Waynesboro police arrest suspect in shooting that injured one
NEWS

Pipeline furor prompts search for 'karst'

Calvin Trice
ctrice@newsleader.com
Avid caver Phil Lucas stands at the end of a footbridge just outside one of the entrances to Water Sinks Cave in Highland County, on Thursday.
  • Our report on the study of karst took us from local experts to a globally-acclaimed scientist.

The ground under Augusta County, the way it's formed, is simple to conceptualize if you picture one grocery store item.

A block of Swiss cheese.

Specific geology beneath the surface, and the chemistry that forms it, defines this county and the surrounding region as much as the mountains that shape the terrain above ground.

The limestone that has made the Shenandoah Valley an agricultural breadbasket is a factor in the sinkholes that open up along Interstate 81.

And now it's in the path of a proposed underground natural gas pipeline — one of the biggest and most controversial planned developments in the area's history — that has raised concerns about karst, the geological formation that is a natural signature of the western Virginia landscape.

But what is "karst," and is it really an issue? Can it support a pipeline safely?

To learn more about the science of the local karst geology, I decided to get under the surface of the Dominion pipeline debate in search of the best scientific minds on the subject.

For that, I looked for a guru at the top of the pyramid of karst science to answer common questions a novice might raise. I went in search of a rock star, so to speak.

Avid caver Phil Lucas approaches Owl Cave, one of the caves on his property in Highland County, on Thursday, Feb. 12, 2015.

Common sight on farms

I had many questions swirling in my brain as I began. Is the ground beneath our feet melting away, and are surface collapses imminent? What is the danger of sinkholes swallowing pipelines or roads?

One thing all experts wanted to clarify at the start of my journey was that karst isn't a single thing or formation. It's not a rock (not geological kin to quartz, say), and it's neither a cave nor a sinkhole.

It's a topography or a landscape like desert or wetlands that refers to parallel features all over the world but with features that vary by location.

Since local "karst" has been one of the points used in arguments about the pipeline, the first place to look for experts on the topic seemed to be right where we live — atop the limestone, above caves and amid the outcroppings.

Several people involved in the pipeline debate referred me to Bobby Whitescarver, a retired field conservationist who served for three decades with the U.S. Department of Agriculture's Natural Resources Conservation Service.

The limestone at the focus of Shenandoah Valley karst makes the soil fertile and agricultural fields well drained of water, Whitescarver said. "From an agricultural standpoint, it's excellent soil."

And it's everywhere, along with depressions, or natural dips in the landscape that indicate mature sinkholes where soils have spilled into underground caves but then settled slowly rather than collapsed suddenly, Whitescarver said.

"There's probably not a farm that doesn't have a sinkhole," he said.

The USDA has since the 1960s mapped all such depressions. However, there is no map that catalogs all the underground caves causing them now, or possibly in the future. Developers drilling for water often make the newest finds, Whitescarver said.

"That's why when people drill wells, sometimes the drill bit just falls into a cave," he said. "Not all the caves have been discovered."

Bouncing west, then straight down

My inquiries led me to focus on finding a regional expert who had spent time underground, who knew that terrain. I wanted to know more about what the ground looks like 5 feet deep or 50 or 200, if you could see into it.

Making use of the light on his helmet, avid caver Phil Lucas talks about his own efforts in exploring Water Sinks Cave in Highland County during an interview on Thursday, Feb. 12, 2015.

Rick Lambert's name popped up. It turns out that his expertise on karst hails from the same passion that draws others to study this terrain: caving.

Lambert is a Highland County resident who is a member of the Virginia Speleological Survey, the organization of caving enthusiasts.

He's been on the earth for 55 years, and he's been caving for 50 of them. Caves are a signature of Virginia's karst system, along with the sinkholes and "blind valleys," through which water runs off a mountain to form a stream that doesn't flow into rivers, lakes or oceans, but flows into the ground and continues beneath the surface.

Lambert has studied karst formations in which the rock is too unstable for caves, and other terrain where the caverns lurk just beneath the surface.

"I have seen caves that only had two feet of rock between the roof of the cave and the field a farmer was driving his tractor on," he said. As the limestone dissolves, the surface above it disappears.

"If you have an entrance to a cave, the cave has reached the surface," Lambert said.

One of his biggest concerns about the proposed pipeline are filled, or buried sinkholes, Lambert said.

They're caused by caverns covered with soil that's gradually spilling from the surface into the cave through a hole in the cave roof. They can be tricky to detect, even with technology, he said.

"I don't know how in the world they would find a blind or filled sinkhole," Lambert said. "It would be luck, or they would find it afterward when it opened up."

Those sinks form holes and get buried again with dirt in cycles, naturally.

"It's a continual process," Lambert added.

Pathways for water

Phil Lucas first became hooked on caves as a 7-year-old on adventures with his older brother in the hills behind their home in Harrisonburg.

