MS. DIANE REHMThanks for joining us. I’m Diane Rehm. Sinkhole activity has been making headlines recently, but scientists say they've been occurring for eons. In this hour, we talk about what causes sinkholes and what they can teach us about the environment. Joining me in the studio, Randall Orndorff of the U.S. Geological Survey and from WSHU in Fairfield, Conn., David Owen of the New Yorker Magazine. He wrote "Florida's Sinkhole Peril," which appears in the March 18 issue. Do join us, 800-433-8850. Send us an email to drshow@wamu.org. Follow us on Facebook or send us a tweet. Good morning to both of you.

MR. RANDALL ORNDORFFGood morning.

MR. DAVID OWENGood morning.

REHMDavid, I'll start with you because I gather you visited Seffner, Fla. a few weeks ago. Describe what you saw.

OWENWell, I didn't actually see the sinkhole that Mr. Bush fell into. I was in other parts of Florida and saw other sinkholes. If you look at Florida on Google Earth, you realize that it's a landscape that's been shaped by activity in the underlying rock layers, in the karst geology. Florida sits on a kind of rock that the acidic water from rainwater over eons has etched many underground passageways, the size of caves in many cases and occasionally they collapse.

REHMRandy, explain to us exactly what karst is.

ORNDORFFAbsolutely. Karst is a terrain that's underlain by soluble rock, just like Dave just mentioned, rock that can dissolve. Throughout the country the major rock types that do this are limestone and gypsum. We also have what we call salt karst, but the terrain is generally characterized by sinkholes, caves, large springs and this major underground drainage.

REHMNow, is that throughout the country?

ORNDORFFYeah, but like I said, about 20 percent of the U.S. is underlain by rocks like this or this karst terrain. And it's basically just about every state in the nation has some kind of karst terrain, but it has a lot to do with the amount of rainfall that you get that's going to add the water to the environment to cause the more dissolution that you get.

REHMNow, we've been hearing a lot about sinkholes lately. Is that just coincidence or are more of these sinkholes taking place?

ORNDORFFKind of a difficult question. Of course, sinkholes happen all the time. And in the various parts of the country a lot of the karst terrain is agricultural country. So you have a lot of sinkholes that occur out in farmers' fields and in the woods and places like that, that never make the headlines. But as we develop into the karst lands throughout the country, just our interactions, our human interactions are going to maybe exasperate some of the situations or it's just the fact that we're seeing more of them.

REHMHuman interactions like what?

ORNDORFFWell, for instance, if you think about the natural environment, when it rains, the rain will percolate down in through the soil to get into the groundwater system. It just percolates through the soil. As we pave highways, we put up buildings, those are impervious services. So the water can no longer just naturally go into the ground like it did before. It runs off these impervious services. We concentrate the water into, you know, drainage ditches and things like that. And so we're concentrating that water getting in and that can increase the speed of some of this dissolution.

REHMAre they getting bigger?

ORNDORFFWell, I mean, basically, when you're talking about a sinkhole you have to have a void in the subsurface. A lot of times, like the ones in Florida, you don't see them as they grow. So they are getting bigger. They're growing basically from below upward toward the surface. And when you can no longer hold the weight of that soil, that water or anything that we put on the surface, that’s when you get these collapses.

REHMDavid, why do you think there are so many sinkholes in Florida?

OWENWell, Florida, the kind of geology that you just described underlies all of Florida. At one time sea level much higher and the entire Florida peninsula is underlain by rock of the very type that was just being described. So it's all over that state, as well as in other parts of the country, but Florida especially and particularly the area around Tampa, which is near where Seffner is, which is known as sinkhole alley because of the large number of sinkholes that have occurred there.

REHMBut are there also large numbers of people living there?

OWENExactly. And that has two consequences. One is that the human pressures that encourage the sinkhole collapses, such as huge draw downs from underground water supplies, which is sort of like knocking the legs out from under a stool. Part of what holds the ground up sometimes is the water that's in the ground. And as we draw that down sinkholes can be more likely to occur. Also, just as human population spread we put ourselves more in harm's way. The largest earthquake that occurred in the history of the United States killed nobody or almost nobody because it happened in the 1800s and in a part of the country where there was nobody living.

