# Possible sink hole on my property, what do I do? **URL:** \ **Category:** Factual Questions\ **Created:** [November 26, 2019, 2:58pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013 "2019-11-26T14:58:14Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![slash2k](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@slash2k](https://boards.straightdope.com/u/slash2k)\ **Post date:** [November 27, 2019, 3:27am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/21 "2019-11-27T03:27:36Z")
> [@Northern\_Piper](#): > > Yes. Are you suggesting that sinkholes are only dangerous in Florida? 😕 I don’t think he’s suggesting that. However, monster sinkholes like the one that swallowed the man in his house usually require [karst geology](https://en.wikipedia.org/wiki/Karst), and Montgomery County, Pennsylvania, isn’t an area particularly known to have widespread karst topography (unlike, say, Florida, where pretty much the whole state is a sinkhole waiting to happen). ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [November 27, 2019, 5:34am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/22 "2019-11-27T05:34:33Z")
Last spring, a street in my city was closed off because a pothole turned out to just be a sign of the collapse of an unused sewer line under the street, and there was about 15 feet of dead space under the street at one point. Let us know what happens. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [November 27, 2019, 10:31am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/23 "2019-11-27T10:31:13Z")
> [@NAF1138](#): > > Hi, I live in Pennsylvania where I thought these things didn’t happen [This story](https://www.dailymail.co.uk/news/article-2303031/Jeff-Bush-First-look-INSIDE-Florida-sinkhole-swallowed-man-slept.html) about the Florida case where a man died says “Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania are the states most affected by sinkholes, according to the U.S. Geological Survey”. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 27, 2019, 2:30pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/24 "2019-11-27T14:30:35Z")
[Here’s a primer on the PA sinkholes](http://www.docs.dcnr.pa.gov/cs/groups/public/documents/document/dcnr_014591.pdf). Not a lot of info on what to do when you have one, but some interesting notes and at the end a reference to the Dept. of Agriculture which might help you. I should be talking to a civil engineer who lives in that area over the weekend, maybe I can get some info for you. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 27, 2019, 3:49pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/25 "2019-11-27T15:49:58Z")
Also, can you get a little more specific on the location. My brother lives in West Norriton, I assume you are somewhere in that area. Since it’s a pretty small hole is there some chance there was once a well there? Or an old septic system? ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [November 27, 2019, 4:13pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/26 "2019-11-27T16:13:29Z")
> [@Alpha\_Twit](#): > > I doubt heavily it’s related to a sewer line. You would be smelling it by now if that was the problem. Storm drains don’t give off as bad as smell as a sewage system. I had a similar situation in an old house once and it turned out to be a broken storm drain system. City dug it up,installed a pipe sleeve and back to normal. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 27, 2019, 4:22pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/27 "2019-11-27T16:22:07Z")
That area has a lot of sinkholes. Way back when there was one opened up in the far corner of the parking lot for the King of Prussia mall. They filled it, and it’s probably got a building on top of it now. Just feet away a whole section of Rt. 202 collapsed in front of the mall, they filled it and it looks like the road runs right over the same spot. Only a mile away or less there was a public golf course where several sink holes opened up, creating a new kind of golf obstacle. I suppose they do things to reinforce the ground before filling a hole so it won’t just collapse again, but it seems like that just allows the hole to grow bigger underground and someday a much larger hole will appear. ---
**Author:** ![NAF1138](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naf1138/32/3245_2.png) [@NAF1138](https://boards.straightdope.com/u/NAF1138)\ **Post date:** [November 27, 2019, 6:53pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/28 "2019-11-27T18:53:28Z")
> [@TriPolar](#): > > Also, can you get a little more specific on the location. My brother lives in West Norriton, I assume you are somewhere in that area. > > Since it’s a pretty small hole is there some chance there was once a well there? Or an old septic system? I live in Upper Gwynedd township, it’s close to Lansdale, so about 15 minutes north of your brother. ---
**Author:** ![chela](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chela/32/21582_2.png) [@chela](https://boards.straightdope.com/u/chela)\ **Post date:** [November 27, 2019, 10:42pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/29 "2019-11-27T22:42:29Z")
> [@Northern\_Piper](#): > > Yes. Are you suggesting that sinkholes are only dangerous in Florida? 😕 Don’t be confused,you sounded like a smug alarmist with useless anecdotes for the situation. Because if your house was about to be swallowed you fucking scram before you dither on the phone with a request for a municipal inspection, not a 24/7 dept ymmfv. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 30, 2019, 4:23pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/30 "2019-11-30T16:23:11Z")
> [@NAF1138](#): > > I live in Upper Gwynedd township, it’s close to Lansdale, so about 15 minutes north of your brother. So, your first step is to go to the township or county, whichever has a public works department and start with them. They’ll know if it’s related to any existing utilities or perhaps an old well, and if not they should recommend what you do next. I realize that’s not much info but it’s a way to get started for you. However, if a highway overpass shows up on your property my guy can give you a lot of help 🙂 ---
