Last fall the US Department of Agriculture released a draft of a report evaluating conservation practices in the Chesapeake Bay Watershed. The USDA report stated 81% of farms lacked comprehensive nutrient management plans and practices. The report found that on over 2 million acres of cropland, that conservation practices are not being used at all. According to the current version of the EPA watershed model (to be revised in 2011), cropland accounts for 25% of sediment in the bay, 32% of the nitrogen and 27.5% of the phosphorus while accounting for only 10% of the Chesapeake Bay watershed acreage.
The EPA model’s allocation of pollution origination is the basis for the current “green community” anti agriculture stance. The agricultural sector is being viewed as an excessive polluter, though farm management practices have improved over the years. The Chesapeake Bay Watershed Model is a good tool in understanding how nitrogen, sediment, and phosphorus loads from different sources are delivered to the Bay. On a major tributary basis, real world data has been used to calibrate and validate the watershed portion of the model. Thus, it can provide predictive results of implementing best management practices, a useful tool to help make decisions about tradeoffs to control the loads of nutrients and sediment in the Chesapeake Bay Watershed. Implementing and maintaining best management practices and conservation plans on farms is difficult, because it involves changing often long established practices and the way that farmers manage their land and operations and requires a management plan for each operation no matter the size.
Frightened by the prospects of the economic impact of the federally mandated TMDLs forcing farmers to build fencing to keep livestock out of creeks and drainage areas that flow in the watershed and institute comprehensive nutrient management plans on all crop lands, a coalition of agricultural groups engaged LimnoTech, an Ann Arbor headquartered environmental consulting firm, to mount a challenge to the TMDLs. They compared EPA’s Total Maximum Daily Loads with those in the draft U.S. Department of Agriculture (USDA) report “Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Chesapeake Bay Region,” and produced a report titled, “Comparison of Draft Load Estimates for Cultivated Cropland in the Chesapeake Bay Watershed.”
Inconsistencies in data and modeling were found between the EPA and USDA. This is no surprise since there are significant problems with underreporting of nutrient contamination from the urban/suburban sector in the EPA model, while the calibrated and validated totals for the major tributaries are probably reasonably accurate based on the sampling validation. So, if the urban/suburban segment is under counted in its contribution to the nutrient contamination, then some sector or sectors are being assigned that additional load. It is probably true that a significant portion of the nutrient load from the urban/suburban sector has been attributed agriculture, and if you look at the potentially revised urban/suburban load with the septic and the wastewater treatment plants (after all the wastewater is coming from the urban/suburban sector) it becomes clear that the urban/suburban populations are responsible for the lions share of contamination. In addition, the food produced by the agricultural sector feeds the urban and suburban populations.
There is a world food crisis building. Virginia is blessed with a moderate climate and adequate rainfall. Eliminating agriculture from the Chesapeake Bay Watershed is short sighted and quite frankly a really bad idea on so many levels. Nonetheless, farm practices and land management need to change. The TMDLs require a reduction in total nutrient loading in the Chesapeake Bay Watershed. To achieve the TMDLs improvements in wastewater treatment plants, agricultural nutrient management plans, stormwater managements and reductions in population and economic activities are the only sources of these reductions. Agriculture is generally considered the least cost method of reducing sediment nitrogen and phosphorus. Implementing these changes will allow us to feed more people with the same land resources, bringing agriculture to the next level. We will carry this cost in either increased cost of food, or hidden in a nutrient trading program as an overall tax to economic activity. Nutrient contamination is about populations. We need to be very careful not to kill the economic viability of the region to meet the TMDL.