Sinkholes: Causes Types Formation And Effects
As the name suggests, sinkholes involve land sinking, causing holes on the ground. They are cavities or pits in the ground that form when water erodes an underlying rock layer, or if the rock is limestone, salt beds, or carbonate rock, which can naturally dissolve by groundwater circulating through them.
As the rock dissolves, spaces and caverns develop underground causing the surface to be susceptible to sinkholes. Sinkholes are very dramatic as land can stay intact for quite some time until the underground spaces get very big. If there is not enough support for the land above the spaces, a sudden collapse of the land surface will occur, resulting in sinkholes.
Depending on the location, the damage was done underground and many other factors, a sinkhole can be about one meter in depth and width and can go as deep and as wide as hundreds of feet and beyond. One of the largest sinkholes known is one in the limestone mountains of Nongle in Guangxi Zhuang region in southern China. The sinkhole measures 656 ft long, 328 ft broad and 387 ft deep and when measured from the access point on the mountain ridge, the sinkhole is even deeper, at 1,476 ft. The worlds deepest sinkhole is in Chongqing, China, reaching down 662 meters.
How Do Water Leaks Cause Sinkholes
Sinkholes are caused by water eroding the ground underneath your home. The ground beneath your home isnt all solid. If you dug far enough down, youd eventually find pockets of air, or pockets of water The ground is still stable despite these gaps unless large amounts of water pour in and move the dirt around.
If theres a water main leak, or even if you have a major leak in your home, the excess water can erode your ground. If enough dirt is moved, the ground collapses into the gap. From our vantage point on the surface, it seems like a whole section of the ground suddenly drops down, even though it has been eroding for some time. Thats why leak detection is so critical, to prevent sinkholes.
Right now, as Californias water tables are fuller than they have been for a while, theres a lot more movement going on underground than there normally is. Further, we also have a lot of sand-like soil. Sandy soils have much smaller particles than clay soils or other types of dirt. Its easier for these small particles to be moved around by a sudden rush of water.
Sinkholes can also be caused by dissolvable rocks, such as rock salt and limestone. These types of rocks are more easily swept away by water. California doesnt have much of these rocks, so sinkholes arent as common here as they are in other areas.
What Should You Do If A Sinkhole Appears In Your Yard
If a sinkhole is threatening your home or its structural integrity, vacate the property immediately. Call 911 to alert the proper emergency personnel and alert a building inspector. A professional inspection should be conducted to determine if the structure is safe for habitation.
If the sinkhole is relatively small, it can most likely be filled in. However, its important to conduct a sewer line inspection to determine the precise cause of the sinkhole. If you simply fill the hole in without inspecting your pipes, you may have another sinkhole before long including even more extensive damage.
Its also important to remember that sinkholes on private property are the property owners responsibility.
Why Does Bad Plumbing Cause Sinkholes
Bad sewer line patchwork and ineffective point repair is unfortunately very common in the bigger cities within the San Francisco Bay Area. Many companies particularly non-licensed professionals frequently skip the appropriate quality assurance necessary to prevent future damage. These mistakes may lead to potholes and leaks that eventually cause sinkholes to emerge in the area surrounding the pipe.
The Signs Of An Underground Water Leak
Given the rise of sinkholes, its wise to know how to spot a sinkhole on your property before the ground gives way. Here are the signs:
- Cracks in the foundation
- Cracks in your driveway, sidewalk
- The home seems to lean
- Doors wont close properly
- Areas on your lawn are greener or browner than normal
- Your water bill is much higher than normal
- Water pressure has dropped off significantly
- You can hear running water when you shouldnt
In most circumstances, it will take a very serious leak to create a sinkhole, unless the water conditions beneath your home are very unusual. Thats why sinkholes are more common below city water mains, which can deliver huge amounts of water quickly.
There will typically be many warning signs of a sinkhole on your property before it falls through. However, as sinkholes are so damaging and dangerous, if you suspect your property may be developing one, you should get expert help from a trusted plumber right away. Our sewer experts in Concord can help. Were also proud to service communities throughout greater Contra Costa.
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How Are Sinkholes Formed
1. The effect of water: As already mentioned, groundwater is the overwhelming reason for the formation of sinkholes. They often occur in karst terrain which are areas where soluble bedrock such as limestone or gypsum can be dissolved in water. The bedrock becomes exposed to the water and is gradually worn down over time, some holes become ponds as they are filled with water and at any second, sinkholes could appear and swallow huge chunks of land with anything on them including roads, houses and even human beings and animals.
