Air Quality Rule Change Means Lower Hurdle for Washington State Landfill Owners

The Washington State Department of Ecology is revising the air quality thresholds for toxic air pollutants (TAPs; WAC 173-460), based on best available science. These proposed changes have some significant effects for landfill owners looking to keep air quality good, protective of human health and the environment, and doing so cost effectively. The key proposed changes are:

The last flare this landfill in Port Angeles will ever need. When the gas is no longer combustible, reliable treatment will be provided by biofilter technology – made easier by recent updates in air quality criteria.

  • Two of the most conservative constituents commonly found in landfill gas, benzene and vinyl chloride, will have higher thresholds (by factors of 3.7 and 8.9, respectively).

  • The threshold for hydrogen sulfide – a common driver for odor control in landfill gas – did not change. However, biofilter technology is showing promise as an economic and reliable method for polishing treatment.

  • The threshold for trichloroethene went down by a factor of 0.4. This constituent has also been commonly found in landfill gas, and the new threshold may or may not change our clients’ treatment obligations.

What this means for landfill owners is that air quality compliance should be easier to demonstrate. This means:

  • Downscaling treatment at older landfills can focus on odor control instead of destruction efficiency for volatile organic compounds (VOCs) as TAPs.

  • The costs associated with flaring landfill gas can be re-directed to biofilter technology for polishing treatment for odor control.

  • The schedule for ending or minimizing post-closure obligations associated with landfill gas treatment can be accelerated.

Next Steps

This rule-making process is on-going, and details of the process are provided at Ecology’s website:

A hearing on the re-calculated air quality thresholds is planned for July 16, 2019, and comments are due be July 23, 2019.

Barring delays, the new rule on air quality thresholds becomes effective in late October 2019.

For more information on what the implication of these changes for landfill owners and managers, contact Associate Engineer Peter Bannister at (206) 780-7728 and

Meet Aaron Fitts and Jasmin Jamal!

Aaron Fitts recently joined Aspect's Bellingham office and Jasmin Jamal recently joined Aspect's Portland office.  Here are five questions we asked to get to know them better.

Aaron Fitts, LG, Staff Geologist

Aaron and 2 1/2-year-old son Arthur.

Aaron and 2 1/2-year-old son Arthur.

  1.  Where are you from? If you’re not from the Pacific Northwest, what brought you here? 
    I grew up in central Maine. The landscape in Maine and New England is a lot like the Pacific Northwest (PNW), except the mountains are smaller and the winters are colder. I spent all my time growing up in the woods or on the coast; I spent the summers racing bikes, surfing, and whitewater guiding, and in the winter I’d be climbing mountains, snowboarding, and cross-country skiing. It turned out that you could do all these things in the PNW too, but it’s also way more fun here!
  2. What inspired you to pursue geology? 
    At the end of my Junior year of college, I had completed most of the requirements for a degree in physics and found myself with just electives left for my senior year. I was a bit sick of being stuck in physics laboratories all the time and saw geology as an opportunity to spend some time outside. I took eight geology courses in one year and was able to get a dual-degree. Ironically, I ended up spending most of my time in a basement geochemistry laboratory, though, I got out enough to make it worth it. I decided that I wanted to go to grad school where I could be in landscapes a bit more exciting than the Northeast. My undergraduate advisor recommended that I contact his colleague at Western Washington University in Bellingham, telling me that it was near the coast but surrounded by mountains. That was literally all I knew about the area when I drove across the country to get here. It ended up being a good decision.
  3. What excites you and keeps you motivated? 
    Troubleshooting and problem-solving while working with clients, contractors, and co-workers is my favorite thing about working in this field. There’s something very satisfying about getting something complicated to work out in the end. Getting to do the type of science that I enjoy and seeing cool places at the same time is just a great bonus on top of it all.
  4. What do you like to do when you aren’t working? 
    Lately, my favorite activity has been reexperiencing childhood activities with my two boys (11-months and 2.5-years old). My toddler is obsessed with riding his bike and running on the trails and my infant is obsessed with anything his big brother is doing. My wife and I do our best to keep up with them, but they’re a handful. When we do find time for ourselves, we usually end up riding our bikes anyway.
  5. Where in the world would you like to travel next? 
    There are a lot of places around the world I’d like to visit; generally, any place with mountains, probably Chile or Argentina. Honestly though, even given the choice, I’d probably most like to just go to the Methow Valley. I really like it there.

Jasmin Jamal, EIT, Staff Engineer

Jasmin at the Trillium Falls near the Redwood National and State Parks in Humboldt County

Jasmin at the Trillium Falls near the Redwood National and State Parks in Humboldt County

  1. Where are you from? If you’re not from the Pacific Northwest, what brought you here?
    I am from a city called Orange, in a county called Orange, in a state called California. My life-partner Jonathon and I visited Portland a few years back and immediately agreed that this was where we needed to be. Last summer, I finished grad school, he requested a job transfer, and before we knew it, we landed in Portland!
  2. What inspired you to pursue environmental engineering? What made you curious about it?
    Growing up, my mom frequently took my sisters and me on camping, hiking, and biking adventures. I loved the outdoors as a kid but never imagined pursuing an environmental job as a career--I always wanted to be a teacher. During college, I stumbled upon the earth science program and fell in love. Around the time that I finished my undergrad, environmental engineering was introduced as a master’s program at my university. The variety of topics covered in the program were intriguing, so I went for it and fell in love for the second time! My interest in teaching hasn’t ceased but I envision myself now as more of a grey-haired professor.
  3. What excites you and keeps you motivated?
    I like the diversity behind environmental engineering and am motivated by the fact that the environment is ever changing. I hope to work in multiple areas of interest including wastewater and surface water treatment, solid waste management and design, fate and transport of chemicals, and soil and groundwater remediation.
  4. What do you like to do when you aren’t working?
    I enjoy hiking, biking, and camping, but I probably like all of that as much as I like being horizontal with my cat Carrie.
  5. What five people would be your dream party guests?
    I’m going to pick a mixture of living and dead:
    1. My Uncle Tom (deceased)
    2. Barack Obama (living)
    3. Carrie Brownstein (living)
    4. 011 from “Stranger Things” (fictional)
    5. John Muir (deceased)