Section 316(b) Regulations: The Yin and Yang of Fish Survival and Power Plant Operation

Issue 7 and Volume 108.

By: Brian K. Schimmoller, Managing Editor

New cooling water intake rules will require significant expenditures of time and resources, but the flexibility of the rules should facilitate compliance.

What do you get when you cross 80 trillion gallons of power plant cooling water with more than 200 million pounds of aquatic organisms? Besides a bad case of fish breath, you get EPA’s final regulations for cooling water intake structures at large power plants. On February 16, 2004, EPA Administrator Mike Leavitt signed a final rule to protect fish, shellfish and other aquatic life from inadvertently being killed by intake structures at existing large power stations that use once-through cooling systems.

The rules define and clarify text included in Section 316(b) of the Clean Water Act. Section 316(b) requires EPA to ensure that “the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.” EPA divided its rulemaking related to Section 316(b) into three phases. Phase I, for new facilities, was completed in December 2001. Phase II, for existing power plants that are designed to withdraw 50 million gallons per day or more and that use at least 25% of their withdrawn water for cooling purposes, is the subject of the February 16 ruling. Phase III, for smaller power plants and certain industrial facilities, is scheduled for proposal in November 2004.

The new Phase II rule establishes performance standards for cooling water intake structures (see table), based on mortality impacts on aquatic life caused by impingement and entrainment. All existing large power plants will be required to reduce the number of organisms killed when they are pinned against parts of the intake structure (“impingement mortality”) by 80-95% from the Calculation Baseline. The Calculation Baseline is the impingement mortality and entrainment that would occur if the facility had a shoreline, near-surface intake with a 3/8-inch mesh, traveling water screen but no other measures to reduce impingement mortality and entrainment. Certain facilities will also have to reduce the number of organisms drawn into the cooling system (“entrainment”) by 60-90% from the Calculation Baseline.

Long History

Since passage back in the 1970s, the Clean Water Act’s 316(b) regulations have been applied and interpreted on a case-by-case basis, generally administered by the state agencies responsible for the NPDES (National Pollutant Discharge Elimination System) permitting process. Agency staff used “best professional judgment” to determine whether or not power plant operations would result in adverse environmental impact to the aquatic environment.

The standard for review evolved out of a draft EPA guidance document issued in 1977. “EPA tried to promulgate regulations based on the document, but they were thrown out by the courts on procedural grounds,” says Mark Gerath, Water Resources Specialist with ENSR International. “Defining what constituted an adverse environmental impact was never simple and often triggered heated debate. Were the mathematical models used in the population analyses meaningful? Were they properly calibrated?” Moreover, the states placed varying levels of importance on compliance with 316(b) regulations. Maryland, Florida, California, the Great Lakes states, and the Northeast states typically did extensive work, making plants show they had installed effective technology to minimize adverse environmental impact. Some other states did little more than cursory evaluation.

In the first two phases of the 316(b) regulations already announced, EPA worked from two main premises: one, that using once-through cooling uses too much water, resulting in potentially large impacts to aquatic life; and two, that the best alternative to once-through cooling is closed-loop cooling — cooling towers or ponds. EPA recognized, however, that requiring cooling tower retrofits at all existing power plants would be very expensive (hundreds of millions of dollars in many cases), result in a power hit and related non-aquatic environmental impacts, require a lengthy shutdown, and likely encounter significant space constraints.

“EPA realized that a cooling tower wouldn’t be feasible in most situations,” says Gerath. “They believed, however, that other mitigation technologies could be just as effective in reducing actual impingement mortality and entrainment rates to a ‘level commensurate with’ closed-loop cooling. That’s why there’s a range in the compliance figures. EPA is saying, ‘one size doesn’t fit all,’ but by combining technologies or combining technologies with operational measures or restoration, we can get to that ‘level commensurate with’ value.”


The final rule provides generators with flexibility by offering five compliance options. Four are based on meeting the applicable performance standards and the fifth allows the facility to request a site-specific determination of best technology available (BTA) for minimizing adverse environmental impacts.

