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HomeArcataDr. Wendy Ring: The Scotia Biomass power plant operation needs to be shut down

Dr. Wendy Ring: The Scotia Biomass power plant operation needs to be shut down

Video of the City Council presentation:  21 minutes
Estimated reading time ~15 minutes for all.
Originally published:  August 16, 2023

Biomass is renewable, in theory … but it is not clean

To go directly to:
     Video of Dr. Ring’s presentation. 21 minutes
     Biomass Energy in Humboldt County — from 350 Humboldt
             350 Humboldt Policy Statement on Burning Woody Biomass – May 2023 – new
            Biomass Energy in Humboldt County – 350 Humboldt – 2018
     Humboldt’s Dirtiest Power Plant has been Breaking the Rules for Years
          Reprinted from The Northcoast Environmental Center website

The Scotia biomass plant produces in the order of ten times the amount of pollution when compared with PG&E’s Humboldt Bay natural gas-fired power plant.


Pollutants include benzene, formaldehyde, acrolein, dioxin, polycyclic aromatic hydrocarbons, and arsenic.


At the August 16, 2023, Arcata City Council meeting, Dr. Wendy Ring gave a presentation on the Scotia Biomass electric-generating power plant. This power plant burns waste wood from lumber mill operations to generate electricity. That electricity is sold to the Redwood Coast Energy Authority, who use the biomass power plant as the source of 40% of  their blend of renewable energy for our use here in Humboldt County.

The burning of wood waste creates a large amount of greenhouse-gas emissions. The carbon in the wood waste is released into the atmosphere as CO2 gas. An alternative to the burning of the wood waste would be a composting operation. This has the benefit of continuing to sequester the carbon content of the wood, and to not release that carbon into the atmosphere.

Electricity production from biomass produces between three and seven times the amount of CO2 emissions per megawatt-hour of electricity, compared to other electrical generating plants in California.

The Scotia plant produces the same amount of greenhouse gas emissions as approximately 3/4 of the all the cars in Humboldt County, combined.

Dr. Ring’s presentation also discussed the health aspects of the burning of wood waste at the Scotia power plant. There is “legal” pollution — that is, the pollution that is allowed within the law — and there is “illegal” pollution, or the pollution that is excess of existing regulations. The plant has three boilers; just one of the boilers was found to have over 700 violations of pollution limits.

The Scotia biomass plant produces in the order of ten times the amount of pollution when compared with PG&E’s Humboldt Bay natural gas-fired power plant. Pollutants include benzene, formaldehyde, acrolein, dioxin, polycyclic aromatic hydrocarbons, and arsenic.

Dr. Ring urges the Arcata City Council to recommend that the Redwood Coast Energy Authority remove the Scotia biomass plant from its sources of renewable electric power for Humboldt County.


Dr. Wendy Ring
Presentation at the Arcata City Council, August 16, 2023
21 minutes 38 seconds



350 Humboldt Policy Statement on Burning Woody Biomass – May 2023

350 Humboldt joins the growing scientific consensus that incinerating wood to produce heat and electricity is not carbon neutral. The biogenic, renewable nature of trees and other biomass does not counteract the high carbon intensity of combustion, which contributes to global warming for many years into the future. As 500 scientists said in a petition to world leaders in 2021: “Regrowing trees and displacement of fossil fuels may eventually pay off this carbon debt, but regrowth takes time the world does not have to solve climate change. As numerous studies have shown, this burning of wood will increase warming for decades to centuries.” [1]   We must absolutely minimize all GHGs if civilization and other living things are to avoid the most catastrophic effects of climate change. 

Making biomass electricity is a sensible option only when there is no less carbon-intensive way to dispose of wood waste or forest residues. Fortunately, modern technologies successfully use biomass as a feedstock for a variety of products. The list includes wood products such as oriented strand board, veneer lumber, plywood, etc.; new materials such as nano cellulose and bioplastics; soil amendments such as compost, mulch, and biochar; and fuels such as ethanol, renewable natural gas, and hydrogen. These fuels can be used to generate electricity or as low carbon alternatives to fossil fuels.  

In addition to its warming effects, burning biomass for electricity produces significant air pollution, which––as in Humboldt––affects disadvantaged communities. This is particularly true when––as in Humboldt––the equipment is old and very far from state of the art.

