Sourced from published county fee schedules (Multnomah via the City of Portland, effective July 10, 2026; Marion, effective July 1, 2026; North Central Public Health FY2026–27; Deschutes FY2026; Washington County; Clackamas County), Oregon DEQ’s onsite program fee notice, OAR 340-071-0140, and dated third-party reports individually attributed below — last checked August 2026.
Start here: the number most people find first is wrong
Search for what a septic system costs in Portland and you will land on an aggregator page. As of its August 4, 2026 update, Angi puts septic installation in Portland at $5,449 to $8,957, average $7,203.
Now open Multnomah County’s own fee schedule, effective July 10, 2026. A site evaluation is $2,198. A standard system installation permit is $3,126.
We are not saying the real number is higher by some specific amount, because we do not know the real number and neither does anyone else publishing one. We are saying the most-quoted figure for Oregon’s largest metro is arithmetically impossible on that county’s own schedule.
What Oregon actually publishes: permit fees
This is the part with real numbers behind it. Every contract county sets its own schedule under OAR 340-071-0140(9)(a), and the spread is large. These are the schedules we have been able to retrieve and date.
| County / office | Schedule dated | Site evaluation | Standard system permit | Sand filter |
|---|---|---|---|---|
| North Central Public Health Sherman · Wasco |
FY2026–27 | $913 | $1,084 | $1,856 |
| Marion | July 1, 2026 | $1,098 | $1,298 | $2,058 |
| Deschutes | FY2026 | $1,264 | $1,794 | $2,886 |
| Washington | November 1, 2025 – June 30, 2026 — expired | $1,184 | $1,474 | $2,499 |
| Clackamas | undated “2025” | $1,696 | $1,825 | $2,425 |
| Multnomah via City of Portland |
July 10, 2026 | $2,198 | $3,126 | — |
| DEQ statewide Curry · Jackson · Josephine |
July 1, 2021 — superseded | $700 | $1,038 | $1,566 |
Same system, same statewide rulebook: $1,084 in Sherman or Wasco, $3,126 in Multnomah. Nothing about the property explains that. It is which desk you apply to.
• Washington County’s schedule expired on June 30, 2026. The figures are the last ones published; the current ones are not posted.
• Clackamas publishes no effective date. Two of its schedules disagree with each other. We show the higher pair and flag both as undated.
• The DEQ row is out of date and DEQ knows it. See below — it is the single most misleading number in Oregon septic right now.
Get Free Quotes From Local Septic Pros
Three fields, about fifteen seconds. No cost and no obligation.
We pass your request to licensed local companies so they can quote you directly. Your details are never published or sold on.
DEQ’s own posted fee table is wrong by a third
DEQ states plainly on its program page: “DEQ Onsite Program fees increase 33%, effective July 1, 2026, as authorized by the Oregon State Legislature and approved by the Environmental Quality Commission.” The increase is a 3% annual adjustment plus a 30% recalibration, with the Environmental Quality Commission delegating adoption to the DEQ Director on January 15, 2026.
The fee table still sitting at DEQ’s own canonical URL says it runs “from August 1, 2020, through June 30, 2021” and “takes effect on July 1, 2021.” We could not find a post-July-2026 statewide table published anywhere.
So if you live in Curry, Jackson or Josephine — the three counties DEQ permits directly — the numbers in our table above are the 2021 ones, and your actual fees are approximately a third higher. We are showing them because they are what DEQ publishes, not because they are current. Call the DEQ Medford office on 541-776-6010 before you budget.
The one fee that is the same everywhere
Under OAR 340-071-0140(10)(a), DEQ and every contract county must levy a surcharge on each site evaluation, report, permit and other application-based activity. It is the only genuinely statewide septic number in Oregon.
| Surcharge | In effect from |
|---|---|
| $100 | July 1, 2021 |
| $117 | August 1, 2024 |
| $159 | on or after July 1, 2026 |
The surcharge does not apply to pumper truck inspections, annual report evaluation fees, or installer and maintenance-provider certification.
One figure we are deliberately not publishing: a “$120 statewide surcharge” appears on one undated county schedule. It conflicts with the $117 figure carried by two dated sources. One of them is stale and we cannot tell which, so we are not treating $120 as a statewide number.
