The City of Portland has an intergovernmental agreement with Multnomah County and the State of Oregon Department of Environmental Quality (DEQ) to serve as the regulatory agency overseeing the administration of DEQ’s On-Site Wastewater Treatment Systems Rules, commonly referred to as Oregon septic code, for all of Multnomah County.
The City of Portland reviews projects that may impact septic systems in the City of Portland, City of Gresham, City of Maywood Park, City of Troutdale, City of Fairview, Corbett, Cascade Locks, Scappoose, and unincorporated Multnomah County.
Required and important septic evaluation forms
Types of septic evaluations
The City of Portland reviews any proposed development or partitioning of properties that utilize septic systems. This includes interior and exterior development of existing homes or structures, replacement dwellings, property line adjustments, and land divisions. If someone wants to develop a vacant lot that will need a septic system, the first step is to obtain septic approval with a Site Evaluation Report.
Septic Review Certification: The Septic Review Certification process verifies that the proposed development will not impact the septic system or replacement drainfield area by reviewing for minimum setbacks from septic tanks and drainfields. It is required when any of the following are proposed:
- Change in footprint of existing structures (additions, decks, patios)
- Grading, paving, or retaining walls
- New structures (pole barns, sheds, garages, replacement dwellings)
- Any interior remodel that adds basement-level plumbing or bedrooms
- Any newly created parcel(s)/lots(s) including Property Line Adjustments and Land Divisions
Authorization Notice: An Authorization Notice is a written document issued by City of Portland Septic Sanitarians that determines whether an existing septic system appears adequate for its intended use. An Authorization Notice is required when any of the following are proposed:
- Adding one or more bedrooms
- Increasing employees in a commercial business or adding showers for employees
- Any other increase in projected daily sewage flow to a septic system
- Reconnection to a septic system (e.g. replacement dwelling)
- Use a septic system that was installed more than 5 years ago and never used
- Hardship dwellings as approved under local zoning and land use planning regulations
A site visit is required for an Authorization Notice if the system is greater than ten years old or if a sand filter, alternative treatment technology, or pressure distribution system has been used.
If any part of the septic system is determined to be inadequate for the proposed use, an Alteration or Repair Septic Installation Permit will be required.
An Authorization Notice may not be issued if the proposal increases the projected daily sewage flow by more than 300 gallons above the design capacity of the existing system or by more than 50% of the design capacity of the existing system. If the proposal meets either of these criteria, an approved Site Evaluation and New Construction Septic Installation Permit is required.
Site Evaluation Report: The Site Evaluation Report Process is a report on the evaluation of a site to determine whether it is suitable for a septic system. The City of Portland Septic Sanitarians look at soil test pits in the proposed primary and replacement drainfield areas to evaluate the soil conditions along with the property characteristics to determine if the site is suitable for a septic system and, if so, what type of system. Additional guidance for test pit location and the Site Evaluation Report process may be found on DEQ’s website. If a repair drainfield is needed and there is not an approved Site Evaluation Report for the property with soil notes, a Repair Site Evaluation is required.
How to get a signed Septic Review Certification
For a Septic Review Certification application, you'll need the following items in the septic evaluation submittal packet:
- Scaled legible site plan showing all existing and proposed development, septic tank, primary and replacement septic drainfields, private well (if applicable), property lines, and any notable property characteristics such as streams, retaining walls, decks, pasture, etc.
- The site plan must include the proposed stormwater disposal facility and location for any new impervious surface over 500 sq ft. Please contact Multnomah County Land Use Planning for more information regarding the engineered stormwater requirement.
- Floor plans for each level of the home or structure with room identification for additions and interior remodels; hand drawn is sufficient
- Floor plans for any proposed accessory structures
- A Septic Review Certification form with Step 1 completed
- A completed Septic Evaluation Application
- A completed Authorized Representative Form if the applicant is someone other than the property owner
Please note all required Septic Review Certification submittals are listed on page 2 of the Septic Review Certification Form and the front and back of the Septic Evaluation Application.
All submitted items will be reviewed and compared to any septic records we may have for the property to determine whether the proposed development meets required setbacks in septic code. The Septic Sanitarian may request a site visit to confirm the location of the septic system components and whether required setbacks to the proposed development are met. For the site visit, it may be requested to have the septic tank and distribution unit(s) uncovered or the drainfield lines field located and flagged out. For new construction, a stakeout of the primary and replacement drainfields may be requested.
How to get an Authorization Notice
For an Authorization Notice application, you'll need the following items in the septic evaluation submittal packet:
- Scaled legible site plan showing all existing and proposed development, septic tank, primary and replacement septic drainfields, private well (if applicable), property lines, and any notable property characteristics such as streams, retaining walls, decks, pasture, etc.
- The site plan must include the proposed stormwater disposal facility and location for any new impervious surface over 500 sq ft. Please contact Multnomah County Land Use Planning for more information regarding the engineered stormwater requirement.
- Floor plans for each level of the existing home or structure with room identification – hand drawn is sufficient
- Floor plans for each level of the proposed home or structure with room identification – hand drawn is sufficient
- Floor plans for any proposed accessory structures
- An Existing System Evaluation Report (ESER) completed by a DEQ-certified septic professional. See the ESER Fact Sheet about the process.
- For an Authorization Notice with Site Visit, the septic tank will need to be pumped and a report on the condition of the tank will be required, along with a copy of the pump receipt. For the site visit:
- All distribution unit(s) will need to be uncovered
- All drainfield lines will need to be field located and flagged out
Note: If replacement of the septic tank is part of the project proposal, the tank does not need to be pumped or have an ESER completed.
- For an Authorization Notice without Site Visit, the septic tank will need to be pumped and a report on the condition of the tank will be required, along with a copy of the pump receipt. All eight pages of the ESER form must be completed, including comments on the drainfield type and condition.
