The state-federal Bay Program partnership has approved controversial recommendations to award greater nitrogen and phosphorus reduction credits for farms that have nutrient management plans, one of the most widespread nutrient control practices used on the region’s farms.

The change could help states edge closer to meeting their Bay nutrient reduction goals. 

But the approval came with a big caveat — it was conditioned on states providing information about how well nutrient management plans are actually implemented. That could mean that fewer plans get counted toward Bay goals.

“We probably haven’t focused enough on that in the past,” said Nick DiPasquale, director of the EPA Bay Program Office. “I am hoping that out of this whole thing we will have more realistic numbers. That is the ultimate objective — to try to get as close to reality as we possibly can, based on the information that currently exists.”

The decision is the latest development in a long-running controversy over how to credit nutrient management plans. 

Such plans guide the timing, rate and placement of manure and chemical fertilizer on farm fields. By optimizing nutrient applications, they can help farmers meet crop production goals while reducing both costs and the potential that unused nitrogen and phosphorus will reach local waterways.

There is little dispute over the merit of nutrient management plans. But critics have questioned the extent to which they should be credited toward meeting Bay nitrogen and phosphorus goals because of uncertainty over how well plans are actually implemented.

In 2010, the EPA reduced the credits it gave for nutrient management plans because data indicated the amount of manure and fertilizer available in the watershed exceeded what would be needed by crops if all those plans were being followed. When those changes were applied to the computer models used to estimate nutrient reduction progress, though, they also produced results that seemed implausible in some counties.

States, alarmed by the reduced value of nutrient management, complained to the EPA. In 2011, states and the EPA agreed to revisit the nutrient management issue, and the Bay Program appointed a panel of recognized experts to determine the amount of nitrogen and phosphorus reductions that should be credited for nutrient management — one of many expert panels created by the Bay Program to establish the nutrient and sediment removal effectiveness of various best management practices.

The nutrient management expert panel produced several recommendations that would increase nitrogen and phosphorus reduction credits for the most basic forms of nutrient management, as well as providing additional reduction credits for advanced techniques that more precisely adjust the amount of nutrients, and how they are applied, to particular fields.

Some recommendations — particularly for phosphorus — have drawn sharp criticism from environmental groups as well as some scientists, who contended the supporting science was weak. In some situations, they said, the recommendations could allow phosphorus concentrations to increase in soils, rather than decrease.

When several Bay Program panels, including its Agricultural Workgroup and Water Quality Goal Implementation Team, failed to reach consensus on the expert panel’s phosphorus recommendations, the issue ultimately went to the program’s Management Board, which includes senior officials from state and federal agencies and representatives from various Bay committees.

At the board’s Sept. 30 meeting, environmental groups argued that the recommendations would overestimate phosphorus reductions at a time when the Bay Program has indicated that those estimates are already overly optimistic. 

Beth McGee, a senior scientist with the Chesapeake Bay Foundation, noted that the Bay Program will begin using a new computer model in 2018 that is expected to make more realistic phosphorus estimates. “If we grossly over-credit phosphorus now, we are only going to be worse off when the model changes,” she warned.

States officials countered that the recommendations reflected the best judgment by a team of experts and that failing to adopt them would send a bad signal to farmers, many of whom already feel their work is not adequately counted toward Bay goals.

“Five years after a blunder negated the effects of nutrient management, we finally have something that can reasonably estimate, based on the science available, the effect of implementing nutrient management on the landscape,” said James Davis-Martin, of the Virginia Department of Environmental Quality, and co-chair of the Bay Program’s Water Quality Goal Implementation Team.

Ultimately, the Management Board accepted the phosphorus recommendations, under the condition that states provide information showing how well the plans are actually implemented. 

EPA officials have since said they would use the information about implementation to evaluate all nutrient management acres submitted by the states, not just those getting the advanced phosphorus credits.

As a result, the amount of nitrogen and phosphorus reductions credited to nutrient management per acre could increase, but the total number of acres credited for the plans may be reduced.

Some states already do that — Maryland reduces the number of nutrient management acres it claims by about a third based on its own surveys showing that plans often are not fully implemented.

If states do not have compliance information, EPA officials have said they would determine a default value to apply to a state’s total reported acres under nutrient management based on surveys conducted by the U.S. Department of Agriculture, the EPA and potentially other sources. Those surveys typically show lower levels of implementation than what states report.

In terms of meeting Baywide goals, officials say it’s too early to say how the impact of increased pollution control credits for nutrient management will balance out with the potential of fewer acres being counted.

In fact, a Bay Program workgroup is working with all six states to determine what data is needed — and available — to demonstrate nutrient management plan implementation.

But many state officials have expressed frustration with the demand for compliance information. 

The Bay Program has developed a separate verification program that requires all of the states to develop programs to verify that all best management practices — from nutrient management plans to riparian forest buffers to various stormwater controls — are in place and functioning by 2018. Starting that year, management practices that are not verified will not count toward nutrient reduction goals.

Some state officials said the EPA has unilaterally changed the Bay Program’s verification time frame by singling out nutrient management for increased reporting requirements three years ahead of schedule.

“I think frankly that it is disingenuous to argue that this is different than what we talked about for verification,” Davis-Martin said. “It is exactly what the partnership had already agreed to in terms of a time line and process for developing those verification procedures.”

As a result, he said his, and other, states may not be able to assemble the needed information in time to get full credit for their nutrient management programs.

EPA officials dispute that they have unilaterally sped up the verification program. They say the compliance data being sought is simply better documenting state protocols they already follow to assure the quality of data submitted annually for assessing nutrient reduction progress.

“We are not going to simply say, send us all your acres and we are going to assume 100 percent compliance,” DiPasquale said. “And in the long run, it really serves the partnership and the jurisdictions to not put ourselves in a situation where we ignore the realities on the ground. To do that undermines the integrity of the program.”

Officials hope to have data about nutrient management compliance in December.

The nutrient management reductions are in the process of being re-evaluated by a new expert panel to determine how the practice should be applied in the Bay Program’s new watershed model. But that expert panel is looking at breaking nutrient management into a series of specific actions, such as manure incorporation into the soil, rather than just counting a plan itself, which could be easier to track in the future.