**Author:** ![NAF1138](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naf1138/32/3245_2.png) [@NAF1138](https://boards.straightdope.com/u/NAF1138)\ **Post date:** [November 30, 2019, 4:35pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/31 "2019-11-30T16:35:58Z")
> [@TriPolar](#): > > So, your first step is to go to the township or county, whichever has a public works department and start with them. They’ll know if it’s related to any existing utilities or perhaps an old well, and if not they should recommend what you do next. > > I realize that’s not much info but it’s a way to get started for you. However, if a highway overpass shows up on your property my guy can give you a lot of help 🙂 Well that’s better than nothing. My homeowners insurance told me they won’t cover sink holes unless it’s non natural (so they cover it if it’s an underground pipe because I have specific coverage for that, but not if it’s just the way the ground is? It sounds like they are going to make things difficult for a claim regardless). So hopefully the township can help. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [November 30, 2019, 4:57pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/32 "2019-11-30T16:57:06Z")
yeah, don’t mess around. sinkholes can be like icebergs, what you see at ground level might just be a small part of it. 3 years ago a botched repair on a main sewer trunk two years prior caused a large junction to collapse, nearly swallowing a house and irreparably damaging two more. > **[State Of Emergency Declared In Fraser As Sinkhole Threatens Homes](https://www.cbsnews.com/detroit/news/some-fraser-residents-evacuated-from-homes-in-danger-of-sinkhole/)** > > About 20 residents living on Eberlein Dr. in Fraser — near 15 Mile Rd. and Hayes Rd. — were evacuated from their homes over the Christmas holiday weekend after a massive sinkhole began opening up underneath some of the community's homes. ---
**Author:** ![Borborygmi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/borborygmi/32/217_2.png) [@Borborygmi](https://boards.straightdope.com/u/Borborygmi)\ **Post date:** [November 30, 2019, 6:06pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/33 "2019-11-30T18:06:51Z")
I opened the thread to offer the possibility that it may be an abandoned septic tank although I see that a few people have already covered this. A hole like NAF’s opened up in the front yard of my parents’ house a few years ago… if not for being incredibly dangerous it would have been kind of comical; it looked like something out a cartoon. They resolved it by filling the abandoned septic tank with gravel. ---
**Author:** ![Enola\_Gay](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@Enola\_Gay](https://boards.straightdope.com/u/Enola_Gay)\ **Post date:** [November 30, 2019, 7:46pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/34 "2019-11-30T19:46:05Z")
When my sister lived in Pennsylvania, she had a sink hole in her front yard that was about 3 feet in diameter. It was on the patch of grass between the sidewalk and the street, which belonged to the city. They put yellow tape around it for a while & eventually filled it with concrete. ---
**Author:** ![Enola\_Gay](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@Enola\_Gay](https://boards.straightdope.com/u/Enola_Gay)\ **Post date:** [November 30, 2019, 9:11pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/35 "2019-11-30T21:11:19Z")
Just got some clarification from my sister. She said they first filled it with gravel, then topped it off with a layer of concrete, then a layer of soil, then sod. She moved from that house, so no idea if it ever recurred. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 30, 2019, 9:44pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/36 "2019-11-30T21:44:45Z")
**[Moderating]** > [@chela](#): > > Don’t be confused,you sounded like a smug alarmist with useless anecdotes for the situation. Because if your house was about to be swallowed you fucking scram before you dither on the phone with a request for a municipal inspection, not a 24/7 dept ymmfv. And you sound like you’re making personal attacks in GQ. That’ll be a Warning. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [November 30, 2019, 9:58pm UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/37 "2019-11-30T21:58:08Z")
Based on the age of your house, I think the hole could possibly be from the final decomposition of construction debris they buried there rather than hauling to the dump. If you think about the terrain around your house, would you expect that the hole is within the area they would have shaped to manage the excavation spoils, give you proper drainage, allow for a driveway, and that sort of thing? I have a hole that I think arose from that cause, and construction people have looked at it and said that’s what they think. ---
**Author:** ![brossa](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/brossa/32/3040_2.png) [@brossa](https://boards.straightdope.com/u/brossa)\ **Post date:** [December 1, 2019, 2:17am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/38 "2019-12-01T02:17:27Z")
At my childhood home (~100 yr old farmhouse) there was a tiny black spot on the gravel driveway that my father thought was an oil patch, so he tried to rake a bit of gravel over it. The spot ate the rake, which fell straight down an old stone-lined well that had been covered with thick oak planks and buried with gravel; the planks had finally rotted through. The well was just big enough around that a guy could lay stones in a ring, and twelve or so feet deep. The bottom was choked with debris; who knows how far down it actually went. I know that it took more than one dumptruck load of sand to fill it; we capped it with concrete and fresh gravel. ---
**Author:** ![Morgyn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/morgyn/32/3041_2.png) [@Morgyn](https://boards.straightdope.com/u/Morgyn)\ **Post date:** [December 1, 2019, 2:32am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/39 "2019-12-01T02:32:29Z")
> [@NAF1138](#): > > I live in Upper Gwynedd township, it’s close to Lansdale, so about 15 minutes north of your brother. Wow. I live in Pottstown, and I drive through Upper Gwynedd on my work in the office days. No idea there were Dopers that close by. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [December 1, 2019, 2:34am UTC](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013/40 "2019-12-01T02:34:54Z")
> [@brossa](#): > > … it took more than one dumptruck load of sand to fill it; we capped it with concrete and fresh gravel. I sure hope you first checked for gold doubloons & pieces of eight - pirates love to stash those in abandoned wells (or so I’m told). [Previous page](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013.md?page=1) [Next page](https://boards.straightdope.com/t/possible-sink-hole-on-my-property-what-do-i-do/844013.md?page=3)