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  • 1.  Sump Pump Design

    Posted 12-24-2018 08:45 AM
    Edited by Tirza Austin 12-24-2018 09:05 AM
    Hello everyone,

    I want to design a sump pump for a sewage system. For designing this sump volume an influent (incoming) discharge is required. I just need to know is we take peak discharge or average discharge for designing the volume of sump?

    Thanks!

    ------------------------------
    Syed Alvi M.ASCE
    junior engineer
    Techno Consult International
    Karachi
    923242637117
    ------------------------------


  • 2.  RE: Sump Pump Design

    Posted 12-25-2018 10:39 PM
    ​My experience is that you would design for average daily flow (ADF) multiplied by a peaking factor that is set by local regulations. I expect peaking factor values vary.  What values have others in your location used?

    ------------------------------
    Michael Meadows Ph.D., P.E., F.ASCE
    Assoc Professor
    Univ Of South Carolina
    Columbia SC
    (803) 777-3614
    ------------------------------

    Original Message


  • 3.  RE: Sump Pump Design

    Posted 12-26-2018 11:30 AM
    Edited by Tirza Austin 12-26-2018 11:29 AM
    Once you have determined the peak flow rate into the sump the minimum design volume necessary would be:

    V(min) = Q(out)*T(min)/4

    Q(out) = the pumping rate which is assumed to be half of the peak inflow rate.

    T(min) = Minimum cycle time between pump starts.

    If the pump rate is NOT half of the peak inflow rate then you would need to write the formula in terms of T(min) and solve by an iterative process:

    T(min) = [V(min)/Q(in)] + [V(min)/Q(out)-Q(in))]





    ------------------------------
    Daniel Rosenberg P.E., M.ASCE
    AECOM
    Cleveland OH
    (216)416-2000
    ------------------------------

    Original Message


  • 4.  RE: Sump Pump Design

    Posted 12-27-2018 08:18 AM
    Edited by Tirza Austin 12-27-2018 08:18 AM
    Thanks for your response. In standard (which I am following) we have a statement "The effective volume of the wet well shall be based on the design average flow."

    Mean for designing the volume we have to use design average flow. If we think logically, we have peak flow once on an hour remaining we have average flow condition. If we design the volume on peak so we have requirement of high volume in comparison to volume calculated for average flow. Also we know that the high volume for low flow cause sedimentation in sump which is not allowed. High volume causes high cost of construction.

    Please share your views.

    Also, please share reference standard in support of using peak flow flow calculating sump volume. (if any)

    Thanks!

    ------------------------------
    Syed Alvi M.ASCE
    junior engineer
    Techno Consult International
    Karachi
    923242637117
    ------------------------------

    Original Message


  • 5.  RE: Sump Pump Design

    Posted 12-27-2018 11:10 AM
    Edited by Tirza Austin 12-27-2018 11:09 AM

    You will have the hourly or daily peak but as was mentioned previously there will likely be a wet weather induced peak flow that you can determine using a peaking factor. Here in Ohio we generally use the Ten State Standards per local  guidelines. The Ten State Standards provides this figure and formula for determining the peaking factor. Other areas may have different standards.

     

     

     


    Sincerely,

     

    Daniel M Rosenberg, P.E.
    Technical Specialist, Water/Wastewater, Eastern Midwest Region
    D +1-216-416-6121
    dan.rosenberg@...

    AECOM
    1300E. 9th Street
    5th Floor
    Cleveland, Ohio 44114, United States of America
    T +1-216-910-2000
    aecom.com

    Built to deliver a better world

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    Original Message


  • 6.  RE: Sump Pump Design

    Posted 12-28-2018 08:25 AM
    Edited by Tirza Austin 12-28-2018 08:24 AM
      |   view attached
    We are in arid zone we have separate collection system (i-e storm water drain separate and sanitary sewer separate).
    In Ten State Standards it is mentioned that wet well (sump) to be designed on average flow condition.
    See attached. 

    ------------------------------
    Syed Alvi M.ASCE
    junior engineer
    Techno Consult International
    Karachi
    923242637117
    ------------------------------

    Original Message


  • 7.  RE: Sump Pump Design

    Posted 12-26-2018 11:29 AM
    Edited by Tirza Austin 12-26-2018 11:29 AM
    Syed,

    By "sump pump" I assume that you are referring to a sewage pump station, where the sump is what we usually refer to as the "wet well." The best-practice design considerations are as follows. The flow rate to be handled by the pump station depends on the peak flow to be handled when the pump station is first brought on line, and the ultimate peak flow to be handled by the pump station. Particular attention should be paid to dry-weather flows and rainfall-dependent inflows to the sewer system served by the pump station. Design flow rates for pump stations are typically based on the average dry-weather flow and the peak wet-weather flow. Since flow rates typically vary over the lifetime of a pump, it is usually convenient to select a pump that can handle future increased flows by changing the impeller size from smaller to larger within the same pump casing.


    ------------------------------
    David Chin Ph.D., P.E., D.WRE, F.ASCE
    Professor
    University of Miami
    Coral Gables FL
    (305) 284-3391
    ------------------------------

    Original Message


  • 8.  RE: Sump Pump Design

    Posted 12-28-2018 04:31 PM
    Edited by Tirza Austin 12-28-2018 04:30 PM
    Some sewage systems are subject to infiltration during rain events.  Make sure your inflow data takes due account of this.

    ------------------------------
    James Anderson, MASCE
    Principal
    Anderson Consulting
    North Richland Hills, TX
    817-946-9943
    James
    ------------------------------

    Original Message


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