Fish Tech

EPRI and Santee Cooper pilot new technologies to improve fish survivability

By Chris Warren

New technology to help fish scale dams and reach their spawning grounds isn’t typically destined for pop culture fame. But that is exactly what happened when the Whooshh Passage Portal was first introduced in 2019. Meant to serve as an alternative to fish ladders and lifts, the portal uses a combination of piping, suction, and mist to whisk fish up and over dams.

The technology, also dubbed the fish cannon, was sufficiently novel to catch the attention of comedian Stephen Colbert, who featured it on his late-night show in a segment dubbed “Big News In Fish Transport.” Colbert even offered up a few alternative names for the portal, including the “trout spout” and “flinging Nemo.”

Clearly, though, the makers of the portal didn’t create the technology to be meme-worthy; it was developed to solve a real-world challenge. “There are fish species that need to get upstream to spawn; that’s part of their life cycle,” said Jon Black, an EPRI technical executive who manages the Aquatic Resource Protection Program. “Fish ladders and fish lifts, which are like elevators for fish, are super expensive. They are made of concrete and steel and require a big engineering process. And there’s no guarantee that they’re going to be attractive to fish, so you run the risk of putting in a ladder or a lift that doesn’t get many fish over the dam.”

Santee Cooper Pilots the Whooshh Passage Portal

Real-world testing is necessary to gauge the viability of new technologies like the portal. South Carolina-based utility Santee Cooper recently received an EPRI Technology Transfer Award for piloting the Whooshh Passage Portal along with two other technologies aimed at enhancing fish survival near the utility’s generation facilities.

Santee Cooper’s origins are decidedly aquatic. The Santee Cooper Power and Navigation Project was the largest earth-moving project in American history when it was built between 1939 and 1942. By creating Lake Moultrie and Lake Marion, the project made hydroelectric power generation possible, which delivered much-needed electricity to Depression-era rural South Carolina.

According to Will Stevick, Santee Cooper’s director of construction services management, regulatory compliance, cost, and environmental stewardship drove the utility’s willingness to test the portal to see if it could help American shad in the Santee River get up and over a 40-foot-high spillway at one of its hydropower facilities.

“As part of our FERC (Federal Energy Regulatory Commission) licensing for the dams and dikes involved in generating hydropower, we are required to recommend a method to get migratory fish over the St. Stephen spillway structure at Lake Marion,” Stevick said. “We are going to do whatever it takes to be compliant with all FERC regulations.”

The utility had reasons beyond regulatory compliance to investigate the portal. The area’s economy benefits from healthy populations of shad and herring for commercial and sport fishing. “Environmental stewardship is one of our corporate values,” Stevick said. “We are going to do what it takes to operate the lakes and our hydropower facilities in an environmentally responsible manner. With or without regulatory oversight, it’s the right thing to do to make sure that the shad are as uninhibited as possible.”

The Portal’s Unique Capabilities

One of the most innovative features of the Whooshh Passage Portal is its simple, removable design, allowing it to be easily taken out of the water when there’s a risk of ice or flood damage. This is made possible by the portal’s floating barge, which houses an entryway where fish swim in and ascend a short fish ladder before being gently propelled through the tube by air pressure, safely transporting them over the dam.

While fish ladders are designed to accommodate the swimming capabilities of specific species, the portal can potentially benefit a wider range of fish. “In the case of this technology, if you can collect the fish at the bottom, you can transport them passively up through the tube,” said Paul Jacobson, an EPRI technical executive. “This allows you to help a much wider range of species with different swimming capabilities.” Fish also expend a lot of energy to climb ladders. The portal allows them to conserve energy for the final swim to spawning areas.

Areas beyond fish spawning can benefit from the portal. For example, before being transported through the portal’s tube, the fish pass a camera equipped with artificial intelligence (AI). The camera can instantly identify the species of each fish, which can help contain invasive species that damage ecosystems. “You can divert the invasive species that you don’t want to pass above the dam. They can be shunted into a tank for removal or sent back to the tailwater,” Jacobson said. “The dam then remains a barrier to the spread of invasive, unwanted species.”

