Stehekin Powerhouse, Stehekin

We propose to approve ​Chelan County Public Utility District (PUD) No. 1 Stehekin Powerhouse's air quality notice of construction (NOC) application. We will hold a public comment period if one is requested.

Chelan County PUD submitted a notice of construction application for the Stehekin Powerhouse in Stehekin. Chelan County PUD proposes to replace an older diesel generator with a newer one with more advanced pollution controls.

The proposed project will increase most emissions from the powerhouse:

• 6.18 tons per year carbon monoxide (CO)
• 0.21 tons per year particulate matter (PM)
• 0.21 tons per year PM₁₀
• 0.21 tons per year PM_2.5
• 0.21 tons per year volatile organic compounds (VOCs)
• 0.01 tons per year sulfur dioxide (SO₂)
• Decrease of 1.3 nitrogen oxides (NO_x)

Document for review

• Stehekin Powerhouse notice of construction (NOC) application and associated documents

If we determine this proposal satisfies the requirements of Chapter 173-400 WAC, we plan to approve the application. We will hold a public comment period on a draft air permit ("approval order") that includes this change if we receive a written request by July 20, 2026.

To request a public comment period, use one of the ways listed below.

To find out if there are more records for this project, contact our Public Records Office.

This notice was posted on July 2, 2026.

Background

A notice of construction permit is required before installing a new source of air pollution or modifying an existing source of air pollution. This permit is sometimes called a "pre-construction permit" because a business must have one before starting construction or operating their business.

A notice of construction air permit limits the amount of air pollutants a business can emit.