In Option 1, a facility can reduce flow to a “level commensurate with” a closed-cycle recirculation system or reduce through-screen design intake velocity to 0.5 ft/s or less. “Option 1 provides utilities with a clear exit-ramp strategy,” says Gerath. “Few if any of the Phase II plants are likely to go this route, but it basically says, if you convert to closed-loop cooling, you’re done.” Another Option, 1a, provides for a more limited “exit” if the facility is not subject to entrainment controls and the through-screen velocity is less than 0.5 ft/s.

In Option 2, a facility can demonstrate that current technology and facility operations result in a reduction in impingement and entrainment commensurate with the numerical performance standard. “For example, a facility that has previously retrofitted the intake structure to reduce impingement and entrainment can conduct studies to demonstrate that the technology currently meets the performance standards,” says Manitia Moultrie, Director of 316(b) NPDES Permitting with Golder Associates. “The burden of proof will lie with the plant owner, however, so they need to be reasonably certain the standards are being met.” The Compliance Demonstration Study (CDS) is the means of showing compliance with this and other options.

In Option 3, a facility can select and implement technologies, operational measures, and/or restoration measures to reduce impingement and entrainment. “The third option will likely be the most frequently used,” says Gregory Howick, Senior Aquatic Ecologist with Burns & McDonnell. “We expect many intakes on freshwater rivers will be retrofitted with new traveling screens with fish handling systems. Facilities that obtain cooling water from lakes may elect to install fish barrier nets or wedge-wire passive screens that have a through-screen velocity of no more than 0.5 ft/s. Some facilities may be able to modify their intakes and/or traveling screens to get the velocity reduction necessary to come into compliance with the new regulations. For facilities that must meet the entrainment standard, habitat restoration is likely to be a popular, if not the only, cost-effective option.”

Option 3 provides power plant owners and operators with a significant level of flexibility, but it could also put the plant in a vicious regulatory circle. The permitting agency, for example, could initially state that a given plant’s plan achieves BTA status. If subsequent monitoring, however, indicates that the performance goals aren’t being met, the agency could have the plant on the hook for additional technology or operational changes. “Such a scenario has many owners worried,” says Gerath. “However, it won’t be in most states’ interests to go down this path. They don’t have the resources to deal with this issue repeatedly. Most states will want to get a reasonable solution in place that meets the compliance requirements without beating it to death.”

In Option 4, a facility can install a state-approved technology to reduce impingement and entrainment. In the rule, one such technology — submerged cylindrical wedge-wire screens for use on a fresh water river or stream — is specifically identified. Other criteria must be met, however, according to Moultrie: flow must be counter-current to promote cleaning of the screen, the maximum through-screen velocity cannot exceed 0.5 ft/s, the slot size must be appropriate for adequate protection, and all condenser flow must be directed through the screen. Gerath is enthusiastic about Option 4. “If utilities can work with state agencies to approve other technologies, the upfront studies will be much simpler and there obviously will be a greater chance of achieving BTA status.”

Option 5, which enables facilities to select and implement alternate design, technology and operational measures, is something of a wild card. Its use depends on the utility’s ability to prove (i) that the costs associated with meeting the performance standards are “significantly greater than” the costs EPA has determined, or (ii) that the costs of compliance are “significantly greater than” the resource benefits that would be achieved within the waterbody. In essence, Option 5 provides the “case-by-case” subjectivity EPA had been trying to eliminate via the new 316(b) rules.

“Option 5 is not necessarily the best option for all facilities,” says Moultrie. “Over the next six months, EPA will likely have published reference cost documents on its web site to assist in the definition of ‘significantly greater’ and help guide the decision-making process.” Gerath is not so sure. “EPA has studiously avoided defining what constitutes ‘significantly greater than.’ In writing and on the phone, they say that such determinations will be ‘up to the Director.’ Is ‘significantly greater than’ 10% more, twice as much, or ten times as much? Without a decision by the Director, Option 5 could be a chancy alternative.” In addition, the final rule calls for the implementation of any “cost-effective” measures even if they don’t fully meet the compliance goals. As important as this approach is, the implementation details will require a lot of thought.

Compliance Process

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The steps involved in achieving compliance with 316(b) Phase II are neither simple nor straightforward. The accompanying figure depicts a flowchart developed to help visualize the process that ENSR encourages its clients to review before embarking on an expensive compliance planning process. The flowchart outlines the type of information that should be analyzed before taking any action (box in upper left). The chart then walks the user through a series of questions to determine which option or options are most viable.