Lessons Learned and a New Pilot

Santee Cooper’s test of the Whooshh Passage Portal failed to transport American shad over the utility’s dam. The portal functioned as expected; the problem was that the deployment was not ideally suited to the behavior of the fish. “The system has worked very well with salmon, which are very aggressive, strong upstream swimmers,” Jacobson said. “While certainly capable of vigorous upstream movement, the American shad is not as capable a swimmer as the salmon, and they require different conditions at the entrance to the fishway.”

In the spring of 2024, Santee Cooper and EPRI tested a different fish transport technology. Like the Whooshh portal, the Fishheart system includes a floating entryway and tubing that carries fish over dams. However, the Fishheart system does not require fish to climb a short ladder, which may deter some from entering.

Santee Cooper’s trial of the technology was successful in transporting many fish species over the dam. The percentage of fish at the bottom of the dam that chose to enter the Fishheart is not yet clear. Regardless, the pilots, which were both funded by the U.S. Department of Energy’s (DOE) Water Power Technologies Office, will help inform Santee Cooper as it evaluates different ways to help local fish reach their spawning areas upstream. “We knew very little going into this, and we learned a lot,” Stevick said. “We’re looking for a cost-effective solution, and these tests will help us evaluate options and provide insights to inform other utilities.”

Measuring and Mitigating the Impact of Selenium

EPRI and Santee Cooper piloted two other novel technologies designed to improve fish survivability. Both technologies seek to better protect fish from selenium, a known fish biotoxin produced at coal power plants.

Taken together, the technologies aim to accelerate the speed of selenium measurements and increase the effectiveness of treatment. Santee Cooper tested both the OndaVia Selenium Sensor and the Montrose Selenium Removal system for several months at its Cross Generating Station in Pineville, South Carolina.

Testing selenium concentrations in waterways has typically been a slow process. “Currently, you have to take a sample, put it on ice, send it to a laboratory, and then wait at least two weeks to get your results,” said Jason Monnell, a principal technical leader in EPRI’s Water Management Technology Program.

The long delay between sending samples to be tested and receiving results can limit the effectiveness of remediation efforts because plant operating conditions that impact selenium concentrations can change dramatically.

For example, biological treatment techniques can include the use of microorganisms that accumulate selenium as they grow. However, if there are long lags between taking samples and learning results, the first indication that selenium concentrations are too high could be insect mortality. “If you go from being in compliance to being 20 times out of compliance with selenium concentrations, you won’t know for two or more weeks,” Monnell said. “And you won’t know that your bugs aren’t happy until your bugs die.”

The OndaVia Selenium Sensor, by contrast, provides results under 30 minutes. The ability to test frequently and get results means that treatment and removal measures can be responsive to current plant conditions. Real-time information about changing plant operations allows for quick adjustments to treatment and removal.“

At Santee Cooper, the accuracy of the OndaVia measurements were encouraging. Additional developments to harden the technology for use in the field, improve efficiency, and use the correct proportion of reagents are ongoing. However, the results indicate that the sensor could be valuable for utilities, mining, pharmaceuticals, oil refining, and semiconductors.

Santee Cooper and EPRI also tested the Montrose selenium removal system at the Cross Generating Station. Like the OndaVia sensor, the system represents a sharp departure from how selenium is typically removed from water. “A conventional selenium biological wastewater treatment plant right now runs on hundreds of amps and 480 volts because it needs huge pumps to convey 300 gallons a minute through it at pressure to go through anoxic conditions needed to remove selenium,” Monnell said.

By contrast, the Montrose selenium removal system runs on just 120 volts and just a few amps. It relies on biologically active absorptive media, meaning a substance designed to attract and bind selenium from water. The system is equipped with telemetry that allows it to be controlled remotely. In the pilot, the system was able to remove selenium to meet effluent limits and other frequently regulated metals. The project identified ways to improve the system that are being implemented.

The fact that the system needs little power and can be controlled by off-site operators could make it especially suitable for remote locations and facilities no longer generating power. Significant cost savings are possible because the system removes the need to have an employee overseeing an on-site thermal wastewater treatment system. The economic benefit of remote-controlled wastewater treatment over 30 to 50 years is significant when considering the cost of personnel alone.

EPRI and its members will continue to develop passive treatment methods for treating water that has low power needs and minimal operator involvement. Future pilots and demonstrations that remove selenium, arsenic, mercury, and other toxins are being developed. “We are going to take these lessons learned and figure out how you apply it to the next iteration of technologies,” Monnell said.

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