Study: Vermont Yankee thermal discharge into Connecticut River exceeds limits

Vermont Yankee

Vermont Yankee on the banks of the Connecticut River. Photo by Deborah Lazar/Special to The Commons

A recent scientific study found that Vermont Yankee has a record of discharging water at temperatures above permitted levels. Even so, the nuclear plant has not violated its discharge permit under the Clean Water Act.

This finding — said David Deen, who chairs the House Committee on Fish, Wildlife and Water Resources — points to a major hole in the state’s permitting process for Yankee’s discharge. The Vermont Agency of Natural Resources issues National Pollutant Discharge Elimination System permits for the state. This practice differs from that in Massachusetts and New Hampshire, where the U.S. Environmental Protection Agency issues such permits.

Ultimately, Deen said, the state agency has the power to correct what he and others view as an environmental hazard, potentially affecting fish populations in the Connecticut River.

The recent study, which was conducted by the Massachusetts-based engineering firm Hydro Analysis, focused on Vermont Yankee’s thermal discharge into the Connecticut River. The Connecticut River Watershed Council, which employs Deen as a river steward, commissioned it.

The study found that from 2006-2010, between the months of May and October, Vermont Yankee’s discharge exceeded the permitted rise in temperature 58 percent of the time. In June, that number rose to 74 percent. The report also noted that temperature increases near the nuclear plant held at least 22.5 miles downstream in Massachusetts.

The temperature limits that the permit imposes vary from 13.4 degrees above ambient water temperature in winter to 2 degrees above that temperature in summer, depending on the temperature of the water.

But as the study points out, the permit does not directly take into account the actual temperature of the river.

“It may appear that Vermont Yankee is required to limit increases in Connecticut River water temperature to within specified ranges. There is, however, no such requirement in Vermont Yankee’s NPDES permit,” reads the study. “The NPDES permit instead specifies that Vermont Yankee calculate a theoretical river temperature increase and does not regulate the actual temperature rise in the Connecticut River.”

To figure out the rise in river temperature from Vermont Yankee discharge, state regulators use a calculation that dates back to 1978. The calculation takes the rate of heat delivered to the river and divides it by a multiple of the water’s density, temperature and volumetric flow.

According to Deen and others, the equation is at the root of the permitting problem.

“That equation is in fact masking a temperature rise beyond what is in the permit,” said Deen.

But Vermont Yankee officials say that this new study is the problem.

“Based on our initial review, we are very concerned about the methodology and the validity of the data used and thus believe that the report is seriously flawed,” said Vermont Yankee spokesman James Sinclair. “We are working with expert consultants to counter the Hydro Analysis claims.”

Yankee officials also vehemently disagree with Deen’s assertion that there’s an issue with the equation.

“It is based on sound science and adequately protects the river environment,” said Sinclair. “In addition, the current permit was upheld by both the Vermont Environmental Court and the Vermont Supreme Court.”

That permit, which is an extension of the one that expired six years prior, is what Deen and the director of the watershed council, Andrew Fisk, would like to see replaced.

“The current permit is entirely insufficient to protect the aquatic life of the Connecticut River,” said Fisk. “Entergy has not proved its case that the temperature increases it’s allowed are protective.”

That’s a claim that a team of scientists from Vermont, New Hampshire and Massachusetts are investigating. They’re looking at whether Vermont Yankee’s discharge practices are harming fish populations.

But, according to Gerry Szal, a Massachusetts biologist on the team, the Clean Water Act goes easy on power generators.

“The people who wrote the Clean Water Act knew that electricity was generated this way, and they wanted to give these guys a break,” he said. “They didn’t make these laws as onerous for power generators as other facilities because there’s an assumed public good that comes with generating power for people.”

The future of the discharge permit

Vermont Yankee’s discharge permit expired on March 31, 2006. Before it expired, however, Yankee officials submitted a new application.

“The way the Clean Water Act works is as long as you have an application in before the current permit expires, you’re good to go,” said Fisk.

The Agency of Natural Resources, in return, issued Vermont Yankee an amended version of the previous permit with minor changes.

As a result, Vermont Yankee is essentially using the same discharge permit it has been using since 2001. Deen and Fisk view this as a problem, since the plant and science have changed in the past decade and the current permit doesn’t jibe with the state’s new water quality standards, which took effect at the end of 2011.