Note: Please contact 503-823-6892 or septic@portlandoregon.gov for assistance determining whether a site visit is required.
- For an Authorization Notice with Site Visit, the septic tank will need to be pumped and a report on the condition of the tank will be required, along with a copy of the pump receipt. For the site visit:
- A Septic Review Certification form with Step 1 completed (if in unincorporated Multnomah County)
- A completed Septic Evaluation Application
- A completed Authorized Representative Form if the applicant is someone other than the property owner
Please note all required Authorization Notice submittals are listed on the front and back of the Septic Evaluation Application.
All submitted items will be reviewed and compared to any septic records we may have for the property to determine whether the proposed development meets the required setbacks in septic code (download pdf and see Table 1). Once the development plans are approved, the Site Visit will be conducted. If you are in unincorporated Multnomah County, pending an approved site visit, the Septic Review Certification will be signed. Please note that in order to obtain Septic approval for the final building permit either the Authorization Notice must be issued or any required Septic Installation Permit must be issued. Both an issued Authorization Notice and an issued Septic Installation Permit require Multnomah County Land Use Planning approval or approval from the relevant jurisdiction if in an incorporated area for the proposed development.
How to get a Site Evaluation Report
For a Site Evaluation Report application, you’ll need the following items in the septic evaluation submittal packet:
- Scaled legible site plan showing all existing development, existing septic system (if applicable), private well (if applicable), property lines, utilities, and any notable property characteristics such as streams, man-made cuts, etc.
- The site plan must include the locations of 3 test pits (new construction) or 1-2 test pits (repair). Each test pit must have a measured distance to two property lines or fixed points, and the distance to the nearest test pit. Please see below for sample test pit site plan.
- Test pits should be approximately 75 feet apart and represent the proposed primary and replacement drainfield areas. The primary and replacement drainfield areas should not have any other development planned in these areas. Test pits should represent the lower and upper slope positions the drainfield lines may encompass and anything that may change on contour (e.g. swale, mound, etc).
- All test pits must be 3 x 3 x 5 feet deep and stepped or sloped for safe access for the Septic Sanitarian. Please see below for sample test pit preparation.
- A completed Septic Evaluation Application
- A completed Authorized Representative Form if the applicant is someone other than the property owner
Please note: All required submittals are listed on the front and back of the Septic Evaluation Application.
Once a complete application is received, the Septic Sanitarian will contact you to schedule the Site Evaluation. Provided there is access to the site and the test pit locations are obvious, no one needs to be present to meet the Septic Sanitarian for the Site Evaluation. After the initial Site Evaluation has been completed, the Septic Sanitarian will either complete the Site Evaluation Report or request additional test pits. Reports may take up to two weeks to be completed after the test pits are evaluated.
Who can do the work
- A trade license or other registration is not required to prepare plans and apply for a Septic Review Certification, Authorization Notice, or Site Evaluation.
- A trade license or other registration is not required to uncover septic system components or dig soil test pits. Locates must always be called for prior to any excavation.
- A certified septic professional must complete an Existing System Evaluation Report for an Authorization Notice.
- A licensed and/or certified septic professional can be of assistance when planning where to locate soil test pits and a septic system and in locating any septic system components and preparing site plans.
How to submit your completed application
Submit the completed application package that includes all items on the checklists above (also listed on the front and back of the Septic Installation Application) one of two ways:
- Via email to septic@portlandoregon.gov. Once a complete application is received, an evaluation 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.
- Via mail to: 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, an evaluation 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 a minimum of 20 working days for review. You will be notified of the status by either a checksheet (formal request for revision), contact to schedule a site visit, or a signed Septic Review Certification.
Checksheets will be sent to 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 checksheet within 90 days. New fees will apply.
All documentation will be sent to the applicant and property owner.
A vacant piece of land through construction
This section summarizes the septic steps needed to take a vacant piece of land in unincorporated Multnomah County through construction.
Step 1: Research the zoning on the property with Multnomah County Land Use Planning.
Step 2: Consider future development on the property and where all the components could be placed.
Step 3: Decide the best place for the primary and replacement drainfield area. A septic professional can assist with this. Dig at least three test pits. Apply for a Site Evaluation Report. Note: Do not dig test pits for new construction in National Scenic Area without contacting Multnomah County Land Use Planning.
Step 4: Obtain an approved Site Evaluation Report. Use the report to locate and size the septic system.
Step 5: Create the building permit-level site plan with all proposed development: house/structures, garage, accessory building, driveways, well and/or water line, engineered stormwater disposal, etc. Create floor plans. Submit for a Septic Review Certification.
Step 6: Obtain a signed Septic Review Certification. Submit plans to Multnomah County Land Use Planning.
Step 7: Obtain final Building Permit Approval via a signed Building Permit Review Form from Multnomah County Land Use Planning.
Step 8: Submit for a Septic Installation Permit with the signed Building Permit Review Form that demonstrates approval from Multnomah County Land Use Planning.
Step 9: Obtain an issued Septic Installation Permit. Once the septic permit is issued, the Septic Sanitarian will sign the Building Permit Review Form for the City of Gresham or approve the Residential Subsurface Review Line on a City of Portland Building Permit.
Step 10: Have septic system installed per permit conditions and request a precover inspection. Receive an approved septic inspection. Receive approved trade permits (plumbing for sanitary line and electrical if needed). Receive a septic permit final (Certificate of Satisfactory Completion) prior to Certificate of Final Occupancy.
Septic installation permits in Multnomah County
Learn more about septic installation permits in Multnomah County.
Contact septic sanitarians
If you have questions about septic evaluations, please call the Onsite Septic Permits and Inspections phone number at 503-823-6892.