Regional chlorine / sodium hypochlorite shortage: How we’re conserving to protect public health and the environment

We continue to treat wastewater to full regulatory standards during this region-wide supply shortage. We work 24/7 to serve over 1.8 million residents and clean about 190 million gallons of water per day.

What is happening

A nationwide shortage of sodium hypochlorite – a chlorine compound and disinfectant in common household bleach and the primary disinfectant in our wastewater treatment process – triggered by a supply-chain disruption, is impacting wastewater treatment operations throughout the Northwest, including King County. Like several other utilities in the region, our staff is conserving the disinfectant while we try to secure continued supply. We are working closely with the King County Office of Emergency Management, State Department of Health, and the State Department of Ecology on this issue. We are also coordinating with industry organizations and sharing information with other utilities along the West Coast.

At this time, we have adequate disinfectant supply and operational flexibility to treat wastewater to full regulatory standards. We are constantly monitoring the situation and evaluating our supplies and procedures to ensure public health is protected.

This is an evolving situation and updates will be posted here and on Public Health’s site here.

Engineers inspect the sodium hypochlorite tanks at West Point Treatment Plant

Actions we are taking to protect water quality

We’re taking action and precautions to protect public health and the water quality during this region-wide shortage of the disinfectant. We currently have enough sodium hypochlorite to treat wastewater at each our regional treatment plants, and we’re making contingency plans in case the nationwide shortage continues. The King County Office of Emergency Management and state agencies are assisting and advising our utility and other utilities in the region.  

We use sodium hypochlorite in the final stages of wastewater treatment to kill any remaining viruses and bacteria. It is also used in our recycled water production and for some odor control at facilities across our regional system. In an abundance of caution, we are already conserving our current supply of sodium hypochlorite and prioritizing it for wastewater treatment to preserve public health and comply with state regulations. We have paused our recycled water production and some odor control.

Conserving the disinfectant does limit our ability to control some odors, which may temporarily impact neighbors near our treatment plants, pump stations and other facilities. Odors that may be released from suspending some of our odor control functions are not harmful. Sodium hypochlorite is just one of the many ways we control odors – in addition to trapping air from our processes, biofiltering, and carbon scrubbing. Both regulations and policies established by the Puget Sound Clean Air Agency and the City of Seattle require us to monitor and control odors, and we are working closely with those agencies on this issue.

We are committed to transparency

We will keep you informed as we learn more and determine next steps. As the situation unfolds, continue to visit our blog for updates.

What you can do

We encourage everyone to sign up for alerts from Public Health to stay informed about this and other events that affect our community.

If you smell something you think is coming from our facilities, call our 24/7 odor control hotline so our operators can track down the source. Every odor complaint is logged and tracked, and we make it their goal to respond and identify the issue within two hours.