Washington
Water and Wastewater Treatment Design
Engineering for municipal and industrial water and wastewater treatment plants, package plants, upgrades and permits.
What the work involves
Engineers plan and design treatment processes, pumping, tanks, buildings and controls for drinking water and wastewater plants, plus package plants for developments and industrial pretreatment. Work usually starts with a facility plan, then design, permitting, funding applications such as State Revolving Fund loans, and construction phase services.
Local conditions we plan for
- Cascadia Subduction Zone and Seattle Fault seismic hazard
- Landslides on wet slopes
- Liquefiable soils near Puget Sound
- Wildfire east of the Cascades
Building code: 2021 IBC/IRC adopted at the state level (ICC adoption chart, April 2026).
When you need it
- Plant nearing capacity or aging out
- New or tighter discharge permit limits
- Development needs a package treatment plant
- Industrial facility needs pretreatment
- Utility applying for state revolving fund financing
Frequently asked questions
How much does water and Wastewater Treatment Design cost?
Across the US, water and Wastewater Treatment Design usually costs $50,000 to $1,000,000. Estimate. Fees scale with construction cost and commonly run to a substantial percentage of it on public projects; small package plants are at the low end.
How long does water and Wastewater Treatment Design take?
Plan on 6 months to several years from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.
Do I need a licensed PE for water and Wastewater Treatment Design?
In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.
How do I verify an engineer's license in Washington?
Engineers practicing in Washington are licensed by the Washington State Board of Registration for Professional Engineers and Land Surveyors. You can confirm a license number and its status in the board's public license search before you sign a contract.
Which building code applies in Washington?
2021 IBC/IRC adopted at the state level (ICC adoption chart, April 2026). Cities and counties can add local amendments, which is one reason to hire an engineer who works in your area.
What site problems do engineers see most in Washington?
Common issues include cascadia Subduction Zone and Seattle Fault seismic hazard, landslides on wet slopes, liquefiable soils near Puget Sound and wildfire east of the Cascades.