The Chesapeake Bay watershed is home to approximately 17 million people. There are numerous pollutants that eventually end up in the bay, but according to a Chesapeake Bay Foundation (CBF) study, nitrogen and phosphorus are the most ubiquitous and harmful. In excess quantities, these elements destroy habitats and cause fish kills. The largest source for these pollutants is agriculture, namely manure produced by livestock in concentrated feeding operations (CAFOS). Livestock outnumbers the watershed’s human population by 11 to 1. The manure from these animals is often placed in waste lagoons or spread over crops. The USDA’s National Resource Conservation Service estimates that 1,500,000 excess tons of manure are applied annually. Studies show that within two years, about half of the manure’s nutrient content leaches from the soil into streams or groundwater, ultimately ending up in the bay.
It is clear that a combination of strategies must be followed to minimize the input of nitrogen and phosphorous. The first would be to reduce the pollutants in manure. A study at Cornell University found that the amount of nitrogen in manure could be reduced drastically while maintaining the quality of eggs, milk, etc. through careful feed management. Secondly, runoff mitigation techniques (p. 18-19 of CBF report) could be utilized to prevent runoff when manure is applied. Cover crops during the winter months can be highly effective at holding nutrients in the soil. Riparian buffers can also remove up to 90% of pollutants if manages properly (p. 19-20 CBF report). Alternative uses for manure could be explored as well, such as abandoned mine reclamation (p. 19 CBF report). The nutrients in manure provide great restorative value when combined with lime to these lands.
Finally, once lower nutrient levels are reached, states across the watershed need to agree on a cap to ensure that additional sources of pollution from population growth and land development do not cancel out progress made in pollution mitigation. Reaching these levels, however, is a long way off. A study by the University of Maryland found that EPA had been overstating bay restoration progress, and that pollution level goals will not be met by the 2010 deadline.
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I completely agree with some of your solutions. I go to lake Anna often in Virginia and I am amazed at the farm land that surrounds the lake. The worst part is that its all cattle farms and the farmers don't seem to be taking any steps to control the runoff into the lake which does eventually drain into the bay. The cattle actually stand in the water and just hang out. I know a few years back there was research done on these farms and they found the nitrogen levels to be extremely high. I could not find the source online for it. I do not see why the nitrogen levels are not being cut more drastically due to the fact that all they need to do is monitor the feeding more closely. It is troublesome to see that that reaching the levels is a long way off.
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