May 2010, Vol. 22, No.5

Stakeholders Mull ‘Consequences’ of Chesapeake Bay TMDL Strategy

The U.S. Environmental Protection Agency (EPA) in December let the other shoe drop after unveiling its strategy in November for developing and implementing a total maximum daily load (TMDL) for Chesapeake Bay. The November announcement set “rigorous expectations” for actions to be taken by bay watershed states (Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia) and the District of Columbia to achieve bay restoration by 2025. Then, on Dec. 29, EPA issued a “consequences letter” stating alternative actions it may take if those expectations are not met. 

 

Bay watershed states and the District of Columbia have until Nov. 1 to submit detailed watershed implementation plans to reduce “nutrient and sediment loads needed to attain water quality standards.” EPA then will issue a final TMDL in December.

The consequences letter describes options open to EPA if states or the district fail to submit “sufficient” plans, “effectively implement” them, or fulfill 2-year performance milestones. For example, to counter insufficient plans or performance, EPA could, among other alternatives, expand permit coverage to currently unregulated sources or reallocate load reductions from nonpoint sources to point sources.

Expanded federal role? For some, the letter introduces an unprecedented element of federal regulation into what traditionally has been a cooperative regional effort to restore the bay. They also fear the strategy may set a precedent for similar expansion of the federal role in restoring other impaired waters. Others, including EPA, say the letter underlines the agency’s determination to establish and implement the bay TMDL but adds no “new” federal regulatory dimension.

This disagreement may stem in part from the fact that while EPA is required under a 1998 consent decree to establish a bay TMDL by May 2011, the agency framed its November strategy statement as also being the means to “fulfill the mandate” of U.S. President Barack Obama’s May 2009 executive order declaring the bay a national treasure and calling for a federally led cleanup. In addition, EPA in January announced it will develop national stormwater rules for development sites and could establish stormwater restrictions that extend “beyond national requirements” in the bay watershed.

Setting federal-level “consequences” for state actions is “absolutely new” to the TMDL process, said Kathleen Maloney, a principal of Maloney and Associates (Annapolis, Md.) and chief lobbyist for the Maryland State Builders Association (Annapolis). “We were told years ago ... that the TMDL allocation is not a regulation [but] an EPA-promulgated ‘pollution diet,’” she said. Under EPA’s new strategy, she said, “when you have this pollution diet ... then you marry that with the consequences document, it is operating just like a regulation.”

Some stakeholders frame the matter in more dire terms. “In my years of working with the Clean Water Act, I have never seen a memo like the consequences memo that came out Dec. 29, 2009 — ever,” said Don Parrish, senior director of regulatory relations at the American Farm Bureau (Washington, D.C.). “It basically threatens a nuclear option. From my standpoint, that’s a [policy] change, and it’s a ‘watershed change,’ to throw a pun in.”

“EPA is definitely trying to assert that they have more jurisdiction broadly than they actually do,” Parrish said. “EPA has the authority to require states to finalize TMDLs, but the law stops short of allowing it to implement them. ... I think what you’re seeing is a big push by EPA to try to remove the flexibility that a state has in how to implement TMDLs.”

EPA denies this. “We’re not talking about federalizing the Chesapeake Bay cleanup program,” said J. Charles (“Chuck”) Fox, senior adviser to EPA Administrator Lisa P. Jackson. “Under the law and under past practice, the states have the lead in implementing the federal Clean Water Act, and we expect that fundamental relationship to continue. However, we are talking about collectively improving the performance and accountability of the bay program. … We define it as bringing in a new era of federal leadership.”

Some veterans of the restoration effort see EPA’s strategy as the latest chapter in a history of cooperative attempts to restore the bay. “In broad scope, we’ve got a sequence of activities that goes back to 1999 that’s leading us up to where we are now,” said Doug Siglin, federal affairs director of the Chesapeake Bay Foundation (Annapolis, Md.). Those involved in “the cooperative process that has been unrolling ... to develop this TMDL have agreed that it needs to come with consequences, so the consequences letter wasn’t a surprise to anybody,” he said.

Adding to the fears of those who view the strategy as an expansion of federal authority are two virtually identical congressional bills introduced in October that would revise Sec. 117 of the Clean Water Act to codify Obama’s executive order. Some say the bills, in effect, also would codify the bay TMDL, setting a legal precedent for using the strategy elsewhere. The Senate bill (S. 1816) is sponsored by Benjamin L. Cardin (D–Md.); the principal sponsor of the House version (H.R. 3852) is Elijah E. Cummings (D–Md.).

“The Cardin and Cummings approach kind of federalizes everything,” Parrish said. “In our opinion, it sets water quality ... above all other considerations in a watershed. [It] puts the Clean Water Act in the position of evolving into something very much like an Endangered Species Act, where nothing gets done. ... We think it’s a horrible idea to codify the executive order. We think it’s a horrible idea to put into statute a TMDL that should be allowed to change over time.”