OWENAnd earthquake of the same size that occurred under a city like Los Angeles or San Francisco would be a disaster unlike anything we've ever known.

REHMNow, Randy, we've been hearing a lot of late about fracking. Is there any indication that fracking could be exacerbating these underground sinkholes and perhaps creating them or pushing them?

ORNDORFFYeah, at this point in time we don't have any data that supports that. Most of the fracking activities are occurring in areas where mainly you're looking at the shales. There may be limestone or soluble rock within the rock column that they're going into, but generally speaking there hasn't been a one to one correlation with the fracking activities and karst. I think one thing we are interested in looking at is when you take the gas or the oil from the subsurface and you move it through the pipelines, you know the pipelines going over karst areas would be something to be concerned about.

REHMSo from your point of view, which areas of the country are most susceptible?

OWENTo sinkholes?

REHMYeah.

OWENWell, obviously Florida. But we also have large areas in the middle part of the country around the Ozarks of Missouri and into Illinois. And so a lot of large sinkholes in those areas. The Shenandoah Valley, the great valley of the East that goes from basically Alabama, up into Pennsylvania and New York, West Texas, parts of West Texas around San Antonio and places like that.

REHMWe have posted a map of those areas on our website, drshow.org, if you'd care to take a look. Randy, tell us about the situation in Bayou Corne?

ORNDORFFWell, I don't all the details. We have looked at that because of it being a sinkhole, but in this case it happened in what we call a salt dome. So all around the Gulf Coast region, Texas and Louisiana we have these salt beds that over time they migrate toward the surface. Salt is a very tight rock. It's, you know, it's very impervious. I mean it's very tight, but it's also a commodity. So we mine the salt and they also use it to be able to store oil and gas in these things because it's got that tight vessel.

ORNDORFFBut salt is also soluble. You ever put salt in a glass and pour water on it, you know it can dissolve. So how you get the water actually moving in those salt domes could start up the dissolution and migrate toward the surface in the case of Bayou Corne. Also there was one in Daisetta, Texas, back in 2008, a very similar situation. The Bijou Corn one, we think that that salt cavern looks like it was pretty close to the edge of that salt dome. So there may be some instability related to that, but as far as the details, we're not really sure yet.

REHMWell, we're talking about eight and a half acres, Randy, that became a sinkhole. David, can you talk about that?

OWENWell, I think an important point is that there is this very close relationship between what we do on the surface and what we do underground. And I think we tend to ignore effects that we can't see. And so we will extract things from underground and think that we're not having an impact on our environment just because we can't see it. But, it's very much the case. You can't pull material out forever without having consequences. So even in a case where, you know, the geology of a collapsing salt dome may be different from the geology of a collapsing sinkhole, but there is still a very great similarity and our activities on the surface can have huge impacts on what happens, even though we can't see it.

REHMBut eight and a half acres is a pretty darn big sinkhole. I mean--go ahead, David.

OWENI was going to say, it was very big. And the cavities underneath can be tremendous. And Randy can talk about this more, but an example just in the Seffner sinkhole, there was a very small opening on the surface. But it didn't form just that day. A cavity underneath had formed and become large enough, not only to collapse, but also to absorb a huge amount of material from above. There was a 60-foot column of stuff that just disappeared. So it's not something that happens in the space of a single night.

REHMBut in that Bayou Corne area you had some 150 residences totally evacuated. What's happened to them?

ORNDORFFYeah, as far as I can tell, the community itself does not actually sit on the salt dome. It sits just off the salt dome, but because of the migration of various fluids and gasses, I think is more the concern there. There's been a lot of methane release, probably natural. The thing about salt domes is along the edge of the salt domes you have geologic formations that trap oil and gas. And we think that the methane is coming from that situation.

REHMRandall Orndorff, he's director of Geology and Paleoclimate Science Center of the U.S. Geological Survey. Short break and right back.

