A sink hole was discovered Monday at the site of the new sports complex in Fredericktown.
Fredericktown City Engineer Tim Baer said the hole was discovered during excavating and had some trees growing out of it and measured a couple feet deep and around five foot in diameter.
"We didn't want to just cover it up so we decided to dig it out and see what it was," Baer said. "We dug down until we got to solid rock. What we typically find is a hole down in the fractured rock and you can look down in there and see where it opens up into a cave."
Baer said talking to locals it seems caves are not very prevalent in the area but in some cases, such as in Perry County, large caves can form due to water getting down into the cracks of limestone which opens up the caves.
"Sometimes you can crawl down in there, sometimes you can't but this is where the water is typically going," Baer said.
Baer said two sink holes were found. The first one had very little surface water going into it and the second one was harder to tell due to the incline of the land.
"We dug down and found the first rock ledge and then we dug down another 10 feet or so to get down to where we hit another ledge of rock," Baer said. "We didn't really find an opening down there. We've had these before to where you never really find an opening yet the water is going somewhere ... there is fractured rock, small cracks in the rock and it's going down there."
Baer said the holes were approximately 10 feet wide and 10 feet deep after they were dug out and it did not look like there was a cave beneath either of them. He also said he believed the two holes may have been connected.
"Once we dug down to the second ledge of rock and water started coming in it put about a foot of water in the hole and then it stopped," Baer said. "The other one we dug down lower, elevation wise, and never did hit any water."
Baer said there are multiple ways to fix the holes such as placing a pipe in each hole to act as a vent or by filling them with large rocks and concreting over the top.
"(Air has to) go somewhere so sometimes it works with a vent, sometimes it works with intake where water can get in," Baer said. "So what we typically do is we put a pipe vertical over it and seal the outside with concrete so we don't have any water getting in on the outside of the pipe. We seal the best we can with concrete and back fill the pipe."
Baer said neither of the holes would take in any water with all of the service water going into the retention base.
"There is a way to seal this thing up and keep it from opening back up again," Baer said. "We just have to decide what's the best way."
Baer said both holes are beneath the area which will be the fourth field with one of the holes in the bull pen area and the other in the field.
"We will fix them up and make them work," Baer said. "We needed to dig them up and fix them because we are putting another six foot of dirt on top of that."
Baer said the discovery of the sink holes has not slowed progress on the ball fields.
"It's nothing to be worried about we aren't going into the abyss or anything," Baer said.
This week the holes were filled with rock and topped with concrete.