He got serious about it by the time he was 15 when he went exploring on his bicycle with candles in his pockets. He made a career as a power company manager, raised a family and then retired in 1994 on property southwest of McDowell because it has caves.

"It's just some quirk of my personality," said Lucas, 71. "Caves and karst are my primary passions in life."

For most of his caving life, he's not kept a log book. Lucas, who was president of the Virginia Speleological Survey for three decades, has nevertheless discovered 30 miles of previously unknown underground passages, but that's just since he's retired.

He motors up and down the pathways of his property on his all-terrain cart, the "Dragon Wagon," named for his favorite fantasy creature. He's dug new passages and secured them with 30-inch-wide culvert tubing. On the side, Lucas cuts wood to access cave openings.

On his property, he seems to have shaped enough hardwood to build the frame of a small home.

His adventures take him past a 100-feet limestone cliff and several depressions that sink into the ground nearly as far. When the local stream flows from the blind valley, it disappears into the cliff.

Lucas keeps a mental map of possible connections to Wishing Well and Water Sinks caves. His speculation is based on digital graphic files detailing all the passages chartered so far, but they're closely guarded and available only to serious cavers.

"We're very careful about public dissemination of knowledge of where caves are," he said. The wrong kind of adventurers might snap off a stalactite "spike" formed for thousands of years by a drip from a cave ceiling.

He's well past sport or recreational caving. Lucas is a documenter who caves only for a purpose, he said.

One of his passions within his passion is connecting the complex hydrology of karst — in which water often flows beneath the local water table — from source to stream or spring. "Caves can act like big water pipes," Lucas said. "Some caves are completely water-filled, and some caves are completely dry."

Western Virginians have only in recent decades learned how their land stewardship connects to the water they drink, and how their waste can leach into the water supply, Lucas said.

"Now, I think most people understand that there is a direct connection — much more so than in a non-karst terrain," he said.

Creatures in the water

Avid caver Phil Lucas stands over the entrance to Helictite Cave in the bottom of a sink on his property. He talks about the cave as well as karst during an interview in Highland County, on Thursday, Feb. 12, 2015.

Dominion, betting on a pipeline to get natural gas from big drilling fields to customers, has leaned on scientists as it has planned the project.

For the open house the company held Jan. 20 at Augusta Expo, one of the karst experts was Bob Denton, a senior geologist and soil scientist with GeoConcepts Engineering in Ashburn.

The firm had originally contracted with the parent company for Columbia Gas for environmental study and protection around its transmission lines. Dominion hired them to study the corridor that the Richmond-based utility giant has mapped for its 550-mile pipeline proposal that would run from West Virginia to North Carolina.

Where the karst environment is concerned, Denton said their focus is on one creature in particular — the Madison cave isopod. It's a half-inch-long, shrimp-like crustacean found in the deep waters of the karst terrain. First discovered in Augusta County, it's believed to have colonized the Valley through some connection with an ocean around the time of the dinosaurs.

The tiny creature is a natural mining canary, so to speak, for the region's water source, Denton said.

"If we protect that habitat, basically, we protect people's water supply," he said.

The limestone that frames the area's karst terrain is more than 300 million years old. It's actually very hard and strong.

"The reason why karst can be a geo-hazard is not because the limestone is collapsing or dissolving beneath our feet," Denton said. The hazard is soil moving into preexisting openings, creating the buried sinkholes referenced above.

When people pump water out of the ground or into it, they can accelerate the "hourglass" effect by pushing soils into openings faster or washing them away. That's the reason sinkholes develop around quarries, stormwater management ponds, leaking underground storage tanks or sewer lines, Denton said.

"The most common contaminant found in karst is coliform bacteria, the kind of bacteria formed from sewage," he said.

Controversy, and the arguments behind it

Fossil formations inside Owl Cave, one of the caves on property belonging to caver Phil Lucas in Highland County.

Denton and his firm will be supervising the construction of the Dominion pipeline, if approved, to make sure any threats to the terrain or habitat are spotted and repaired, he said.

"Hopefully, we won't have that problem," Denton said. "We'll basically be inspecting every inch of the trench."

The ancient population of Madison isopoods, little known, is central to the work of another Virginia karst expert offered by Dominion representatives and pipeline opponents.

Will Orndorff is the karst protection coordinator for the state Department of Conservation and Recreation, and the fingernail-length crustacean is key to protecting karst topography, he said.

It's covered by the endangered species act, so development threats to the terrain can trigger a host of federal protections if they threaten the creature's habitat. Often, it's the only tool available in the department's box to safeguard sensitive underground environment, Orndorff said.

"The endangered species act will give higher protection to invertebrate species than we have laws to give to human populations," Orndorff said.

Orndorff's work is an outgrowth of the conservation department's mission to preserve biodiversity, and by extension, natural water supplies. Three-quarters of I-81 rests on karst formed from limestone or dolomite, the second-most prevalent soluble terrain that creates karst, he said.

For development projects that intersect with an area of significant biodiversity, the state counsels changes to building plans, further studies or avoidance.