In consequence of these facts, 350 Humboldt will pursue a variety of policies and actions through its Legislative Committee and through special campaigns as needed, including: 

  • Work to change policies. Biomass electricity obtained by incinerating wood should no longer receive special dispensations or incentives from the California state government. Biopower should be removed from the Renewable Portfolio Standard.[2] The CPUC should remove it from its emissions exemptions.[3] Biopower should be counted under Cap and Trade and must pay for each ton of GHG emissions over 25,000 a year as other power generators do.[4] All jurisdictions must include emissions from the combustion of biomass in their inventories of greenhouse gases.[5] 
  • Work to change RCEA. Biomass power currently being purchased by the Redwood Coast Energy Authority should be replaced by renewable sources in line with the RCEA Board’s 2018 pledge to use only “clean and renewable” power sources in 2025 and thereafter.
  • Work to block pellet plants. The Humboldt County Board of Supervisors should not support in any way the current development of two gigantic factories to produce wood pellets for burning for power in other countries.

We also note that wood stoves have the same issues of pollution (of selves and neighbors) and greenhouse gas emissions. For the climate we need electrification of all homes, but in rural Humboldt power outages are a significant risk in that case. The Climate Action Plan committee will work to promote alternatives for individual households that will provide backup during power outages but reduce pollution and global warming.[6]



[2] The Renewable Portfolio Standard is a list of fuels for producing electricity. Biomass is legally “renewable” though it is not in actual Life Cycle Analyses.

[3] The California Public Utilities Commission currently is required by law to maintain Emission Performance Standard (EPS) for all electrical utilities. In a 2007 rulemaking, the Commission set the EPS for all Load Serving Entities  (LSEs) at 1,100 pounds (lbs) of carbon dioxide (CO2) per megawatt hour (MWh). Biomass power, however, was exempted 15 years ago on a temporary basis.

[4] Other electric power generators are subject to cap and trade under which they must not exceed emissions over a set limit so they are forced to buy “credits” from those who have excess. The current price per credit is $26.34 per metric ton of CO2. Biomass power plants are exempted. 

[5] For example, the CalEnviroScreen program tracks emissions near sensitive populations including those from power plants, but biomass power is exempt even though it is the dirtiest source of energy in California.

[6] Propane, for example, has about half the global warming effect as fuel oil and can be used in indoor space heaters, so may make a good backup. ; ;  

Biomass Energy in Humboldt County
350 Humboldt – 2018

19 pages. 
From the introduction:

350 Humboldt advocates for a transition to 100% clean, renewable electricity in Humboldt
County by 2025 in order to cut greenhouse gas (GHG) emissions and curb climate change.
Because most electricity in the County is provided by the Redwood Coast Energy Authority’s
Community Choice Energy (CCE) program, this 100% clean energy goal can be achieved by
changing the CCE’s grid mix.

The Redwood Coast Energy Authority (RCEA) currently purchases power from two local
biomass plants. Whether energy from these plants, as well as biomass energy from other sources, should be considered clean and renewable has been a matter of significant debate in the community as well as within 350 Humboldt.

Issues of concern include the effects of biomass energy production on forest health, climate change, and air quality, as well as the potential for the above-market cost of energy from the biomass plants to divert funds away from wind, wave, and solar projects.


The following article is reprinted from The Northcoast Environmental Center website.
The original can be seen here.

Humboldt’s Dirtiest Power Plant has been Breaking the Rules for Years

Wendy Ring, Guest Author

Have you ever had a medical test which found an abnormality other than what the doctor was looking for, and that required another test which determined the first abnormality was OK but turned up another unexpected finding, leading to another test?  Doctors call those unexpected and ultimately unimportant abnormalities “incidental findings”, and the frequency with which they occur is why we are careful to only order tests which might change our treatment.  But every now and then, one of these unexpected results and the chain of investigations it incites do turn out to be important. I recently had an experience like this, but the investigation wasn’t medical and its conclusion has health implications for our entire community.   

I discovered that Humboldt County’s dirtiest power plant has been breaking pollution laws for years and so has the regulator who is supposed to catch them.  I’m talking about the biomass plant in Scotia, which emits a host of toxic, endocrine disrupting, and carcinogenic chemicals along with fine particulates which transport these toxins from the lungs into the bloodstream and ultimately to our vital organs.  I’m also talking about the North Coast Unified Air Quality Management District (NCUAQMD aka “the air district”) the agency charged with enforcing state and federal pollution laws. And I’m talking about Redwood Community Energy Authority (RCEA) which aided and abetted by supporting the biomass plant with ratepayer dollars while assuring the community it was clean energy conforming to state and federal standards.   

