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Innovative sewage solutions pitched to replace Bellingham’s aging system

Proposals include turning sludge into toilet paper or drying sludge on heated, rotating disks

Bellingham officials are reviewing four proposals from firms across the U.S. who would update the Post Point Wastewater Treatment Plant in Fairhaven. Officials asked applicants to come up with a process more sustainable than the 50-year-old incinerators the city uses now.
Bellingham officials are reviewing four proposals from firms across the U.S. who would update the Post Point Wastewater Treatment Plant in Fairhaven. Officials asked applicants to come up with a process more sustainable than the 50-year-old incinerators the city uses now. (Hailey Hoffman/Cascadia Daily News)
By Ralph Schwartz Local Government Reporter

The future of sewage treatment in Bellingham might involve high heat without fire, or water that is far removed from any natural state. 

As another option, the city might install a fancy dryer at the Post Point Wastewater Treatment Plant in Fairhaven. Or city leaders could simply have the sewage sludge transported to a soil farm in Eastern Washington.

In all, four companies — two local, one from California and one on the East Coast — proposed innovative technologies to city officials who look to transform the aging sewage treatment facility into something more environmentally beneficial and sustainable, with an end product that can be sold for reuse. 

A Bellingham-based business with a soil farm in Connell, Franklin County, would bring the city’s sewage waste full circle. The sludge would become soil for growing high-fiber grasses that would be made into toilet paper.

“Sewage to soils to grass fiber-derived toilet paper keeps the cycle of disposed products in a tight, environmentally secure loop,” the company stated in its proposal, with perhaps a slight wink.

photo  This conceptual view of a Connell Soil Farm lagoon illustrates how fibrous grass will be grown on a soil bed composed of sewage solids. The grass would be used to make toilet paper. (Image courtesy of Connell Soil Farm)  

The city also aims to reduce its greenhouse gas emissions at the sewage treatment plant.

Currently, plant operators remove the water from the waste stream and burn 4,650 tons of solids annually in 50-year-old incinerators. 

“There are only a handful of solutions that show promise for handling wastewater solids in a sustainable way,” said Riley Grant, communications and outreach manager for Bellingham Public Works. 

“Bellingham is looking to be leaders in helping to develop technologies that will protect our environment, reduce emissions and keep rates affordable,” Grant added.

For now, city officials intend to run a pilot project with one or more of the applicants, to see how their processes work on a smaller scale. 

Applicants are asking for as much as $8 million up front to participate in the pilot, but public works officials say the city can pay for the tests with existing sewer funds. 

“Pilot testing allows us to explore new options before we make a big investment, but it also means that we do not have a definitive timeline at this point,” Grant said.

A full conversion of Post Point from 20th-century incinerators to something more sustainable — potentially using cutting-edge technology — is several years away. The final cost of any upgrades, and the impact on ratepayers, are still unknown. 

Debate over the proposals at city council is expected to begin early next year. 

The proposals

Council members should be ready for a chemistry lesson when they weigh their options for Post Point.

photo  This schematic shows the main components of Bioforcetech’s pyrolysis unit, which converts wastewater solids into biochar. (Image courtesy of Bioforcetech Corporation)  

One applicant, Bioforcetech (BFT) from South San Francisco, California, proposes a process called pyrolysis, which involves heating sewage sludge in the absence of oxygen. The treatment avoids the pollution risks that come with simply burning the waste.

“Given this unique approach to thermal conversion, regulatory authorities … have formally recognized that BFT’s pyrolysis process is not considered incineration,” the company wrote in its proposal to the city.

BFT is asking for $8.4 million to fund the pilot run, plus $20,000 a week for company staffing on-site. The company says it would rather avoid testing in Bellingham and have city officials review its current operations in Redwood City, California.

photo  This diagram shows how 374Water’s supercritical water oxidation system works for treating sewage sludge. (Image courtesy of 374Water)  

Another modern approach to sewage treatment comes from 374Water, which would dissolve sludge into its most basic components using water in a “supercritical state” — reached at temperatures exceeding 700 degrees and pressures more than 200 times stronger than earth’s atmosphere. The company’s name comes from the supercritical temperature for water on the Celsius scale.

This so-called “fourth state” of water — neither solid, liquid nor gas — is able to break organic matter into water, carbon dioxide and minerals.

374Water’s proposed cost to the city for the pilot test is modest compared to BFT’s at just $570,500. 

