Is a sinkhole in Carlsbad’s future?

by Michael Mosher on July 24, 2012

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The collapse of two North Eddy County brine wells in 2008 sparked fears that a similar collapse might happen in Carlsbad. Four years later, the city is still waiting for the state to take action. 

“We can’t move on until something is done,” Mayor Dale Janway said. “To alleviate fears, that will have to be fixed.” 

After the collapses, New Mexico State officials became concerned with the condition of the two brine wells near the South Y, the intersection of U.S. 285 and 62/180. 

“If they knew that it would collapse on a certain date, they’d be getting it done much quicker. But we don’t know. It could be happening right now or it could happen in 10 years,” said George Veni, executive director of the National Cave and Karst Institute. “Most people look at this look at it as a matter of when, not if. Most people think it will happen.” 

The brine well is ripe for collapse because of conditions created by drilling down into a layer of natural salt and injecting fresh water into the salt layer. The water dissolves the salt, creating an underground cavity from which salt brine is pumped back to the surface for use in oilfield applications. 

When the underground cavity is unable to hold the weight above, it becomes unstable like the ones in Ar-tesia and Loco Hills, and a collapse may occur. 

The clock may be ticking in Carlsbad, but Veni believes the city and state have been taking all the neces-sary precautions. “There are so many alarms 

and precautions and monitoring in place, and the county has plenty of emer-gency precautions in place. I’d be shocked if anyone got hurt.” Veni said. 

Potential damage could be extensive as the irrigation canal and the immediate area that includes the Circle S feed store and El Dorado Mobile Home Park might be affected. While those areas would experience the brunt of the damage, the subsidence of the earth around the collapse might stretch to U.S. 285. 

If a collapse happens, it would most likely start out as a 10 or 20 foot hole and expand from there depend-ing on the composition of the area around it. The sinkhole in Artesia is estimated to be about 360 feet wide and roughly 145 feet deep while the Loco Hills site is estimated at nearly 300 feet with a depth of 165 feet. 

“Once you have a hole in the ground, the earth around it is going to slump and fill in the hole in the ground,” Veni said. He explained that the subsidence may not look as catastrophic, but it would do exten-sive damage to the areas around the southern parts of town. “It may not catastrophic in the sense of a build-ing disappearing, but the damage it could cause would be significant.” 

With the New Mexico Department of Energy, Mineral, and Natural Resources’ Oil Conservation Division currently in control of the property, the city of Carlsbad has to wait for the state to take a final action on the site to make sure it doesn’t become an issue in the future. 

“It is an issue of responsibility. We’ve done what we needed to do, and we’ve done what we can to prepare for any safety hazards that might be involved.” City Administrator Jon Tully said. “The state has picked it up now and is responsible for the monitoring.” 

The site has changed hands several times since concerns were sparked five years ago when the sites in Artesia at Jim’s Water Service and another site in Loco Hills had sudden collapses. 

In the brine well site in Carlsbad, two wells operated to form a pear-shaped well 400 feet wide. New Mex-ico state officials feared a catastrophic collapse might also happen in Carlsbad, prompting the state to inter-vene for public safety issues. 

According to one state official, the site is still at risk, with constant, steady readings showing movement in the cavity below the earth, but said predicting a collapse can be like trying to predict an earth-quake. 

But just like predicting an earthquake, there are ways to monitor activity and keep a close eye on the well’s condition. The state is currently monitoring the site around the clock with a number of automated sensors, and frequent on-site checks are conducted to give Carlsbad residents plenty of notice if signs of collapse begin to appear. 

The state may be in charge now, but the city had formed the Carlsbad Brine Well Working Group in 2009, which included emergency management, financial, legal and public communications committees. 

“When we realized it had the potential to collapse, we knew we needed to begin monitoring to make sure if something happened, we would be ready.” said Ned Elkins, who along with Veni were members of the technical committee for the Carlsbad Brine Well Working Group. However, since the state took over con-trol of the site, it been more than a year since the committee has held a meeting. At the time of the 2008 brine well collapses, I&W Inc. operated the site, but the state quickly stepped in to shut down the site. It began 24-hour monitoring to see if the brine well was at risk for collapse. I&W even-tually declared bankruptcy, pointing to the loss of the brine well as the main reasons. Before I&W declared bankruptcy, it was sued by the city and state. Now the local and state government are looking to sue the insurance companies that I&W was insured by to pay for whatever action in necessary to make sure the well doesn’t become a sinkhole. I&W maintained that the site wasn’t a major risk for collapse and they had taken due diligence to prevent that from happening. The OCD pointed out the similarities between Carlsbad’s brine well and the sites in Loco Hills and Jim’s Water Service, and began watching the site. While the state still maintains control of the site, the city of Carlsbad is now waiting for action to be taken. 

But fixing the problem won’t be as simple as filling the site in with an appropriate material. If done im-properly, the brine well could collapse to become the very problem the city is looking to avoid. 

“All these studies are to better understand the size and shape of the thing so we know the kind of damage they can do, but also to figure out what to do to stop it. To plug it or fill it or do whatever needs to be done to stop it from happening,” Veni said. “I understand people’s attitude of just wanting to go do it, but it needs to be done right.” 

The state has put out a request for proposals on how to fix the problem but no timetable has been set yet for when a project might begin. 

“It’s a balancing act what the state is doing. On the one hand, they want to act promptly and quickly, be-cause the concern is this thing is going to fall in, and they want to get it done so it doesn’t collapse while all these studies are being done,” Veni said. “On the other hand, they want to do it right so they don’t cause the collapse while trying to fix it.” 

The clock is ticking, and Carlsbad will have to wait for the next move. Hopefully it doesn’t have to wait too long.

Full article…here

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