REHMAnd in this hour, we're talking about something that has happened with a little too much regularity of late, the opening of sinkholes. One in Florida literally swallowed a gentleman who was sleeping in this bed. Another happened on a golf course in Illinois. And joining us now from Toronto is Erin Brockovich. She's a consumer advocate, environmental activist. Her role in helping to win the largest settlement ever paid in a direct action lawsuit was portrayed by Julia Roberts in the movie "Erin Brockovich." Good morning to you, Erin. Good to talk to you again.

MS. ERIN BROCKOVICHHey, it's nice to talk to you.

REHMThank you.

BROCKOVICHThanks for having me on.

REHMThank you. Tell us how you got involved with the Bayou Corne?

BROCKOVICHSeveral of the community members, you know, had come to me. I, like every else, you know, saw it on the news and read it in the paper. And more often than not what happens with me is countless communities, when they, you know, either have an accident or an environmental problem or something such as we see in the Bayou Corne, they will typically work with, you know, agencies and those that are there to help them.

BROCKOVICHBut when the process flows where they don't start getting the answers they want or think they need to hear -- and in this situation, they were very concerned because they were under mandatory evacuation. They couldn't get back into their homes. So out of frustration, they contacted me and that is ultimately how I got involved with the residents and the community.

REHMSo you've got about 350 residents evacuated from that area, is that correct?

BROCKOVICHYeah, there's about 150 homes.

REHMRight.

BROCKOVICHAnd within those homes, you know, you can have two, three, four occupants. And...

REHMSo -- and you've got an eight-and-a-half acre area large sinkhole. Is that correct?

BROCKOVICHThat is correct. And I can maybe help by just kind of giving you a visual of the area, because I just left there last Sunday. And from a highway you can see the sinkhole but what you really see -- it just looks like a lake now because they have a very high water table in Louisiana. And when it collapsed all this water came running in. And just kind of diagonally across the freeway is where these residents live out on a bayou.

BROCKOVICHAnd I will tell you, it's really lovely. It is quiet back there. They have their boats. They're on the bayou. They can fish. It's just a wonderful feeling. And to be out there now is a very feeling because they're all evacuated. And when this fault dome, which is a cavern underneath -- and as one of your guests said earlier, you know, they store oil and gas down there, they store other chemicals down there -- when it collapsed all that gas had to disperse somewhere. And it went underneath these homes.

BROCKOVICHSo current reports that we've read even show that there's like 250 psi, pound of pressure, underneath these homes. So the potential for an explosion is very realistic. So they've been out of their homes now for eight months. And they're just now maybe starting to get some answers. We'll have to watch and see what happens. But...

REHMIs there any indication as to just what caused this sinkhole in the first place?

BROCKOVICHWell, in this situation, you know, our understanding from all the reports that we're gathering -- and the community has been very busy being active as well in getting information -- you know, they're extracting brine. And apparently one of the wells failed that OCI Chemical was using there that caused the sinkhole.

BROCKOVICHNow we've also looked further into it and when companies have these fault domes, you know, they are responsible for its maintenance. And there was just no maintenance on this. And there had been some indication that there was problems but nobody was addressing it. And so...

REHMNow let me just bring David in on this. David Owen, have you seen areas where there are indications that a sinkhole could be about to happen?

OWENWell, as I -- I think you can look at Florida and see many indications that sinkholes are about to happen. They happen with some regularity. There's a difference between the kind of naturally occurring sinkholes that you see in a karst environment, where even if they're accelerated by human activity and something like what we saw in the Bayou, which is pretty much directly the result of human activity -- or solely the result of human activity.

OWENSo -- but there, you know, there are many places I think that -- and I think Randy will say that you don't get a lot of warning necessarily. Sometimes there's a kind of sinkhole that you'll see subsidence. The ground will sink. You'll see foundations cracking. But at the same time, you can have one just like the one in Seffner where suddenly the ground gives way, or the one that swallowed up the golfer.

REHMNow, Randy, what about the one in Bayou?