I stumbled upon all this while trying to answer a question, but first I need to explain why I was asking. For full disclosure, I’m hardly impartial about biomass.  I’ve been trying to get RCEA to stop buying biomass energy for years. With only 7 years left to cut Humboldt’s greenhouse emissions in half, we need big fast greenhouse gas reductions. Hastening the demise of the biomass plant by depriving it of our energy dollars is realistically one of the only ways we can do that.   Closing the plant would cut annual emissions by 300,000 metric tons while redirecting mill waste to uses like compost for application on working lands and green hydrogen production might avoid or sequester 100,000 tons more. None of that addresses our fossil fuel addiction but with time running out and climate impacts accelerating, we must do what we can. 

In addition to its impact on climate, biomass takes a toll on our health.  EPA modeling estimates that Humboldt Sawmill Company’s biomass plant costs us $4-6 million annually in heart attacks, asthma attacks, cancer, hospitalizations and premature deaths.  When the EPA came out with new emission limits for biomass plants,  I wondered if this could be the key to shutting our aging local plant down. It turns out it’s not. But the “incidental findings” from reading the EPA regulations and reviewing the reports the plant submits for compliance led me to an entirely different conclusion.  The plant hasn’t met federal standards for years and the body charged with enforcing these rules has been letting them get away with it.  I thought, “surely this can’t be true,” and kept looking for records to prove myself wrong, but instead found the situation was even worse.  State laws were broken as well, and not by the power plant, but by the agency supposed to regulate them. I uncovered more than I can write about without boring you to death with nerdy details, but here are the most important things.

Fine particulates are the most dangerous pollutant coming from the biomass plant. These emissions are regulated under the federal Clean Air Act but the EPA delegates their enforcement to regional air quality management districts, like NCUAQMD.   To prove compliance, power plants must measure the actual concentration of particulates in a sample from their smokestack every 1-3 years and operate continuous opacity monitors.  Since all of a community’s protection between smokestack tests relies on these opacity monitors,  federal rules require quarterly quality assurance and an annual performance tests which must be reported to the air district.  

Over the last 6 years no annual performance tests of opacity monitors were done,  no quarterly testing was reported, and no action was taken by the air district.  During most of those years, the smokestack tests at least met EPA standards,  up until September 2022. That test sample showed high levels of particulates but the air district wasn’t notified for 2 months. With untested opacity monitors as an inadequate backstop and the last stack test done 2 years prior,  the plant may have exceeded federal pollution limits for as long as 2 years. 

The biomass plant emits another class of pollutants called air toxics. These include chemicals like benzene, dioxin, and formaldehyde which cause cancer, developmental abnormalities, and other acute and chronic health consequences.  California’s Air Toxics Hot Spot Act directs air districts to follow certain procedures to protect communities.  NCUAQMD last took a halfhearted stab at enforcing this law over 20 years ago and then pulled a Rip Van Winkle.  While the law required risk to the community from the biomass plant’s toxic emissions to be re-evaluated every 4 years,  22 years went by and nothing was done.  

During that time, the plant’s toxic emissions increased,  nearly 40 additional biomass pollutants were added to the state’s air toxics list,  cancer potency factors were increased and health risk assessment procedures updated to account for childhood exposures, and the biomass plant’s priority score, used to measure the urgency of evaluating community health risk, rose from 79 to 5599.  Any one of the above events should have triggered a re evaluation, and the annual air toxic reports the state requires of air districts could have served as a reminder,  but no reports were ever written and no new assessment was ever done.  If a re-assessment had revealed a high risk, the community would have been informed and the plant required to reduce its toxic emissions, but without quadrennial reviews, these opportunities were lost. 

After getting reinforcements from the California Air Resources Board to join my pressure campaign,  we were able to get NCUAQMD to agree to start fully enforcing state and federal laws at the biomass plant.  That doesn’t hit rewind and suck years of pollution back into their smokestacks, and even when the rules are followed they still allow biomass plants to pollute as much as coal.  I can’t tell you what this pollution has cost our community’s health.  The $4-6 million a year I quoted earlier is based on particulate emissions when the plant follows the law, and doesn’t account for air toxics at all.  Did these years of broken laws cause your grandfather’s heart attack or your best friend’s cancer?  We’ll never know.  

What I can tell you is that anything that incurs millions of dollars in annual health costs, creates a toxic hot spot and requires continuous policing by the air district, isn’t clean energy.  In 2019 RCEA recognized this by committing to plan for a long-term transition away from biomass combustion  and provide 100% clean and renewable energy by 2025.  Then they broke these promises by extending the biomass contract to 2031.  

Incinerating mill waste is a dirty archaic technology that pollutes the air and destroys valuable feedstock for real climate solutions.  It needs to end and the violations I’ve described allow RCEA to get out of their contract early, but they won’t do it without strong community pressure.  If you want real clean energy, contact the city council member or supervisor who represents you on RCEA’s board and ask them to dump biomass now.  


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