Concrete slab under grass

[Bonnie Trenga]

Hi. We live in an old orange grove. We still have many orange trees (around 20) in our almost one-acre property. Today we were digging up in the back of the yard in the hopes of clearing weeds and planting two new fruit trees. It appears there's a 10-foot by 10-foot concrete slab under the dirt. It's about four inches thick. Near the middle is a round area about the size of a dinner plate, and surrounding this round area are five or six long things sticking out of the concrete, what my husband thinks are threaded screws. (We were digging in the dark after the kids went to bed, hoping there would be a clear marking on the concrete. Nope.) Anyway, my husband thinks this is the foundation of a long-ago-used piece of machinery or something used for irrigation. We currently have flood irrigation but not in this area of the yard. This area is elevated by less than a foot. Below is grass and fruit trees.

1) Can anyone guess what this is?

2) How do we get it out?

Thanks, Bonnie

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[tbird]

It may be the septic system tank or cover!

[Bonnie Trenga]

Could be messy!

But we don't have a septic tank.

Hubby asks: "Does a septic tank have some kind of door or access on the top or side to clean it out?"

My question: Would the city or water company have anything to do with this and would we need permission to bulldoze it out?

[Brad Manor]

Might be the top of an old cistern used to store irrigation water for the grove. Just a guess.

-Brad

[ozofprev]

Sure, a septic tank has a lid that is normally about 2' square. Once it's removed, smart people get far away while the septic guy crams a hose into the mess and sucks it out.

That doesn't sound like your situation. Your hubby could be right about some machinery being attached to the threaded bolts. Were there any indications along the perimeter that walls might have been in place? Perhaps a small shed? (Got pics?)

Demolition/removal isn't terrible, but it is labor intensive. If the concrete is reinforced, or if it is high-density, then the job is a little tougher. "Normal" concrete is about 150 lbs/cu. ft. and that's probably what you are looking at.

[hausdok]

Hi Bonnie,

Call Chris Prickett or Scott Warga. They are inspectors in your area and they'll most-probably be familiar with what you've found. I don't have their phone numbers available, but you should be able to find them on the inspector search feature at http://www.ashi.org. Just plug in your city and submit the search and it should pull them up.

ONE TEAM - ONE FIGHT!!!

Mike

[kurt]

Orange trees....that sounds really nice.

I'm betting a dime it was a mount for a piece of equipment; threaded concrete rods in a circular configuration sticking up out of a slab has got to be a mount.

[Bonnie Trenga]

Thanks. It's actually seven inches thick.

Around nearby groves I've seen cylindrical cisterns so that's probably what it was.

How do we get it out?

[ozofprev]

Bonnie,

Scott Warga probably needs a good workout. I'm sure he would do it for a basket of oranges next season. (Maybe two)

There's no magic to it. Jackhammers, strong backs and a truck.

[Bonnie Trenga]

We always have way too many oranges! I'd be happy to send a bunch to you all (COD of course!).

Our lawn guy has a jackhammer and is coming over today. Vamos a ver que dice.

[kurt]

Jackhammers? Nice idea, but I'd be getting the guy w/the biggest front end loader in the 'hood. That, and a cutting torch.

If it's an equipment mount, which it's gotta be, you probably got multiple layers of reinforcing mesh or rebar, all tied & detailed into the mounting bolts. That complicates things. A lot. Jackhammers aren't going to do much other than make holes.

Especially in a 7" slab.

[Jim Katen]

Originally posted by Bonnie Trenga

Thanks. It's actually seven inches thick.

Around nearby groves I've seen cylindrical cisterns so that's probably what it was.

How do we get it out?

A seven-inch-thick slab is not fun to break up and remove with a jackhammer. You might consider hiring a small backhoe and truck.

- Jim Katen, Oregon

[Bonnie Trenga]

Thanks guys. You're the best.

[ozofprev]

It wasn't just a jackhammer - it was a jackhammer and Scott W! I was hoping for pictures.

Wusses

[Bonnie Trenga]

Hubby just spoke with a neighbor, who thinks it is the remnants of a windmill used to warm up the citrus trees when there was a frost. If it was gas or electric powered, would you think there'd still be a still-active gas or electric line? We don't want to blow up anything.

What a pain!!

[hausdok]

Hi,

I've uploaded the photo. It's definitely the base for a tower or piece of equipment of some sort.

OT - OF!!!

M.

[kurt]

S'funny. The first thing I thought was pylon mounted fan for moving air to prevent frost damage. Technically, not a windmill.

Pretty common in orange groves back in the day.

I doubt there's an active gas or electric line, but I'd be looking before I was digging.

[Jim Katen]

Originally posted by Bonnie Trenga

Hubby just spoke with a neighbor, who thinks it is the remnants of a windmill used to warm up the citrus trees when there was a frost. If it was gas or electric powered, would you think there'd still be a still-active gas or electric line? We don't want to blow up anything.

What a pain!!

You ought to be able to get the local utilities to do a locate for free. Call them in the morning.

Frankly, though, if there were electricity or gas you ought to see an electric box cover or a gas stub near the bolts somewhere.

Another thought: Rent out the slab to a cell-phone company. AT&T might pay you $30k per year to have a cell tower there.

- Jim Katen, Oregon

[ozofprev]

Bonnie,

You described it perfectly.

Heavy equipment would be nice, but when we (Habitat for Humanity) run into a concrete slab, we gather the college kids and give then sledge-hammers. I've seen 8' square slabs 4-6 inches thick go away in a week (no rebar). A jackhammer is a luxury for us.[:-banghea

[Bonnie Trenga]

We don't see any box or anything. We'll call the utilities in the morning. It was fun shoveling with hubby but it's time to leave it to the professionals.

Interesting idea about the cell tower!

Thanks for your input.

[carle3]

I know the utilities will locate their own lines but I do not think they will track down lines that are not their responsibility. In my area diggers hot line will mark the service laterals but any private buried line, to like a shed, is not identified nor marked.

[JEuriech]

Bonnie,

The concrete may be from an old windmill, however I have never seen a windmill in that area. If I was to guess, I would think it's a mount from an irrigation pump. More than likely there is an old well in the area. Some old pumps are driven by windmill, however it could be electric.

You may want to call Arizona Blue Stake and have them come out and check the area first. http://www.azbluestake.com/main/main/index.html

Jeff Euriech

Peoria Arizona

[Bonnie Trenga]

Thanks for your input, Mr AZ. We're having srp, cox and mesa come out to examine it.

My other thought is that with all the scorpions in the area (and house) it must be a scorpion den!

[Brian G]

Oranges, concrete, and scorpions, oh my!

Oranges, concrete, and scorpions, oh my!

Brian G.

Don't Squeeze the Scorpions []

[Bonnie Trenga]

Well, this could morph into a whole new thread about venomous house anti-guests. I can't even pee in the middle of the night because I'm afraid of what I might step on.