Post Point Wastewater Treatment

Outdated stormwater, sewer, water treatment and wastewater treatment infrastructure is failing to meet today’s demands — let alone tomorrow’s. The City of Bellingham has an opportunity to set an example for the region and beyond by building climate-resilient, safe and environmentally responsible wastewater infrastructure for the future.

In the City of Bellingham, the wastewater produced by more than 90,000 people is treated at the Post Point Wastewater Treatment plant located in Fairhaven along the coastline of Bellingham Bay and the Salish Sea. This sewage water contains human waste, along with everything else we flush down our drains, including soaps, cleaners, pharmaceuticals, and more – a cocktail of nutrients and toxic chemicals. Post Point, which first began operations in 1974, currently uses incinerators to burn sewage sludge derived when water is separated from solids in the treatment process. These incinerators are at risk of failure due to age and years of deferred maintenance. They also spew climate pollution into the air as a byproduct. It’s clear that some course of action is needed to ensure effective, continued wastewater treatment for a growing population while also addressing three core community concerns: cost, climate and contaminants.

The decision at hand

For the past several years, the City has been focused on a technology called anaerobic digestion as a replacement for the incineration process. Anaerobic digesters rely on bacteria to break down sewage sludge into a dense, compost-like byproduct known as biosolids. In some instances, biosolids are sold and used as fertilizer for croplands, parks and gardens. Unfortunately, anaerobic digestion does not break down toxic contaminants we know are present in our city’s wastewater, including Contaminants of Emerging Concern like plastics, fire retardants, PFAS (Per- and PolyFluoroAlkyl substances) and PCB’s (PolyChlorinated Biphenyls).

RE Sources’ primary concern is making sure we never spread biosolids containing toxic forever chemicals on lands in our region or beyond. We can’t afford to take such a risk when it comes to protecting our soils, local food systems, groundwater, waterways and community health. 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.

In addition to toxic contaminants in the sludge produced at wastewater treatment plants, we also need to address nutrient contamination related to the discharge of water from the treatment plant into the Salish Sea. RE Sources supported strengthening the Department of Ecology’s permit requirements for wastewater treatment plants, as they are a significant source of nutrient pollution threatening our vital and unique Salish Sea ecosystems.

New developments and a future-facing solution

In late summer 2022, Bellingham Mayor Seth Fleetwood requested a pause on the City’s plan to move forward with an anaerobic digestion upgrade at Post Point, citing cost estimates that have ballooned from $200 million to potentially $1 billion thanks to inflation and other factors. The Mayor asked Bellingham City Council to consider a revised approach of making repairs needed to keep the wastewater treatment plants current incinerators in operation.

RE Sources supports the proposed approach of pausing the anaerobic digestion plan and making short-term fixes to the incinerators, AND we encourage the City to take this opportunity to consider additional options. Instead of relying solely on Band-Aid solutions in patching the incinerators (which does not further our City’s greenhouse reduction goals), we urge the City to:

  1. Consider all available options, including thermal processes such as gasification and pyrolysis, with the help of a new third-party consultant.
  2. Solicit input from the public on how to best move forward (funds are already allocated for outreach).
  3. Ask the state legislature to secure funding for this project to reduce the burden on taxpayers and help us serve as a model for other cities to follow.

Unlike anaerobic digestion, thermal processes like gasification can break down the strong chemical bonds in persistent toxic chemicals. Additionally, the process generates useful byproducts including syn-gas, which can be used on-site to power the plant’s operations, and biochar. This material is far drier and lighter than biosolids, so in addition to being safer, it’s also cheaper to transport and use as a soil amendment.

Anaerobic digestion is currently a more broadly adopted method for processing sewage sludge, but emerging science around the health impacts of PFAS chemicals and soil contamination means plants around the country using this technology may soon have few safe or affordable options for responsibly disposing of biosolids. Moreover, there are inherent equity issues when a community generates toxic waste that it needs to dispose of in other communities, often poorer ones with less recourse to refuse it. It’s a costly headache and toxic burden that Bellingham could leap-frog by investing in thermal processing, either in place of, or in tandem with, the current incineration system.

It’s your future

We as a community have an important decision to make when it comes to investing in wastewater treatment infrastructure that will balance considerations of cost, contaminants, and climate.


