Septic Permits: New Construction, Repairs, and Alterations

Properties use septic systems for sanitary disposal if they do not have physical or legal access to a public sewer. Learn about applying for septic permits for new construction, alteration and repairs in Multnomah County. Get the application forms and information about septic installation permits.

Application forms updated on Aug 1, 2024, reflect the Oregon DEQ Surcharge fee increase.
The DEQ Surcharge Fee increase is a one-time fee increase of approximately 14% in addition to the broader 3% fee increase. Visit DEQ for more info.

Required and important septic installation permit application forms

Types of septic installation permits

Septic Installation Permits are for new construction, repair of existing septic systems, or alteration of existing septic systems. Repairs and alterations can be done in septic tanks only and/or drainfields. Repair and alteration of drainfields and all new construction require an approved Site Evaluation Report (also referred to as soil test pits, land feasibility study, or “perc test”). Please refer to the Septic Evaluation Page for additional information.

Repair Permits: Installation of all portions of an existing septic system necessary to eliminate a public health hazard (failed septic system)

• Minor Repair Permit: Required to replace an existing septic tank or distribution unit. Required when a property owner replaces a broken effluent sewer (solid pipe outlet of the septic tank).
• Major Repair Permit: Required to replace the septic drainfield, soil absorption area, a sand filter / alternative treatment technology unit, or any part of these components. Replacing a septic drainfield or soil absorption area requires an approved Site Evaluation Report. System types can include standard, capping fill, and alternative treatment technology/sand filter (see below).

Alteration Permits: Voluntary expansion or change in location of an existing septic component or system

• Minor Alteration Permit: Required to relocate or move an existing septic tank, distribution unit, or effluent sewer.
• Major Alteration Permit: Required to alter or move the septic drainfield, soil absorption area, or a sand filter / alternative treatment technology unit. Altering a septic drainfield or soil absorption area requires an approved Site Evaluation Report. System types can include standard, capping fill, and alternative treatment technology/sand filter (see below).

New Construction Permits: Installation of a new septic system on a vacant parcel or an alteration to an existing septic system that exceeds the existing system design capacity by more than 300 gallons per day or 50%. System types can include standard, capping fill, and alternative treatment technology/sand filter (see below).

• Standard System: septic system with a septic tank, distribution unit(s), and drainfield. The septic tank may include a pump (requires an additional pump evaluation fee), but the drainfield is gravity flow.
• Capping Fill: septic system with a septic tank, distribution unit(s), and drainfield with a shallower trench depth (minimum 12”) and a soil cap of a specified depth and texture. The septic tank may include a pump (requires an additional pump evaluation fee), but the drainfield is gravity flow.
• Alternative Treatment Technology (ATT)/Sand Filter: septic system with a septic tank, ATT unit or sand filter, and a soil absorption area (typically a drainfield). ATTs/Sand Filters pre-clean the septic effluent from a septic tank before it reaches the drainfield, reducing total suspended solids and biochemical oxygen demand. Higher treatment standards also reduce fecal coliform and total nitrogen. This type of septic system may be required for some soil/groundwater conditions and/or slope percentages. This type of septic system reduces the required drainfield lineal footage by approximately ½ to 2/3 and can also be useful for meeting development and septic requirements on small and/or constrained lots.
• There are other less common types of septic systems including pressure distribution, seepage trenches, steep slope systems, and seepage pits (repairs only).

What you need to get a septic permit

For new construction permits, repair septic permits and alteration permits you'll need the following items in the septic permit submittal packet:

• Scaled legible site plan showing all existing and proposed development, proposed septic system, designated replacement drainfield area, private well (if applicable), water line, property lines, and any property characteristics that require setbacks (streams, retaining walls, utilities, etc)
• Product specification sheets for the septic components that will be installed, e.g. septic tank, drainfield media with max/min trench depth, ATT unit, etc. All products must be approved by DEQ.
• Elevations of the following relative to the ground surface over the septic tank:
  • Top of the septic tank
  • Invert of the septic tank outlet
  • Invert of the header pipe of each drainfield line
  • Beginning, middle, and end elevations of each drainfield line (if installing a drainfield under a Major Permit)

  Please note: All required submittals are listed on the front and back of the Septic Installation Application.

