Sump pit basin 40" deep required?

Discussion in 'Illinois Plumbing Code Questions' started by serge0n, May 10, 2013.

  1. serge0n

    serge0n New Member

    Messages:
    2
    Location:
    Skokie, IL
    Hi everyone, I've been reading this forum for quite some time, but this is my first post.

    I have an overhead sewer project going on in my basement right now and when the plumbing inspector stopped by he said that my old sump pit is not up to code and has to be expanded so that sump basin's inlet is at the drain tile level which is 2' below the basement floor. My sump pit is about 50 years old and it has a clay liner. It is 18x24" in size.

    My plumber that is working on the sewer suggested to expand my current sump pit to 24x40 and that way the inlet will be at the drain tile level, as required by the inspector.

    I've never heard of a sump pit that deep.
    Does anyone know what IL plumbing code says about sump pit sizing and inlet levels? I've searched and couldn't find any sump pit regulations in the code. Can I install a basic 18x24 plastic sump basin and have holes drilled in the bottom so that ground water can get into the basin from below?

    I've already spent a fortune on the overhead sewer and want to avoid any additions to the bill as much as possible.
  2. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Messages:
    1,705
    Location:
    Chicago, IL
    No you can not drill holes in the bottom of the pit. I have installed many 30" by 30" and 30" by 36" pits. The extra width helps with how long it takes the pit to fill allowing the pump the proper rest time between cycles. Why get cheap all of a sudden? As you said you spent a fortune on the overhead sewer conversion, why cheap out on the sump pump pit, and have your basement flood out again for not having a properly sized and installed sump pump pit?

    There is a formula to figuring out the size of a sump pump pit. I don't have it in front of me at this time, but it has to do with total square footage of the roof, property, and the 100 year rain fall numbers. 99% of the homes built use the 18x24 pits and get ok use out of it till a good rain hits the area. Then the pump is over worked, and burns out. Some people even with a small rain the pump gets overworked and burns out due to short cycling.

    What I would do if I was in your place and wanted to meet what the inspector wants, is ask the inspector what he recommends.
    SEB likes this.
  3. serge0n

    serge0n New Member

    Messages:
    2
    Location:
    Skokie, IL
    Thanks a lot, SewerRatz! I did as you have suggested and the inspector's recommendation was to make the pit deeper, install a new 18x24 basin in there with an inlet closer to the bottom and add a fireglass extension on top of it. Would you do the same if you were working on a project like that?
    On Sunday my plumber suggested the same thing and I guess that's what needs to be done.

    Is this formula actually a part of the Illinois Plumbing Code or it is something established on a municipality level?

    I'm not trying to cheap out, just want to understand my options here. Money's running out. :) And I wonder what my plumber was thinking when he gave me a total estimate for the project, but omitted the expansion of the original sump pit from the scope. Sure, he couldn't have known the depth of the drain tile pipe, but he should've suspected a replacement is in order and included that in the bottom line.
  4. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Messages:
    1,705
    Location:
    Chicago, IL
    Sorry for the delay in the reply. I have been running the shop solo for a while now, and when I get home, I am wiped out. The formula was something the pump manufactures put out. This way you can have a properly sized pit to handle the incoming water without short cycling their pumps. Short cycling will burn a pump out in no time. I would say go with a 24x24 basin with the extension if needed. The reason for the wider basin is for the pumps that have a fixed on/off point, you can get more rest time between cycles since the extra diameter will take longer to fill the pit in height.

    You can go with a 18" dia pit and use a switch like the Ion Genesis switch (which is costly), it lets you set a higher turn on level. For example most fixed on/off pumps like the Zoeller M53 turn on at 7" and off at 3" The Ion Genesis would work with a pump that does not have a switch like the Zoeller N53 (N means no switch), the switch is strapped onto the pipe near the bottom of the pit. This is the off level, then you can set the controller to turn on at any level above that, say like 12" for an on point. This would provide a nice amount of rest time between cycles on the narrow pits, just want to be sure to have it turn on before the drain tiles are flooded out and then you get seepage from the cracks in the floor. http://www.ionstormpro.com/iongenesis/

    Now I like to install the wider and deeper pits, with the Ion Genesis switch. This way I can get the most out of the pump system. Another advantage to having a wider pump pit is it will allow to install a second pump, or a battery back up pump in the pit with ease.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,026
    Location:
    Cave Creek, Arizona
    pit

    The depth of the sewer below the floor level determines how deep into the ground the pit has to go, since the "usable" volume is below the pipe's inlet, otherwise the water would flow into the pipe and fill it. Once that depth is determined, THEN you add a collar or extension on the top to bring it up to floor level. These parameters mean the pit could be 30" deep, the normal one, or 12 FEET deep which I have worked on when the pump is outside the building.
  6. SEB

    SEB New Member

    Messages:
    1
    SewerRatz -- I live in a high water table area in NJ and my pump cycles constantly. I'm trying to find someone who can install the bigger basins, but can't find anyone!! Can you tell me where I might find the 30x30 or 30x36 sump basins? At least I could get the basin by myself and then find someone to install it? Thank you...

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