HomeMy WebLinkAboutC_Odor_Evaluation_Update_260428
South Treatment Plant
1200 Monster Road SW
Renton, WA 98057
April 28, 2026
Dave Keeney
Biosoilds Project Coordinator – Compost
206-477-6575
dkeeney@kingcounty.gov
MEMORANDUM FOR RECORD
Subject: Update regarding odor monitoring and community engagement at our
composting facility
Since starting the South Plant Biosolids Compost Pilot in November 2024, our team has
conducted weekly, on-site odor monitoring at the facility. This is part of our ongoing
operational practice. Throughout this monitoring, we have rarely observed odors outside of
the compost operation area, and never out to the fenceline of the wastewater treatment
plant.
In addition to our routine monitoring, the treatment plant maintains a dedicated
community phone line for odor-related concerns. Since starting the compost system, we
have only received one complaint that, upon investigation, was determined to be linked to
activity at the compost facility, in July 2025. Following that incident, we adjusted to our
operational process to let piles mature more before the first turn. Since that change was
made, we have not received any similar complaints.
We remain committed to continuous monitoring and operational practices that minimize
odor production.