'Weak' legal protection

One of the recent threats to karst geology has been development. Builders once shied away from karst topography because its sensitivity made it cost prohibitive. Technology has since brought the costs down, and Virginia has few laws to protect the areas in the Shenandoah Valley, Orndorff said.

"Progressive development has pushed development into these marginal areas," he said. "Regulatory protection of these marginal (environmental) areas is very weak."

Without more safeguards against development, water diversion could make the ground in the region more unstable. Meanwhile contaminants will pollute the valley's underground aquifers that have traditionally provided drinking water and a reliable source of farm irrigation.

All groundwater in the region has traces of the weed killer atrazine, elevated nutrients from agriculture or some other contaminants from the human environmental footprint. People are beginning to define the karst environment as much as karst geology has shaped the way humans live, Orndorff said.

"There's impact in both directions," he said.

Top of the chain

As much as I had learned, it felt like we needed to hear from one final expert, someone all sides agrees has world-class knowledge about our karst.

William White, professor emeritus of Penn State and an expert on karst formations, explaining Crump Spring Cave to participants of the Karst Conference in Bowling Green in June 2011.

It took some, ahem, digging. Finally enough people clued me in to one name: William B. White.

I'd like to say he was mysterious and hard to reach. But White wasn't any harder to schedule than you would imagine a busy scholar would be.

He is one of the preeminent, scientific knights of karst in the nation, perhaps in the world.

White is blunt about the survival prospects of our specific beautiful landscape: we might as well kiss it goodbye, at least eventually. "You're slowly losing your valley down there," said White, a professor emeritus for Penn State.

Limestone and dolomite are dissolving away. But it's happening at about the rate of an inch every 1,000 years. So millions of years from now, the valley will be history.

White earned his doctorate in thermodynamics and chemistry at Penn State in 1962. His expertise grew from a pastime that he developed in college, though. Caves. He worked a job as a cave guide during his time at Juniata College. "I just gradually became more and more interested in the scientific aspects of the subject and just continued that down through the years, and suddenly I'm writing books on the subject," White said.

One was called "Geomorphology and Hydrology of Karst Terrains," which some refer to as the subject's encyclopedia.

As White tells it, the story of the region's karst dates back hundreds of millions of years through plate tectonic forces. When, over jillions of years, one plate slammed into another, limestone was pushed to the surface. When rain fell it combined with carbon dioxide from the air and from the plants that grew atop the formation, then ran into cracks in the limestone, which is made mainly of calcium carbonate. (Carbon dioxide makes rain slightly acidic. It wouldn't be undrinkable, but it has just enough acid to corrode limestone.)

Over eons, cracks melted away into holes, then tunnels, then enormous caverns, creating the voids in today's underground terrain. Caves take from 10,000-100,000 years to hollow out that way, White said. "Then you get the cave passages like those that are the spectacular showcases that you have in Virginia."

Hidden below

On the surface, the Valley's fertile soil masks a rugged topography with irregular bedrock that can result in unexpected barriers for road builders and random outcroppings on farms.

"It would be a very, very rugged topography if you didn't have reasonably thick soil on top of it," White said.

That's why the buried cones that form sinkholes by channeling soils into openings into caves are so common. The most damaging ones are those that let dirt into the caverns below while maintaining a "roof" of soil just beneath the surface we walk on. The cavity from the sink gets bigger, and the roof of it thinner and thinner until it collapses suddenly.

"Then, typically in the spring, when a frost melts, there's a sink hole tomorrow morning that wasn't there last night," White said.

An irregular bedrock poses similar risks to a project like the pipeline as it does to homeowners. Ground-penetrating radar can detect voids beneath the surface, but only to a certain distance, often about 20 feet in our region, he said.

"If they have to cut down through bedrock, you can make a trench that looks like solid rock and everything looks fine," he said. "But you've dug your trench and stopped six inches above an underground cave."

That unevenness bedevils homeowners after their homes have settled and compacted the soil beneath their foundation. The support might give way for a corner of the home built atop a thinner cave roof. The house gets twisted, then doors won't open and windows won't close.

Sinks can be stabilized for construction if they're discovered. One popular technique covers the opening with course rock, then graded rock on top of that, which maintains the drain for water without letting soil through.

Is pipeline construction safe for Virginia? White said he doesn't know of sinkholes damaging underground utility lines in the state's limestone karst formations.

He did reaffirm that the buried sinkholes are the biggest danger, because they're so hard for scientists to discern. "You can look at the bottom of the trench, and it looks like solid rock, and think, what's the problem?" he said.

Still, the hazards would vary from one mile of an underground pipeline to the next. Generalizations can't be applied.

I found my scientist, one with world-class knowledge of karst, but the question of interstate pipeline safety remains elusive. It's a worry that seems likely to be decided by a utility and regulators, all the while being coached from the sidelines by the public.

There'll be no way to know if they choose the right path, until a moment of calamity or until nothing at all happens and today's debate is forgotten and part of the landscape.