By Josephine Moore
Source The Register-Herald, Beckley, W.Va.
A temporary solution for motorists to safely drive around a sinkhole expanding at the northern entrance to Hinton could be in place as early as this weekend.
During a press conference Tuesday morning at Hinton City Hall, Joe Pack, chief engineer of district operations with the West Virginia Division of Highways, said preparations are underway to construct a temporary steel bridge along W.Va. 20 in the lane opposite the large sinkhole.
"Our plans are to construct a steel bridge which will sit on the road surface," Pack told media and community members gathered in City Hall.
"It will span around 125 foot in length from end to end, which will span the hole in its entirety, and it will sit on what's solid ground now of what we're all driving on."
Pack said the temporary bridge will ensure the safety of motorists even in the event that the borders of the sinkhole expand.
"If the hole continues to increase in size, the bridge will span and be on solid ground on either side," he said. "...The bridge will stay there intact until the drilling is complete, the hole is filled in and the road surface is returned."
Pack said the temporary bridge is something the state has erected and removed in other parts of the state when necessary and takes anywhere from 24 hours to two days to build.
The bridge will be about 16 feet wide, which is only wide enough for one-way traffic, meaning the temporary traffic lights at either end of the road will remain in place until the sinkhole is filled in.
While the temporary bridge is being put together, Pack said the roadway will be shut down.
As Summers County Schools are expected to close next week for the Thanksgiving break, Pack said they will likely begin construction of the temporary bridge on Friday in order to lessen the impact on motorists who will have to use alternative routes.
Pack said that decision has yet to be finalized but the division will issue a press release when they settle on a firm date.
When the sinkhole was initially discovered in mid-June in the Hinton Police Department's parking lot, it was about 6 feet wide and 30 feet deep, according to MetroNews.
Following heavy rainfall from the remnants of Hurricane Nicole over the weekend, Pack said the diameter of the hole greatly expanded consuming one lane of W.Va. 20 as well as a portion of the foundation of the nearby city police station.
Pack said the ultimate cause of the sinkhole was a collapse of the existing drainage structure that sits roughly 40 feet below the surface of the road.
"The existing drainage structure that is there, by our estimation, was constructed sometime in the 1930s," he said. "It is a stack stone wall structure with a concrete arch roof roughly 90 years old. Sometime within the last few years, because this stuff does not happen overnight, more than likely the roof started having some structural issues. It collapsed sometime this summer, which has clogged and blocked the existing pipe. That is what's causing the erosion that you see at the top of the structure."
Pack said the existing drainage structure is 5 feet in height.
Running directly under the road and though this drain is a stream called Brier Branch, which feeds into the nearby New River.
At one point, Pack said a 100-foot bridge stood where the sinkhole hole is now which connected Hinton with W.Va. 20.
"It was then filled in, through the years, and that's how we've gotten to where we are," he said.
Since the sinkhole was discovered, roughly six months ago, Pack said his division has been working on a plan to reroute the water coming in from Brier Branch and then fill in the existing hole. However, he said they ran into many complications.
"The worst factor that we came into knowledge is when we did some test drilling of the soil on the backside of the (police) building, there is a toxic amount level of lead in the soil," Pack said.
He said disturbing that area was ruled out as an option because of the complications that would accompany disturbing contaminated soil.
"According to our conversation with the Department of Environmental Protection, as long as (that soil) is not disturbed, it is not a hazard," Pack said.
While they have come up with a plan that completely avoids this lead-contaminated soil, Pack said it's not been without difficulty, which is why the design phase has taken several months.
"We have to do everything we can to avoid that material to expedite the completion of the project, which has made us take a route that we don't normally take, which is an approximate 300-foot-long horizontal drill project," he said.
Pack said this type of project is known as a "bore and jack" project, which entails using "a horizontal drill to bore a ... 6-foot-diameter steel pipe which will end up being the drainage structure."
Pack said the design for the process is still in the works but is nearly complete. He added that he anticipates bidding the project by the end of the year and estimates it will cost between $4-6 million.
Although he could not give an expected start date or time frame for completion of the project, Pack said it would all happen as soon as possible.
"The companies that do this type of work move fast," he said. "And this is not work that is weather-contingent. If there's 12 inches of snow on the ground, they can do this work. This is not like paving or concrete or anything that is weather-related."
At the end of the meeting Hinton Mayor Jack Scott and Summers County Schools Superintendent David Warvel thanked Pack for his work thus far given all the complications.
Scott added that he was pleased to learn Tuesday from Pack that it may be possible to salvage the police building which sits on the edge of the sinkhole.
"We're glad to hear today that we can maybe salvage the building," Scott said, adding that the police department was moved out when the sinkhole was first discovered and has since relocated to a building in downtown Hinton.
"We've got a couple of local hospitals and another organization that might be interested in utilizing that building."
He added that he feels more at ease knowing that there is a temporary as well as permanent plan in place and hopes the community will be understanding and patient.
"There are other ways in and out of here. A couple of days' inconvenience for the bridge, I think, is a small price to pay for the safety to get back and forth from schools to tourism," Scott said. "We're seeing some good things happen here. We're tearing down homes, we're fixing up the streets, we're seeing a lot of positive light because of the national park so it's just a minor setback."
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