Back flow preventer for water driven sump pump

Discussion in 'Plumbing Building Code' started by Falcon195, Apr 8, 2019.

Help Support Plumbing Forums by donating:

  1. Apr 8, 2019 #1

    Falcon195

    Falcon195

    Falcon195

    New Member

    Joined:
    Nov 19, 2018
    Messages:
    2
    Likes Received:
    0
    Location:
    Ohio
    I had a Liberty Sump jet water driven back up sump pump installed. The plumber used a $30.00 Watts dual check valve in the inlet water line to the sump pump.
    After doing some research I am under the impression that to be code compliant a redused pressure zone backflow preventer which costs about $300.00 needs to be installed in the. Am I correct ?
     
  2. Apr 8, 2019 #2

    Geofd

    Geofd

    Geofd

    Professional Professional

    Joined:
    Jan 20, 2018
    Messages:
    1,061
    Likes Received:
    151
    Location:
    Boston, Massachusetts
    yes....if the double check fails there is no way tp know unless you test it...with an rpz there is a relief port that will drip water on pressure fluctuations and reverse flow
    connecting your water line to that pump system could contaminate your water and city/town water source is considered a high hazard you may find those regulations
    at the dept of enviormental protection web site.....
     
    frodo likes this.
  3. Apr 9, 2019 #3

    Diehard

    Diehard

    Diehard

    Well-Known Member

    Joined:
    Aug 19, 2017
    Messages:
    1,053
    Likes Received:
    201
    Location:
    North reading, Mass.
    I believe what it boils down to, as far as the type of device required, would be based on whether it is subject to Back Pressure or just Back Siphonage.
    And that could be based on whether the discharges of each type pump are tied into each other or run independently and whether it meets with the approval of the public water system purveyor.

    The following was taken from the Ohio Cross Control Regulations of 2015.

    Water Operated Sump Pumps/Devices
    Some devices use the pressure provided by the public water system to operate. For example, water-operated backup sump pumps for homes and businesses utilize water pressure through the venturi principle instead of electricity to power the movement of collected sump water to the building’s drains. Such a configuration creates a cross-connection between the potable public water supply and liquid of a questionable quality. Due consideration must be given to the level of protection that is necessary to mitigate the hazard associated with the cross-connection. If alternative means exist which do not utilize water pressure or public water supply to operate the unit, they should take priority.

    Specifically for water-operated backup sump pumps the following shall be taken into consideration:

    1. Water-operated sump pumps pose a potential backflow hazard by way of a cross-connection between the drinking water supply and the contaminated water in the sump pit. This hazard is increased during flooding conditions. The main sump pump offers a potential of imposing backpressure against the water supply line to the water-operated backup sump pump if the discharge lines are combined. A majority of these pumps provide a vacuum breaker device for protection against backsiphonage. A vacuum breaker device would not provide the level of protection necessary if a backpressure situation should occur and would be made obsolete if it became submerged during a flooding situation.


    2. The public water system purveyor must analyze each household or building considering installation of a water-operated sump pump on an individual basis to determine if a backflow hazard has been mitigated.

    3. In all situations in which a water-operated backup sump pump is installed, the main sump pump and the water-operated backup sump pump should have completely separate discharge piping. Separate discharge piping is necessary if the backflow preventer installed is not rated for backpressure.

    4. The installation of water-operated backup sump pump units should also be coordinated with the local building department, local health department, or the Ohio Department of Commerce, Industrial Compliance Division which regulates larger residential and commercial plumbing applications. For installation in a non-residential building, one of these authorities will approve the plans and inspect the plumbing installation to ensure that proper backflow prevention is provided. For residential buildings, the proposed plumbing installation may be reviewed and inspected where a local certified building department or a local health department is available to enforce the plumbing code. Water-powered sump pumps are permitted in the Ohio Plumbing Code. At time of issuance, the relevant sections of the OPC include sections 608.3, 608.12, 608.16.6, and 1113.1.5 (Rules 4101:3-6-01 and 4101:3-11-01 of the Administrative Code).