What the system itself costs — and why we will not give you one number
Permit fees are the part Oregon publishes. The installed cost is the part it does not. We searched state agencies, OSU Extension and the conservation districts specifically for a current dated figure and found none.
What exists is a scatter of figures from different years, different system types and different kinds of source. Here is all of it, with what is wrong with each one stated next to it. None of these is a quote and none should be treated as one.
| Figure | What it covers | Source | Why to be careful |
|---|---|---|---|
| $18,000–$22,000 | Orenco AX-20 with bottomless sand filter, installed | Deschutes County Community Development | Undated. A specific engineered configuration, not a typical system |
| $6,000–$16,000 | Advanced treatment retrofits, varying by model | Deschutes County Community Development | Undated. Retrofit, not new install |
| $7,000–$16,000 | Conventional system upgrade | Deschutes County report, 2025 | The report itself says this is a 2008 figure. Quoted in 2025, priced in 2008 |
| $18,000 plus $2,000 inspection | Full replacement to code, Coos Bay | Craft3, January 28, 2026 | Dated and recent — but one homeowner, not a survey |
| “a $30,000 project” | Cited as out of reach for the homeowner | Legislative testimony, January 21, 2025 | Advocacy context; no breakdown given |
| $25,000–$65,000 | Repair and replacement | Oregon Capital Chronicle, November 9, 2021 | Unattributed in the article. No underlying source given, and five years old |
| $45,000 | Ceiling on a single bid | Clackamas Soil & Water Conservation District | Not a price — but a public body chose that ceiling, which says something about the top of the real range |
Read that table as a range of uncertainty, not a range of prices. The honest summary is that a straightforward gravity system on good soil sits well below an engineered or sand-filter system on difficult ground, and that the gap in Oregon is wide enough that a statewide average would mislead almost everyone who read it.
What actually drives your number
Soil and site, decided before you get a price. The site evaluation determines what the agent will permit. A property that passes for a standard gravity system and one that needs a sand filter or an advanced treatment unit are not the same project, and the fee schedules show the difference: in every county above, the sand filter permit alone costs roughly double the standard permit.
Which county you are in. Not for the rules — those are identical statewide — but for the fees, which vary 2.9×. If you are unsure which office issues your permit, check who handles your county; in fourteen counties it is a shared office, and in six it is one counter in Burns.
Site-specific requirements the agent can impose. Under OAR 340-071-0130(1), if the agent judges the minimum standards inadequate for your particular site, they must require something more protective — and must give you written reasons why. That written statement is worth asking for: it tells you exactly what is driving your cost, and it creates a record you can question.
Get an actual price for your property
The only number that means anything is a quote against your own site evaluation. We can put you in touch with licensed local installers who work in your county. There is no cost to you.
Before you budget for the full amount — grant and loan programs exist for septic repair and replacement. See what help is available in Oregon.
Need Help With New Installation?
Tell us what’s going on and we’ll connect you with a licensed Oregon provider. Free, and no obligation.
Independent — not affiliated with the Oregon Department of Environmental Quality or any county health department, and not a septic contractor.
Frequently Asked Questions
How much does a septic system cost to install in Oregon?
No Oregon state agency, university extension service or conservation district publishes a current dated installed cost, and we are not going to invent one. What is published is permit fees, which run from about $1,084 to $3,126 for the same standard system depending on county.
Why are online septic cost estimates for Portland unreliable?
Because they are smaller than the county’s own paperwork. One widely-cited aggregator puts Portland installation at $5,449 to $8,957. Multnomah County’s site evaluation ($2,198) plus its standard installation permit ($3,126) come to $5,324 before any work begins.
What drives the cost of an Oregon septic system?
Mainly the site evaluation result, which decides what system type can be permitted. A sand filter permit costs roughly double a standard system permit in every county schedule we retrieved. Which county you are in matters too, because fees vary about 2.9 times.
Does a maintenance contract add ongoing cost?
Yes, for some systems. Under OAR 340-071-0132 a pressurized distribution system or residential sand filter permitted after January 1, 2014, and any recirculating gravel filter or advanced treatment unit regardless of age, must carry a perpetual maintenance contract.