The following contaminants have ALL been detected in Bellingham’s sewage sludge:

  • Heavy Metals
    • arsenic
    • barium
    • cadmium
    • chromium
    • lead
    • mercury
    • selenium
    • silver
  • Contaminants of Emerging Concern
    • plastics
    • fire retardants
    • PFAS (Per- and PolyFluoroAlkyl substances)
    • PCB’s (PolyChlorinated Biphenyls)
    • dioxins furans
  • Hydrocarbons and petrochemicals
  • Pharmaceuticals
  • Steroids and hormones

2022, Sept. – Mayor Fleetwood recommends a pause on plans to implement anaerobic digestion upgrades at Post Point, citing ballooning cost estimates from $220 million to potentially $1 billion.

2022, Aug – California has added PFAS to the list of chemicals that require consumer warnings

2022, Aug – Public Works announces that it will spend $700,000 to evaluate post digestion technologies and to carry out an education and outreach program both conducted by Brown & Caldwell Consultants.

2022, Jun – EPA issued drinking water recommendations that warn that PFOA and PFOS in trace quantities (parts per trillion) undetectable quantities of PFOA and PFOS pose significant human health risks.

2022, Apr – Bellingham City Council voted unanimously to spend $220 million on the Post Point Wastewater Treatment upgrades including the construction of 4 anaerobic digesters but to also fund a study that evaluates the best option for disposing of the biosolids and to include a public engagement component. Note: estimated cost has gone up potentially doubling

2022, Apr. – Maine becomes the first state to ban the practice of spreading PFAS-contaminated sewage sludge as fertilizer.

2021, Nov – Post Point Sewage Solids test results are made public in a 3,000+ page document. Results show that Post Point Sewage Solids are contaminated but because contaminants are not regulated, the City continues to pursue the making and land spreading of toxic biosolids.

2021, July – RE Sources presents to City Council and requests that Sewage Solids be tested for contaminants. The City Council approves the request unanimously.

2019 – RE Sources and Mt Baker Sierra Club began expressing concerns about the safety of land spreading biosolids

2018 – EPA publishes alarming report that identifies 352 pollutants in biosolids including pharmaceuticals, steroids, and flame retardants and admits it does not have enough information to regulate these pollutants.

2016-19 – Used the Triple Bottom Line Plus (TBL+) criteria to decide on Anaerobic Digestion to make Class A biosolids cakes and to capture methane gas. Biosolids would be sold to a third party to be blended into a solid amendment that would then be spread in Whatcom and Skagit counties.

2017 – City of Bellingham publishes an updated Climate Action Plan and highlights the inefficiencies and the greenhouse gas emissions by the incinerators at Post Point.

2012 – City of Bellingham Public Works and Consultants decide to pursue Anaerobic Digestion to replace aging incinerators. Technologies were not evaluated on how well they treated contaminants such as PFAS, PCBs, pharmaceuticals, flame retardants, or microplastics.

Thermochemical processes such as gasification (with O2) or pyrolysis (w/o O2) degrade large molecules such as PFAS and PCBs with high temperatures into their non harmful elemental forms.  Anaerobic digestion only breaks down food like particles, not forever chemicals, and leaves a lot of material (energy) behind.  Gasification and pyrolysis produce more energy from breaking down sludge than anaerobic digestion and, unlike incineration, they create syngas that can be used to power themselves without emitting greenhouse and other toxic gasses. The end product biochar is largely free from chemical contaminants and can be used as a soil amendment, filtration media, or for carbon storage. Thermochemical processes are considered carbon neutral (syngas is used to power the gasification or pyrolysis unit) and if you consider that you no longer have to truck sewage solids anywhere they can even be considered carbon negative. 

Benefits of using thermal tech’s gas on site for energy, being more self-sufficient than biosolid digesters and not requiring gas like the incinerator does. And not using big trucks to ship the biosolids elsewhere. Federal funding is available for projects that curb climate emissions in the way that thermal processing does, and we can curb emissions even more than biosolids would. 