2. Naturally-occurring cracks: These cracks and small voids underneath the surface are hollowed out by water erosion, with only a cover of soil or sediment remaining on the top. If the hole continues to expand, the cover can no longer support its own weight and will collapse, revealing the cavern underneath
3. Heavy rains after a drought: After a prolonged drought, the surface is exposed enough and loses its strength. If heavy rains follow, they will cause immense pressure on the ground, that it sinks, creating sinkholes
Know The Signs Of An Underground Water Leak And Sinkholes
Sinkholes in Central Florida can be natural or man made. Water from broken pipe can penetrate through mud and rocks and erode the ground underneath and cause sinkholes. Sometimes, heavy weight on soft soil can result in collapse of ground, resulting in a sinkhole,according to Conserve Energy Future.
Firefighters responded about 7:30 a.m. for a small depression and by 9:30 a.m. the sinkhole grew large enough to swallow up an entire house and spread to another home in the Land O Lakes neighborhood. The sinkhole, which measured 250 feet wide and at least 50 feet deep, has forced evacuations of residents of surrounding homes.
Underground water leaks can be alarming for home and business owners. Because they can be so destructive, water leaks need to be repaired right away, they can easily lead to foundation damage.
Know the signs of an underground water leak
Unusual wet areas or ponding water in the yard, landscaping, or swimming pool area.
An area on the property that is lush and greener than the rest or an area that is brown and dry.
A noticeable drop in water pressure
Cracking, potholes, or depressions in the pavement or concrete foundation.
The building appears to be leaning or has an uneven flooring.
Unexplained increase in your water bill.
The should of running water, whooshing, splashing or a babbling brook, when all the water in the home is turned off
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Why You Will Need A Professional To Repair Your Sinkhole
Some sinkholes are easy to fix by simply filling them in and properly compacting them, others can be hazardous to deal with.
Whenever you see a sinkhole, youre looking at it from the surface, depending on the extent of the damage, there could be more to the issue than meets the eye. Sinkholes of any size can be dangerous, especially to children or pets.
Sinkholes can form in the vicinity of highly sensitive infrastructure, such as your electrical lines, sewer pipe, or water line. This can make it difficult to perform the correct techniques to safely fill it in. DES would ensure that any plumbing or engineering consult would be called in to assess the problem from every angle before proceeding.
Lack of Required Equipment
In some extreme cases, a sinkhole will cause damage to your foundation, exterior wall, or exterior stairs due to its proximity to these structures.
For example, sinkholes that develop under sidewalks will tip the concrete at a pitch, where it will break or continue sinking. In this case the hazard created is one of falling/ injury towards pedestrians.
Massive Sinkhole Caused By Storm Drain Sits Unfixed In Front Of Dekalb County Home
DeKalb County homeowner says leaders do nothing to fix massive sinkhole
The family is upset and wants something done before someone gets hurt. A watermain leak led to her driveway collapsing and the hole expanding.
ATLANTA – A DeKalb County homeowner said shes absolutely fed up with a massive sinkhole in her front yard.
She claims its been this way for months and the county is not doing anything to fix it.
“I mean do you see this? We cant use our driveway at all,” Amanda Hammett said.
Amanda Hammett stands in front of a giant sinkhole in her front yard in DeKalb County.
The massive sinkhole in font of Hammetts Timberland Road home is hard to miss.
“We came home one day and there was an indentation in the yard. It was odd and then there was a small quarter sized hole in the driveway,” Hammett said.
That was back on December 30.
“They actually discovered a water main leak that was right in this area. They patched it quickly and filled in the driveway. We were able to drive on the driveway. That first visit their Backhoe fell through and collapsed into the hole,” Hammett said.
DeKalb County said it will need to repair a storm drain that causes a massive sinkhole in the front yard of a home.
The hole has been crumbling and growing since January.
Hammett said a storm drain was disconnected and county crews must fix that before the hole can be filled. The question is when?
Amanda Hammett said a storm drain caused a giant sinkhole in her front yard.
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Underground Flow Or Spring
Sometimes running water can be heard in a sink hole. If a sewer or water pipe leak is not suspected, the water is likely from an underground spring that is uphill from the depression. It has eroded away soil under the surface causing an underground cavity. The ground surface settles into the cavity causing the depression.
Controlling an Underground Spring. In these cases, the water flow cannot be stopped, but it can be controlled. Installing a small French drain or catch basin and pipe uphill of the erosion site to capture the flow and replacing the eroded area with fill soil can solve the problem. In some cases, the flow can be captured and used as a source of water for irrigation or other purposes. The flow should be routed carefully to a suitable area so as to not cause erosion and flooding elsewhere. If the affected area is large, you may want to hire a landscaping or drainage company to do the work.
Infiltration/exfiltration Of Drainage Pipes Cause Major Street Damage
A large sinkhole has recently appeared on a street in the middle of Melbournes CBD.
It confirmed the issue was caused by a crack in a barrel drain running along the street.
Ordinarily, a crack in a pipe by itself is not enough to cause a sinkhole.
But degradation over time can lead to compounding of pipe defects such as tree roots growing through the cracks, corrosion of any pipe reinforcement, and infiltration/exfiltration .
The biggest culprit here is likely infiltration/exfiltration.
