A hundred years ago, wastewater “treatment” consisted of pit privies, buckets, and open ditches that collected human waste with the primary purpose of preventing disease.
Eventually, buried sewage lines replaced most of these more primitive practices, but the waste was still untreated and dumped directly into rivers and oceans, relying on dilution and saltwater to mitigate any harmful effects. There were obvious impacts to receiving waters, including algal blooms, fish kills, and odors—initiating the need to treat sewage. Simple filtration, solids settling, dewatering, chlorination, and digestion using microbes were some of the first treatments, primarily designed to separate solids from liquids, reduce nutrient discharges, and disinfect the wastewater.
Then, in 1972, the Clean Water Act set national regulations for the release of wastewater in the U.S., which meant that wastewater could no longer be discharged without a permit. A wastewater permit ensures the regulation of effluent (the liquid leaving a wastewater treatment plant) for solids, chlorine, biological oxygen demand, pH, turbidity, flow, and fecal coliform bacteria. Soon, the Washington State permit will include nutrient control, too. Yet there are still known toxic contaminants in effluent—such as pharmaceuticals, PFAS, PCBs, microplastics, or flame retardants—that are not monitored nor regulated.
Sewage solids are regulated depending on how they are processed. In Bellingham, the sludge is burned in incinerators at Post Point and therefore regulated by the Northwest Clean Air Agency (NWCAA). Particulate matter, hydrogen chloride, carbon monoxide, metals, nitrogen oxides, dioxins/furans, and sulfur dioxide are all regulated—and released into the environment at Marine Park every hour of every day of the year.
Still, today’s most stringent air quality standards were established in 2011, long before PFAS (“forever chemicals”) were on anybody’s radar. This means PFAS, flame retardants, PCBs, and other toxics are knowingly being released into the environment but are neither monitored nor regulated—the current air permit is no longer protecting human health.
While air pollution is the primary concern coming from the incinerators, it’s important to know that there is also highly contaminated wastewater coming from the wet scrubbers that treat the emissions. These contaminants go into the effluent that are released into the Bay. Also, a considerable amount of ash is produced in the incineration process (one truck load per week) and taken to the landfill.
The very apparent truth is that treatment technologies and regulatory permits have not kept up with the harmful contaminants that are found and collected in sewage at wastewater treatment plants. Currently, many treatment plants—like Post Point—are not treating the contaminants but rather redistributing them into our water, air, and land.
Fortunately, there are modern-day technologies available that can treat sewage waste in a more sustainable manner. Thermochemical technologies, such as gasification, pyrolysis, and hydrothermal liquefaction, all show promise in tackling our wastewater woes. These technologies utilize heat and pressure, without combustion, to convert organic matter into fundamental building blocks as well as valuable energy.
Gasification combines high temperatures and a limited amount of oxygen to create synthesis gas (syngas) and biochar. There are fully operational sludge processing gasifiers in the U.S. (New Jersey, Pennsylvania, and Tennessee), Australia, Austria, Denmark, Italy, Germany, Norway, Spain, UK, Japan, and China, with facilities planning to open in Washington and Maine. This technology has been around for more than 200 years but only recently been applied to sewage sludge treatment.
Pyrolysis uses high temperatures without oxygen to yield bio-oil, biochar, and synthetic gas. There are fully operational facilities in the U.S. (located in California and New York). Like gasification, this technology has been around for over 100 years but only recently been applied to sewage sludge treatment.
Hydrothermal liquefaction (HTL) involves using high pressure and moderate temperatures to process wet biomass into liquid crude oil, eliminating the need to centrifuge or press the sludge prior to processing. There are demonstration and fully operational HTL sludge processing facilities in Canada, Denmark, Australia, and Turkey. Unlike the previous two technologies, HTL has been around for less than 50 years.
All three of these technologies have the capability of being carbon neutral because the energy that is produced by heating the organic sludge can be used to power the reaction itself. In other words, they are self sufficient in regards to energy usage. In some circumstances, the process can even be considered carbon negative because the end product, biochar, actually sequesters carbon. Additionally, these technologies have shown to destroy harmful contaminants such as PFAS, and because there is little to no oxygen during the reaction, they produce far less emissions than traditional incineration.
In November 2025, RE Sources’ North Sound Waterkeeper Kirsten McDade—along with three members of the Sludge Coalition, Mike Montazeri, Rodd Pemble, and Atul Deshmane—visited two gasifier facilities: Aries Gasifier in Linden, New Jersey and Earthcare Solution Gasifiers in Bethel, Pennsylvania.
The Aries Gasifier in Linden, NJ is a huge regional gasifier that processes 400 tons of dewatered sewage sludge per day—that’s sludge from about a million people! It receives sludge from wastewater treatment plants up to 500 miles away, some that has been anaerobically digested, some has not. The gasifiers burn between 1250 and 1350° F, which is plenty hot to destroy the hard-to-break bonds of a PFAS molecule. Natural gas is used to start the gasifier and to keep a pilot flame, otherwise the gasifier powers itself.
The gasifier produces twenty tons of biochar per day and although it has been tested for PFAS and found to be PFAS free, it is currently going to a landfill. The hope is that this biochar can be used in a more beneficial manner in the near future. Aries is planning to build another regional gasifier in Maine, where land spreading sewage sludge is banned by law because of PFAS contamination.
At the Earthcare Solutions facility in Bethel, PA, there are actually two gasifiers in this rural town. Each unit can process 40 tons of dewatered sewage sludge per day, which is comparable to the amount that is processed in Bellingham. One gasifier unit processes agricultural waste, such as pig and poultry waste, producing biochar that can be OMRI certified (organic certification) and sold as a high-end fertilizer. The second unit processes sewage sludge and also generates biochar but, like Aires biochar, even though the biochar has been deemed PFAS-free, it currently goes to the landfill. At this time, biochar from sewage sludge is not OMRI certifiable. The hope is that with additional, long-term monitoring, we can better assess the safety of biochar and find beneficial uses.
The Earthcare Solutions gasifier facility appears to be a good model for Bellingham and Whatcom County as a whole. (Note: Employees from the City of Bellingham Public Works department visited the Earthcare facility on May 14, 2026.) One gasifier unit would be a good fit for Bellingham and could be built right at Post Point to replace the incinerators. Another option would be to build two gasifier units in Whatcom county and have a regional facility.
Whatcom County has five wastewater treatment plants: Bellingham, Ferndale, Lummi Nation, Lynden, and Everson, and they could all contribute sludge to a local gasifier. Whatcom County also has a productive agricultural community that produces a wide variety of agricultural waste, including an abundance of cow manure. Other organic waste such as marijuana farm residue and forestry slash could be included in this regional waste processing facility.
A regional gasification facility would accomplish so many of our community goals. We would reduce our carbon emissions by capturing and using the energy generated from breaking down organic material instead of releasing it into the atmosphere. We would control and contain toxic contamination by reducing air emissions and destroying PFAS and other persistent chemicals. We would reduce the amount of pollution that goes into our waterways by managing animal waste more responsibly. And we would boost our economy by creating a biochar production facility.
A truly collaborative, regional gasifier facility would take a cooperative approach by city and county governments, tribal nations, community organizations and members, and private companies. RE Sources and the Sludge Coalition have already started building meaningful relationships with many of these stakeholders and we are optimistic that we can see this dream become a reality.
This is the second in a three-part series of blogs. You can read about community concerns and common misconceptions for this issue here.