Delmarva Chicken Industry's Small Role in Water Pollution
A number of ill-informed persons and critics of the chicken industry often complain about the role of the Delmarva chicken industry in Chesapeake Bay water quality issues. The facts provide compelling data showing the relatively small role Delmarva’s chicken industry plays in water pollution in the 64,000 square mile Chesapeake Bay watershed.
• The amount of land in the 11 Delmarva broiler chicken producing counties makes up just 7.7% of the 64,000 square mile Bay watershed. Just 7.7% and only about half of Accomack County, Virginia, just a portion of Worcester County, Maryland, and just 1/3 of Delaware drains to the Chesapeake Bay, so the amount of land in our chicken growing area is relatively small.
• The September 2007 EPA Chesapeake Bay Program report Development Growth Outpacing Progress in Watershed Efforts to Restore the Chesapeake Bay shows that throughout the entire watershed, the categories of wastewater, septic, mixed open, and urban runoff exceed agriculture’s contribution to nutrient pollution. For nitrogen, these human-caused activities account for 44% of the nitrogen in the bay versus 40% for agriculture, and for phosphorus, its 52% for human-caused activities versus 45% for agriculture.
• The 1999 U.S. Geological Survey study Monitoring Nutrients in the Major Rivers Draining to Chesapeake Bay looked at the nine largest rivers flowing to the Bay. This report concluded, “Collectively, the Susquehanna, the Potomac, and the James Rivers contributed about 95% of the annual nitrogen load and about 87% of the annual phosphorus load from the nine major rivers draining to Chesapeake Bay from 1990 through 1998.” The Choptank River, the smallest of the nine, the only one on the Delmarva Peninsula, and a river near lots of chicken houses, contributed less than 1% of the stream flow, the total nitrogen load, and the total phosphorus load according to this study.
• In June 2006, the Chesapeake Bay Foundation indicated that agricultural lands in all of Maryland, not just on the Eastern shore, constituted just 5% of the land in the Bay watershed and contributed only 7.75% of the entire nitrogen load to the Bay. Again, as you think about where nutrients are originating, you have to think about well beyond the Delmarva Peninsula and our chicken industry.
• According to a January 2007 report by the Maryland Department of Legislative Services, the District of Columbia and states other than Maryland were responsible for 79% of the total nitrogen load from all sources and 80% of the total phosphorus load coming into the Bay in 2004. Clearly this indicates that any meaningful steps to reduce nutrients reaching the Bay have to be watershed-wide and cannot focus just on Maryland, Maryland agriculture, and Maryland’s poultry industry.
• According to EPA Chesapeake Bay program data, progress is being made overall in reaching the 2010 nutrient reduction goals. Using 1985 as the baseline, 44% of the overall nitrogen goal has been achieved while 60% of the phosphorus goal has been achieved. The success rate in agriculture throughout the watershed is at about the same levels. However, since 1985 there has been a negative 90% in achieving the 2010 nitrogen goal in urban/suburban areas and a negative 67% for phosphorus. Agriculture is moving in the right direction while urban/suburban is dragging us backwards.
• At a meeting of the Maryland Board of Public Works in May 2007, Dr. Bob Summers, deputy secretary of the Maryland Department of the Environment, provided data showing that agricultural lands contribute from 20 to 25% less nitrogen than from developed lands, another reason to keep farmland as farmland.
• Farmland helps filter water. Impervious surfaces don’t. There has been a significant increase in impervious surfaces in recent years throughout the watershed. In the 1990s, impervious surfaces increased by 41% while the human population grew by just 8%. Unpaved, undeveloped land like farmland is good for the bay and the chicken industry helps keep local farmers in business.
• Since 1998, there has been a 7.6% improvement in feed conversion and that means more nutrients staying in the birds and not being in the manure. According to University of Maryland Assistant Professor Roselina Angel, between 1959 and 2001, there was a 75% reduction in N & P excreted from broiler chickens. That is a remarkable accomplishment.
• Since Delmarva’s poultry companies began using the Phytase enzyme about eight years ago, there has been about a 30% reduction in phosphorus being excreted by the chickens.
• According to the Maryland Department of the Environment, overflows from state-regulated and state-permitted wastewater treatment plants this year exceeded 458 million gallons. That’s just this year alone. These are discharges into the waters of the state and eventually much of that enters the Chesapeake Bay.
• According to a recent University of Delaware study that looked at nitrogen losses from outside, uncovered manure piles, total losses from properly stockpiled manure over time are minimal, averaging approximately 12 pounds of total nitrogen over the length of the storage period from a 100-ton pile which occupies about 1/25th of an acre.
• It would require a 25,000 acre pile of uncovered manure to lose the amount of nitrogen put out by just three wastewater treatment plants in the central Maryland Patapsco/Back River watershed. And the Maryland Department of the Environment is worried about a few shovelfuls of chicken manure lying on the ground!
These data and others clearly show that Delmarva’s chicken industry plays a small role in overall Chesapeake Bay pollution. Our challenge has been and remains to get people to know and believe these facts. You can help by sharing these points with people you know.