Whatcom County ROSS and Skagit County transfer rules, side by side
Two neighboring counties, two separate rules. Whatcom County requires a current Report of System Status, a ROSS, on file when a home is offered for sale, produced by an Operations and Maintenance Specialist licensed by the county. Skagit County requires an operation and maintenance inspection by a certified specialist before a property transfer, written into county code. Neither county's paperwork or timing substitutes for the other's.
What does Whatcom County require when a home goes on the market?
A current report on file with the county, before the listing rather than before the closing. Whatcom County Health and Community Services states it as: "When a property is offered for sale, a current inspection report, called a 'Report of System Status' (ROSS), must be on file with the Whatcom County Health and Community Services." Whatcom County Health and Community Services, Operation and Maintenance (checked 2026-08-03).
The timing is the part sellers miss. "Offered for sale" is earlier than "under contract" and much earlier than "closing". A Whatcom County seller who waits for an accepted offer before thinking about the septic system has already passed the point the county describes. If the last evaluation on file has aged out, the ROSS becomes a listing task, not a closing task.
Who is allowed to perform a Whatcom County ROSS evaluation?
An Operations and Maintenance Specialist licensed by Whatcom County. The county is explicit that an Operations and Maintenance Specialist licensed by the county. A homeowner may not evaluate their own system when the evaluation is for a sale or property transfer. That closes the door on the most common cost-saving idea a seller has, and it closes it for a reason: the report is the county's evidence, and evidence written by the party who benefits from a clean result is not evidence.
Washington has no single statewide septic license, so "licensed" here means licensed by Whatcom County for this specific work. A contractor certified in Snohomish County for operation and maintenance is not automatically the right person for a Bellingham or Lynden property. Ask which county issued the credential, every time. The Whatcom County septic page collects what the county requires in one place.
How often does Whatcom County require an evaluation between sales?
Evaluations are required every three years for a conventional gravity system and once a year for every other type. Whatcom County Health and Community Services, Operation and Maintenance (checked 2026-08-03).
In practice that splits Whatcom County properties into two groups. A conventional gravity drainfield is on a three year rhythm. Everything else, which in this part of the state means most mound systems, pressure distribution systems, sand filters, and anything with a pump, is on a yearly one. If you own a pumped system and you keep the yearly evaluations current, the sale requirement mostly takes care of itself. If you have let them lapse, the sale is what surfaces it. The operation and maintenance page covers that recurring cycle and who has to sign it off.
What does Skagit County require before a property transfer?
An operation and maintenance inspection by a certified specialist. In Skagit the requirement sits in county code rather than on a county web page, at Skagit County Code 12.05.160(2):
"Before any property transfer, an operations and maintenance inspection must be completed by a certified O&M specialist, except when a complete O&M inspection has been conducted within six months prior to the property transfer by a certified O&M specialist."
Skagit County Code 12.05.160(2) (checked 2026-08-03)
Read the second half of that sentence, because it is something Whatcom does not offer: an inspection done in the six months before the transfer already satisfies it, so a recent one can carry the sale. A Skagit seller who has kept up with maintenance may already be done.
Who you can call is a narrower question here than it looks. Skagit certifies its own installers, pumpers, and operation and maintenance specialists, and it runs the inspection credential at two levels. A Level 1 provider is certified to inspect conventional gravity, conventional pressure distribution, and gravity with pump systems. A Level 2 provider covers the other public domain types, which is where mound and sand filter systems sit, plus proprietary and alternative systems. A mound system therefore needs a Level 2 provider. Skagit County Code 12.05.030 and 12.05.230 (checked 2026-08-03). One more Skagit rule runs outside sales entirely: A system with a proprietary treatment product has to be inspected every year by a certified operations and maintenance specialist, separately from anything a sale triggers.
One Skagit figure is still missing here, and it is the fee. Skagit sets its fees by resolution rather than in the code, in a document called the Schedule of Charges, so the current amount comes from the health department rather than from the code text. If you are selling in Mount Vernon, Burlington, Sedro-Woolley, Anacortes, or anywhere else in the county on an on-site system, get the amount from Skagit County Public Health rather than from this page. The Skagit County septic page covers the rest of the process.
The two counties side by side
| Question | Whatcom County | Skagit County |
|---|---|---|
| What the sale triggers | A current Report of System Status (ROSS) on file with the county | An operation and maintenance inspection before the transfer |
| When it bites | When the home is offered for sale | Before the property transfer, unless a certified specialist completed a full inspection in the six months before it |
| Who performs it | An Operations and Maintenance Specialist licensed by the county. Never the homeowner, for a sale | A certified operations and maintenance specialist, Level 1 or Level 2 depending on the system. Never the homeowner, for a sale |
| Routine cycle between sales | Three years for conventional gravity, yearly for all other types | Yearly for a system with a proprietary treatment product. The county adopts the state schedule for the rest |
| Where the code sits | Published by the county health department | Skagit County Code 12.05.160(2) |
| The fee | Not published here. Ask the county | Set by resolution in the county Schedule of Charges, so the amount comes from the health department |
| Health authority | Whatcom County Health and Community Services, Bellingham | Skagit County Public Health, Mount Vernon |
Two cells still say to ask the county, and both are fees. Neither county publishes an amount this site has been able to read at the source, so neither gets a figure here. That is a gap in what has been verified, not a gap in what the counties require.
