Comments to EPA on Chesapeake Bay Initiatives

April 27, 2010

Water Docket
Environmental Protection Agency
Mail Code: 2822T
1200 Pennsylvania Avenue NW
Washington, DC 20460

Re: Docket No. EPA-HQ-OW-2010-0164, Executive Order 13508 Chesapeake Bay Protection and Restoration Section 502 Guidance

To Whom It May Concern:

Environmental Working Group (EWG) is a research and advocacy nonprofit with considerable expertise in nonpoint source pollution. Our goal is to bring the best data and science to bear to inform the development of policy to reduce such pollution, particularly from agricultural sources.

We read with considerable interest the U.S. Environmental Protection Agency’s proposed guidance for federal land management in the Chesapeake Bay, paying particular attention to the tools and practices suggested for controlling phosphorus pollution. Phosphorus that leaches from or runs off of agricultural fields in the Chesapeake Bay watershed is a major factor causing the failing health of the Bay ecosystem.

With this letter, we commend the agency for its careful attention to the important role of agriculture in Bay restoration, and applaud a number of specific implementation measures outlined. In addition, we ask for clarity regarding manure application on soils for which phosphorus saturation is an inadequate means of assessing the potential for this nutrient to contaminate local waterways. Finally, we challenge the EPA to address the widely acknowledged phosphorus imbalance in the region with specific proposals designed both to equilibrate imports and exports of the nutrient, and to hold poultry integrators responsible for their fair share of the cost of dealing responsibly with the waste created by their chickens. While at present these measures would apply to federal lands only, we think the guidance developed in this document should also help inform policy to address the same issues on private lands throughout the watershed.

EWG strongly supports numerous agricultural pollution control measures outlined by the EPA. According to the agency, “Agriculture is the single largest source of nutrients and sediments to the Chesapeake Bay, responsible for 43 percent of the N, 45 percent of the P, and 60 percent of the sediment loads” (EPA 2010; 1.1.3 page 2-3, lines 33-34). The tools and practices outlined in the current document are a significant improvement over existing land management measures that have proved inadequate in addressing agricultural pollution. Particularly promising proposals include:

  • Prohibiting additions of manure or fertilizer to soils with phosphorus saturation greater than 20 percent
  • Replacing high nutrient loading crops like corn and soybeans in areas at high risk for water quality impacts with sound alternatives
  • Retiring highly erodible lands from both cropland and pasture, replacing them with perennial native vegetation
  • Minimizing commercial fertilizer use where manure nutrients are available
  • Managing animal feed to minimize nutrients in manure
  • Restricting access of livestock to streams through fencing or other effective measures to reduce nutrient inputs, stream bank erosion, and sediment inputs
  • Managing nutrient applications to row crop land to minimize nutrients available for runoff by a) applying manure and chemical fertilizer during the growing season only, b) not applying manure to frozen ground, and c) injecting or incorporating all manure and organic fertilizer to minimize available nutrients
  • Using suitable cover crops on all acres that have received manure or chemical fertilizer
  • Adopting fertilizer application buffers or minimum setbacks from in-field ditches, intermittent streams, tributaries, and surface waters
  • Protecting and restoring wetlands and riparian areas
  • Using controlled drainage, ditch management, and bioreactors as necessary to minimize off-farm transport of nutrients
  • Establishing and maintaining forest buffers on at least 70 percent of all shorelines and streambanks in the watershed

Broad implementation of the many proven land management practices outlined by EPA in this document will result in cost-effective reductions in agricultural contamination entering the Chesapeake Bay for years to come.

The EPA must clarify guidance regarding phosphorus application. Existing state guidelines concerning additions of manure to soil employ particularly lenient phosphorus site indices that allow repeated applications of the nutrient in excess of crop needs. Use of these indices in land management results in agricultural fields with increased phosphorus pollution potential over time, making this tool fundamentally unsustainable (Maguire 2007).

EWG advocates nutrient management scenarios that provide nutrients only when crops need them and when water quality impacts will be negligible. Appropriate management techniques will rely on soil test phosphorus levels, as well as hydrological considerations. However, we recognize that the phosphorus saturation-based measures outlined by EPA will result in considerably less manure application to land as compared to current land management practices (Kovzelove 2010), and support this change as an interim measure. In particular, we greatly appreciate the guidance concerning a halt to phosphorus additions with saturation above 20 percent, as greater levels of saturation are widely found to dramatically increase phosphorus pollution from agricultural fields (Butler 2005).