ORNDORFFWell, like I said, it's, you know, a very different situation but, I mean, all sinkholes form because you have some kind of a void underneath the ground. And the Bayou Corne, that void was cavern that they had mined salt from, that I -- my understanding was, was closed down for some time before this happened. So I see the Bayou Corne is a very -- it's a very complex situation.

ORNDORFFThe USGS isn't studying this one directly. The state has been mostly involved. But the data that we do see, you know, it's not just the sinkhole. As Erin said, about the potential for the -- it's the gas migration, be it from a natural source or from one of these other sources. So that's what makes it a very different situation then what David was just talking about in Florida. We have very different kind of karst.

REHMNow, Erin, to what extent has Governor Bobby Jindal gotten involved?

BROCKOVICHWell, we were down there, like I said, just last Sunday -- or the Sunday before actually, and again with a very restless community, with a lot of questions unanswered. And having heard that the governor would come out but he couldn't. And listen, we all imagine governors are busy and sometimes they can't always get to a place. But for this community they felt it was a very big emergency.

BROCKOVICHWe had a big community meeting and was definitely in the paper. And the following day or two later the community heard that Governor Jindal would be there. He did come. He did meet with the companies. What we currently know is happening is that Texas Brine is going to start appraisal processes to buy these people out. And he has put together a commissioned blue ribbon panel to begin to take a look at what happened. And maybe we can get some more answers through this panel.

BROCKOVICHAnd so now we're going to just sit and wait and watch here for the next 30 days to see if Texas Brine will quickly do the right thing and give these people the value of their homes and potentially any other damages that they really are entitled to and -- so they can get on with their lives. And we'll have to watch and see.

REHMErin, as I understand it, the sinkhole is indeed growing. Is that correct?

BROCKOVICHIs it growing?

REHMYes.

BROCKOVICHYes, that is correct. And we've kind of known this since the -- since it initially happened. And of course they've been watching and it's kind of sinking and it's more sections falling off. It's getting closer to this massive freeway. So I'm certain that they're watching it but just last week there was a lot of seismic activity. And another section did in fact collapse and it's pushing its way towards this freeway. So the answer to that is yes.

REHMSo how long does it take a sinkhole to finish growing, Randy?

ORNDORFFWell, that's a really tough question. Obviously it depends on the environment that you're looking at. I mean, first off it's all about space. So how much space is there in that void that was below? So, you know, that would be one factor. The other factor then is the stability. You know, in the case of a lot of sinkholes, when they collapse they look like cylinders. But, you know, mother nature wants to try to stabilize things, so most sinkholes start to -- the slope on the edges lessen so it turns into more of a bowl shape. That's what it really wants to do.

ORNDORFFSo a lot of this sloughing that we're seeing, even in the Bayou Corne one, part of that is just trying to stabilize. I guess what the question really is, is -- we know it's a very large void there -- how much more material can it take? What's the pathway to get there? So in that one it's a very tough one to answer.

REHMAnd, Erin, I'm also wondering about hydraulic fracturing and to what extent you may have looked at that as a possible cause.

BROCKOVICHWell, you know, we're definitely looking at, as I kind of mentioned earlier, what was going on out there was a failed well that they used to extract brine. So there is some fracking in the area. We're still taking a look at that, but it's pretty well established what happened is with this well number three, where they were doing the extractions for brine and the well failed, that could have had some impact on either seismic activity or something that ultimately made that dome completely collapse.

REHMAll right.

BROCKOVICHBut fracking is obviously an issue throughout the United States, that just scads of communities are coming to us about. I think it's something that we will have to talk about and we will have to address, one being the groundwater contamination and the other issues that communities are experiencing. And nobody wants us to not be energy, you know, dependant ourselves, but there is a right way and a wrong way to frack a well.

BROCKOVICHAnd I think that we have to look at it could be more costly but the right way and a responsible way to do that so we don't continue to damage the environment and pollute the water and have bad outcomes for communities and people's health and welfare.

REHMSure. David, in your writing of this piece in your investigation, did you find any relationship between sinkholes and hydraulic fracturing?