Sedron Technologies, run by Peter Janicki and affiliated with Janicki Industries in Sedro-Woolley, has been refining its nonchemical process involving a complex machine since 2017. The Varcor, as it’s called, has had a few iterations since then and is in full-scale operations on wastewater in Sumner, Pierce County, and on dairy farms in Indiana and Texas. 

The Varcor dries sewage sludge on heated, rotating disks.The process achieves energy efficiency by compressing the steam produced during drying and using it to keep the disks heated.

Sedron would bill the city $1.295 million with a promise to credit that amount back if it wins the full-scale job.

photo  Sedron Technologies operates a sewage dryer in Sumner, Pierce County. The Sedro-Woolley company proposes bringing similar equipment to Bellingham’s Post Point Wastewater Treatment Plant. (Image courtesy of Sedron Technologies)  

Connell Soil Farm is managed by Brent Cowden, who has owned gravel and trucking companies in Whatcom County; and Larry McCarter, owner of Recycling & Disposal Services, a garbage transfer station in Ferndale.

The applicants tout the simplicity of their proposal, from the city’s perspective. Rather than bringing advanced treatment methods to the Fairhaven site, Connell Soil Farm would take the sludge from Post Point to its farm, where it would be spread as soil.

“It will be as simple as the city transferring the City of Bellingham sewage waste into our transportation containers,” the company’s application said. “Zero expensive build-out at Post Point is needed beyond access to loading docks.”

Connell Soil Farm would charge the city $525 per ton to transport sewage sludge that’s less than 6% solid.

Digesters dumped

In September 2022, the city abandoned plans to replace the incinerators with anaerobic digesters, which are tanks that break down the sludge into methane gas and a solid that can be marketed as fertilizer. Mayor Seth Fleetwood at the time cited environmental concerns and the high cost of the digesters as the reason for halting the project. 

The city estimated the digesters would cost up to $430 million, and officials anticipated significant rate hikes on residents’ utility bills. City council heard a report in May 2022 indicating sewer rates would increase 228% over two decades.

Also, environmentalists were concerned about the risk of pollutants in the digesters’ solid byproduct, particularly so-called “forever chemicals” or PFAs (per- and polyfluoroalkyl substances). Studies have shown possible links between PFAs and a variety of adverse health effects, including some cancers and developmental delays.

Benefits promised

BFT and 374Water both claim their systems eliminate PFAs to undetectable levels. While Sedron Technologies acknowledges that PFAs remain after the waste exits their dryers, the company foresees harmless end uses for its product, including fuel for cement-making kilns.

Connell Soil Farm skirts the PFA issue by depositing the sludge in lined lagoons, sealed off from the soil underneath. The company’s crop would wind up as a paper product, not a food source.

All four companies promised to help Bellingham meet its goal to reduce carbon emissions.

The three businesses that would build treatment facilities at Post Point — BFT, 374Water and Sedron Technologies — would save energy by using the heat they generated to keep the system running. BFT’s pyrolysis reduces sewage sludge to a high-carbon product called biochar that can be added to soil as a way to sequester carbon away from the atmosphere, according to the company’s proposal.

374Water says its process would add carbon dioxide to the atmosphere but avoids production of methane, a more potent greenhouse gas.

Connell Soil Farm points out that the city would stop burning 24 million cubic feet of natural gas simply by turning off its Post Point incinerators. The city estimated in 2019 that its sewage system contributes 40% of its overall carbon output.

The 4 Post Point proposals at a glance

Sedron Technologies: The Sedro-Woolley company, a partner of Janicki Industries, has developed a complex machine that dries sludge efficiently. It has sold its system to dairy farms east of the Rockies and wastewater treatment plants around Sumner, Pierce County.

Bioforcetech: This company, based in South San Francisco, California, would use pyrolysis to break down sewage sludge under high temperatures into a flammable gas and biochar. The system gains efficiency by burning the resulting gas for fuel. 

374Water: This Durham, North Carolina company’s name refers to the Celsius temperature at which water becomes “supercritical” under high pressure, an extreme state that is neither liquid nor steam. In these conditions, sewage — including any toxins — breaks down into its basic parts: water, carbon dioxide and minerals.

Connell Soil Farm: Rather than treating the sewage on site, this Bellingham company proposes transporting it to a farm outside Connell, Franklin County, where the sludge would fill lined lagoons and serve as soil for grasses that would be made into toilet paper.

This story was updated at 9:19 a.m. Monday, Nov. 27 to correct the amount of sewage incinerated annually at the Post Point Wastewater Treatment Plant. The amount is 4,650 tons, not “more than 2 tons.” Cascadia Daily News regrets the error.

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