Silt is a major topic in Ballville Dam debate

FREMONT – There’s a lot of silt trapped behind the Ballville Dam in the Sandusky River, and if and when the structure is removed, hundreds of thousands of cubic yards of the sediment will flow downstream.

Proponents and opponents of dam removal agree on that statement. Disagreements arise, however, over such questions as how much silt, what’s in the silt, and what is the potential impact of the sediment’s release.

The city is set to proceed with its long-anticipated dam-removal project in the coming weeks, even as it awaits the outcome of a federal lawsuit filed by the Sierra Club’s Ohio chapter seeking an injunction to stop action at the Ballville Township site.

Ray Grob, 85, of Fremont, has been a longtime opponent of dam removal and laments what he thinks will happen to walleye and white bass spawning grounds, as well as sensitive marshlands, if the dam is taken down and a substantial amount of silt is released.

“I don’t want to see it gone,” Grob said Thursday as he talked about the dam.

He feels his calls to save it have fallen on deaf ears with removal proponents such as the Ohio Department of Natural Resources and the city’s administration.

Grob said he is concerned about 2 to 3 feet of muck from the silt covering fish spawning areas and preventing walleye from laying eggs on the certain type of gravel they need for reproduction.

Fred Snyder, a retired Ohio State University professor and fisheries extension biologist from Fremont, said he thinks the dam removal issue has been turned into a lot of “what if” scenarios by opponents rather than focusing on available data on silt release as it relates to the Ballville Dam.

Snyder is in favor of removing the dam and said that every dam removal in the United States he’s aware of has been an environmental success story.

Staggered release

He said he does not fear the silt eliminating the walleye spawning ground or causing severe damage to marshlands once the dam is down and the silt dispersed downstream.

Snyder said the city’s plan to notch the dam, creating a staggered release of the sediment, would allow for the river to naturally flush the silt and prevent it from collecting in overwhelming quantities and damaging fish spawning areas.

“It has been turned into more of a political apple than a scientific apple,” Snyder said of the dam removal project.

As to how much silt lies behind the dam, there is a wide disparity in volume estimates.

Grob estimates the amount of silt trapped behind the dam measures 1.6 million cubic yards, with that sediment stretching along the riverbed from the dam almost a mile to the Tindall Bridge.

“It will take repeated high-water episodes to clean all that out,” said Grob, who wrote a book about the Sandusky River and has canoed more than 3,000 miles in his lifetime.

The city’s silt estimate, based on an August 2014 written response to a U.S. Army Corps of Engineers request for information, is closer to half of Grob’s figure.

Even the lower estimate of 840,000 cubic yards is a lot of silt — enough to fill more than 60,000 dump trucks, according to some estimates.

That response, which relied heavily on the U.S. Fish and Wildlife Service’s final environmental impact statement for the dam project, estimated that there is 840,000 cubic yards of silt behind the dam.

Between 1979 and 2002, the Sandusky River watershed delivered 8.828 million cubic yards of sediment to the U.S. Geological Survey Gauge located at the Tindall Bridge.

143,000 cubic yards a day

Engineering firm Stantec Inc. estimated in 2011 that about 867,000 cubic yards of silt was delivered by the watershed in a single year, and 143,000 cubic yards in a single day, with a mean annual load of 368,000 cubic yards.

“While dam removal would certainly contribute sediment to the river, in most years loads would fall within the natural range of variation for the watershed,” the city wrote to the Army Corps of Engineers.

In its lawsuit filed in July in U.S. District Court, the Ohio Sierra Club chapter argued forcefully for more testing of the impounded material as well as stronger consideration for dredging and sediment removal from behind the dam.

The Sierra Club, in its complaint, cited a 2002 study that estimated 1.3 million cubic yards of silt had collected behind the dam and described the material as being in the form of fine sediments composed of silty clays with occasional sand and gravel deposits.

The News-Messenger contacted the U.S. Army Corps of Engineers on Wednesday about the dam removal project, which would require a permit from the Corps to proceed.

Bruce Sanders, public affairs officer for the Corps’ Buffalo District, said it was the agency’s policy to not comment on matters in which there is pending litigation.

The U.S. Army Corps of Engineers was named along with Mayor Jim Ellis and the U.S. Fish and Wildlife Service as defendants in the Sierra Club lawsuit.

The Sierra Club’s call in its lawsuit for more testing of the silt and its removal through a dredging option was widely dismissed as too costly by administration officials. Ellis said publicly in July 2014 that estimated sediment dredging and removal costs could go as high as $50 million.

Snyder said he hoped Fremont residents were aware of the costs involved if the city is forced to reverse course and dredge the river.

“The cost of dredging would be astronomical,” Snyder said.

Environmental costs cited

Jen Miller, the Sierra Club’s state director, said recently that she thinks the city and the U.S. Fish and Wildlife Service went overboard with their estimates of dredging costs and underestimated the potential costs of releasing the sediment now backed up behind the dam.

Miller said she didn’t have specific numbers on what the Sierra Club thought it would cost to dredge and remove the sediment.

But the director said it was her opinion that dredging the river would be a lot cheaper than letting harmful chemicals and agricultural runoff damage walleye spawning grounds and wetlands areas along the Sandusky River.

Grob said that, about three to four decades ago, today’s agricultural conservation and safety methods were not in place to prevent that kind of runoff from polluting the river and the silt. That changed with the use of equipment such as filter strips, and by farmers adopting no-till planting systems, he said.

Still, Grob said he was concerned about the sediments and the potential impact those materials might have on Lake Erie.

In its lawsuit, the Sierra Club contends that the sediment behind the dam is known to be contaminated with nitrogen and phosphorous and also contains DDT, arsenic, lead, chromium, aluminum and other toxic heavy metals, as well as toluene, from a 1998 industrial spill of paint thinner in the area.

In July 2014, Dina Pierce, an Ohio Environmental Protection Agency spokeswoman, said the most recent sampling of sediment trapped behind the dam was taken by Bowling Green State University professor James Evans in 2007.

Evans submitted his findings to the Corps of Engineers, Pierce said.

Pierce said the Corps looked at those findings and found that sediment released downstream during dam removal would have a negligible impact, from a contamination standpoint, on water quality and aquatic life in the Sandusky River.

Contamination levels

Pierce said the Corps of Engineers found low levels of contamination in the sediment sampling, which was consistent with what the Ohio EPA found in 2001 when it took samples.

The city cited the Evans’ 2007 sediment analysis — done in conjunction with the University of Toledo — in its 2014 response to the U.S. Army Corps of Engineers and stated that a comparison of metal concentrations found in Ballville sediments, normalized for aluminum, to those in Lake Erie sediments showed an appreciably lower concentration of the metals and contaminants in silt behind the dam.

Snyder said that analysis also determined that phosphorus levels in the sediment behind the dam were no higher than levels found in sediment downstream.

The city also referenced the 1998 paint thinner spill and stated that toluene was unlikely to be present in the sediments behind the Ballville Dam, because of the chemical’s rapid degradation in surface water.

With the Fremont City Council’s approval of the city’s $1.6 million guaranteed maximum price amendment with MWH Constructors for the Ballville Dam removal project’s first phase, the city is on track to start work in September.

Ellis has repeatedly stressed the need to start on the project or risk losing a $2 million federal grant that would help pay for dam removal.

On Thursday, Grob said that issues such as the retention of the $2 million grant were insignificant compared with the larger issues associated with the project and the potential impacts of the silt on the river’s ecosystem.

dacarson@gannett.com

419-334-1046

Twitter: @DanielCarson7