Technology leaders in the field:


US Thermal Operations (and there are more around the world)

Fully Operational:

  1. Lebanon, TN  Lebanon Waste-to-Energy Plant; (2016-present); [Aries gasification]- around 1000 WT/year, mixed biosolids and tires/wood chips— but phasing into just going with biosolids.  
  2. Covington, TN (2014 -present); [Aries gasification]- around 1000 WT/year, mixed biosolids and wood wastes.
  3. Redwood City, CA; Silicon Valley Clean Water [Bioforcetech pyrolysis].  Biosolids to energy and biochar (2016 -present).
  4. Schenectady, NY Biowaste Pyrolysis Plant; [Biowaste Pyrolysis Solutions (BPS) and Technotherm]; operational August 2022; processing 40,000 tons/year of dewatered sludge. 
  5. Los Angeles, CA; [Kore pyrolysis full-scale system]; commercial-scale demonstration project started August 2021; processing 24 T/day including biosolids.  

Coming Very Soon: 

  1. Linden, NJ [Aries Linden Biosolids Gasification Facility] 1/2022 construction completed; mid-2022 commissioning; 430 T/day biosolids. 
  2. Edmonds, WA  WWTP;  [Ecoremedy gasification]; operational November, 2022.
  3. San Bernardino CA; Anaergia’s Rialto Bioenergy Facility, [Anaergia pyrolysis processing biosolids and food waste]. Startup planned in 2019 and as of 2022: “will soon complete the addition of Anaergia’s PyroSys™ pyrolysis technology to produce NutriChar™ biochar fertilizer. “–capacity to convert up to 1,000 tons per day of wastewater biosolids and landfill-diverted, organic waste. 
  4. San Luis Obispo, CA; The San Luis Obispo Anaerobic Digestion Facility’s CHAR High Temperature Pyrolysis System; [CHAR Technologies with Hitachi Zosen Inova]. Completion is expected in 2022. The project will process 18,000 tons/year of solid anaerobic digestate into 1,320 ton of green hydrogen/year, and 2,800 tons/year of biocarbon. 

In Development: 

  1. Newark, NJ; Newark Biochar Production Facility [Aries gasification]. The facility (in development with an install date posted as 12/27/21)  will process and dispose of up to 430 wet tons/day of domestic wastewater treated biosolids from 3rd parties. 
  2. Taunton, MA; [Aries] Taunton Biosolids Gasification Project; construction could begin as early as spring/summer of 2023- operational as early as mid-2024.
  3. Lost Hills, CA; [Aries] continues the planning and designing for the;  Aries-Holloway Bioenergy Facility [gasification of agricultural waste] to be built in on five acres in Full operations projected Q3 2021.
  4. St. Mary’s County Metropolitan Commission, California MD; Ongoing  (2019+) development of a Bioforcetech post-digestion pyrolysis system.
  5. Redding, CA; Clear Creek WWTP Pyrolysis Phase 1 Project. [Bioforcetech]     Installation of biodryers and pyrolysis units for biosolids treatment for solids reduction. Construction start expected September 2022.
  6. Moreau, NY; Saratoga Biochar Solutions – pyrolysis system for The facility is designed to process up to 15% of the biosolids generated in NY and produces a revolutionary new bio-fertilizer; Carbon Fertilizer™.

Facilities using Hydrothermal Carbonization  

Converting wastewater solids into natural gas and bio-crude oil

  1. Phoenixville, PA; Hydrothermal Carbonization Facility. [New Energy Optimization and SoMax] ; running alongside anaerobic digesters early in 2020 and easing in to handling all the biosolids. Construction began in February 2022, The project will be completed in phases with a full transition from anaerobic digestion to HTC expected in the second quarter of this year, though officials said it could take until the end of 2022.
  2. Anacortes, WA; [Anacortes WWTP had begun talks and design plans with Genifuel for hydrothermal carbonization, 2021, but told to ‘pause’ for reconsiderations from their city council]
  3. Central San’s Wastewater Treatment Plant, Contra Costa CA; Hydrothermal Processing of Wastewater Solids (HYPOWERS) Demonstration Facility. [Genifuel] This project will design, build and commission a demonstration-scale skid-mounted hydrothermal processing unit to process wastewater solids at an existing wastewater treatment plant.  currently- the project is proceeding with Phase 2 (construction and operation).


