In 2022, after pressure from the community and ballooning costs, then-Bellingham Mayor Seth Fleetwood requested a pause on the City’s plan to move forward with an anaerobic digestion upgrade at the Post Point Wastewater Treatment plant. The original projected $200 million construction and development costs had risen to a potential $1 billion. The environmental community considered this decision a win.
But this left the City with a new decision to make: look for an alternative technology that would also likely have significant costs, or “upgrade” the incinerators to meet the necessary standards. The City is focused on pursuing the latter. RE Sources is not convinced that this is the path to take. There are still many unanswered questions around costs, greenhouse gas emissions and continued exposure of community members to contaminants through air and water pollution. We are in contact with city staff, the Mayor and City Council to learn more about their process.
While anaerobic digesters use bacteria to turn sewage sludge into a dense, compost-like byproduct known as biosolids, the process does not break down toxic contaminants present in our city’s wastewater. These Contaminants of Emerging Concern, such as plastics, fire retardants, microplastics, PFAS (Per- and PolyFluoroAlkyl substances) and PCBs (PolyChlorinated Biphenyls) have become a serious consideration when it comes to treating wastewater.
In some instances, biosolids are sold and used as fertilizer for croplands, parks and gardens. This can bring these toxic chemicals into direct contact with drinking water sources and soil used to grow food. RE Sources’ primary concern was making sure we never spread biosolids containing toxic forever chemicals on lands in our region or beyond. Just this year, Maine passed legislation prohibiting the land application of biosolids known to contain PFAS in the wake of widespread cropland contamination and poisoned well water on farms in the state. We can’t afford to take such a risk when it comes to protecting our soils, local food systems, groundwater, waterways and community health.
Also during this time, the Department of Ecology developed a nutrient permit for Wastewater Treatment Plants that discharge into the Salish Sea—a move RE Sources supported. Post Point will be required to monitor and potentially reduce the nitrogen that is in the discharge water. Anthropogenic nitrogen sources such as those coming from wastewater treatment plants are causing excess algae to grow in the Salish Sea, especially during the warmer, sunnier summer months. When the algae die and decompose, oxygen is consumed making some areas so low in dissolved oxygen that marine organisms struggle to breathe. Anaerobic digesting would have contributed more nitrogen into the wastewater and would have required more costly measures to remove. Another reason we are happy that the City pivoted away from building the digesters.
The lesser of two evils
There are two potential interim solutions that would allow the City to turn off the incinerators almost immediately: landfills or lagoons. We urge the City to look at short term, temporary solutions to minimize pollution and reduce the use of fossil fuels. Two cities just to the south of us, Lynnwood and Edmonds, have shuttered their incinerators and are currently trucking their sewage solids to a landfill as they too reimagine their solids processing.
It is estimated that Bellingham’s wastewater treatment plant produces about two truckloads of sewage sludge every day, which would cost the city an estimated $4 million dollars per year to dispose of in a landfill. This is a fraction of the anticipated $54 million that the City plans to spend fixing the incinerators. Containing the sludge in lagoons has also been presented as a temporary solution.
However, neither lagoons nor landfills can treat the toxics in sewage sludge (nor can incinerators) but they can contain it. Landfills and lagoons also have the technology to capture and use methane that is produced, as well as monitor for any leakage. The incinerators, on the other hand, will continue to release toxic pollution into our air and waterways. It is for these reasons that we feel landfills and lagoons are the lesser of two evils.
Buying time
Once the sewage sludge is diverted to landfill we can begin working towards a more sustainable solids processing technology. The first, logical step in any sludge processing is to invest in a dryer. Raw sewage is 99% water and if the water is removed, it will make transporting the solids off site much cheaper. Drying is also the technology used as a precursor for most other solids processing and would be a good investment for the plant.
Investing in a healthy, forward-facing solution
Promising, emerging sewage sludge processing technologies are on the horizon. For example, a gasifier in Bethel, Pennsylvania has been successfully processing sewage sludge for more than a year with great results. Gasifiers burn at a very high temperature and pressure, with third party tests confirming that nearly all of the PFAS is destroyed.
This gasifier is also a closed loop system — the energy, in the form of syngas, produced from gasifying the sludge is used to power the gasifier itself and hot air that is emitted goes back to dry the solids.The only fossil fuels used is to start the gasifier, once running the valve is turned off. The biochar endproduct can be used in a variety of products, such as stormwater filtration or in making carbon-neutral concrete. The City of Edmonds is also about to transition to gasification.
At this moment, there is no silver bullet to our sludge woes. The City of Bellingham will need to do a proper alternative analysis to determine what technology will best meet the needs of the community. We hope the City will be transparent with this process and invite the public into the discussion. Up until now, most of the planning and negotiating has occurred behind closed doors. In the meantime, turning off the incinerators and temporarily landfilling our sewage sludge creates the necessary time that we need to carefully evaluate what our next steps will be.