The question of whether the EPA exceeded its authority, or merely did what the law required, in developing the Chesapeake Bay cleanup plan reached the 3rd U.S. Circuit Court of Appeals in Philadelphia in November.

The three-judge panel that heard oral arguments Nov. 18 often sounded skeptical of the appellants’ argument that the EPA intruded on state responsibilities when it issued the Chesapeake Bay Total Maximum Daily Load in December 2010.

Within weeks of the EPA’s action, the American Farm Bureau Federation and a coalition of mostly agricultural trade groups sued to stop the TMDL. Federal District Judge Sylvia Rambo heard the case, and in a September 2013 ruling rejected their arguments.

Now, they are appealing Rambo’s decision. Rambo wrote that the EPA had played a “critical” role in working with states over a period of years to develop a pollution-reduction strategy that encompassed the Bay’s entire 64,000-square-mile watershed. She called the Bay TMDL an example of “cooperative federalism” between the states and the EPA.

The Clean Water Act requires that a total maximum daily load be developed for waterways that fail to meet water quality standards. A TMDL is a calculation of how much pollution a water body can receive and still meet water quality standards.

In the Bay’s case, the TMDL — established by the EPA after years of meetings with state officials — set the maximum amount of nitrogen, phosphorus and sediment pollution that the Bay could receive and still meet clean water standards for dissolved oxygen, water clarity and chlorophyll a (a measure of algae).

The appellants say the EPA exceeded its authority because the Bay TMDL also allocated the required pollution reductions among the watershed states and to various pollution sectors within the states, such as wastewater treatment plants, agriculture and stormwater.

Under the TMDL, states could also face a variety of federal actions if they fall short of cleanup goals.

Richard Schwartz, the attorney representing the Farm Bureau and its supporters, argued that the Clean Water Act reserved authority to regulate runoff, or nonpoint, pollution, for the states. Therefore, the EPA exceeded its authority in establishing limits for sectors such as agriculture.

Schwartz contended that the act also restricted the EPA to simply establishing a “total” load to the Bay, and did not authorize it to divide the load. Further, he said the EPA lacked authority to set cleanup deadlines or require that states show “reasonable assurance” that their programs would achieve pollution goals, both of which were part of the Bay TMDL.

Asked by Judge Jane Roth, one of the judges hearing the appeal, whether states could cede such authority to the EPA, as they largely did with the Bay TMDL, Schwartz replied they could not.

“EPA gets all of its authority from Congress,” he said. “So if EPA takes actions that Congress did not authorize, the states cannot confer authority that Congress denied.”

EPA’s authority to force pollution reductions was largely limited to overseeing the National Pollution Discharge Elimination System, which issues permits to wastewater treatment plants and other “point source” discharges, Schwartz said.

The judges questioned whether the EPA could be charged both with setting limits on “total” pollution while also having its authority restricted to one group of polluters. “How can you have a coherent policy if we are following the path you are suggesting?” asked Judge Thomas Ambro.

Schwartz responded that the proper way to deal with the Bay’s water quality problems is through the Chesapeake Bay Program, a voluntary state-federal partnership that has existed since 1983, where states and the EPA share responsibilities and can work cooperatively to address complex problems. Schwartz said it was a “fallacy” to believe that the only way to clean the Bay was through a TMDL.

Department of Justice Attorney David Gunter, representing the EPA, argued that Congress gave the agency discretion in how to implement the Clean Water Act and interpret its TMDL requirements.

He said the EPA was charged by the act with ensuring that states achieve water quality standards. He said the EPA’s authority to write its own, or approve state-written, TMDLs in order to achieve those standards has been upheld “over and over” by the courts. In that process, he said, “what EPA has found…is that it is essential to include allocations in order to achieve” water quality goals.

Gunter noted that when Congress reauthorized the portion of the Clean Water Act that established the Chesapeake Bay Program in 2000, it recognized that a greater EPA oversight role was needed by directing the agency to require that states write and implement plans to reduce pollution.

“The reason that Congress did that is it had seen decades of efforts by states to do this on their own,” Gunter said. “The states had already established a total number [for Bay pollution] and were failing to come up with the coordination among themselves to reach allocations. One problem was they didn’t all know what each other was doing, and they had no assurance that if they made the hard policy choices to control pollution that other states would do their part.”

Gunter was joined by three attorneys representing other groups that had taken the EPA’s side in the case.

Chris Pomeroy, representing wastewater treatment plant operators in Virginia and Maryland, said those entities supported the “holistic” cleanup approach taken by the TMDL to address all sources of pollution.

“Without the TMDL’s allocation process, we really would be left in an unworkable process…leaving us to duke it out permit by permit…with no process for sorting out what our slice of the pie [was] for a given facility would be,” Pomeroy said. “That process is absolutely essential for making the Clean Water Act work.”

Steven Hahn, representing Pennsylvania wastewater treatment plant operators, said the argument that the EPA acted alone to establish allocations “is factually untrue, and not supported by the record.”

Limits for wastewater treatment plant discharges in Pennsylvania, he said, had been negotiated by plant operators and the state Department of Environmental Protection, then incorporated into the TMDL.

Jon Mueller, of the Chesapeake Bay Foundation, recounted how the voluntary approach previously taken by the Bay Program repeatedly had set cleanup goals, only to see them come up short. For success, he told the judges,“we are totally reliant on the EPA to take action.”

For Bay cleanup supporters, he said, “the TMDL represents the moment in time, for if it is struck down, the Bay will not be restored.”

A decision is expected in several months. Joining Roth and Ambro on the panel was Judge Anthony Scirica.