WP 66a, 66b: Title 5 Large System Upgrades

Use this approval for upgrades of large septic systems and review for consistency with Title 5.

Septic Systems / Title 5 Contact Information

The Details

What you need

These permits ensure that large septic systems perform appropriately.

You must apply for these approvals:

  • If you want to upgrade a system with a design flow of more than 10,000 but less than 15,000 gallons per day (WP 66a)
  • If MassDEP determines that a system or proposed system requires agency review to ensure consistency with Title 5 (WP 66b)



How to apply

See details in Step 5, below.

Next steps

  1. Review the Instructions

    Guidance on how to prepare your application, including a completeness checklist.

  2. Complete the Application Form

    You may fill out and save the Microsoft Word form on your computer. The PDF version has to be printed out and completed by hand.

  3. Obtain a Transmittal Form and Number

    A unique Transmittal Number is needed for each application you submit to MassDEP.

  4. Look up the Permit Application Fee

    See page 6 of the fee schedule below.

  5. Mail your Application and Fee Payment

    Submit fee and one copy of the MassDEP Transmittal Form to:

    Department of Environmental Protection
    P. O. Box 4062
    Boston, MA 02211

    For WP 66a:

    Send 2 copies of the application form to the Title 5 Permitting Program at the appropriate MassDEP Regional Office (see listing below).

    For WP 66b:

    Send 2 copies of the application form to:

    Department of Environmental Protection
    Title 5 Permitting Program
    One Winter Street
    Boston, MA 02108



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