OWENI didn't look at fracking but I think there's kind of an underlying lesson in both cases, which we can look at Florida's geology and see how directly activities on the surface affect what is underground in our water supply. And we can see how quickly what happens underground affects us above. And we're doing very similar thing with fracking. It's not a natural geological process but we're pushing materials into subterranean strata. And it has an impact, just as it does in Florida by other means. But it's really very much the same.

OWENAnd I think if you look at what has happened in Florida over eons, you get a sort of capsule lesson in the interrelationship between people and geology and it runs in both directions.

REHMAnd of course all the while, New York State is debating whether to let those licenses go on hydraulic fracturing. And you're listening to "The Diane Rehm Show. Let's open the phones, 800-433-8850. First to Louisville, Ky. Good morning, John.

JOHNHello.

REHMHi.

JOHNI used to -- a long time ago I lived in Horse Cave, Ky. It's near Mammoth -- not far from Mammoth Cave and I remember -- recall that there was a sinkhole on the property where I was. And at the time people would just dump things in it. And there was a car disappearing into the one on our property. But the good news is that there's a lot more respect for the karst area now, because at the time there was a cave in the middle of the town. People could not go into it because of the noxious gas coming out of it.

JOHNAnd they've long since cleaned up the groundwater to the point that they have cave tours again, which they hadn't had for probably 80 or 90 years at the time.

REHMThat's interesting. So what he's saying is, you can bring this area back.

ORNDORFFAbsolutely. The thing about a karst terrain when you have such soluble rock in these huge caves and the water's running through it, yeah, contamination gets into it very rapidly. You know, before we really understood the science, you know, the folks living in these karst areas, you know, think about it. It's a hole sitting there. What a great place to put your trash. It's out of sight. And then we've learned more about how that contamination happens.

ORNDORFFBut there are states across the nation that have these programs that will help clean up these landfills basically that are in these sinkholes. And we're finding that the water can recover quite well. I think David saw some of that even in Florida, understanding the Floridian aquifer.

OWENThat's definitely true and Florida has made great efforts to ameliorate many of those damages. If you drive through Florida you'll see huge areas beside highways, beside buildings that are meant to contain water runoff from the paved areas and hold it for a while and let it sink into the ground slowly rather than running the way Randy described earlier as it goes into torrent.

OWENAnd so it -- I think it shows us in both ways that it's why a terrain like Florida's is very useful. It shows you both how quickly you can ruin an underground resource and then also what you need to do to make it better.

REHMAll right. To Blacksburg, Va. Good morning, Devonne.

DEVONNEGood morning, Diane. Thanks for taking my call.

REHMSurely.

DEVONNEOn the map on your website it shows a karst region of Appalachia, southwestern Virginia, where there's an ammunition plant that's been straddling the New River producing highly acidic water, releasing things to the noted sinkholes there since 1941. And I'm just wondering if there's any federal effort to take a look at large chemical manufacturing plants like the Radford Army Ammunition plant that's sitting on karst topography atop a drinking water source, the New River, releasing all kinds of toxins, and again, this highly acidic water.

DEVONNEThere was actually an acid leak that occurred at the plant on July 1 and approximately 8,000 gallons of either sulphuric or nitric -- I'm not sure -- but acid leaked out of their production line. And some of it went directly into the New River. Some of it went to the drinking water -- or a wastewater treatment plant there. But people who live here are concerned because we love the New River Valley. It's beautiful because of the karst. The rolling hills are magnificent.

DEVONNEBut the ammunition plant's been there since 1941 releasing stuff into the sinkholes that are documented in the EPA reports and putting stuff in the river. And it's just kind of -- you know, it's a little concerning. So is there any federal effort to look at chemical facilities and take some proactive enforcement action to investigate the safety for the surrounding communities?

REHMAll right, Devonne. We've got to take a short break here. But when we come back I'll ask Randall and Erin and David what they know about that area. We'll get an answer for you.

REHMAnd we're back talking with Randall Orndorff. He's a geologist at the U.S. Geological Survey. David Owen joins us from WSHU in Fairfield, Conn. He's a staff writer for the New Yorker magazine, also a contributing editor of Golf Digest. Erin Brockovich joins from Toronto. She's an environmental activist and legal clerk who spearheaded the largest direct action lawsuit of its kind against Pacific Gas and Electric Company of California. Randall, can you address our caller's concerns about the area she spoke of in Appalachia?

