THURSDAY, MAY 9.2002
THE UNIVERSITY DAILY KANSAN = 5A
BENEATH
CONTINUED FROM PAGE 1A
The fires would rage into the night. Meanwhile, geysers of natural gas and salt water were spewing out of the ground throughout the city.
It would take several weeks to figure out why the central Kansas town of 40,000 blew up.
The explosions sparked scientific and legal investigations that are still ongoing.
Back in Lawrence, geologists at the University of Kansas-based Kansas Geological Survey followed reports about the explosions throughout the day.
Lee Allison, state geologist and director of the Kansas Geological Survey, said the scientists assumed the fires were caused by a gas pipe leak, but they became more convinced there was a different problem when they learned about the geysers around the city. After reports of the geysers came in, the Kansas Geological Survey staff knew it was more than just a leak downtown.
The destruction was not over. The next day, a mobile home in the Big Chief Mobile Home Park in east Hutchinson exploded. Its two residents were killed.
Hutchinson public safety officials still did not know where the gas was coming from.
The Kansas Department of Health and Environmentand the Kansas Gas Service worked to vent the gas from beneath the earth's surface but had problems locating the underground gas pockets.
Weeks later, the Kansas Geological Survey team prepared to leave for Arizona to work on a project for the U.S. Army.
The survey's trucks were loaded with equipment, and crews from all over the country had flown to Arizona, ready to begin the project.
"We were ready to leave the next morning," Allison said.
Those plans were to change abruptly.
KDHE realized it needed the equipment and personnel bound for Arizona in Hutchinson to help identify the underground pathways the gas followed.
The governor issued a declaration that night, which dispatched the Arizona-bound scientists to Hutchinson.
search in the area to find the source of the problems.
"It was like calling out the National Guard," Allison said. "He directed us to go to Hutchinson to the aid of the residents."
They now think they know what caused the Hutchinson explosions. But science and the law move slowly. The official story may take years to work its way through the courts, but the scientists have put together three clues they found in the strange and unique geology under Hutchinson.
Allison; Lynn Watney, petroleum research scientist; Allyson Anderson, graduate student in geology, and other scientists and technicians at the agency began a
These clues offer the most complete explanation offered so faras to why the city burned.
CLUE 1: DOLOMITE
Before investigators could find the source of the gas, their first priority was to vent the gas still under the city.
Kansas Geological Survey crews used a special truck with built-in earth-shaking equipment — called a thumper truck — to send mini-earthquake-like shock waves into the ground. The KU scientists then used specialized microphones to create underground images similar to fetal sonograms to detect where large amounts of gas still sat beneath the surface.
Watney said that they found that the gas had traveled through a zone of dolomite, a limestone-like rock, that ran below the surface of the city.
The layer of dolomite was only about 10feet thick in most places and hard to detect.
"The properties of the rock were subtle in this case," he said.
Watney said the crews also discovered cracks in the dolomite, fractured by pressures in the earth that helped the gas flow through the layer.
The question of where the gas came from still remained.
From early on, city and state officials and KU geologists thought they knew. CLUE2: LEAKY WELL
Almost eight miles northwest of downtown Hutchinson, a grassy field next to Kansas Highway 96, near the site of an old railroad stop once called Yaggy.
The tall, white pipes protruding from the earth are the only features that set the Yaggy field apart from other fields in central Kansas.
components of a gas well. It is supposed to create a solid, impermeable zone from which gas cannot escape.
Geologic engineer Joe Ratigan studied the S-1 well in great detail.
Ratigan said that Consolidated Gas, the original owner of the field, had plugged the casings of the wells with cement when it stopped using the site to store propane. Silver Tip Services, the company that bought the Yaggy field from Consolidated, unplugged the well in 1993.
The steel casing that runs from above ground down into the salt jug is one of the most crucial
One well in particular — called the "S-1" well — in the southwest corner of the field, had a casing problem.
The Vaggy field has a history as one of the central points on the natural gas hub in central Kansas. Built in the late 1970s to store propane, the 70 gas wells store gas in "jugs," caverns hollowed out of salt layers beneath the Earth's surface.
When Silver Tip Services opened it up, a metal object buried in the plug deflected its drill bit. The drill bit created a hole in the well's casing. Ritagan said.
Frazier said field engineers had watched the pressure drop on the morning of January 17, 2001 in the S-1 well. But the Yaggy field is seven miles from downtown.
CLUE 3: BRINE WELLS
"There was a question if the gas could travel the eight miles into Hutchinson," Allison said. "It's possible if the right conditions exist."
Watney said the geologists knew the salt layer under Hutchinson was riddled with empty caverns called brine wells.
The salt layer that runs beneath the area has long been a source of income for large corporations and small family operations. In the late 1800s, residents of the area would drill wells of their own that reached down into the salt layer.