The science is clear that some portions of the landscape are much more likely to deliver phosphorus and other pollutants to water bodies. The sole reliance on phosphorus saturation-based measures could permit inappropriate phosphorus additions in such areas. Hydrologically active soils are likely to release phosphorus into nearby streams and rivers, even at low levels of saturation.

The EPA guidance acknowledges the role of hydrology through provisions such as exclusion of phosphorus additions to highly erodible lands and within setbacks near ditches, intermittent streams, and other waterways. However, there is not necessarily a direct hydrological connection between highly erodible land, as currently defined, and delivery of nutrients and sediments to the Bay. Furthermore, the EPA does not provide a clear definition regarding the width of setbacks, and only provides vague advice concerning a few other factors important to the hydrology of fields: “It is important for the nutrient management plan to address the slope and movement patterns for water as runoff in a field, because P saturation does not dictate the probability of P in runoff to move to a ditch or local waterbody” (EPA 2010; 2.1.1 page 2-16, lines 16-18).

We prefer an approach that restricts nutrient application in hydrologically active areas. Such areas may or may not be currently defined as highly erodible, or within vaguely defined setbacks. Without a clearer delineation of those landscapes for which phosphorus saturation is not an adequate measure of potential phosphorus pollution, this guidance could encourage manure application to fields hydrologically unsuitable for this use, resulting in greater levels of phosphorus discharge to the Bay.

The EPA guidance does not alleviate the underlying phosphorus imbalance in the Chesapeake Bay region. According to the EPA, “a significant nutrient imbalance exists in the bay watershed so that there is an excess of P being produced in the watershed, resulting in excess P being available for delivery to the bay through surface and ground waters” (EPA 2010; 2.1 page 2-11, lines 5-8). Furthermore, “To meet the 2025 nutrient goals for the Chesapeake Bay, the agricultural community will need to broadly adopt new markets and alternative manure uses” (EPA 2010; 1.1.4 page 2-5, lines 28-30).

Unfortunately, the EPA essentially ignores this fundamental problem in its guidance. Its only recommendation for reducing phosphorus imports is to minimize commercial fertilizer use where manure nutrients are available. No measures are provided for removing phosphorus from the region through “new markets” or “alternative manure uses.” Without addressing the underlying cause of much of the nutrient pollution entering the Chesapeake Bay, how can the EPA truly hope to reduce the load of contaminants in our waterways?

As it stands, the EPA guidance is incomplete. The agency must amend its document with a detailed discussion of the non-traditional markets and alternative uses for manure currently available and under development. In particular, the role of poultry integrators in sharing a substantial part of the capital and operating costs of developing and implementing such remedial measures must be delineated. Effective solutions to this most critical problem will remain out of reach unless these companies take responsibility for the manure generated by their chickens.

The EPA has provided a promising guidance document that could do much to alleviate the pollution problems of the Chesapeake Bay – if the agency addresses the few glaring gaps we have highlighted in this letter. This guidance could and should be used to inform and accelerate efforts to deal with the same issues on privately owned agricultural and forest land in the watershed. We appreciate the opportunity to comment, and look forward to working with the agency to heal Bay ecosystems.


Rebecca Sutton, Ph.D.
Senior Scientist, Environmental Working Group
2201 Broadway, Suite 308
Oakland, CA 94612


Butler JS, Coale FJ. 2005. Phosphorus Leaching in Manure-Amended Atlantic Coastal Plain Soils. J. Environ. Qual. 34:370–381.

EPA (Environmental Protection Agency). 2010. Executive Order 13508 Chesapeake Bay Protection and Restoration Section 502 Guidance. Docket No. EPA-HQ-OW-2010-0164. Available at:

Kovzelove C, Simpson T, Korcak R. 2010. Quantification and Implications of Surplus Phosphorus and Manure in Major Animal Production Regions of Maryland, Pennsylvania, and Virginia. Water Stewardship. Available at:

Maguire RO, Ketterings QM, Lemunyon JL, Leytem AB, Mullins G, Osmond DL, Weld JL. 2007. Phosphorous Indices to Predict Risk for Phosphorous Losses. SER-17 Position Paper. Available at:

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