The schedule for compliance with Phase II is based on the facility’s NPDES permit renewal date. For those facilities whose NPDES permit expires within four years of rule publication, the owner can request up to a three-and-a-half year delay in submittal of BTA material and supporting documentation. For those facilities whose NPDES permit expires beyond four years, the BTA application and supporting materials are due 180 days ahead of the NPDES permit renewal date.

NPDES permits must be renewed every five years. This implies that about 80% of all Phase II facilities will be on the same schedule for completing their 316(b) studies. “Concerns exist that shortages of qualified contractors, particularly in the areas of fisheries and the identification of larval fish and shellfish, may arise,” says Howick. “This situation could make conducting the studies more expensive for facilities that delay lining up the needed assistance. In addition, chronically under-funded state agencies responsible for discharge permitting may become overwhelmed by avalanches of Proposals for Information Collection and Comprehensive Demonstration Studies.”

The CDS is the mechanism for showing that the selected option meets the goals of the rule (including site-specific BTA, if appropriate). Depending on the option, the CDS may consist of several separate studies variously focused on the biology, technology, restoration measures, and/or economics. Depending on the scope of the studies (agreed to through negotiation on the Proposal for Information Collection), the studies might be lengthy and costly. They will certainly require a complex synthesis of the various technical disciplines. Having reviewed the CDS, the NPDES agency might conclude that the collected data do not support that the performance goals are being met. In this case, additional study and additional controls may be required.

The Proposal for Information Collection, which is due 15 months before the permit application, describes what data will need to be collected and analyzed to characterize impingement and entrainment at a given plant and to demonstrate the effectiveness of existing or proposed technologies to achieve impingement and entrainment standards. Plant data such as historical intake flows, intake structure design and operation, previous impingement and entrainment studies, waterbody characteristics, and affected species will need to be gathered. The required studies are not particularly difficult for qualified specialists, but they can be time consuming, according to Howick. The Impingement Mortality and/or Entrainment Characterization Study, for example, requires the identification of the fish and shellfish species that occur in the vicinity of a facility’s intake and are impinged and/or entrained, and how the abundances of these species vary annually, seasonally, and daily.

For plants that opt to install technology or use operational measures to achieve compliance, a Design and Construction Technology Plan is required to describe the technology and provide estimates of impingement mortality and entrainment reductions. The plan must also demonstrate that the selected measures reflect BTA.

Strictly speaking, compliance with Phase II regulations is based on demonstration of meeting the performance standards. Verification monitoring (to demonstrate compliance) for at least two years is indicated in the rules. “Because there is uncertainty associated with the application of various technologies under various conditions, the rule provides the option of demonstrating compliance through the implementation of a Technology Installation and Operation Plan (TIOP),” says Moultrie. The TIOP enables facilities to “adaptively manage” technologies and operations suitable to the facility’s specific conditions. The ability to adaptively manage sounds attractive — and screams of flexibility — but it should be addressed with caution because the permitting agency may conceivably require a series of changes to meet an ambiguous target unless “compliance” is clearly defined in the TIOP.

Despite EPA’s efforts to correlate the Phase II regulations to a quantifiable standard, a large amount of leeway remains. Conceptually, a plant with no protection technology in place can measure impingement and entrainment rates now, implement changes, and then measure the subsequent impingement and entrainment rates. “Conceptually, that’s simple, but the devil is in the details,” says Gerath. “Biological populations are variable and can fluctuate by huge amounts. For example, we’re looking at one plant where the rate of impingement of fish varies 100,000-fold one year to the next.” In such a situation, compliance might depend on the Director’s discretion. The Director conceivably has the authority to de-emphasize episodic and extreme events, says Gerath.

