Dodged a bullet - found a sinkhole

[MHarryE]

It's a cenote - you may find virgins sacrificed by an ancient culture in the bottom. But I remember that from Mexico and the similar holes. You are in MA, aren't you? MA - Salem is in MA - witch trials - definitely onto something more than a simple sinkhole here.

 

[PhysAssist]

I'm glad you weren't seriously injured!

We've experience with sinkholes here in our yard. The builder/prior owner buried tree stumps and other organic in several areas, when he was clearing the area for the house and septic fields These sites were unmarked, but we have been finding them one by one over the past 20 years of living here. First, we'll see a low area develop, then a small hole, and then it will collapse and leave an open pit of variable size. Then we start to fill it in. I found the first one much like you did falling in with one of my legs up to my left hip-luckily without injury.

When I was about 10, we developed an area of quicksand in my parents front yard, when a watermain developed a mild leak. My dad carefully stuck a 12' piece of quarter round molding virtually completely into the area. He had to leave it there because he couldn't pull back hard enough to get it back out. My brother and I had great fun watching the water authority crews trying to dig down through that soupy sandy mess.

I did some extensive reading about sinkholes (cenote, whatever-there are many different terms used interchangably) when that guy in Florida disappeared in the sinkhole that sucked down his bedroom, and all the sources agreed that it is often difficult to tell the true extent of the hole from the surface, so as others have suggested

Be Careful!

Best wishes for safe and inexpensive resolution,

Thomas

 

[caps]

We had a similar thing happen where I used to live West of Baltimore in Maryland. There was a spring that ran steady for at least 15 years that dried up. I remember we used to push a piece of 4 inch vent pipe over the outlet and it would push the water up about a foot or so above the ground level. One of the neighborhood kids was poking around it after it dried up and fell into a hole that was about three foot in diameter and about 6 foot deep with ankle deep water at the bottom. No one was hurt but it sure scared the heck out of him. As kids we used to play in the spring frequently when it was flowing and there was no indication of any sort of cavity. Best guess is that when it dried up the soil settled as the water receded and left the hole.

 

[farmgirl19]

It looks like your foot is close to where you "went in", in the one photo. That is probably too close to be safe. Be careful, please!

 

[Don87]

I did some poking around in the area today, though didn't get a chance to excavate (I had to move a big pile of dirt first). The water in the hole was crystal clear (so maybe a spring?), feeling the bottom with a stick there's rocks in the bottom, some areas are gravel and some are much deeper and mud on the bottom. It extends about 4' in one direction and there are some areas around that are 5' deep mud (can push a stick in 5 foot with minor effort). I think it's been developing for a while now that I look at it. Last fall I cut a tree (you can see the stump in the pictures) because the roots had just pulled out and it was lifting out of the ground with the wind, other trees around had started to die and I lost a couple of others. The whole area is slightly sunken vs the other ground and there's a thick mat of tree roots, which is what's holding the surface up, where I fell through I stepped between the roots. I've roped the area off with flagging tape and will wait for it to dry before digging in further. The stone wall near it is my property line, so I probably will be unable to drain it - but maybe I can fill it with rocks and get a stable surface, my hope was to use the area to park a trailer.

The area of the sinkhole. The hole in the center is where my foot went through.
View attachment 319598

Another view showing where the area is. Note there's a compacted Pad for parking right next to it. The drain pipe is for my downspouts though due to a gutter problem (tree hit it), almost nothing drains out of it, it runs out the other end.
View attachment 319599

where my foot went through, looks innocent enough!
View attachment 319600

Inside the hole. The water is pretty clear and the level is about 6" under the level of the ground, the top level is being supported mostly by tree roots.
View attachment 319601

Not to alarm you, but I would be very concerned after seeing the pictures. The next sinkhole could destabilize the building, depending on the flow direction of that underground stream.

I would consider calling in an expert of some sort right away.

 

[tcreeley]

In my area we have 13' to 25' dug wells lined with stones all the way dating back to the 1800's. They are usually filled in, some are not. Debris could have capped it off, limbs etc and you punched through walking. A lot of western Mass is limestone, but growing up in the Berkshires, I never heard of anything like caverns. Who knows. I think it is an old well. Maybe the house or barn fell in on it 150 years ago and rotted away leaving vegetation. I always look for stones in a pattern, or apple trees nearbye and a bit of mounding.

-Just looked at your pictures- old cesspool/septic.....? Goodluck Just saw story on a sinkhole in Lexington and another in Holyoke.

 

[tractchores]

Thanks. Im monitoring it, but haven't dug it out yet because its so wet. Its a good 20' from the building with a compacted parking area in between, so a good distance. I checked it yesterday and there has been no change and the water isn't moving so i don't think it will grow. I think an old well or something might be the culprit. As far as i know there is no limestone in the area, definitely no mines and there weren't any other dwelling as it was pasture and an orchard back to the 1700's

 

[Pharm]

We have sink holes that pop up every once in a while. It is almost always related to water - be it underground springs or other manifestations. We had a big one open up last year where we suspect an underground spring is located in a field where we plant crops. It was probably about 7 foot deep and big enough to swallow me riding an ATV. I had one about the size of yours just open up again. Last year I filled it with dirt but it's back again this year - we've had heavy rains this year which I suspect is the culprit.

 

[paulharvey]

When ever you collapse it and go to backfill it make sure to use a high plastic clay/fat clay and plug it up. If you can get a couple of feet if nasty plastic clay in there your probably good for another generation.

 

[foote2floor]

My father and i once excavated a small area to extend a side walk for wheelchair access. He found something odd and hopped off the tractor, he fell knee deep in a recently abandoned septic tank with a 1/4 inch plywood lid. Needless to say I let him go home for the day, and he drove home without shoes, socks, or pants that day.

Consider yourself lucky it is "clear water"