Side sewer permits in City of Mercer Island: fees, timeline & requirements (2026)
Everything you need to know about pulling a side sewer permit in City of Mercer Island, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Apply via MyBuildingPermit.com..
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to City of Mercer Island's source.
When does a side sewer need a permit in City of Mercer Island?
The side-sewer permit is issued by whichever utility owns the sanitary sewer — the city, a sewer or water district, or a regional utility — under that utility's own code, with WAC 51-56 (2021 UPC) governing how the building sewer is laid. WHICH UTILITY IS A PER-PROPERTY FACT: a lot can sit inside a city for permitting and outside its sewer district, so confirm the owner of the main before applying. Triggered by a new connection, repair of more than about 2 ft of pipe, relining (CIPP), or capping at the property line for a demolition.
From City of Mercer Island's own code
“Applicant must obtain all necessary and required permit approvals prior to commencing any construction of a side sewer or any modification of any existing side sewer.”Source ↗verified 2026-09-06
Required submittals
- site plan with sewer line route
- depth + slope detail
- cleanout locations
- utility locate ticket
Inspection sequence
- pre-cover (open trench)
- air / water test
- final
Contractor specialties needed
side-sewer-contractor
Who can do this work in City of Mercer Island?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout City of Mercer Island and King County. Kolmo prepares the drawings and submittals, files the side sewer permit with Apply via MyBuildingPermit.com., carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a City of Mercer Island side sewer quote.
Notes & caveats
Issuing body is the sanitary sewer utility, NOT the building department, and inspection is the utility's too. SOME utilities additionally require the contractor to hold a side-sewer card or registration before they will issue; it is not universal, so check the serving utility's own rules rather than assuming either way.
Side sewer permit fee estimate in City of Mercer Island
Worked example for a $25,000 side sewer project (plumbing permit). Your actual fee scales with project valuation.
| Building permit fee | $300 |
| Plan review | $195 |
| WA state surcharge | $6.5 |
| Estimated total | $501.5 |
Side-sewer permits typically $150-$500; depth-based surcharge in some cities. Utility-issued, not building-permit-issued. Computed from the City of Mercer Island fee bracket schedule · source ↗. Impact/utility fees may apply separately.
How to apply yourself
- 1. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Mercer Island side sewer — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (4).
- 3. Submit through the city portal: Apply via MyBuildingPermit.com. ↗
- 4. Track review (typical: —). Respond to reviewer comments promptly.
- 5. Pay issuance fees (Side-sewer permits typically $150-$500; depth-based surcharge in some cities. Utility-issued, not building-permit-issued.) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
We pull side sewer permits in City of Mercer Island every month. We prepare the drawings and submittals, file with Apply via MyBuildingPermit.com., handle reviewer comments, and build the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Side sewer permits in City of Mercer Island — FAQ
When does a side sewer need a permit in City of Mercer Island?
The side-sewer permit is issued by whichever utility owns the sanitary sewer — the city, a sewer or water district, or a regional utility — under that utility's own code, with WAC 51-56 (2021 UPC) governing how the building sewer is laid. WHICH UTILITY IS A PER-PROPERTY FACT: a lot can sit inside a city for permitting and outside its sewer district, so confirm the owner of the main before applying. Triggered by a new connection, repair of more than about 2 ft of pipe, relining (CIPP), or capping at the property line for a demolition.
How much does a side sewer permit cost in City of Mercer Island?
For a $25,000 side sewer project, the estimated City of Mercer Island permit fee is about $501.5 — building fee $300 + plan review $195 + surcharges. Fees scale with project valuation per the city schedule.