ORNDORFFYeah, that kind of goes back to the issue we talked about before about kind of the farmers putting their trash in the sinkholes. Well, that ammunition plant was started back in the 1940s I believe. So, you know, we didn't know enough then as we do now, so there's obviously a lot of contamination, you know, that was probably a part of that situation. Of course now we have the concerns about what's happening today. So we're always trying to balance how we can still utilize karst lands because they're there.

ORNDORFFTo be specific about that, when as far as what's going on environmentally, I think it -- I'm pretty sure the Environmental Protection Agency has something going on there, but as a science agency, I don't know any specifics about that. But I know the federal government is aware of that arsenal.

REHMDavid, any comment?

OWENI don't know anything about that one, but I think that in some ways people in karst environments are fortunate in that they will see the effects fairly directly. Where we are also accustomed to dumping things into holes in other places where the effects are not visible and are not immediate, but are still in the long run as consequential as they are in places where we see them in runoff from springs a mile away.

REHMErin Brockovich.

BROCKOVICHSo, yeah, I can definitely chime on this one. I mean, I think that what's happening now is we are seeing the end result of a lot of what we have done through the '50s, '60s, '70s, '80s and '90s, and whether, you know, we have just let our waste go out in the woods. It's found its way into the water, whether we dump it in to caverns. I mean, there's a whole lot of processes where we haven't disposed of our waste properly, is now in our environment and we are seeing the end result such as the call you just got.

BROCKOVICHAnd I'm very familiar with that area, because about a year and a half ago I got involved in what I call creating a people's reporting registry, where people such as your last caller, these communities could report to me and we could place them on a map so that we could begin to look at where some of these locations were. Now, that map today has already 4,000 sites sitting on it of reports such as your last caller. So I'm familiar with this area and we are looking into it. And, yes, the EPA is supposed to be there, but it has become a very false sense of security, I'm sorry to say it, for countless communities across this nation.

BROCKOVICHAnd whether they are absent because they have no funding, let's be honest about that, or they're overburdened, which they are, and they're understaffed. They can't possibly get to all of these locations. So if I look at my map of 4,000 people reporting, and that number grows every day, we also have to look at we have some 35 to 40,000 superfund sites that we still need to address. And we're still adding to that list every day. So there is a problem that is affecting the entire nation and we need to begin to sooner than later start finding some solutions and/or the funds or process how we can begin a cleanup process because...

REHMAll right. David, do you want to comment?

OWENYeah, I was going to say it's not always the obvious -- it's not always just the obvious sources of pollution like an ammunition plant. In Tallahassee for a quarter of a century the public utility got rid of treated waste water by using it to spray irrigate very large farm fields south of the city. And it seemed like an environmentally enlightened practice. You know, it's a win, win. And yet, the Florida Geological Survey was able to determine by doing an underground tracing that the nutrients from that activity that were basically destroying the ecosystem of a river 10 miles away.

OWENSo it's not always just the human activities that are obviously violations of the environment. There are many things that we do that we think of as benign that have comparable impacts or similar impacts.

REHMAll right. Let's go to York, Penn. Good morning, Helen.

HELENGood morning. Thank you, Diane, for visiting with us last week (unintelligible).

REHMOh, I enjoyed myself. Thank you.

HELENI don't want to throw something new into the pot, but what about urban sinkholes, particularly the city of Harrisburg and I know Baltimore? We've got a substructure of sewage pipes, many of them terracotta, and a lot of them put in in the 1800s. And when they get cracks, they leak. And because of the limestone and the composite of that, it gradually wears away and then we have a big collapse of sinkholes. And the cities have no funds to take care of this.

REHMWow. Randall.

