Supreme Court hears wastewater treatment costs case

June 10, 2024

The Washington State Supreme Court recently heard oral arguments in a wastewater treatment costs case with implications for homeowners and builders.

The case, Birch Bay Water and Sewer District, et al. v. Department of Ecology (DOE), deals with whether or not DOE can impose new requirements on wastewater treatment plants (WWTP) without following the Administrative Procedure Act (APA).

The Building Industry Association of Washington (BIAW) filed an amicus brief supporting Birch Bay Water and Sewer and others earlier this year.  That group included the City of Tacoma, Birch Bay Water and Sewer District, Kitsap County, Southwest Suburban Sewer District and Alderwood Water and Wastewater District.

Wastewater treatment costs case sets costly precedent

In its lawsuit against DOE, the group argued the agency lacked authority to impose tertiary treatment requirements at wastewater treatment plants (WWTP) without following the Administrative Procedure Act (APA).

During the argument, the court acknowledged the costly impact of upgrades of WWTPs in the Puget Sound area.

In its brief, BIAW directed the court to review its Washington Center for Housing Studies’ Housing Affordability Index (HAI). The latest HAI shows roughly 84% of Washington households can’t afford a median-priced home.

DOE’s directive on total inorganic nitrogen (TIN) caps at WWTPs could increase costs so high it would make it nearly impossible for people to own or build homes in Washington, BIAW contends.

The City of Tacoma estimates the costs to upgrade facilities for nutrient removal could be as high as $1.314 billion.

Expensive outcomes if DOE prevails

Both the lower court and the Division III Court of Appeals ruled in favor of those challenging DOE.

However, if the department wins its appeal, BIAW warns the state will see:

• Increased housing costs for homeowners and renters, potentially adding $500 to monthly sewer bills; and
• Significant delays and costs for building permits, putting affordable housing projects in limbo.

BIAW is optimistic that the Court heard the valid concerns raised against DOEs “rulemaking” in the form of a letter. It could be several months before the court issues its decision