Anticipated costs for wastewater treatment upgrades have been a topic of discussion in our community, and for good reason. The short answer is that if anything, gasification would likely be cheaper than the anaerobic digester approach, all other infrastructure and maintenance costs being equal.

Here’s a more nuanced and much longer answer: When deciding how to proceed, it’s important to take a holistic view of which options best meet all three priorities of cost, climate AND contaminants. It’s also important to consider upfront costs associated with purchasing and/or repairing equipment and bringing it online, as well as the ongoing potential costs (or potential revenues) associated with the byproducts of wastewater sewage sludge treatment. 

Unfortunately, any of our three options – repairing aging incinerators, installing anaerobic digesters, or gasification units – will bring substantial costs. Ratepayers will likely see rate increases regardless of the path chosen because of years of deferred maintenance and investment that kept sewage utility bills artificially low. What remains to be seen is the degree to which federal funding via the Bipartisan Infrastructure Bill and state funding could be leveraged to cover substantial portions of the cost and reduce the financial burden on individual ratepayers. RE Sources is exploring these opportunities and is encouraging the City of Bellingham to do the same.

Anaerobic Digestion
Capital investment costs will be substantial for any upgrades, but in addition to likely costing the most to purchase and bring online, anaerobic digestion also creates a substantial recurring cost if state or federal regulators move to restrict or prohibit the land-spreading of biosolids known to contain PFAS or other forever chemicals (as has already happened in Maine). Biosolids are a heavy, wet byproduct that would likely need to be trucked long distances and landfilled on an ongoing basis, adding to the operation’s costs as well as its carbon footprint. The estimated costs for upgrades including anaerobic digesters quoted by Mayor Fleetwood in Cascadia Daily News approached $1 billion, and that does not account for potential recurring biosolids disposal costs. The estimated costs of the anaerobic digestion system alone (with loan interest) would be roughly $430 million of that $1 billion price tag. According to the City, using anaerobic digesters would also increase nutrient removal costs by $200 million.


Gasification (a type of thermal treatment)
Gasification units would likely be cheaper than anaerobic digesters to acquire and bring online, and would create a lighter, non-toxic soil amendment that could actually be sold (revenue generating) rather than trucked away and landfilled. Two gasification units would cost an estimated $100 million.

It’s worth noting that gasification units could be used either as a replacement for all of Post Point’s incinerators or as a compliment to some of them. These technologies are not mutually exclusive. 


Repair and Maintenance of Existing Incinerators
Repairs to the existing incinerators are likely necessary at this point, given the amount of time it would take to plan and implement other types of sewage sludge treatment. Estimates solely for repairing existing incinerators currently sit at around $100 million. 

It’s also estimated that another $21 million is needed for plant wide generators, $200 million for nutrient removal (see more on this below), $30 million for operations and maintenance related to nutrient removal, and $50 million for inflation, contributing to an all-told price tab of $541 million. See the Department of Public Works’ recent (September 2022) presentation to the City’s Natural Resources Committee for a cost comparison between the anaerobic digester (resource recovery) plan and the incinerator repair and maintenance plan (p.14).

Pursuing the incinerator maintenance approach alone raises additional questions: how much time will the repairs buy us? What happens when parts for these decades-old systems are no longer in circulation? What will it cost to bring the emissions from the incinerators in line with air pollution regulations, and what about the greenhouse gas emissions and local air pollution impacts? 


A note about costs for removing nutrients from wastewater
Because of strengthened Department of Ecology permit requirements, we’ll need to invest at least roughly $200 million to ensure we remove enough nutrients from the Post Point’s wastewater before the treated water is released into the Salish Sea as effluent. With the anaerobic digestion plan, the price tag for nutrient removal potentially doubles to $400 million.

Strengthening the nutrient general permits for the 58 wastewater treatment plants that empty into the Salish Sea was a crucial step toward recovering the health of the region’s iconic Salish Sea ecosystems and marine life. We’ll need to make this investment regardless of how sewage sludge is processed. State-level grant funds may also be available for these investments. 


That’s a lot of information, and all prices quoted are subject to changes due to inflation, loan terms, and numerous other factors. The bottom line is we face substantial costs just to keep Post Point in operation and in compliance with state regulations. It’s RE Sources’ view that gasification is the best available option for sewage sludge processing when you consider climate, contaminants and cost.

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