Equating EPA’s bay TMDL strategy and the executive order is misguided, according to Sue Walitsky, Cardin’s national communications director. “[The] executive order is largely independent of the TMDL,” she said. “Some have a fundamental misunderstanding of the connection — or lack thereof — because the TMDL is real and it is going forward completely independent of the legislation.” However, she noted, “[i]n order to meet the challenges that come with the TMDL, the legislation establishes a series of actions and funding opportunities that exactly parallel the TMDL process.” Regarding federal controls, she said, the bill “clearly gives the responsibility to each bay state to design and implement its own restoration plan. The federal government will require the states to live up to their obligations.”

“Potential opponents around the country are looking at the national implications of the [Cardin–Cummings bills] and not liking what they see — the national implications being that the Clean Water Act would be much more explicit that once you [develop] the TMDL, you have to take the actions to achieve it,” Siglin said.

Finding a balance. One key action EPA is expecting states to take is finding — and ensuring — an appropriate balance between point and nonpoint source controls, Fox said. “We have set a rigorous criterion for the principal bay states — Pennsylvania, Maryland, and Virginia — that we expect their nonpoint source pollution control programs ... to be, quote, ‘enforceable and otherwise binding.’ We say that because we need to achieve what we call ‘reasonable assurance’ that these nonpoint source controls will be achieved. ... So, we are applying a new rigor that has not been applied in other parts of the country before.”

Applying pressure from above may be insufficient, suggested Edward Graham, Water Resources Program director in the Department of Environmental Programs at the Metropolitan Washington (D.C.) Council of Governments. EPA “still [has] a ways to go toward really engaging the locals that have responsibility for actual implementation, and that includes wastewater plants, urban stormwater folks, and agriculture,” he said. In addition, he predicted, “EPA is going to have a lot of pushback if it says, ‘Well, states, you didn’t step up to the plate and hammer the farmers, so we’re going to punish the wastewater plants.’”

States face a particular problem in meeting EPA’s expectation for “reasonable assurance” that nonpoint source load reductions will be met, because the term is undefined, noted Alan Pollock, manager of water quality programs in the Virginia Department of Environmental Quality. “No one really has a good idea of what that means,” he said. “What judgments, what criteria are used?”

This ambiguity could have major consequences for wastewater plants and other point sources, said Brooks Smith, a partner on the Environmental Team in the law firm of Hunton & Williams (Richmond, Va.). “EPA has never defined how much assurance is reasonable or, to put it another way, how much reasonable assurance is enough, which leaves it as a completely subjective decision. ... So it’s all at the risk of point sources to bear the brunt of not enough reasonable assurance.”

This problem ultimately could become EPA’s dilemma, Graham said, “because the majority of the water quality problems in the bay is nonpoint-source-driven. ... You could close all the wastewater treatment plants down, and you’d still have a big, big challenge from the nonpoint source side.”

Such dour assessments may be misplaced, according to George Hawkins, general manager of the District of Columbia Water and Sewer Authority. If a state cannot provide adequate reasonable assurance that nonpoint source pollution can be controlled sufficiently, he said, “my understanding is that EPA would ... not necessarily shift [responsibility] from one category to another, but it may impose a program that, based on its experience or knowledge on a national basis, does provide reasonable assurance it would work for nonpoint sources.”

Which view is correct should be known soon: Preliminary draft implementation plans are due on EPA’s desk June 1.

 

— Jim Bishop , WE&T

 

Incineration Option for Solids Disposal, Energy Recovery Is Burning Brighter

 

High fuel prices and a waning economy have renewed interest in harnessing energy from wastewater treatment processes, industry experts say. This topic typically prompts discussions of using digester gas as an alternative fuel source. Recently, however, the subject has sparked interest in incineration as a method for both managing wastewater residuals and recovering energy.

“Incineration in the past has been viewed by the public as a dirty, wasteful thing that produces air pollution and has a direct impact on the neighborhood and property values,” said David Oerke, principal technologist at CH2M Hill (Englewood, Colo.). Modern, fluidized-bed incinerators (FBIs) “are much more energy-efficient and produce much less air pollution” than older, multiple-hearth incinerators (MHIs), he said, “and they recover the waste heat.” FBIs “can almost be sold as a lower-energy option, compared to hauling the material 100 miles [160 km],” he concluded.

Most solids incinerators installed since the early 1980s have been FBIs, because they are “more efficient, more stable, and easier to operate” than MHIs, according to a U.S. Environmental Protection Agency (EPA) fact sheet (EPA 832-F-03-013). An MHI “consists of a refractory-lined, circular steel shell with several shelves (or hearths) and a central, rotating hollow cast iron shaft from which arms extend,” the sheet says. “Solids are fed onto the top hearth and raked slowly to the center in a spiral path. The solids burn on the middle hearth, producing temperatures in excess of 482°C (900°F).”