ORNDORFFWell, yeah, you know, we can talk about -- obviously we study the karst terrain type sinkholes, but, you know, we term sinkholes can be a catchall. And we see them in almost all of our urban environments. Like I said, all it takes is a void underground. So your sewage systems, your water mains, your storm drains, they're basically manmade caves. And as our infrastructure ages, just like the caller, like Helen just said, we have those issues where you can start leaking into those pipes and you end up with the situation.

ORNDORFFI think one of the most spectacular, if you want to call it, sinkholes that we have seen was in Guatemala City, I think it was 2010, which was like a sewage pipe that was at least 100 feet underground. And I think the pictures of that were just spectacular. That was not a karst sinkhole. That was an infrastructure deterioration.

REHMI see. And here's a Tweet which says, "The Devil's Millhopper is a sinkhole so old it has unique flora so big that it's a state park in Florida." David, have you seen that?

OWENYes, I have. And there are some spectacular places in Florida. There's rivers that disappear underground and then emerge miles away. It's a -- Florida's geology has been described as Swiss cheese coated with soil, so there are a number like this. There's one called Big Dismal that I visited. And there was a swinging rope over it where, you know, heedless teens throw themselves into it. But it looks like it's a round, shallow pond in the woods, but it's actually -- the water depth is 80 feet. And then the cavity below if much bigger than that because it had to not only swallow that 80 foot column of rock and soil, but all the trees and everything above it.

REHMAll right. To Cleveland, Ohio, good morning, Vicky.

VICKYThank you. I (unintelligible) to a small lake that -- I don't know how many years ago it was, but due to drilling, they hit a salt dome and the whole lake, you know, just disappeared within hours. And it made me think, we were looking forward to wind turbines in Lake Erie. And I know that they mine salt from underneath Lake Erie. Is there any problem with that?

REHMErin Brockovich.

BROCKOVICHThat particular question I know one of your other experts might be better to answer because I haven't had anyone raise that issue with me. But, you know, I will definitely interject here. The word infrastructure is fascinating and you do -- the world underneath us that we take for granted that we don't see is absolutely fascinating. And whether it be natural or manmade, we do have infrastructures there that are in very desperate need of repair. So as we have this conversation and we see these sinkholes occurring, it is definitely telling us that we need to look at this infrastructure and make the repairs for that (unintelligible)

REHMDo you agree with that, Randall?

ORNDORFFYeah, absolutely. But back to Vicky's question about the Lake Erie bit, you know, we don't maybe know the answer to that specifically. The important thing is that we do the proper studies before we -- you know, before we do the development, the wind turbines or, you know, a housing development, things like that. You know, the science and the understanding of the environment is paramount before we do these types of things.

REHMAll right. To Marthasville, Mo. Hi there, Jerry.

JERRYOh, hi, hello. I had a question for your previous guests about companies that outsource. If it's okay I'd like to...

REHMI'm sorry, I'm not understanding what you're saying.

JERRYOh, why not hit companies that outsource jobs to other countries, how about...

REHMI'm sorry, you know, that was our last hour's program, rather than this hour's. Let's go to New Orleans, La. Joe, you're on the air.

JOEHi, Diane, thanks for taking my call. This is an interesting show. I think Ms. Brockovich is being kind to the governor here. Governor Jindal avoided the situation for months. He was out campaigning for Governor Romney. He was visiting New Hampshire and South Carolina. The residents of Bayou Corne at first had questions, and then there was some disbelief, and then anger, which I think led them to Ms. Brockovich. And finally the governor after -- gosh, I can't remember when the collapse happened, but it's been a long time. Finally he shows up last Wednesday for a press conference. And I just wanted to make that statement about our governor.

REHMErin.

BROCKOVICHWell, your caller is sharing some of the frustrations that we've clearly heard from the community. And the collapse was about eight, nine months ago. And, again, a great deal of the frustration was coming because there weren't answers from the state. They did want the governor to come. He didn't, but he did finally show up. And now we're going to have to watch and see if they make good on their word. And this community is still as frustrated as your last caller. And they felt that a response should've been immediately, not eight months later.

REHMOkay. So, Erin, who is going to be held responsible? Is it the Texas Brine Company? Or is it the state of Louisiana?