    Figure 44 provides a schematic of a type of water-operated backup sump pump.
    Clipboard01.jpg

    Figure 44. Schematic of a water-operated backup sump pump installation which uses
    potable water supply to facilitate suction of fluids from the sump pit to
    discharge location if primary pump fails.
     
  4. Apr 9, 2019 #4

    Geofd

    Geofd

    Geofd

    Professional Professional

    Joined:
    Jan 20, 2018
    Messages:
    1,061
    Likes Received:
    151
    Location:
    Boston, Massachusetts
    when installing your rpz install a spring loaded check valve within 1 ft before the device....this will stop pressure fluctuations,causing the device to chatter or drip
     
    frodo likes this.
  5. Apr 12, 2019 at 2:19 AM #5

    frodo

    frodo

    frodo

    Just call me Macgyver Professional Supporting Member

    Joined:
    Sep 28, 2014
    Messages:
    7,022
    Likes Received:
    2,197
    Location:
    ,
  6. Apr 12, 2019 at 11:19 PM #6

    Diehard

    Diehard

    Diehard

    Well-Known Member

    Joined:
    Aug 19, 2017
    Messages:
    1,053
    Likes Received:
    201
    Location:
    North reading, Mass.
    A dual check valve is not legal if a cross connection exists downstream.

    As the OP suspected. Hence the reason he questioned if a Reduced Pressure Zone Backflow Preventer was required.

    Geofd agreed with he OP and added some useful information if he was to use a RPZ.

    But if the piping is arranged so that there is no possibility of a cross connection, as stated in the Ohio Cross Control Regulations, he may not need either device.
     
  7. Apr 13, 2019 at 1:39 AM #7

    frodo

    frodo

    frodo

    Just call me Macgyver Professional Supporting Member

    Joined:
    Sep 28, 2014
    Messages:
    7,022
    Likes Received:
    2,197
    Location:
    ,
    please provide the piping arrangement you are proposing that will elevate the possibility of a cross connection
    between potable and non-potable
     
  8. Apr 13, 2019 at 2:21 AM #8

    Diehard

    Diehard

    Diehard

    Well-Known Member

    Joined:
    Aug 19, 2017
    Messages:
    1,053
    Likes Received:
    201
    Location:
    North reading, Mass.
    Not sure if you meant eliminate the possibility but here it is.
    As stated in the Ohio Cross Control Regulations and repeated in my post #3 above, "The main sump pump offers a potential of imposing back pressure against the water supply line to the water-operated backup sump pump if the discharge lines are combined."
    In the absence of back pressure a pressure type vacuum breaker is a better selection for protecting the water supply.

    EDIT: I am not proposing a "piping arrangement that will elevate the possibility of a cross connection". If I was, then connecting those 2 pump discharge lines together would be an answer.
     
  9. Apr 13, 2019 at 2:46 AM #9

    frodo

    frodo

    frodo

    Just call me Macgyver Professional Supporting Member

    Joined:
    Sep 28, 2014
    Messages:
    7,022
    Likes Received:
    2,197
    Location:
    ,
  10. Apr 14, 2019 at 12:37 AM #10

    Diehard

    Diehard

    Diehard

    Well-Known Member

    Joined:
    Aug 19, 2017
    Messages:
    1,053
    Likes Received:
    201
    Location:
    North reading, Mass.
    Yes but this information doesn't change anything I posted from the referenced Ohio Cross Control Regulations.

    EDIT: My original statements, "I believe what it boils down to, as far as the type of device required, would be based on whether it is subject to Back Pressure or just Back Siphonage.
    And that could be based on whether the discharges of each type pump are tied into each other or run independently and whether it meets with the approval of the public water system purveyor.",
    still apply.

    The key here is that an RPZ is required when back pressure is possible in conjunction with a high hazard.There are other devices besides an RPZ that are approved for high hazards, in the absence of back pressure. There are methods and devices that are safer than RPZ's.
     
    Last edited: Apr 15, 2019 at 1:58 AM

Share This Page