Exterior Sump Pump Basin Popped Out Of Ground!

Discussion in 'Pumps and Tanks Well Forum & Blog' started by Perry58, May 20, 2012.

  1. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    A plumber, who advised that I could do the job myself, said that I needed to replace an existing exterior sump pump and basin for drainage of stormwater from our lawn. There has always been a lot of ponding due to underlying clay. The exterior pump system discharges through 1 1/2" PVC piping to a sump pump system in our crawl space that then discharges to a stormwater drain on the other side of our yard. My prior Flotec and similar Home Depot-bought pumps kept dying after one season. I was advised to enlarge the pit diameter to reduce the frequency of the on/ off cycle. I dug a 30" deep hole and installed Jackel (resin?) 18" dia. x 24" deep basin and a Storm Pro 1/2 HP Cast Iron/Stainless Steel pump with vertical magnetic float and built-in release hole to avoid air buildup. I lined the bottom of the dirt pit with about 6" of gravel. I drilled about 60 - 1/8" holes around all sides of the basin in 3 rows in about an 8" band that started about 1" from the bottom. I then covered the outside of the basin with landscaping weedblock fabric. After inserting the basin in the ground, I poured a 5" diameter layer of gravel all around the sides of the basin from bottom to top, so that I had the gravel as an outer filter and the fabric as an inner filter. The Storm-Pro had a 2" discharge hole so I used a 2" to 1 1/2" adapter to connect to existing plumbing, which had a check valve. All clamps were tightened properly and the check valve was in the proper position. I rested the pump on four bricks in the bottom of the basin to give it a little elevation from sediments. I tested the pump by pouring water in the pit and it appeared to be working. I then closed the lid and put two more bricks on top to keep the basin lid shut without having to mess with unscrewing for service.I went out to check it after some heavy rain and found that the entire pit had pushed out of the ground and was bobbing on the surface of a full pit of water! I heard the pump running, so I unplugged it. After everything dried out, I went back and looked. The filter fabric did not seem to be clogged, but about 10 to 15 of the 60 inlet holes appeared to have sediment or tiny gravel particles. (Filter fabric may not have been glued sufficiently?) That would still leave about 45-50 inlet holes. If the pit was filling up with water, that should ADD weight along with the 6 bricks. I can only think that somehow the pressure under the pit must have been greater than the pressure inside the pit. I would think that would only occur if all the holes and/or the fabric had been clogged. I am scratching my head about this. Any good suggestions? Thanks much.
  2. Cookie

    Cookie .

    Messages:
    5,658
    Location:
    .
    Enlarge the holes to 1/2" and add a bunch to the bottom. Your water was not coming in quick enough or fast enough, and the water pressure caused it to pop up. You may want to add more holes on the side just randomly.
  3. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    Cookie, Thanks. I originally followed the advice of a website that said to restrict the holes to 1/8". Going to 1/2" seems like some pretty large holes. Don't you think that 1/4" would be sufficient?
  4. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    Which website told you to drill the 1/8" holes?
  5. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,273
    Location:
    Land of Cheese
    If you think this is bad, imagine it happening to a sewage basin in a basement. It happens.

    The basin holes need to be big enough to allow water in freely. There should be nothing but stone about a foot in width around the sides of the basin. The filter fabric should be around the outside diameter of the stone, to keep the fines from mixing into the stone.
    Last edited: May 20, 2012
  6. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    I don't remember. Why?
  7. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    No thanks. I'll stick to stormwater.:)
  8. dlarrivee

    dlarrivee New Member

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    1,172
    Location:
    Canada
    You don't remember who gave you some advice but you followed it?
  9. Cookie

    Cookie .

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    5,658
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    If you wish to make them 1/4" go ahead, and if it doesn't work, you will have to redo it all over again.
  10. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    Dlarrivee, really? You're cross-examining me about who gave me the advice? I look at a lot of websites. It seemed to be credible. I could go back and find it, but why? What will you do with the information? I posted what I did to install the pit. Do you have something constructive to add?
  11. Perry58

    Perry58 New Member

    Messages:
    6
    Location:
    Northern Virginia
    Cookie, Thanks. If the 1/2" holes are too large, I can't do anything to reverse it. If I move to 1/4" holes, I can increase the size if that doesn't work.
  12. Cookie

    Cookie .

    Messages:
    5,658
    Location:
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    You are welcome Perry, do what you feel comfortable with.
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