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  3. 3 Water heater AI picture
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What does switching from septic to sewer involve?

Going from septic to sewer means a new side sewer to the public main, city and LOTT connection charges, and a county permit to abandon the old tank. Olympia's 2026 estimates put connection fees alone at $4,442 to $13,527, with a possible 50 percent rebate on LOTT's share. Lacey and Tumwater set their own charges, and the county permits the tank abandonment.

Street to Drainfield · updated · sources listed at the end

Narrow trench on a wooded slope with a white wrapped pipe laid in it, small excavator above
1Narrow trench on a wooded slope with a white wrapped pipe laid in it, small excavator aboveLook for: an open trench and new pipe running toward the main; side sewer work like this runs under a city permit.
Round metal-capped pipe end flush with dry grass, a coin beside it for scale
2Round metal-capped pipe end flush with dry grass, a coin beside it for scaleLook for: a round metal cap on a pipe end in the grass, often a cleanout; keep it visible and uncovered.

Who is LOTT, and where does it fit?

LOTT is the treatment partner. The LOTT Clean Water Alliance is the regional wastewater utility serving Lacey, Olympia and Tumwater, a nonprofit formed and governed by four partners: Lacey, Olympia, Tumwater and Thurston County. Each city runs its own pipes, permits and connection process; LOTT treats the wastewater and charges a capacity development charge that the city collects when you connect.

LOTT also helps converting owners. Its community connections page says it offers partial rebates of the connection fee to property owners who switch from septic to public sewer. LOTT's own rates page redirected away from its site on 6 November 2026, so the charge amounts below are the City of Olympia's published figures, not LOTT's.

What does septic to sewer cost in Olympia?

Olympia's septic to sewer page lists four costs, as approximate 2026 figures:

  • a sewer main in the street, if none reaches you: $8,000 to $103,500;
  • the side sewer from house to main: $6,000 to $30,000;
  • abandoning the septic tank: $2,000 to $3,500;
  • connection fees: $4,442 to $13,527.

The connection fees break down as the LOTT capacity development charge ($3,903 or $7,807), the city wastewater general facilities charge ($0 or $4,646), connection permits ($182 to $717 or more), and the septic abandonment permit ($357). That last figure matches the county's 2026 fee schedule: $340 for an abandonment application not tied to another permit, plus the 5 percent technology fee.

What rebates and waivers does Olympia offer?

Two that matter most. The city waives its general facilities charge if you connect within two years of formal notice that sewer is available, within two years of buying the property, or if you qualify for the LOTT rebate. LOTT's rebate on the capacity development charge is typically 50 percent, with an extra 25 percent for owners who meet hardship criteria, first come, first served. The city's incentive section still quotes 2022 dollar amounts, so ask city staff for the current rebate figure.

Lacey points to the same program. The city's 2026 water report mentions a LOTT rebate of 50 to 75 percent off the connection fee and asks owners to contact Lacey Water Resources. Craft3's Clean Water Loan can, in some cases, finance a connection to a nearby municipal sewer; see paying for septic repair.

Do you have to connect to sewer?

In Olympia, usually not, until something changes. The city says connection is generally voluntary, but if your septic system fails, or you expand the house beyond the system's capacity, it will require connection when your property is within 200 feet of an available sewer. It counts more than 800 septic properties already next to a sewer.

Lacey and Tumwater set their own rules, which are not summarized here. If you live in either city, ask its public works department; for Tumwater, start at the City of Tumwater's website.

What happens to the old septic tank?

It is pumped out one last time, then filled in. The county's abandonment bulletin says a Thurston County certified pumper pumps the tank and fills in a pumper slip, the lid is removed or destroyed, and the tank is filled with earth, sand or gravel; disconnecting the inlet and outlet pipes is recommended. The application, with the pumper slip and fee, goes to the county within five days of finishing. Olympia adds that the new side sewer must be completed, inspected and accepted before the tank is taken out of service.

Treat the open tank as a hazard until it is full. Let your contractor do the work, keep children and pets well away, never leave the opening unattended, and never enter or lean into the tank. Until the switch is done, keep treating the drainfield as live, as drainfield dos and don'ts describes.

Yours to do

  • Check Olympia's sewer lookup map or ask your city whether sewer is near.
  • Ask city staff about the LOTT rebate before you get a permit.
  • Get written quotes that say whether permits, connection charges and abandonment are included.
  • Keep the pumper slip and all permit paperwork.
  • Find out who repairs which part of the new line once it is in.

Leave to a licensed or certified pro

  • A licensed contractor registered with the city builds anything in the right-of-way.
  • A county-certified pumper empties the tank before abandonment.
  • Your contractor fills the tank and disconnects the pipes under the county permit.
  • City inspectors accept the side sewer before the tank goes out of service.

On the record

A store to look at

Olympia requires a side sewer cleanout near the property line, and PlumbingSupplyAndMore's cleanouts and plugs section shows the caps, plugs and cleanout fittings that a contractor's quote may list. The supply house is run by the same team as this site.

Go to PlumbingSupplyAndMore

LOTT explains how it cleans the wastewater from Lacey, Olympia and Tumwater before it returns to Budd Inlet. Video from WET Science Center (LOTT Clean Water Alliance); it loads from YouTube only when you press play.

Common questions

Can my side sewer run through a neighbor's yard to reach the main?

Olympia says a side sewer should connect to the main in the street the property fronts and may not cross an adjacent property, except in some easement cases.

Can I reuse the pipe from the house to the septic tank?

Olympia allows it only if that pipe is at least four inches in diameter; the new side sewer is built the rest of the way to the main.

Will I get a monthly sewer bill after connecting?

Yes. Olympia says connected properties pay a monthly sewer utility bill covering collection, treatment and repairs.

Is the LOTT rebate guaranteed?

No. Olympia describes the funding as limited and first come, first served, so ask before you commit.

Sources

  1. What Is LOTT, LOTT Clean Water Alliance — service area and partners; read 6 November 2026
  2. Community Connections, LOTT Clean Water Alliance — partial connection fee rebates for septic conversion; read 6 November 2026
  3. Switching from a septic system to City sewer, City of Olympia — 2026 cost estimates, rebates, waivers, 200-foot rule; read 6 November 2026
  4. 2026 Water Quality Report, City of Lacey — LOTT rebate mention for Lacey connections; read 6 November 2026
  5. Onsite Sewage System Abandonment, Thurston County — abandonment steps and timing; read 6 November 2026
  6. Environmental Health 2026 Fee Schedule, Thurston County — abandonment application fee; read 6 November 2026
  7. Washington Clean Water Loans, Craft3 — financing sewer connection; read 6 November 2026

How this page was put together. Costs come from the City of Olympia's septic to sewer page and the county's 2026 fee schedule, read on 6 November 2026; LOTT's role comes from its own pages. LOTT's current rates and Lacey's and Tumwater's charges and rules could not be confirmed, so they are left out rather than estimated.

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