FBIs also “are vertically oriented, refractory-lined, steel shell cylinders,” the fact sheet explains. “The bottom layer is an inert granular material (usually sand) that is kept in fluid condition during operation by an upflow of air. The sand bed, typically between 0.8–1.0 m (2.5–3 ft) thick, serves as a heat reservoir to promote uniform combustion. The bed is preheated to approximately 649°C (1200°F) using fuel oil or gas before solids are introduced. Solids are fed through nozzles into the fluidized sand bed, where solids and heated sands mix. It is here that liquid is evaporated from the solids and the volatile fraction of the solids burns. Temperatures between 760–816°C (1400–1500°F) are maintained in the combustion zone.”

“The figure you often see on incineration, and I think it comes from EPA data, is that about 20% of the sludge in the United States is being incinerated, and that hasn’t changed much over the years,” said James M. Rowan, thermal process manager for the water business of Black & Veatch Corp. (Overland Park, Kan.) in the company’s Kansas City, Mo., office. However, despite longstanding concerns about air pollution and negative public perceptions of incineration, this could be changing, some observers say.

“People now more and more are talking about incineration — that’s my personal impression — because of the possibility of recouping more energy out of the [treatment] plant,” said Ky Dangtran, biosolids director at Degremont Technologies–Infilco (Richmond, Va.). “A lot of older plants have digesters and would like to eliminate digestion and go straight to incineration, but they need money for that.”

Both air pollution regulations and public perceptions are obstacles to more widespread adoption of incineration to manage wastewater solids, Oerke said. Despite such concerns, Rowan said he has fielded inquiries about incineration from treatment plants where the technology is banned. Also, he speculated, “I think that in terms of greenhouse gases, digestion is going to come under more scrutiny in that methane leads to a greenhouse gas, and you have to account for that. … If you can [use] a process that doesn’t use fossil fuel, you’re much better off.”

If a facility can both conserve and generate energy using a single technology, Rowan added, it becomes even more attractive. “If I can do incineration with undigested sludge and operate that incinerator with heat recovery such that I don’t need auxiliary fuel, it’s really a double win,” he said. “And if I can make electricity with the off-gases from the incinerator, it’s almost a triple win.”

This logic was used in a recent installation of two FBIs at the R.L. Sutton Water Reclamation Facility in Smyrna, Ga., which formerly used two MHIs to manage residuals. The 151,400-m3/d (40-mgd) plant now uses “fluid-bed technology, followed by a heat exchanger, to preheat the air up to 1200°F (650°C), and the flue gas coming out of the heat exchanger is still at about 1000°F (540°C),” Dangtran said. “We move that flue gas into a waste-heat boiler to generate high-pressure steam, which we use to run a turbine generator for electricity.”

The Sutton installation demonstrates that FBI is “a green technology,” Dangtran said. “We do not generate any excess CO2 [carbon dioxide], because we do not burn any fossil fuel … and secondly, we generate electricity.” The installation reduced nitrogen oxide emissions from 2.5 kg/dry Mg (5 lb/dry ton) to 0.98 kg/dry Mg (1.97 lb/dry ton) and cut carbon dioxide emissions from 15.5 kg/dry Mg (31 lb/dry ton) to 0.01 kg/dry Mg (0.02 lb/dry ton).

Engineers at the Degremont Technologies North American Research and Development Center (Richmond, Va.) and Alpine Technology Inc. (Austin, Texas) have been developing a process control strategy based in part on growing interest in incineration as a solids management and energy recovery option. The Thermylis® Advanced Controls System (TACS) is designed to optimize FBI performance by ensuring a consistent solids feed. This is accomplished by using feedback from the FBI system operation to control solids cake characteristics.

Various factors affect incinerator operation, “the most significant of which is the quantity and quality of the incoming fuel — primarily, the wastewater solids residuals,” said Robert F. Kelly, director of research, development, and industrialization at Degremont. “The challenge … in a typical scenario is that preparation of residuals for combustion — the immediate upstream treatment, like dewatering — is often done by a different department and completely independently of the operation of the incinerator itself. The incinerator, basically, is in a mode where [it has] to deal with the incoming fuel and compensate accordingly, for example, by adding auxiliary fuel … to ensure adequate combustion.”

A principal selling point for the control technology is that incineration already is a sustainable solids disposal option, and TACS optimizes the process, Kelly said. “Specifically, it helps minimize or avoid the need for any auxiliary fuel,” he said. “We’re definitely interested in promoting incineration as a ‘green’ and sustainable approach to residuals treatment. The [TACS] program is one additional tool to help with that.”

— Jim Bishop , WE&T

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