The state agencies that administer the NPDES permit program will have a large role to play in the 316(b) compliance process — determining what qualifies as BTA, defining terms such as “significantly greater than” and “level commensurate with,” and ensuring compliance. Getting up to speed on 316(b) will not occur instantaneously, however. “Most of the people who had any experience with 316(b) regulations from the 1970s have retired,” says Gerath. “The majority of the permitting engineers at the state agencies are wastewater engineers who have limited familiarity with the range of biological and aquatic details associated with 316(b).” This indicates that some “education” will be necessary, but it also indicates that utilities may have an opportunity to influence this education. Both Moultrie and Gerath stress the importance of establishing and maintaining close ties to the relevant permitting agency — to avoid surprises and to provide an industry perspective.

One thing utilities must impress upon state agencies is that issues beyond technical feasibility and cost can and should be considered in determining BTA. A given technology must be considered in all its manifestations, including its effects on power reliability, outage schedule, environment (noise, visual, atmosphere), wetlands, etc. “For example, you might be able to install a barrier net or aquatic filter barrier, but it might get in the way of shipping, or ice and debris could conceivably rough up the net,” says Gerath. “The agency isn’t necessarily going to jump to think about these things.”

Cooling water intake structure at the Nearman Creek Generating Plant on the Missouri River in Kansas City, Mo. Photo courtesy of Burns & McDonnell. Click here to enlarge image


Compliance Costs

The costs of complying with the 316(b) Phase II regulations will vary significantly. EPA estimates the rule will cost about $400 million annually to implement and administer, with individual annualized plant costs ranging from zero to more than $10 million. About 150 of the 550 affected plants are estimated to have incremental compliance costs of zero, while the most expensive plant had estimated compliance costs of $12 million/year. This particular plant retrofit involved refitting an offshore intake with a fine-mesh traveling screen. Notably, EPA did not base any of its cost estimates on the addition of cooling towers.

The reasonableness of EPA’s cost estimates are open to debate, of course. In an article in Electric Perspectives, Edison Electric Institute states that EPA’s $400 million estimate undervalues the real expense at individual facilities two- to ten-fold. “Although the rule represents a workable approach toward the continued protection of the environment, it will impose significant and costly new federal requirements on the electric power industry,” says Rich Bozek, EEI’s director of environmental policy.

“The consensus among those we’ve talked to in the regulated community and from the state agencies is that the EPA-estimated costs of the technologies are pretty low,” says Gerath. “The costs of the studies can be quite high if specialized testing is required — such as offshore testing at night. It’s my opinion that the EPA-estimated costs of the compliance studies are pretty low as well.” It’s important to point out that EPA only considered technology installation and operating costs in its estimates, not the permitting and monitoring efforts to demonstrate compliance with the performance goals. Burns & McDonnell’s Howick pegs the costs for studies for Phase II facilities at about $300,000, if impingement mortality is the only applicable performance standard, and about $600,000 if entrainment must be considered.

Aerial view of the Gunderboom Marine Life Exclusion System at the Lovett Generating Station on the Hudson River in Tomkins Cove, N.Y. Photo courtesy of Gunderboom Inc. Click here to enlarge image


Get Moving

So what should utilities do now to avoid becoming a deer in the headlights? Start planning. Take a look at the available technologies and make a first cut at what’s in and what’s out. Contact the state permitting agency to begin advocating certain positions or to promote a given technology for pre-approval. Sit down and carefully determine what types of data will need to be collected in developing a successful compliance program.

“Facilities that act the soonest will get the most highly qualified individuals and the most competitive prices from their consultants,” says Howick. “In addition, the first utilities through the doors of the permitting agencies with their Proposal for Information Collection will have a better chance of influencing the policies of agencies that are just beginning to grapple with their responsibilities for 316(b).”

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Somewhat remarkably, EPA seems to have done a good job synthesizing disparate opinions in developing the Phase II regulations. From a utility perspective, it could have been a lot worse. As part of the legal efforts that prompted the new 316(b) regulations, Riverkeeper was pushing to make cooling towers BTA for Phase II. EPA resisted that pressure, and opted for a more flexible approach. The price of this flexibility, however, is the time and expense associated with the studies to demonstrate that the selected compliance measure meets the performance standard.

The bottom line is that there’s no one technology that’s going to save everyone. What is best for one plant may not be best for another plant 100 miles down the river. And as much as EPA wanted to move away from the site-specific approach, each plant has to be looked at on an individual basis to determine the most cost-effective compliance solution.