Unlike the large-scale operations of Carey Salt and Cargill, which mine salt in the gill, these small brine wells were often capped and forgotten — and never documented.
Fresh water would then circulate through the well and back up to the surface carrying salt water, or brine. Residents would sell the brine to tanneries or use it to cure meat during the days before refrigeration.
Watney estimated there were as many as 150 undocumented wells beneath Hutchinson. At least two of the abandoned brine wells were directly under buildings downtown and below the Big Chief Mobile Home Park in the eastern part of the city. Anderson said the heating and cooling systems of the destroyed structures were located above the abandoned wells. The pilot lights from the systems ignited the free-flowing gas.
THE SOLUTION
KANSAS' SALT INDUSTRY
Independently, the three components — the dolomite layer, the leaking S-1 well and the abandoned brine wells — might not have meant much. Together they led to disaster.
f cracks form in the salt layer, the salt will heal itself. "There is no better way to store gas," she said. Natney said the Department of Energy looked at the area in the 1980s as a potential area to store high-level nuclear waste, but decided the potential risk to Hutchinson was unacceptable. Allison said the vast majority of liquid natural gas was stored in rock, but it was easier and less expensive to store natural gas in salt.
Central Kansas is one of the top suppliers of natural gas for the state and the region.
Allyson Anderson, geology graduate student who is working on her dissertation in Hutchinson, said salt was geologically ideal for storing this natural gas.
Salt acts as a plastic medium,
Anderson said. If pressure increases at one place in the salt layer, the salt will actually flow and move to accommodate the pressure. Because of this behavior,
The dolomite layer, fractured by years of geologic pressures, provided a pathway that led directly beneath Hutchinson. A gas well, damaged years before, appeared to have leaked an undetermined amount of gas into the dolomite zone.
The dolomite itself is not permeable, but the cracks allowed the gas to flow through the layer.
The final piece of the puzzle was the abandoned brine wells. The wells ran through the dolomite layer and gave the gas an easy path to the surface in
PHOTO CONTRIBUTED BY THE HUTCHINSON NEWS
places no one expected.
KU scientists still monitor the area and work on ways to make the city safe.
Anderson continues tests in Hutchinson using sunlight to measure the reflectivity of soils that may be rich with salt, indicating the presence of buried brine wells.
Although the geologists are comfortable with their findings, not everyone agrees.
"If there are natural leaks, there's really nothing we can do," she said. "But if we can find wells and cap them, we can make sure it will never happen again."
If her tests are positive, she will seek funding to mount specialized sensors on airplanes to look for areas that could still be leaking brine.
More work will have to be done before all of the brine wells in the city are discovered and properly capped. Many of the abandoned wells were cut off at the surface and improperly plugged with a bit of cement in the top of the casing instead of filling the casing with cement.
After the explosions, residents filed lawsuits against Kansas Gas Service. The lawsuits included a possible class-action suit from the residents of Reno county. The family of the couple who died in the Big Chief Mobile Home Park also filed suit.
"We're hanging in the balance until the funding comes through," she said.
Anderson said she was optimistic about her research, and the possibility of finding the aban-
Kansas Gas Service spokesman Steve Johnson would not elaborate on what he thought caused the explosion. He said there was no proof the gas came from the Yaggy field.
"We are not using it now in any way, shape or form," he said.
"It hasn't been proven yet that the gas that escaped from the S-1 well went to Hutch directly," he said. "It's just one theory."
To prevent any further problems, Johnson said Kansas Gas Service closed the Yaggy facility.
The company will wait for new regulations from KDHE before it considers reopening the storage site.
Kansas Gas Service still monitors the downtown area and school buildings for traces of gas. It increased its efforts after the explosions.
"We are making sure the city of Hutchinson is safe, and have been since day one," Johnson said.
A Kansas Geological Survey scientist agreed with a proposal to the KDHE to approve a pressure increase in the Yaggy field for Western Resources in 1997.
Johnson said Kansas Gas Service took control of the field from Western Resources the same year.
The jugs at Yaggy were subsequently pressurized to approximately 600 pounds per square inch, an increase of .13 pounds per square inch above the original specifications.
Ratigan said the salt caverns were pressured to store the most gas possible. "You increase pressure; you increase the storage."
Recently, the Department of Energy announced plans to study gas storage. KU scientists plan to submit a technical proposal to further study Hutchinson and develop a nationwide program to improve gas storage safety.
Allison and Watney continue to travel throughout the country to talk about what they learned in Hutchinson. Watney said he expected the courts use the Kansas Geological Survey's data, if not the geologists themselves, as evidence in the various lawsuits.
"I think we're obligated to provide that information," he said.
"There are new regulations for gas storage," Watney said. The new regulations could help prevent another accident like Hutchinson.
Ratigan and the geologists are also involved in forming new state regulations for storage facilities to ensure a higher level of safety.
Contact Hill at shill@kansan.com This story was edited by Kyle Ramsey.