1. ATTENTION returning members. If you are coming here from the old forum for the first time, you will need to reset you password. However, we had an email problem getting password reset links set out to a lot of the email addresses. That problem is temporarily rectified but IF you still have an issue, email me direct at info@thebuildingcodeforum.com and I will give you a temporary password.
    Dismiss Notice
  2. Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by clicking here: Upgrades
    Dismiss Notice

Perk Test - Minutes Per Inch (MPI)

Discussion in 'Sewage' started by BayPointArchitect, Nov 1, 2017.

  1. BayPointArchitect

    Joined:
    Oct 19, 2009
    Messages:
    277
    Likes Received:
    9
    While attempting to determine the rate of absorption, I dug nine holes and filled them with water. I am told that a value greater than 60 MPI is cause for concern. If my MPI is based on the four hour measurements, I have 10 MPI - which is good. Obviously the absorption rate slows after the soil surrounding the hole becomes saturated after 24 hours. So what length of time should I be using?

    https://www.dropbox.com/s/qiqeogrikw2bp66/PercolationTest.pdf?dl=0

    Thanks again!

    ICC Certified Plan Reviewer
    NFPA Certified Fire Plan Examiner
     
  2. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607
    BayPointArchitect likes this.
  3. BayPointArchitect

    Joined:
    Oct 19, 2009
    Messages:
    277
    Likes Received:
    9
    Thanks CDA. Somehow I found that same reference before I started and I could recall some of the information.
    My results are dubious. If the first four hours are considered pre-soaking the holes and the last twenty hours are divided by the drop in water level, then I am stuck with 203 minutes per inch. The results would suggest that my soil is non-absorbent and I am reluctant to expect that any length / size of drainage field will be adequate.
     
  4. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607
    Maybe talk to a septic company in that area to see what they think or normally encounter

    Especially if new systems are set all the time
     
  5. TheCommish

    TheCommish Sawhorse

    Joined:
    Sep 27, 2011
    Messages:
    676
    Likes Received:
    26

Share This Page