Under state water quality standards, discharge and other activities should not raise the temperature of cold-water fish habitats — like that of the Connecticut River — by more than one degree above ambient temperature.

Deen would like to see the new permit restrict the actual discharge temperature below one degree.

To do that, the plant would have to move to closed cycle cooling almost all the time. As Szal explained it, the plant’s Louisiana-based operator, Entergy, is mainly cooling the plant with an open loop, sucking water in from the Connecticut and spitting it back out at a higher temperature. A closed cycle would pass the water through cooling towers, but would require more resources to operate.

“We have consistently called for a modification to the permit that requires increased closed-cycle cooling in order to meet Vermont water quality standards,” said Deen.

Vermont Yankee officials are not keen on this proposal.

“There is no basis to do so, and the plant was not designed for full-time closed-cycle operations,” said Sinclair.

Justin Johnson, deputy commissioner of the Vermont Department of Environmental Conservation, said that issuing a new, more stringent permit is not as simple as it might seem.

“Clearly the time is way longer than we’d like, but the permit itself is the only discharge permit we issue,” he said. “It has a fairly complex set of scientific findings attached to it, and there’s some expertise involved that we don’t have on staff that we have to go outside to get.”

Furthermore, Johnson said the state must be careful in issuing this permit, as the department doesn’t want to instigate or lose a legal battle. Vermont Yankee’s parent company, Entergy, is currently involved in two lawsuits with the state.

“We want to issue a permit that we believe will stand up in court,” he said. “We know that it’s likely to get challenged on the other end, and it doesn’t help either Vermont Yankee or CRWC if we issue a permit that gets overturned if challenged.”

Andrew Stein

Comment Policy requires that all commenters identify themselves by their authentic first and last names. Initials, pseudonyms or screen names are not permissible.

No personal harrassment, abuse, or hate speech is permitted. Be succinct and to the point. Comments should be 1000 characters or fewer. If your comment is over 500 words, consider sending a commentary instead.

We personally review and moderate every comment that is posted here. This takes a lot of time; please consider donating to keep the conversation productive and informative.

The purpose of this policy is to encourage a civil discourse among readers who are willing to stand behind their identities and their comments. VTDigger has created a safe zone for readers who wish to engage in a thoughtful discussion on a range of subjects. We hope you join the conversation. If you have questions or concerns about our commenting platform, please review our Commenting FAQ.

Privacy policy
  • Bob Stannard

    You may recall that the plant was not designed to be operated at a 20% uprate, yet we allowed Entergy to uprate its plant 20%.

    To say the plant wasn’t designed to run its cooling towers more frequently, and subsequently cease heating up our river, is at best disingenuous.

  • Mike Kerin

    This is just one more reason to close the plant down.

  • Guy Page

    Like most Vermonters, I know very little about thermal discharge into rivers. However, I would pose one fairly straightforward “common sense” question: if a manufacturer is required to do “closed loop” cooling, rather than make responsible use of what nature has already provided in the form of cold, running water, won’t that require more electricity? Quite a bit of it, in fact, that could be better used elsewhere? It seems to me that from a cost/environmental perspective, ramping up the electric water cooler is like relying on the electric ice cube maker, instead of just running the tap water until it turns cold enough to drink.

  • Howard Shaffer

    As a startup engineer at Vermont Yankee I’m familiar with the Cooling Tower design. The best information I have is that when the plant first went into operation the towers were used year round. There may be lots of data from that period that will shed some light on the plant’s effects.

    The study’s statement that the plant’s temperature effects can be measured so far downstream doesn’t seem credible to me. In between is the Northfield Mountain Pumped Storage Project that takes a lot of water out of the river at night, and lets it sit in the sun the next day. When peaking power is needed, the water is returned to the river.
    I’ll be intersted to see the measurement locations and how the effect of the pumped storage plant is included.

  • Bob Stannard

    Guy, I think you’re correct, but remember we granted them permission to uprate the plant by 20% in exchange for storing high-level radioactive waste here in Vermont for the next who-knows-how-long. We’ve allowed this corporation to make a lot more money off this plant than they had expected to make. If it costs them more money to not heat the river, well then so be it.

    It’s also worthy to note that Vermont is now in an adversarial relationship with this rogue company as they decided to sue us. In addition, we no longer purchase any power from them. Where’s the incentive to give them any more perks?

Thanks for reporting an error with the story, "Study: Vermont Yankee thermal discharge into Connecticut River exceed..."