BROCKOVICHTexas Brine.

REHMTexas Brine. And they have said that they will relocate these people?

BROCKOVICHWell, the idea that they're probably going to ever get back in their homes shouldn't be an idea. It's too dangerous. I think that is now a dead area.

REHMSure.

BROCKOVICHSo what they will have to do is buy these people out of their home and pay them restitution and the damages that they suffered. And right now they're just in limbo. They think they're coming back. Then they know they're not coming back. They're not getting the answers. They're fearful. They're afraid to go back and get their stuff because they're afraid they're going to blow up. They are concerned about health impacts. They're doing air testing now. They worry about ultimately what will happen to the fish life. And nobody can seem to get them answers quick enough. But this is a situation where you're talking about 250 psi sitting underneath them. Let's be real. These people can't go back there. And let's get them out of there.

REHMAll right.

BROCKOVICHAnd we keep stalling.

REHMAnd you're listening to "The Diane Rehm Show." Let's go to Catskills, N.Y. Good morning, Michael.

MICHAELHi. I just want to say first of all I'm to the left of Al Gore on this. I agree with everything you've said. But the one thing that you haven't brought up -- and I just have a minor in geology, but I've never forgotten this. What you guys are talking about with sinkholes, to make this more accessible to everybody, I think you should mention that this is simply the final stage of cavern building. Carlsbad Caverns, Mammoth Caves, even Dave's Cave down in Marble Falls, Texas, they are going to go through this final stage of cavern building. On their own, if there'd never been humans, they're going to collapse, and then they're going to fill with water and become a lake.

MICHAELYou know, the limestone gets laid down and then it goes under an inland sea and then it gets turned into rock from organic. And when it was lifted to the surface again, as in Florida, the rain starts to pool, like they were talking about, and it opens this space. But once they do, you get this limestone, the water coming down and it picks up the limestone with it. And that's where you get your stalactites and your stalagmites. But the final stage is boom. And a millennia from now that's going to happen in Northern New Mexico. And the visitor's center sitting on top of that massive cavern, it's going to go in.

REHMRandall.

ORNDORFFYeah, absolutely. But it's a very long period of time. I think David said too looking at the karsts in Florida. I mean, we're -- yes, it's a process that takes, you know, millions of years to go through. And, yeah, eventually millions of years from now most of these -- you know, look at areas in China and Puerto Rico that have gone -- that are kind of late stage, more mature than some of the areas in the U.S. And you get these big pinnacles of limestone and then these huge areas of open space. And so absolutely.

ORNDORFFBut the thing about sinkholes is that, you know, we're not talking about like a widespread, you know, event hazard like you see with earthquakes and hurricanes when they come in. There may be a weather situation that causes them, but they're obviously very local.

REHMAll right. But 25, 30 years from now, say, these sinkholes have now been somehow covered up again and a builder goes in, how much investigating is that builder going to do before constructing something else on that same property?

ORNDORFFThat's a good question. They should go through quite a bit of...

REHMDavid, do they do that?

OWENWell, I don't think so. I think in some place as famous as Bayou Corne or Love Canal you have some assurance that people are going to be aware in the future. What you don't see is any kind of ordinary concern in environments where events like these are -- they don't happen all the time, but they happen. And it's like the more -- it's like putting -- if you put chips on every number on the roulette wheel, when the wheel spins, it's going to hit one of them. As we spread out across landscapes that are like this, the likelihood that something is going to fall through increases even though your own chances of being harmed are very small.

REHMSo, Erin, you're going to continue to work not only on Bayou Corne but elsewhere?

BROCKOVICHOh, absolutely. I continue my work here in the U.S. and at a global level for environmentally polluted communities and water pollution issues. Yeah, you know what, I think that's my job until I die.

REHMErin Brockovich, environmental activist. David Owens, staff writer for the New Yorker. His article about sinkholes appears in the March 18 issue. And Randall Orndorff, he's a geologist at the U.S. Geological Survey. Thank you all so much.

ORNDORFFThank you.

OWENThank you.

REHMAnd thanks for listening. I'm Diane Rehm.