  Who can do the work

  • A certified septic installer working for a DEQ-Licensed Onsite System Installer Business is required to construct and install the septic system with an issued septic installation permit. DEQ keeps a list of licensed installer businesses (search by county, including neighboring counties).
  • Alternatively, the property owner or the property owner's regular employee may construct or install a septic system with an issued septic installation permit.

  How to submit your completed application

  Submit the completed application package that includes all items on the checklist above (also listed on the front and back of the Septic Installation Application) one of two ways:

  1. Via email to septic@portlandoregon.gov. Once a complete application is received, a permit number will be set up and information to pay online will be provided. Once payment is provided the project will be put in a queue for review.
  2. Via mail to: City of Portland Permitting & Development, Site Development, 1900 SW 4th Ave., Portland, OR 97201. Once a complete application is received with a check payable to City of Portland, a permit number will be set up and put in a queue for review. Please refer to the current Septic Installation Application for fees.

  Plan review process and checksheets

  Allow 20 working days for review. You will be notified of the status by either a checksheet (formal request for revision) or an issued permit.

  Checksheets will be sent to the applicant and property owner requesting additional information and/or plan revisions if corrections are required. Third and subsequent checksheets will require an additional fee.

  Applications will be cancelled if no response to the checksheet is received within 90 days. New fees will apply.

  An issued permit will be sent to the applicant and property owner and will include a permit description page and all relevant installation plans and specification sheets.
  

  Septic permit inspections

  Please note: We inspect in east county (east of the Willamette River) on Wednesdays and Fridays and in west county (west of the Willamette River) on Tuesdays and Thursdays.

  To schedule an inspection, call the automated inspection request line. Instructions are located at the bottom of your issued permit page. You will need your IVR or permit number and the three-digit code for the inspection. A septic tank inspection is code 836 and a drainfield is code 814. You will receive a call with the time window for the inspection.
  

  Septic inspection results and corrections

  Get the results of the inspection on Portland Maps permit/case search the next day.

  There may be some reasons why the work did not get approved:

  • no access - the inspector may not have been able to inspect the work
  • incomplete work
  • code violations

  The inspector will list the corrections needed on the inspection report.

  Please note for all septic tank permits an approved Plumbing inspection for the sanitary line is required before the septic permit is final. If a pump is required, an approved Electrical inspection is required for both the underground trenching and the septic panel with circuits pulled from the house before the septic final.

  Call for a reinspection after making the corrections. Use the same three-digit inspection code.

  If you make the corrections the same day, please wait until 5 p.m. to request a reinspection. The inspector needs to enter their results before you can schedule the reinspection.

  There is a reinspection fee charged for more than one reinspection for a single issue.
  

  Septic decommissioning permits in Multnomah County

  Learn more about septic decommissioning permits in Multnomah County.
  

  Contact septic inspectors

  If you have questions about septic inspections, please call the Onsite Septic Permits and Inspections phone number at 503-823-6892.

  Additional resources and information

  The City of Portland has an intergovernmental agreement with Multnomah County and the State of Oregon Department of Environmental Quality (DEQ) to conduct septic permitting and inspections for all of Multnomah County, including the City of Portland, City of Gresham, City of Maywood Park, City of Troutdale, City of Fairview, Corbett, Cascade Locks, and Scappoose.

  The City of Portland is the regulatory agency overseeing the administration of DEQ’s On-Site Wastewater Treatment Systems Rules, commonly called septic systems, for Multnomah County.

  • DEQ database of licensed installer businesses
  • DEQ-approved septic tanks
  • DEQ-approved drainfield products
  • DEQ-approved Alternative Treatment Technologies
  • DEQ Hydrosplitter Fact Sheet
  • DEQ Required Setbacks: OAR 340-071-0220 Tables 1-9
  • DEQ septic tank maintenance guidance
  • DEQ Septic System Do’s and Don’ts
  • DEQ Septic Systems: How They Work