Savannah River "metabolism" explored in new flow study

Houseboat lab checks for environmental imbalances

It started with a handful of oranges – and evolved into a quest to unravel the Savannah River’s most complex biological secrets.


“We want to follow the same parcel of water as it goes downstream, to see how it changes – and why,” said research scientist Oscar Flite.

The Southeastern Natural Sciences Academy vice president and his colleagues are using an instrument-packed houseboat to study environmental imbalances between Savannah Harbor and the upper river near Augusta that will force huge and costly changes in the way cities and factories manage their wastewater.

From a regulatory standpoint, there are actually two Savannah Rivers that meet at a lonely point near Clyo, Ga., known as River Mile 61. “That’s the regulatory dividing line,” Flite said.

The upper section, managed by Georgia’s Environmental Protection Division and the S.C. Department of Health & Environmental Control, serves dozens of waste generators vying for a share of the river’s limited assimilative capacity.

Closer to the sea, there is a very different Savannah – overseen by the U.S. Environmental Protection Agency under a very different model influenced by international shipping, estuaries, oxygen levels and saltwater ecosystems.

Years of studies and a 1994 Sierra Club lawsuit yielded an eventual conclusion that Savannah Harbor was deficient in dissolved oxygen. The proposed remedy devised by the EPA was to limit oxygen-depleting discharges, including wastewater released in Augusta, nearly 200 miles upstream.

The pending changes, which remain under review, require cities and industries to reduce certain types of pollution. The current goal is to reduce those oxygen demanding wastes – estimated at 505,042 pounds per day – to a “total maximum daily load,” or TMDL, that falls somewhere between 80,000 and 130,000 pounds.

The cost of complying with the new rules will include everything from permitting studies to investments in new technology and equipment. While a total cost is difficult to estimate, officials say it will easily stretch into millions of dollars.

There is already modeling data from both segments of the river, but the TMDL issue has opened the door for a closer look. Flite and his crew hope to float the entire channel - at the same leisurely pace as the river’s flow – to explore the changes as they happen.

To plan the project, they needed to see how fast the water moves. “We started by throwing oranges into the water to see where they end up,” Flite said. “That seemed to work for a little while, but not for 180 miles.”


THE CURRENT TRIP has taken a year to plan. Using equipment borrowed from Clemson University, and a few pieces they had to invent along the way, the team will spend about two weeks on the river, while watching for changes caused by organics, nitrogen levels, oxygen changes and even the effects of sunlight and tannic acid from blackwater swamps.

“We’re looking for anything that might have been overlooked,” he said. “We’re after the science within the science. Ecologically, we’re trying to figure out what the metabolism of the river is.”

Although regulators are hoping to solve the harbor’s problems by limiting pollution loads far upstream, there are many other factors that influence water quality, along with some evidence that reducing pollution in Augusta may not even improve water quality in the harbor because oxygen levels rise and fall several times before reaching the coast.

“From a technical standpoint, the river is meeting its standards up there in Augusta for dissolved oxygen,” said Bill Melville, the EPA’s regional TMDL coordinator. “But if you follow it downstream, and the models show this clearly, you actually see the impact of that oxygen demand 40 or 50 miles downstream.”

The irony of the situation, he added, is that the higher the quality of the treated waste entering the river, the longer it takes to manifest itself in the environment. “If you dump raw sewage into the river, you’d see the effects immediately.”

Questions that still must be answered include the extent to which decaying leaves and natural vegetation affect water quality. The velocity of the river’s flow could be a factor also.


OVER TIME, THE Savannah River that Augusta’s first settlers navigated has been changed, dammed upstream and shortened downstream. Flite estimates more than 42 miles of the river were gradually eliminated as the Army Corps of Engineers blocked off river bends and oxbows and turned them into landlocked cutoffs in efforts to straighten the navigation channel.

There are dozens of them still visible today, with names like Devil’s Elbow, Fat Meat Point and Whirligig Cutoff.

Flite believes it might someday be possible to improve water quality and increase the river’s waste assimilation capacity simply by improving or restoring the river.

“If some of those cutoffs were reopened, it would increase the detention time and water would take longer to get downstream,” he said. “It would also increase the surface area and retain more fresh water in the floodplain during wet years, so it might even have an effect on drought.”

Corps records are sketchy in terms of how much of the river was eliminated, said spokesman Billy Birdwell. From 1950 to 1979, however, the agency made a number of changes to maintain a 90-foot-wide, nine-foot-deep channel from the harbor to Augusta’s 13th Street.

“These actions included construction of contraction works, closure of cutoffs, bank protection, dredging, removal of snags, over-hanging trees and wrecks, and open-river regulation,” Birdwell said. “The exact number of each of these cannot be determined, although aerial views of the river still show many of them. We’ve done nothing since 1979.”

As the stricter pollution limits get closer to implementation, stakeholders on both sides of the river have worked together to discuss a reallocation of wasteload.

“It’s been a group effort, and that is good,” said Jeff Larson, the assistant chief of the Georgia Environmental Protection Division’s Water Protection Branch. “They started first to get some ideas and ultimately came up with an actual strategy for allocating pounds.”


ALTHOUGH THE GROUP’S proposals remain in discussion stages, and must undergo evaluation by regulators, the ability of stakeholders to work together is a plus, he said, adding that new or revised permits could resume later this year, after being indefinitely placed on hold several years ago.

The EPA’s Melville said there is no official deadline for implementing the new rules.

“There isn’t a strict legal mandatory date but we are trying to implement it as soon as possible,” he said, adding that many industries are operating under “administratively continued” permits that place their operations in regulatory limbo until the new rules are in place.

The stakeholder group, he added, is moving toward a workable proposal. “All the dischargers are on board and they realize they have to commit to these very significant pollution load changes,” Melville said.

Some of those stakeholders are helping to fund Flite’s study. They include Augusta-Richmond County, Columbia County, North Augusta. Georgia Power, PCS Nitrogen, International Paper and academy members.

Although some industries will have to make major changes, Augusta’s wastewater program – a major generator of oxygen demanding wastes – recently completed an eight-year, $85 million series of improvements that have brought the city close to compliance, said Allen Saxon, Augusta’s assistant utilities director for wastewater treatment.

The resulting sewage treatment system is more efficient and more reliable than it has been in the past.

“We’ve already invested funds to meet those new limits,” Saxon said. “So you could say we’ve already taken a big bite of this apple, but there are others who aren’t in that position yet.”



Fri, 10/20/2017 - 23:13

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