King County Department of Natural Resources and Parks Wastewater Treatment Division

Jun 14, 2019

What are your facility drivers/needs?

King County’s Wastewater Treatment Division’s (WTD) mission is to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. King County, Washington, protects water quality and prevents water pollution by providing wastewater treatment to 17 cities and 17 local sewer utilities. The agency serves about 1.5 million people and operates three regional treatment plants which treat about 200 million gallons of sewage per day.

Current drivers include the need to continue progress on an extremely aggressive combined sewer overflow control/treatment program that will consume a significant portion of the capital improvement program budget, implementing the County’s Strategic Action Climate Plan which includes meeting aggressive greenhouse gas emissions targets and preparing for potential future regulatory mandates such as nitrogen discharge limits.


What new technologies have you been evaluating or implementing? 

The WTD is currently initiating a project that will investigate and select a biogas scrubbing technology to replace an aging biomethane scrubbing facility that has been converting digester gas into biomethane and injecting it into the local natural gas pipeline for 28 years. The County also has a long history of supporting a Research Fellowship Program with the University of Washington. The program awards research grants to graduate students conducting research on technologies and processes pertinent to WTD operations. In 2014, WTD worked with three Ph.D. students on topics ranging from identifying optimal conditions for biodegradation of estrogen compounds, bio-augmentation to enhance removal of specific trace organics, and the importance of syntrophic bacteria in the anaerobic degradation (co-digestion) of fats, oils, and greases. 


What technologies are you interested in investigating? 

Currently the agency’s interests include technologies that focus on energy conservation and production, low-energy nitrogen removal processes, and removal and recovery of phosphorus from biosolids.


How has LIFT helped, or how would you like LIFT to help your facility? 

LIFT has provided a forum for bringing together the combined expertise and resources of many highly effective wastewater treatment agencies. This has facilitated more effective collaboration between agencies with similar goals, sharing of alternative approaches to achieve similar goals, a better awareness of what has been tried in the past, and a more clear understanding of what approaches to shared problems/issues have been effective, what has not been effective, and why.


If there were one technology you would pilot or collaborate on tomorrow, what would it be?

We are currently operating a membrane bioreactor pilot to investigate factors impacting mixed liquor filterability and are always interested in looking at new technologies that can improve performance of our facilities, reduce potential impacts, or produce resources from wastewater.