Infiltration/exfiltration can cause the bedding material supporting both the pipe and the road surface to slowly loosen and wash away, which is how a lot of sinkholes develop unnoticed.
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How Can Streamline Plumbing Help Prevent Sinkholes
As sinkholes can be the direct result of a sewer leak, the best way to avoid them on your property is to have your lines inspected regularly.Doing so allows us to catch sewer problems before they become the source of a massive sinkhole on your lawn.
Using drain line camera technology, we can perform thorough inspections of your lines that will reveal any existing damage. If we discover any during this process, we can stop most leaks before a sinkhole develops! After the inspection, we can begin to plan any repairs or replacements that we may need to perform on your sewage system.
Human Activity Not Nature Was The Likely Cause Of The Gaping Sinkhole That Opened Up In The Streets Of Guatemala City On Sunday A Geologist Says
A burst sewer pipe or storm drain probably hollowed out the underground cavity that allowed the chasm to form, according to Sam Bonis, a geologist at Dartmouth College in New Hampshire, who is currently living in Guatemala City .
The Guatemala City sinkhole, estimated to be 60 feet wide and 300 feet deep, appears to have been triggered by the deluge from tropical storm Agatha.
But the cavity formed in the first place because the cityand its underground infrastructurewere built in a region where the first few hundred meters of ground are mostly made up of a material called pumice fill, deposited during past volcanic eruptions.
“Lots of times, volcanic pumice originates as a flow , and because of the heat and the weight, it becomes welded into solid rock,” Bonis said.
“In Guatemala City unconsolidated, it’s loose,” he said. “It hasn’t been hardened into a rock yet, so it’s easily eroded, especially by swift running water.”
In general, the zoning regulations and building codes in Guatemala City are poor, Bonis said, and the few regulations that exist are often ignored. That means leaking pipes could have gone unfixed long enough to create the right conditions for the sinkhole.
In fact, Bonis thinks calling the Guatemala City chasm a sinkhole is a misnomera true sinkhole is an entirely natural phenomenon. There is no scientific term for what happened in Guatemala, he said, adding that he recommends the pit be dubbed a piping feature.
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How To Repair A Sinkhole
If a sinkhole appears that is directly threatening a house or structure, get out immediately. Report the problem to emergency personnel as well as to a building inspector, and wait for an inspection to find out if it is safe to return.
If a sinkhole occurs in the middle of the road, contact local law enforcement agencies. The area should be cordoned off immediately.
But, if the sinkhole is not impacting a house or other structure, and if it is a manageable sizeone to three feet in both diameter and depththen it can be filled in. The Florida Department of Environmental Protection has these recommendations for filling the hole:
1 First, monitor the hole. If it does not get bigger over time, fill it in.
2 Add dry-mix concrete or a concrete plug at the bottom of the hole. This will provide a solid base.
3 After that, add clayey sand. Pure sand, with larger particles, feels gritty, while a fine-textured, clayey sand will feel sticky. Clayey sand will form a barrier that will help prevent water from seeping through the hole and enlarging it. Call a local contractor to find out where to buy clayey sand. If you can’t get any, it is okay to use pure, clean sand.
4 Finally, add sand and topsoil on top to blend in the area with other landscaping. Additional fill may be needed at a later date, but the hole should stabilize eventually.
Why Is Sewer Line Repair Quality Assurance Important
Safety measures should be implemented by experienced plumbing crews to prevent sewer lateral damage from occurring. If quality is compromised, you may find yourself with an unexpected sinkhole on your property.
Your sewer repair team should always follow a quality assurance guidelines to ensure your new pipes dependability and code compliance. You need to make sure these items are in order:
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Sinkholes Near Outside Walls Or Under Stairs
Sinkholes occurring near outside walls or under outdoor staircases usually develop because the soil along the structure was poorly compacted. Over several years, the soil settles and causes a depression or hole.
Tips for Filling in the Sinkhole
- Clean the area. Remove any trash, grass or other debris from the depression.
- Try to determine the extent of the hole by careful excavation and probing
- Incrementally fill the depression with fill soil that has a high amount of clay and low amount of sand. Do not use gravel or rock as a fill material. If you do, water will trickle through the gaps in the gravel and create an even deeper cavity underneath. Shovel a few inches of the fill soil into the bottom of the depression and compact it thoroughly with a soil tamper.
- Continue this process until the depression is flush with the ground. You may want to overfill the hole since the fill soil may compact and settle over time. Remember to make sure the land slopes away from the foundation so that water does not pool next to foundation walls. Ground should slope away from foundation walls, ideally with a grade of 5% over a length of 10 feet. Allow the area to sit for a month or two to ensure that a new sinkhole does not form.
- Before planting, you may want to lay down a few inches of topsoil or potting soil above the filled area. Topsoil can help you establish vegetation.
- Plant seeds or use your choice of landscaping.