Why you cannot borrow one county's answer for the other
Because on-site sewage rules in Washington are administered county by county. Each health jurisdiction writes its own transfer process, issues its own credential to the people who perform the work, and sets its own maintenance cycle. A Whatcom ROSS is not a Skagit inspection. A Snohomish County Report of Property Transfer is neither of them.
This matters most for two groups. Sellers who have moved within the North Sound and assume the process is the one they remember from the last house. And agents working across county lines, where a checklist built for one county quietly misses a step in the next. If you are comparing all three, the North Sound transfer inspection guide lays them out together with the source behind each line.
Does the 2027 statewide rule change either county?
It adds to them rather than replacing them. Washington rule WAC 246-272A-0270 requires a transfer inspection statewide beginning February 1, 2027, by a third party inspector authorized by the local health officer. Read WAC 246-272A-0270 (checked 2026-08-03). Before that date, what applies in Whatcom or Skagit County is the county's own requirement.
The state rule also sets the between-sales schedule at at least once every three years for a basic septic tank and drainfield system, and once a year for every other type of system, unless the local health officer requires it more often. Whatcom County's published cycle already lines up with that shape, which is one reason a Whatcom seller who has kept up with evaluations tends to have less to do than a seller in a county that is only now adding a transfer step. The transfer inspection service page covers what the visit involves in either county.
Common questions
What is a ROSS in Whatcom County?
A Report of System Status. Whatcom County Health and Community Services requires a current one on file when a property is offered for sale, and it is produced by an Operations and Maintenance Specialist licensed by the county.
Can a Whatcom County homeowner do their own evaluation for a sale?
No. The county states that a homeowner may not evaluate their own system when the evaluation is for a sale or property transfer. It has to come from an Operations and Maintenance Specialist licensed by the county.
Does Skagit County use the same form as Whatcom County?
No. Skagit County Code 12.05.160(2) requires an operation and maintenance inspection by a certified specialist before a property transfer, with an exception where a complete inspection was already done in the six months before it. The ROSS is Whatcom paperwork, it does not satisfy Skagit, and neither county's timing applies to the other.
How often does Whatcom County want the system evaluated between sales?
Every three years for a conventional gravity system and once a year for every other type, according to Whatcom County Health and Community Services. A sale can pull an evaluation forward, because the report on file has to be current when the home is offered.
Check your septic transfer requirements in the North Sound
Every figure below links to the county or state page it came from, so you can confirm it yourself rather than take our word for it.
The statewide rule that arrives February 1, 2027
Washington rule WAC 246-272A-0270 adds a property transfer inspection statewide beginning February 1, 2027. It has to be done by a third party inspector the local health officer authorizes. Between sales, the same rule sets the routine schedule: at least once every three years for a basic septic tank and drainfield system, and once a year for every other type of system, unless the local health officer requires it more often. Read WAC 246-272A-0270 (checked 2026-08-03).
What your county requires now
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Snohomish County
Selling a Snohomish County home on a septic system requires a Report of Property Transfer reviewed by the health department before closing.
In force from November 1, 2026.
Who can do it: a certified septic contractor
Who is responsible: the seller.
Timing: 12 months from the date the health department accepts it.
If the county has no as-built record of the system, a certified septic contractor must draw an On-Site Sewage System Site Plan and it is submitted with the application.
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Skagit County
Skagit County requires an operation and maintenance inspection by a certified O and M specialist before any property transfer, unless one was already done in the six months before it.
Who can do it: a certified operations and maintenance specialist
Timing: an inspection done in the six months before the transfer already satisfies it, so a recent one can carry the sale.
A system with a proprietary treatment product has to be inspected every year by a certified operations and maintenance specialist, separately from anything a sale triggers.
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Whatcom County
A Whatcom County home offered for sale must have a current Report of System Status, a ROSS, on file with the county.
Who can do it: an Operations and Maintenance Specialist licensed by the county. A homeowner may not evaluate their own system when the evaluation is for a sale or property transfer.
Timing: evaluations are required every three years for a conventional gravity system and once a year for every other type.
How to check the contractor yourself
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Check the county certification for the work you need
A transfer inspection has to be done by a specialist the county health department certifies for operation and maintenance work. Installing a replacement system is a separate certification. Ask which one the contractor holds, and for which county.
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Check the contractor registration with Washington Labor and Industries
Every contracting business working in Washington must be registered with L and I, which is a bond and insurance filing rather than a skills exam. You can look up the registration and see whether the bond is active. Verify a contractor at lni.wa.gov
Three questions worth asking before you hire
- Which county certification do you hold, and does it cover the work my sale actually needs?
- Is the report you produce the one my county health department accepts, and do you file it or do I?
- If the system fails, what are my options, and are you certified to do that repair or replacement too?
Find out what your county actually requires
Tell us the county and what the property needs. We pass it to one local septic contractor certified by that county health department.
Your request goes to one independent local septic contractor certified by your county health department, serving Snohomish, Skagit, or Whatcom county. It does not go to a national lead list.