be further investigated and our use of pesticides reexamined and rethought.
In rain fed agricultural land, the precipitation washes agricultural chemicals (pesticides and herbicides) along with soil sediment to surface water. In addition, irrigation of the fields can increase the run off. Other sources of non-point souce contamination are confined animal feed lots, grazing, plowing, pesticide spraying , fertilizing, planting and harvesting a crop which can all contribute to run off of contaminants and sediment. The National Water Quality Inventory Report to Congress was intended to identify widespread water quality problems of national significance. This has served as a proxy for the quality of the waters of the nation despite a non systematic approach to identifying water quality by the states and significant limitations to the substances tested for. Many states target their limited monitoring resources to waters they suspect are impaired and, therefore, assess only a small percentage of their waters. These may not reflect conditions in state waters as a whole and tend to reflect areas of concern in the “water community.” The US-EPA in its last report to Congress identified agriculture as the leading cause of water quality impairment of rivers and lakes in the United States. Agriculture is also cited as a leading cause of groundwater pollution in the United States.
There are other significant environmental impacts from agriculture. When agricultural land is irrigated, the water balance in nature is altered. Water is withdrawn from a river, spring, or groundwater and added to agricultural fields. The environmental impact of an irrigation system is dependent on the nature of the water source, the quality of water, the method of delivery and the local geology and climate. Withdrawing ground water beyond the recharge rate may cause the land to subside as happened in the Central Valley of California. Aquifers may become saline. All water contains dissolved salts that attached to the water molecules as it washed over the land or percolated in the ground. Rain also contains some salts. The salts are generally at very low concentrations in “fresh” water’ however, evaporation of water from dry earth leaves much of the salts behind. Over time the salts concentrate. The problem is acute in the Central Valley of California, in China’s North Plain, in Soviet Central Asia (the –istans), parts of the Middle East and the Colorado River Basin. These are all semi-arid areas where irrigation is the basis of agriculture.
Withdrawing both groundwater and surface water can dramatically change the natural hydrology of rivers and water streams, water temperature, and can impact the aquatic ecosystem associated with the surface water. The San Joaquin River in California has been dewatered as has been Owens Lake. The Colorado River runs dry before it reaches the Ocean most years as does the Yellow River in China. The riparian ecosystems and delta estuaries associated with these areas no longer receive fresh water recharge and have been destroyed.
However, irrigation has vastly improved crop yields in many semi-arid climates. As population grows, and the demand for food increases irrigation is unlikely to be discontinued. Methods and control of irrigation can determine the extent of the environmental impact from the irrigation. Improved field irrigation practices are critical to limiting the impact. It is reported that irrigated agricultural land is two and a half times more productive than rain fed agricultural land and the limits of irrigation really are the fresh water resources, the capital costs and the saline buildup over time in the farm land and aquifers. To feed the populations of the earth and protect the earth mankind needs to utilize intelligent and environmentally balanced farming practices employed .
Non-point source contamination comes from run off both agricultural and urban as well as other small sources such as septic and AOSS. Agriculture is reported to be one or the main non-point sources of water pollution and in studies done in the Chesapeake Bay Watershed and Sacramento River Delta and other locations the contamination from agriculture runoff has been the major source of contamination. Pesticide runoff is a large contributor of known pollutants to the watersheds and may be a significant contributor of endocrine disruptors to the freshwater supply. Both rain feed and irrigated agriculture are sources of contamination of fresh water. 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. These pesticides need to be further investigated and our use of pesticides reexamined and rethought.
In rain fed agricultural land, the precipitation washes agricultural chemicals (pesticides and herbicides) along with soil sediment to surface water. In addition, irrigation of the fields can increase the run off. Other sources of non-point souce contamination are confined animal feed lots, grazing, plowing, pesticide spraying , fertilizing, planting and harvesting a crop which can all contribute to run off of contaminants and sediment. The National Water Quality Inventory Report to Congress was intended to identify widespread water quality problems of national significance. This has served as a proxy for the quality of the waters of the nation despite a non systematic approach to identifying water quality by the states and significant limitations to the substances tested for. Many states target their limited monitoring resources to waters they suspect are impaired and, therefore, assess only a small percentage of their waters. These may not reflect conditions in state waters as a whole and tend to reflect areas of concern in the “water community.” The US-EPA in its last report to Congress identified agriculture as the leading cause of water quality impairment of rivers and lakes in the United States. Agriculture is also cited as a leading cause of groundwater pollution in the United States.
There are other significant environmental impacts from agriculture. When agricultural land is irrigated, the water balance in nature is altered. Water is withdrawn from a river, spring, or groundwater and added to agricultural fields. The environmental impact of an irrigation system is dependent on the nature of the water source, the quality of water, the method of delivery and the local geology and climate. Withdrawing ground water beyond the recharge rate may cause the land to subside as happened in the Central Valley of California. Aquifers may become saline. All water contains dissolved salts that attached to the water molecules as it washed over the land or percolated in the ground. Rain also contains some salts. The salts are generally at very low concentrations in “fresh” water’ however, evaporation of water from dry earth leaves much of the salts behind. Over time the salts concentrate. The problem is acute in the Central Valley of California, in China’s North Plain, in Soviet Central Asia (the –istans), parts of the Middle East and the Colorado River Basin. These are all semi-arid areas where irrigation is the basis of agriculture.
Withdrawing both groundwater and surface water can dramatically change the natural hydrology of rivers and water streams, water temperature, and can impact the aquatic ecosystem associated with the surface water. The San Joaquin River in California has been dewatered as has been Owens Lake. The Colorado River runs dry before it reaches the Ocean most years as does the Yellow River in China. The riparian ecosystems and delta estuaries associated with these areas no longer receive fresh water recharge and have been destroyed.
However, irrigation has vastly improved crop yields in many semi-arid climates. As population grows, and the demand for food increases irrigation is unlikely to be discontinued. Methods and control of irrigation can determine the extent of the environmental impact from the irrigation. Improved field irrigation practices are critical to limiting the impact. It is reported that irrigated agricultural land is two and a half times more productive than rain fed agricultural land and the limits of irrigation really are the fresh water resources, the capital costs and the saline buildup over time in the farm land and aquifers. To feed the populations of the earth and protect the earth mankind needs to utilize intelligent and environmentally balanced farming practices employed .
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